51
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Svoboda M, Frost HR, Bosco G. Internal oligo(dT) priming introduces systematic bias in bulk and single-cell RNA sequencing count data. NAR Genom Bioinform 2022; 4:lqac035. [PMID: 35651651 PMCID: PMC9142200 DOI: 10.1093/nargab/lqac035] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Revised: 03/25/2022] [Accepted: 04/29/2022] [Indexed: 12/28/2022] Open
Abstract
Significant advances in RNA sequencing have been recently made possible by using oligo(dT) primers for simultaneous mRNA enrichment and reverse transcription priming. The associated increase in efficiency has enabled more economical bulk RNA sequencing methods and the advent of high-throughput single-cell RNA sequencing, already one of the most widely adopted methods in transcriptomics. However, the effects of off-target oligo(dT) priming on gene expression quantification have not been appreciated. In the present study, we describe the extent, the possible causes, and the consequences of internal oligo(dT) priming across multiple public datasets obtained from various bulk and single-cell RNA sequencing platforms. To explore and address this issue, we developed a computational algorithm for RNA counting methods, which identifies the sequencing read alignments that likely resulted from internal oligo(dT) priming and removes them from the data. Directly comparing filtered datasets to those obtained by an alternative method reveals significant improvements in gene expression measurement. Finally, we infer a list of human genes whose expression quantification is most likely to be affected by internal oligo(dT) priming and predict that when measured using these methods, the expression of most genes may be inflated by at least 10% whereby some genes are affected more than others.
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Affiliation(s)
| | - H Robert Frost
- Department of Biomedical Data Science, Geisel School of Medicine, Dartmouth College, Hanover, NH 03755, USA
| | - Giovanni Bosco
- Correspondence may also be addressed to Giovanni Bosco. Tel: +1 603 650 1210; Fax: +1 603 650 1188;
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52
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Adashev VE, Bazylev SS, Potashnikova DM, Godneeva BK, Shatskikh AS, Olenkina OM, Olenina LV, Kotov AA. Comparative transcriptional analysis uncovers molecular processes in early and mature somatic cyst cells of Drosophila testes. Eur J Cell Biol 2022; 101:151246. [PMID: 35667338 DOI: 10.1016/j.ejcb.2022.151246] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 04/29/2022] [Accepted: 05/27/2022] [Indexed: 11/18/2022] Open
Abstract
The tight interaction between somatic and germline cells is conserved in animal spermatogenesis. The testes of Drosophila melanogaster are the model of choice to identify processes responsible for mature gamete production. However, processes of differentiation and soma-germline interactions occurring in somatic cyst cells are currently understudied. Here we focused on the comparison of transcriptome expression patterns of early and mature somatic cyst cells to find out the developmental changes taking place in them. We employed a FACS-based approach for the isolation of early and mature somatic cyst cells from fly testes, subsequent preparation of RNA-Seq libraries, and analysis of gene differential expression in the sorted cells. We found increased expression of genes involved in cell cycle-related processes in early cyst cells, which is necessary for the proliferation and self-renewal of a crucial population of early cyst cells, cyst stem cells. Genes proposedly required for lamellipodium-like projection organization for proper cyst formation were also detected among the upregulated ones in early cyst cells. Gene Ontology and interactome analyses of upregulated genes in mature cyst cells revealed a striking over-representation of gene categories responsible for metabolic and catabolic cellular processes, as well as genes supporting the energetic state of the cells provided by oxidative phosphorylation that is carried out in mitochondria. Our comparative analyses of differentially expressed genes revealed major peculiarities in early and mature cyst cells and provide novel insight into their regulation, which is important for male fertility.
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Affiliation(s)
- Vladimir E Adashev
- Institute of Molecular Genetics of National Research Center "Kurchatov Institute", 2 Kurchatov Sq., Moscow 123182, Russia.
| | - Sergei S Bazylev
- Institute of Molecular Genetics of National Research Center "Kurchatov Institute", 2 Kurchatov Sq., Moscow 123182, Russia.
| | - Daria M Potashnikova
- Lomonosov Moscow State University, School of Biology, Department of Cell Biology and Histology, Moscow 119234, Russia.
| | - Baira K Godneeva
- Institute of Molecular Genetics of National Research Center "Kurchatov Institute", 2 Kurchatov Sq., Moscow 123182, Russia.
| | - Aleksei S Shatskikh
- Institute of Molecular Genetics of National Research Center "Kurchatov Institute", 2 Kurchatov Sq., Moscow 123182, Russia.
| | - Oxana M Olenkina
- Institute of Molecular Genetics of National Research Center "Kurchatov Institute", 2 Kurchatov Sq., Moscow 123182, Russia.
| | - Ludmila V Olenina
- Institute of Molecular Genetics of National Research Center "Kurchatov Institute", 2 Kurchatov Sq., Moscow 123182, Russia.
| | - Alexei A Kotov
- Institute of Molecular Genetics of National Research Center "Kurchatov Institute", 2 Kurchatov Sq., Moscow 123182, Russia.
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53
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Potapova NA. Nonsense Mutations in Eukaryotes. BIOCHEMISTRY. BIOKHIMIIA 2022; 87:400-412. [PMID: 35790376 DOI: 10.1134/s0006297922050029] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Revised: 02/14/2022] [Accepted: 03/22/2022] [Indexed: 06/15/2023]
Abstract
Nonsense mutations are a type of mutations which results in a premature termination codon occurrence. In general, these mutations have been considered to be among the most harmful ones which lead to premature protein translation termination and result in shortened nonfunctional polypeptide. However, there is evidence that not all nonsense mutations are harmful as well as some molecular mechanisms exist which allow to avoid pathogenic effects of these mutations. This review addresses relevant information on nonsense mutations in eukaryotic genomes, characteristics of these mutations, and different molecular mechanisms preventing or mitigating harmful effects thereof.
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Affiliation(s)
- Nadezhda A Potapova
- Kharkevich Institute for Information Transmission Problems (IITP), Russian Academy of Sciences, Moscow, 127051, Russia.
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54
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Lewerentz J, Johansson AM, Larsson J, Stenberg P. Transposon activity, local duplications and propagation of structural variants across haplotypes drive the evolution of the Drosophila S2 cell line. BMC Genomics 2022; 23:276. [PMID: 35392795 PMCID: PMC8991648 DOI: 10.1186/s12864-022-08472-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Accepted: 03/15/2022] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND Immortalized cell lines are widely used model systems whose genomes are often highly rearranged and polyploid. However, their genome structure is seldom deciphered and is thus not accounted for during analyses. We therefore used linked short- and long-read sequencing to perform haplotype-level reconstruction of the genome of a Drosophila melanogaster cell line (S2-DRSC) with a complex genome structure. RESULTS Using a custom implementation (that is designed to use ultra-long reads in complex genomes with nested rearrangements) to call structural variants (SVs), we found that the most common SV was repetitive sequence insertion or deletion (> 80% of SVs), with Gypsy retrotransposon insertions dominating. The second most common SV was local sequence duplication. SNPs and other SVs were rarer, but several large chromosomal translocations and mitochondrial genome insertions were observed. Haplotypes were highly similar at the nucleotide level but structurally very different. Insertion SVs existed at various haplotype frequencies and were unlinked on chromosomes, demonstrating that haplotypes have different structures and suggesting the existence of a mechanism that allows SVs to propagate across haplotypes. Finally, using public short-read data, we found that transposable element insertions and local duplications are common in other D. melanogaster cell lines. CONCLUSIONS The S2-DRSC cell line evolved through retrotransposon activity and vast local sequence duplications, that we hypothesize were the products of DNA re-replication events. Additionally, mutations can propagate across haplotypes (possibly explained by mitotic recombination), which enables fine-tuning of mutational impact and prevents accumulation of deleterious events, an inherent problem of clonal reproduction. We conclude that traditional linear homozygous genome representation conceals the complexity when dealing with rearranged and heterozygous clonal cells.
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Affiliation(s)
- Jacob Lewerentz
- Department of Molecular Biology, Umeå University, SE-901 87, Umeå, Västerbotten, Sweden.
| | - Anna-Mia Johansson
- Department of Molecular Biology, Umeå University, SE-901 87, Umeå, Västerbotten, Sweden
| | - Jan Larsson
- Department of Molecular Biology, Umeå University, SE-901 87, Umeå, Västerbotten, Sweden.
| | - Per Stenberg
- Department of Ecology and Environmental Sciences, Umeå University, SE-901 87, Umeå, Västerbotten, Sweden.
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55
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Loganathan R, Levings DC, Kim JH, Wells MB, Chiu H, Wu Y, Slattery M, Andrew DJ. Ribbon boosts ribosomal protein gene expression to coordinate organ form and function. J Cell Biol 2022; 221:213030. [PMID: 35195669 PMCID: PMC9237840 DOI: 10.1083/jcb.202110073] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Revised: 12/19/2021] [Accepted: 01/24/2022] [Indexed: 11/22/2022] Open
Abstract
Cell growth is well defined for late (postembryonic) stages of development, but evidence for early (embryonic) cell growth during postmitotic morphogenesis is limited. Here, we report early cell growth as a key characteristic of tubulogenesis in the Drosophila embryonic salivary gland (SG) and trachea. A BTB/POZ domain nuclear factor, Ribbon (Rib), mediates this early cell growth. Rib binds the transcription start site of nearly every SG-expressed ribosomal protein gene (RPG) and is required for full expression of all RPGs tested. Rib binding to RPG promoters in vitro is weak and not sequence specific, suggesting that specificity is achieved through cofactor interactions. Accordingly, we demonstrate Rib’s ability to physically interact with each of the three known regulators of RPG transcription. Surprisingly, Rib-dependent early cell growth in another tubular organ, the embryonic trachea, is not mediated by direct RPG transcription. These findings support a model of early cell growth customized by transcriptional regulatory networks to coordinate organ form and function.
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Affiliation(s)
| | - Daniel C Levings
- Department of Biomedical Sciences, University of Minnesota Medical School, Duluth, MN
| | - Ji Hoon Kim
- Department of Cell Biology, Johns Hopkins University, Baltimore, MD
| | - Michael B Wells
- Department of Cell Biology, Johns Hopkins University, Baltimore, MD
| | - Hannah Chiu
- Department of Cell Biology, Johns Hopkins University, Baltimore, MD
| | - Yifan Wu
- Department of Cell Biology, Johns Hopkins University, Baltimore, MD
| | - Matthew Slattery
- Department of Biomedical Sciences, University of Minnesota Medical School, Duluth, MN
| | - Deborah J Andrew
- Department of Cell Biology, Johns Hopkins University, Baltimore, MD
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56
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Oropeza-Rodriguez E, Clifton BD, Ranz JM. On the genetic basis of the effect of Spiroplasma on the male reproductive fitness of Glossina fuscipes fuscipes. PLoS Pathog 2022; 18:e1010442. [PMID: 35377922 PMCID: PMC8979428 DOI: 10.1371/journal.ppat.1010442] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2021] [Accepted: 03/14/2022] [Indexed: 11/18/2022] Open
Affiliation(s)
- Edward Oropeza-Rodriguez
- Department of Ecology and Evolutionary Biology, University of California Irvine, Irvine, California, United States of America
| | - Bryan D. Clifton
- Department of Ecology and Evolutionary Biology, University of California Irvine, Irvine, California, United States of America
| | - José M. Ranz
- Department of Ecology and Evolutionary Biology, University of California Irvine, Irvine, California, United States of America
- * E-mail:
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57
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Chathoth KT, Mikheeva LA, Crevel G, Wolfe JC, Hunter I, Beckett-Doyle S, Cotterill S, Dai H, Harrison A, Zabet NR. The role of insulators and transcription in 3D chromatin organization of flies. Genome Res 2022; 32:682-698. [PMID: 35354608 PMCID: PMC8997359 DOI: 10.1101/gr.275809.121] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Accepted: 02/17/2022] [Indexed: 11/25/2022]
Abstract
The DNA in many organisms, including humans, is shown to be organized in topologically associating domains (TADs). In Drosophila, several architectural proteins are enriched at TAD borders, but it is still unclear whether these proteins play a functional role in the formation and maintenance of TADs. Here, we show that depletion of BEAF-32, Cp190, Chro, and Dref leads to changes in TAD organization and chromatin loops. Their depletion predominantly affects TAD borders located in regions moderately enriched in repressive modifications and depleted in active ones, whereas TAD borders located in euchromatin are resilient to these knockdowns. Furthermore, transcriptomic data has revealed hundreds of genes displaying differential expression in these knockdowns and showed that the majority of differentially expressed genes are located within reorganized TADs. Our work identifies a novel and functional role for architectural proteins at TAD borders in Drosophila and a link between TAD reorganization and subsequent changes in gene expression.
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Affiliation(s)
- Keerthi T Chathoth
- School of Life Sciences, University of Essex, Colchester CO4 3SQ, United Kingdom
| | - Liudmila A Mikheeva
- School of Life Sciences, University of Essex, Colchester CO4 3SQ, United Kingdom.,Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London E1 2AT, United Kingdom.,Department of Mathematical Sciences, University of Essex, Colchester CO4 3SQ, United Kingdom
| | - Gilles Crevel
- Department Basic Medical Sciences, St. Georges University London, London SW17 0RE, United Kingdom
| | - Jareth C Wolfe
- School of Life Sciences, University of Essex, Colchester CO4 3SQ, United Kingdom.,Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London E1 2AT, United Kingdom.,School of Computer Science and Electronic Engineering, University of Essex, Colchester CO4 3SQ, United Kingdom
| | - Ioni Hunter
- School of Life Sciences, University of Essex, Colchester CO4 3SQ, United Kingdom
| | - Saskia Beckett-Doyle
- School of Life Sciences, University of Essex, Colchester CO4 3SQ, United Kingdom
| | - Sue Cotterill
- Department Basic Medical Sciences, St. Georges University London, London SW17 0RE, United Kingdom
| | - Hongsheng Dai
- Department of Mathematical Sciences, University of Essex, Colchester CO4 3SQ, United Kingdom
| | - Andrew Harrison
- Department of Mathematical Sciences, University of Essex, Colchester CO4 3SQ, United Kingdom
| | - Nicolae Radu Zabet
- School of Life Sciences, University of Essex, Colchester CO4 3SQ, United Kingdom.,Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London E1 2AT, United Kingdom
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58
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Ranz JM, González PM, Su RN, Bedford SJ, Abreu-Goodger C, Markow T. Multiscale analysis of the randomization limits of the chromosomal gene organization between Lepidoptera and Diptera. Proc Biol Sci 2022; 289:20212183. [PMID: 35042416 PMCID: PMC8767184 DOI: 10.1098/rspb.2021.2183] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Accepted: 12/13/2021] [Indexed: 11/12/2022] Open
Abstract
How chromosome gene organization and gene content evolve among distantly related and structurally malleable genomes remains unresolved. This is particularly the case when considering different insect orders. We have compared the highly contiguous genome assemblies of the lepidopteran Danaus plexippus and the dipteran Drosophila melanogaster, which shared a common ancestor around 290 Ma. The gene content of 23 out of 30 D. plexippus chromosomes was significantly associated with one or two of the six chromosomal elements of the Drosophila genome, denoting common ancestry. Despite the phylogenetic distance, 9.6% of the 1-to-1 orthologues still reside within the same ancestral genome neighbourhood. Furthermore, the comparison D. plexippus-Bombyx mori indicated that the rates of chromosome repatterning are lower in Lepidoptera than in Diptera, although still within the same order of magnitude. Concordantly, 14 developmental gene clusters showed a higher tendency to retain full or partial clustering in D. plexippus, further supporting that the physical association between the SuperHox and NK clusters existed in the ancestral bilaterian. Our results illuminate the scope and limits of the evolution of the gene organization and content of the ancestral chromosomes to the Lepidoptera and Diptera while helping reconstruct portions of the genome in their most recent common ancestor.
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Affiliation(s)
- José M. Ranz
- Department of Ecology and Evolutionary Biology, University of California Irvine, Irvine CA 92647, USA
| | - Pablo M. González
- Unidad de Genómica Avanzada (Langebio), CINVESTAV, Irapuato GTO 36824, México
| | - Ryan N. Su
- Department of Ecology and Evolutionary Biology, University of California Irvine, Irvine CA 92647, USA
| | - Sarah J. Bedford
- Department of Ecology and Evolutionary Biology, University of California Irvine, Irvine CA 92647, USA
| | - Cei Abreu-Goodger
- Unidad de Genómica Avanzada (Langebio), CINVESTAV, Irapuato GTO 36824, México
| | - Therese Markow
- Unidad de Genómica Avanzada (Langebio), CINVESTAV, Irapuato GTO 36824, México
- Section of Cell and Developmental Biology, Division of Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA
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59
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Gladman N, Olson A, Wei S, Chougule K, Lu Z, Tello-Ruiz M, Meijs I, Van Buren P, Jiao Y, Wang B, Kumar V, Kumari S, Zhang L, Burke J, Chen J, Burow G, Hayes C, Emendack Y, Xin Z, Ware D. SorghumBase: a web-based portal for sorghum genetic information and community advancement. PLANTA 2022; 255:35. [PMID: 35015132 PMCID: PMC8752523 DOI: 10.1007/s00425-022-03821-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Accepted: 12/27/2021] [Indexed: 05/05/2023]
Abstract
SorghumBase provides a community portal that integrates genetic, genomic, and breeding resources for sorghum germplasm improvement. Public research and development in agriculture rely on proper data and resource sharing within stakeholder communities. For plant breeders, agronomists, molecular biologists, geneticists, and bioinformaticians, centralizing desirable data into a user-friendly hub for crop systems is essential for successful collaborations and breakthroughs in germplasm development. Here, we present the SorghumBase web portal ( https://www.sorghumbase.org ), a resource for the sorghum research community. SorghumBase hosts a wide range of sorghum genomic information in a modular framework, built with open-source software, to provide a sustainable platform. This initial release of SorghumBase includes: (1) five sorghum reference genome assemblies in a pan-genome browser; (2) genetic variant information for natural diversity panels and ethyl methanesulfonate (EMS)-induced mutant populations; (3) search interface and integrated views of various data types; (4) links supporting interconnectivity with other repositories including genebank, QTL, and gene expression databases; and (5) a content management system to support access to community news and training materials. SorghumBase offers sorghum investigators improved data collation and access that will facilitate the growth of a robust research community to support genomics-assisted breeding.
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Affiliation(s)
- Nicholas Gladman
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, 11724, USA
| | - Andrew Olson
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, 11724, USA
| | - Sharon Wei
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, 11724, USA
| | - Kapeel Chougule
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, 11724, USA
| | - Zhenyuan Lu
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, 11724, USA
| | | | - Ivar Meijs
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, 11724, USA
| | - Peter Van Buren
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, 11724, USA
| | - Yinping Jiao
- Department of Plant and Soil Science, Institute of Genomics for Crop Abiotic Stress Tolerance, Texas Tech University, Lubbock, TX, 79409, USA
| | - Bo Wang
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, 11724, USA
| | - Vivek Kumar
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, 11724, USA
| | - Sunita Kumari
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, 11724, USA
| | - Lifang Zhang
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, 11724, USA
| | - John Burke
- Plant Stress and Germplasm Development Unit, Cropping Systems Research Laboratory, U.S. Department of Agriculture-Agricultural Research Service, Lubbock, TX, 79415, USA
| | - Junping Chen
- Plant Stress and Germplasm Development Unit, Cropping Systems Research Laboratory, U.S. Department of Agriculture-Agricultural Research Service, Lubbock, TX, 79415, USA
| | - Gloria Burow
- Plant Stress and Germplasm Development Unit, Cropping Systems Research Laboratory, U.S. Department of Agriculture-Agricultural Research Service, Lubbock, TX, 79415, USA
| | - Chad Hayes
- Plant Stress and Germplasm Development Unit, Cropping Systems Research Laboratory, U.S. Department of Agriculture-Agricultural Research Service, Lubbock, TX, 79415, USA
| | - Yves Emendack
- Plant Stress and Germplasm Development Unit, Cropping Systems Research Laboratory, U.S. Department of Agriculture-Agricultural Research Service, Lubbock, TX, 79415, USA
| | - Zhanguo Xin
- Plant Stress and Germplasm Development Unit, Cropping Systems Research Laboratory, U.S. Department of Agriculture-Agricultural Research Service, Lubbock, TX, 79415, USA
| | - Doreen Ware
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, 11724, USA.
- U.S. Department of Agriculture-Agricultural Research Service, NEA Robert W. Holley Center for Agriculture and Health, Cornell University, Ithaca, NY, 14853, USA.
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60
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Guignard Q, Allison JD, Slippers B. The evolution of insect visual opsin genes with specific consideration of the influence of ocelli and life history traits. BMC Ecol Evol 2022; 22:2. [PMID: 34996358 PMCID: PMC8739693 DOI: 10.1186/s12862-022-01960-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Accepted: 01/04/2022] [Indexed: 11/30/2022] Open
Abstract
Background Visual opsins are expressed in the compound eyes and ocelli of insects and enable light detection. Three distinct phylogenetic groups of visual opsins are found in insects, named long (LW), short (SW) and ultraviolet (UV) wavelength sensitive opsins. Recently, the LW group was found to be duplicated into the LW2b and the LW2a opsins. The expression of LW2b opsins is ocelli specific in some insects (e.g., bees, cricket, scorpion flies), but the gene was not found in other orders possessing three or less ocelli (e.g., dragonflies, beetles, moths, bugs). In flies, two LW2b homologs have been characterised, with one expressed in the ocelli and the other in the compound eyes. To date, it remains unclear which evolutionary forces have driven gains and losses of LW opsins in insects. Here we take advantage of the recent rapid increase in available sequence data (i.e., from insect genomes, targeted PCR amplification, RNAseq) to characterize the phylogenetic relationships of 1000 opsin sequences in 18 orders of Insects. The resulting phylogeny discriminates between four main groups of opsins, and onto this phylogeny we mapped relevant morphological and life history traits. Results Our results demonstrate a conserved LW2b opsin only present in insects with three ocelli. Only two groups (Brachycera and Odonata) possess more than one LW2b opsin, likely linked to their life history. In flies, we hypothesize that the duplication of the LW2b opsin occurred after the transition from aquatic to terrestrial larvae. During this transition, higher flies (Brachycera) lost a copy of the LW2a opsin, still expressed and duplicated in the compound eyes of lower flies (Nematocera). In higher flies, the LW2b opsin has been duplicated and expressed in the compound eyes while the ocelli and the LW2b opsin were lost in lower flies. In dragonflies, specialisation of flight capabilities likely drove the diversification of the LW2b visual opsins. Conclusion The presence of the LW2b opsin in insects possessing three ocelli suggests a role in specific flight capabilities (e.g., stationary flight). This study provides the most complete view of the evolution of visual opsin genes in insects yet, and provides new insight into the influence of ocelli and life history traits on opsin evolution in insects. Supplementary Information The online version contains supplementary material available at 10.1186/s12862-022-01960-8.
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Affiliation(s)
- Quentin Guignard
- Department of Zoology and Entomology, Forestry and Agricultural Biotechnology Institute, University of Pretoria, Pretoria, 0002, South Africa.
| | - Jeremy D Allison
- Department of Zoology and Entomology, Forestry and Agricultural Biotechnology Institute, University of Pretoria, Pretoria, 0002, South Africa.,Natural Resources Canada, Canadian Forest Service, Great Lakes Forestry Centre, 1219 Queen Street E, Sault Ste. Marie, ON, P6A 2E5, Canada
| | - Bernard Slippers
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute, University of Pretoria, Pretoria, 0002, South Africa
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61
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Abstract
Since 1992, FlyBase has provided a freely available online database of information about the model organism Drosophila melanogaster. Data in FlyBase is curated manually from research papers as well as computationally from a variety of relevant sources, to serve as an information hub that enables and accelerates research discovery. This chapter aims to give users new to the database an overview of the layout and types of data available, as well as introducing some tools with which to access the data. More experienced users will find useful information about recent improvements and descriptions to enable more efficient navigation of the database.
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Affiliation(s)
| | - Aoife Larkin
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, UK
| | - Jim Thurmond
- Department of Biology, Indiana University, Bloomington, IN, USA
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62
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Zhang X, Wang T. Plant 3D Chromatin Organization: Important Insights from Chromosome Conformation Capture Analyses of the Last 10 Years. PLANT & CELL PHYSIOLOGY 2021; 62:1648-1661. [PMID: 34486654 PMCID: PMC8664644 DOI: 10.1093/pcp/pcab134] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Revised: 07/25/2021] [Accepted: 09/01/2021] [Indexed: 05/05/2023]
Abstract
Over the past few decades, eukaryotic linear genomes and epigenomes have been widely and extensively studied for understanding gene expression regulation. More recently, the three-dimensional (3D) chromatin organization was found to be important for determining genome functionality, finely tuning physiological processes for appropriate cellular responses. With the development of visualization techniques and chromatin conformation capture (3C)-based techniques, increasing evidence indicates that chromosomal architecture characteristics and chromatin domains with different epigenetic modifications in the nucleus are correlated with transcriptional activities. Subsequent studies have further explored the intricate interplay between 3D genome organization and the function of interacting regions. In this review, we summarize spatial distribution patterns of chromatin, including chromatin positioning, configurations and domains, with a particular focus on the effect of a unique form of interaction between varieties of factors that shape the 3D genome conformation in plants. We further discuss the methods, advantages and limitations of various 3C-based techniques, highlighting the applications of these technologies in plants to identify chromatin domains, and address their dynamic changes and functional implications in evolution, and adaptation to development and changing environmental conditions. Moreover, the future implications and emerging research directions of 3D genome organization are discussed.
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Affiliation(s)
- Xinxin Zhang
- State Key Laboratory of Protein and Plant Gene Research, School of Advanced Agricultural Sciences and School of Life Sciences, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, P. R. China
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, The Chinese Academy of Sciences, Beijing 100093, P. R. China
| | - Tianzuo Wang
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, The Chinese Academy of Sciences, Beijing 100093, P. R. China
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100093, P. R. China
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Kapun M, Nunez JCB, Bogaerts-Márquez M, Murga-Moreno J, Paris M, Outten J, Coronado-Zamora M, Tern C, Rota-Stabelli O, Guerreiro MPG, Casillas S, Orengo DJ, Puerma E, Kankare M, Ometto L, Loeschcke V, Onder BS, Abbott JK, Schaeffer SW, Rajpurohit S, Behrman EL, Schou MF, Merritt TJS, Lazzaro BP, Glaser-Schmitt A, Argyridou E, Staubach F, Wang Y, Tauber E, Serga SV, Fabian DK, Dyer KA, Wheat CW, Parsch J, Grath S, Veselinovic MS, Stamenkovic-Radak M, Jelic M, Buendía-Ruíz AJ, Gómez-Julián MJ, Espinosa-Jimenez ML, Gallardo-Jiménez FD, Patenkovic A, Eric K, Tanaskovic M, Ullastres A, Guio L, Merenciano M, Guirao-Rico S, Horváth V, Obbard DJ, Pasyukova E, Alatortsev VE, Vieira CP, Vieira J, Torres JR, Kozeretska I, Maistrenko OM, Montchamp-Moreau C, Mukha DV, Machado HE, Lamb K, Paulo T, Yusuf L, Barbadilla A, Petrov D, Schmidt P, Gonzalez J, Flatt T, Bergland AO. Drosophila Evolution over Space and Time (DEST): A New Population Genomics Resource. Mol Biol Evol 2021; 38:5782-5805. [PMID: 34469576 PMCID: PMC8662648 DOI: 10.1093/molbev/msab259] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Drosophila melanogaster is a leading model in population genetics and genomics, and a growing number of whole-genome data sets from natural populations of this species have been published over the last years. A major challenge is the integration of disparate data sets, often generated using different sequencing technologies and bioinformatic pipelines, which hampers our ability to address questions about the evolution of this species. Here we address these issues by developing a bioinformatics pipeline that maps pooled sequencing (Pool-Seq) reads from D. melanogaster to a hologenome consisting of fly and symbiont genomes and estimates allele frequencies using either a heuristic (PoolSNP) or a probabilistic variant caller (SNAPE-pooled). We use this pipeline to generate the largest data repository of genomic data available for D. melanogaster to date, encompassing 271 previously published and unpublished population samples from over 100 locations in >20 countries on four continents. Several of these locations have been sampled at different seasons across multiple years. This data set, which we call Drosophila Evolution over Space and Time (DEST), is coupled with sampling and environmental metadata. A web-based genome browser and web portal provide easy access to the SNP data set. We further provide guidelines on how to use Pool-Seq data for model-based demographic inference. Our aim is to provide this scalable platform as a community resource which can be easily extended via future efforts for an even more extensive cosmopolitan data set. Our resource will enable population geneticists to analyze spatiotemporal genetic patterns and evolutionary dynamics of D. melanogaster populations in unprecedented detail.
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Affiliation(s)
- Martin Kapun
- Department of Evolutionary Biology and Environmental Studies, University of
Zürich, Switzerland
- Department of Cell & Developmental Biology, Center of Anatomy and Cell
Biology, Medical University of Vienna, Vienna, Austria
| | - Joaquin C B Nunez
- Department of Biology, University of Virginia, Charlottesville,
VA, USA
| | | | - Jesús Murga-Moreno
- Department of Genetics and Microbiology, Universitat Autònoma de
Barcelona, Barcelona, Spain
- Institute of Biotechnology and Biomedicine, Universitat Autònoma de
Barcelona, Barcelona, Spain
| | - Margot Paris
- Department of Biology, University of Fribourg, Fribourg, Switzerland
| | - Joseph Outten
- Department of Biology, University of Virginia, Charlottesville,
VA, USA
| | | | - Courtney Tern
- Department of Biology, University of Virginia, Charlottesville,
VA, USA
| | - Omar Rota-Stabelli
- Center Agriculture Food Environment, University of Trento, San Michele all'
Adige, Italy
| | | | - Sònia Casillas
- Department of Genetics and Microbiology, Universitat Autònoma de
Barcelona, Barcelona, Spain
- Institute of Biotechnology and Biomedicine, Universitat Autònoma de
Barcelona, Barcelona, Spain
| | - Dorcas J Orengo
- Departament de Genètica, Microbiologia i Estadística, Facultat de Biologia,
Universitat de Barcelona, Barcelona, Spain
- Institut de Recerca de la Biodiversitat (IRBio), Universitat de
Barcelona, Barcelona, Spain
| | - Eva Puerma
- Departament de Genètica, Microbiologia i Estadística, Facultat de Biologia,
Universitat de Barcelona, Barcelona, Spain
- Institut de Recerca de la Biodiversitat (IRBio), Universitat de
Barcelona, Barcelona, Spain
| | - Maaria Kankare
- Department of Biological and Environmental Science, University of
Jyväskylä, Jyväskylä, Finland
| | - Lino Ometto
- Department of Biology and Biotechnology, University of Pavia,
Pavia, Italy
| | | | - Banu S Onder
- Department of Biology, Hacettepe University, Ankara, Turkey
| | | | - Stephen W Schaeffer
- Department of Biology, The Pennsylvania State University,
University Park, PA, USA
| | - Subhash Rajpurohit
- Department of Biology, University of Pennsylvania, Philadelphia,
PA, USA
- Division of Biological and Life Sciences, School of Arts and Sciences,
Ahmedabad University, Ahmedabad, India
| | - Emily L Behrman
- Department of Biology, University of Pennsylvania, Philadelphia,
PA, USA
- Janelia Research Campus, Ashburn, VA, USA
| | - Mads F Schou
- Department of Biology, Aarhus University, Aarhus, Denmark
- Department of Biology, Lund University, Lund, Sweden
| | - Thomas J S Merritt
- Department of Chemistry & Biochemistry, Laurentian
University, Sudbury, ON, Canada
| | - Brian P Lazzaro
- Department of Entomology, Cornell University, Ithaca, NY,
USA
| | - Amanda Glaser-Schmitt
- Division of Evolutionary Biology, Faculty of Biology,
Ludwig-Maximilians-Universität, Munich, Germany
| | - Eliza Argyridou
- Division of Evolutionary Biology, Faculty of Biology,
Ludwig-Maximilians-Universität, Munich, Germany
| | - Fabian Staubach
- Department of Evolution and Ecology, University of Freiburg,
Freiburg, Germany
| | - Yun Wang
- Department of Evolution and Ecology, University of Freiburg,
Freiburg, Germany
| | - Eran Tauber
- Department of Evolutionary and Environmental Biology, Institute of Evolution,
University of Haifa, Haifa, Israel
| | - Svitlana V Serga
- Department of General and Medical Genetics, Taras Shevchenko National
University of Kyiv, Kyiv, Ukraine
- State Institution National Antarctic Scientific Center, Ministry of Education
and Science of Ukraine, Kyiv, Ukraine
| | - Daniel K Fabian
- Department of Genetics, University of Cambridge, Cambridge,
United Kingdom
| | - Kelly A Dyer
- Department of Genetics, University of Georgia, Athens, GA,
USA
| | | | - John Parsch
- Division of Evolutionary Biology, Faculty of Biology,
Ludwig-Maximilians-Universität, Munich, Germany
| | - Sonja Grath
- Division of Evolutionary Biology, Faculty of Biology,
Ludwig-Maximilians-Universität, Munich, Germany
| | | | | | - Mihailo Jelic
- Faculty of Biology, University of Belgrade, Belgrade, Serbia
| | | | | | | | | | - Aleksandra Patenkovic
- Institute for Biological Research “Siniša Stanković”, National Institute of
Republic of Serbia, University of Belgrade, Belgrade, Serbia
| | - Katarina Eric
- Institute for Biological Research “Siniša Stanković”, National Institute of
Republic of Serbia, University of Belgrade, Belgrade, Serbia
| | - Marija Tanaskovic
- Institute for Biological Research “Siniša Stanković”, National Institute of
Republic of Serbia, University of Belgrade, Belgrade, Serbia
| | - Anna Ullastres
- Institute of Evolutionary Biology, CSIC-Universitat Pompeu Fabra,
Barcelona, Spain
| | - Lain Guio
- Institute of Evolutionary Biology, CSIC-Universitat Pompeu Fabra,
Barcelona, Spain
| | - Miriam Merenciano
- Institute of Evolutionary Biology, CSIC-Universitat Pompeu Fabra,
Barcelona, Spain
| | - Sara Guirao-Rico
- Institute of Evolutionary Biology, CSIC-Universitat Pompeu Fabra,
Barcelona, Spain
| | - Vivien Horváth
- Institute of Evolutionary Biology, CSIC-Universitat Pompeu Fabra,
Barcelona, Spain
| | - Darren J Obbard
- Institute of Evolutionary Biology, University of Edinburgh,
Edinburgh, United Kingdom
| | - Elena Pasyukova
- Institute of Molecular Genetics of the National Research Centre “Kurchatov
Institute”, Moscow, Russia
| | - Vladimir E Alatortsev
- Institute of Molecular Genetics of the National Research Centre “Kurchatov
Institute”, Moscow, Russia
| | - Cristina P Vieira
- Instituto de Biologia Molecular e Celular (IBMC), Porto, Portugal
- Instituto de Investigação e Inovação em Saúde, Universidade do
Porto, Porto, Portugal
| | - Jorge Vieira
- Instituto de Biologia Molecular e Celular (IBMC), Porto, Portugal
- Instituto de Investigação e Inovação em Saúde, Universidade do
Porto, Porto, Portugal
| | | | - Iryna Kozeretska
- Department of General and Medical Genetics, Taras Shevchenko National
University of Kyiv, Kyiv, Ukraine
- State Institution National Antarctic Scientific Center, Ministry of Education
and Science of Ukraine, Kyiv, Ukraine
| | - Oleksandr M Maistrenko
- Department of General and Medical Genetics, Taras Shevchenko National
University of Kyiv, Kyiv, Ukraine
- Structural and Computational Biology Unit, European Molecular Biology
Laboratory, Heidelberg, Germany
| | | | - Dmitry V Mukha
- Vavilov Institute of General Genetics, Russian Academy of
Sciences, Moscow, Russia
| | - Heather E Machado
- Department of Biology, Stanford University, Stanford, CA,
USA
- Wellcome Trust Sanger Institute, Hinxton, United Kingdom
| | - Keric Lamb
- Department of Biology, University of Virginia, Charlottesville,
VA, USA
| | - Tânia Paulo
- Departamento de Biologia Animal, Instituto Gulbenkian de Ciência,
Oeiras, Portugal
| | - Leeban Yusuf
- Center for Biological Diversity, University of St. Andrews, St
Andrews, United Kingdom
| | - Antonio Barbadilla
- Department of Genetics and Microbiology, Universitat Autònoma de
Barcelona, Barcelona, Spain
- Institute of Biotechnology and Biomedicine, Universitat Autònoma de
Barcelona, Barcelona, Spain
| | - Dmitri Petrov
- Department of Biology, Stanford University, Stanford, CA,
USA
| | - Paul Schmidt
- Department of Biology, The Pennsylvania State University,
University Park, PA, USA
| | - Josefa Gonzalez
- Institute of Evolutionary Biology, CSIC-Universitat Pompeu Fabra,
Barcelona, Spain
| | - Thomas Flatt
- Department of Biology, University of Fribourg, Fribourg, Switzerland
| | - Alan O Bergland
- Department of Biology, University of Virginia, Charlottesville,
VA, USA
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Larson ED, Komori H, Gibson TJ, Ostgaard CM, Hamm DC, Schnell JM, Lee CY, Harrison MM. Cell-type-specific chromatin occupancy by the pioneer factor Zelda drives key developmental transitions in Drosophila. Nat Commun 2021; 12:7153. [PMID: 34887421 PMCID: PMC8660810 DOI: 10.1038/s41467-021-27506-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Accepted: 11/24/2021] [Indexed: 12/14/2022] Open
Abstract
During Drosophila embryogenesis, the essential pioneer factor Zelda defines hundreds of cis-regulatory regions and in doing so reprograms the zygotic transcriptome. While Zelda is essential later in development, it is unclear how the ability of Zelda to define cis-regulatory regions is shaped by cell-type-specific chromatin architecture. Asymmetric division of neural stem cells (neuroblasts) in the fly brain provide an excellent paradigm for investigating the cell-type-specific functions of this pioneer factor. We show that Zelda synergistically functions with Notch to maintain neuroblasts in an undifferentiated state. Zelda misexpression reprograms progenitor cells to neuroblasts, but this capacity is limited by transcriptional repressors critical for progenitor commitment. Zelda genomic occupancy in neuroblasts is reorganized as compared to the embryo, and this reorganization is correlated with differences in chromatin accessibility and cofactor availability. We propose that Zelda regulates essential transitions in the neuroblasts and embryo through a shared gene-regulatory network driven by cell-type-specific enhancers.
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Affiliation(s)
- Elizabeth D Larson
- Department of Biomolecular Chemistry, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Hideyuki Komori
- Life Sciences Institute, University of Michigan, Ann Arbor, MI, USA
| | - Tyler J Gibson
- Department of Biomolecular Chemistry, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Cyrina M Ostgaard
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Danielle C Hamm
- Department of Biomolecular Chemistry, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
- Human Biology Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| | - Jack M Schnell
- Department of Biomolecular Chemistry, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
- Department of Stem Cell and Regenerative Medicine, Keck School of Medicine of the University of Southern California, Los Angeles, CA, USA
| | - Cheng-Yu Lee
- Division of Genetic Medicine, Department of Internal Medicine and Comprehensive Cancer Center, University of Michigan Medical School, Ann Arbor, MI, USA.
| | - Melissa M Harrison
- Department of Biomolecular Chemistry, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA.
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65
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Wolfe JC, Mikheeva LA, Hagras H, Zabet NR. An explainable artificial intelligence approach for decoding the enhancer histone modifications code and identification of novel enhancers in Drosophila. Genome Biol 2021; 22:308. [PMID: 34749786 PMCID: PMC8574042 DOI: 10.1186/s13059-021-02532-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Accepted: 10/29/2021] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND Enhancers are non-coding regions of the genome that control the activity of target genes. Recent efforts to identify active enhancers experimentally and in silico have proven effective. While these tools can predict the locations of enhancers with a high degree of accuracy, the mechanisms underpinning the activity of enhancers are often unclear. RESULTS Using machine learning (ML) and a rule-based explainable artificial intelligence (XAI) model, we demonstrate that we can predict the location of known enhancers in Drosophila with a high degree of accuracy. Most importantly, we use the rules of the XAI model to provide insight into the underlying combinatorial histone modifications code of enhancers. In addition, we identified a large set of putative enhancers that display the same epigenetic signature as enhancers identified experimentally. These putative enhancers are enriched in nascent transcription, divergent transcription and have 3D contacts with promoters of transcribed genes. However, they display only intermediary enrichment of mediator and cohesin complexes compared to previously characterised active enhancers. We also found that 10-15% of the predicted enhancers display similar characteristics to super enhancers observed in other species. CONCLUSIONS Here, we applied an explainable AI model to predict enhancers with high accuracy. Most importantly, we identified that different combinations of epigenetic marks characterise different groups of enhancers. Finally, we discovered a large set of putative enhancers which display similar characteristics with previously characterised active enhancers.
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Affiliation(s)
- Jareth C Wolfe
- School of Life Sciences, University of Essex, Colchester, CO4 3SQ, UK
- School of Computer Science and Electronic Engineering, University of Essex, Colchester, CO4 3SQ, UK
- Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, E1 2AT, London, UK
| | - Liudmila A Mikheeva
- School of Life Sciences, University of Essex, Colchester, CO4 3SQ, UK
- Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, E1 2AT, London, UK
- Department of Mathematical Sciences, University of Essex, Colchester, CO4 3SQ, UK
| | - Hani Hagras
- School of Computer Science and Electronic Engineering, University of Essex, Colchester, CO4 3SQ, UK.
| | - Nicolae Radu Zabet
- School of Life Sciences, University of Essex, Colchester, CO4 3SQ, UK.
- Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, E1 2AT, London, UK.
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66
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Das S, Caballero M, Kolesnikova T, Zhimulev I, Koren A, Nordman J. Replication timing analysis in polyploid cells reveals Rif1 uses multiple mechanisms to promote underreplication in Drosophila. Genetics 2021; 219:6369517. [PMID: 34740250 PMCID: PMC8570783 DOI: 10.1093/genetics/iyab147] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Accepted: 09/01/2021] [Indexed: 11/23/2022] Open
Abstract
Regulation of DNA replication and copy number is necessary to promote genome stability and maintain cell and tissue function. DNA replication is regulated temporally in a process known as replication timing (RT). Rap1-interacting factor 1 (Rif1) is a key regulator of RT and has a critical function in copy number control in polyploid cells. Previously, we demonstrated that Rif1 functions with SUUR to inhibit replication fork progression and promote underreplication (UR) of specific genomic regions. How Rif1-dependent control of RT factors into its ability to promote UR is unknown. By applying a computational approach to measure RT in Drosophila polyploid cells, we show that SUUR and Rif1 have differential roles in controlling UR and RT. Our findings reveal that Rif1 acts to promote late replication, which is necessary for SUUR-dependent underreplication. Our work provides new insight into the process of UR and its links to RT.
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Affiliation(s)
- Souradip Das
- Department of Biological Sciences, Vanderbilt University, Nashville, TN 37232, USA
| | - Madison Caballero
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA
| | - Tatyana Kolesnikova
- Institute of Molecular and Cellular Biology, Siberian Branch of Russian Academy of Sciences, 630090 Novosibirsk, Russia.,Laboratory of Structural, Functional and Comparative Genomics, Novosibirsk State University, 630090 Novosibirsk, Russia
| | - Igor Zhimulev
- Institute of Molecular and Cellular Biology, Siberian Branch of Russian Academy of Sciences, 630090 Novosibirsk, Russia.,Laboratory of Structural, Functional and Comparative Genomics, Novosibirsk State University, 630090 Novosibirsk, Russia
| | - Amnon Koren
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA
| | - Jared Nordman
- Department of Biological Sciences, Vanderbilt University, Nashville, TN 37232, USA
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67
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Baldwin SR, Mohapatra P, Nagalla M, Sindvani R, Amaya D, Dickson HA, Menuz K. Identification and characterization of CYPs induced in the Drosophila antenna by exposure to a plant odorant. Sci Rep 2021; 11:20530. [PMID: 34654888 PMCID: PMC8521596 DOI: 10.1038/s41598-021-99910-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Accepted: 10/04/2021] [Indexed: 12/13/2022] Open
Abstract
Members of the cytochrome p450 (CYP) enzyme family are abundantly expressed in insect olfactory tissues, where they are thought to act as Odorant Degrading Enzymes (ODEs). However, their contribution to olfactory signaling in vivo is poorly understood. This is due in part to the challenge of identifying which of the dozens of antennal-expressed CYPs might inactivate a given odorant. Here, we tested a high-throughput deorphanization strategy in Drosophila to identify CYPs that are transcriptionally induced by exposure to odorants. We discovered three CYPs selectively upregulated by geranyl acetate using transcriptional profiling. Although these CYPs are broadly expressed in the antenna in non-neuronal cells, electrophysiological recordings from CYP mutants did not reveal any changes in olfactory neuron responses to this odorant. Neurons were desensitized by pre-exposing flies to the odorant, but this effect was similar in CYP mutants. Together, our data suggest that the induction of a CYP gene by an odorant does not necessarily indicate a role for that CYP in neuronal responses to that odorant. We go on to show that some CYPs have highly restricted expression patterns in the antenna, and suggest that such CYPs may be useful candidates for further studies on olfactory CYP function.
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Affiliation(s)
- Shane R Baldwin
- Department of Physiology and Neurobiology, University of Connecticut, Storrs, CT, 06269, USA
- MBF Bioscience, Williston, VT, 05495, USA
| | - Pratyajit Mohapatra
- Department of Physiology and Neurobiology, University of Connecticut, Storrs, CT, 06269, USA
| | - Monica Nagalla
- Department of Physiology and Neurobiology, University of Connecticut, Storrs, CT, 06269, USA
- Feinberg School of Medicine, Northwestern University, Chicago, IL, 60611, USA
| | - Rhea Sindvani
- Department of Physiology and Neurobiology, University of Connecticut, Storrs, CT, 06269, USA
- School of Medicine, University of Connecticut, Farmington, CT, 06032, USA
| | - Desiree Amaya
- Department of Physiology and Neurobiology, University of Connecticut, Storrs, CT, 06269, USA
- Biomedical Sciences Program, Thomas Jefferson University, Philadelphia, PA, 19107, USA
| | - Hope A Dickson
- Department of Physiology and Neurobiology, University of Connecticut, Storrs, CT, 06269, USA
| | - Karen Menuz
- Department of Physiology and Neurobiology, University of Connecticut, Storrs, CT, 06269, USA.
- Institute for Systems Genomics, University of Connecticut, Storrs, CT, 06269, USA.
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68
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Yang L, Wang YW, Lu YY, Li B, Chen KP, Li CJ. Genome-wide identification and characterization of long non-coding RNAs in Tribolium castaneum. INSECT SCIENCE 2021; 28:1262-1276. [PMID: 32978885 DOI: 10.1111/1744-7917.12867] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Revised: 07/19/2020] [Accepted: 08/02/2020] [Indexed: 06/11/2023]
Abstract
Long non-coding RNAs (lncRNAs) are poorly understood in insects. In this study, we performed genome-wide analysis of lncRNAs in Tribolium castaneum by RNA-seq. In total, 4516 lncRNA transcripts corresponding to 3917 genes were identified from late embryos, early larvae, late larvae, early pupae, late pupae and early adults of T. castaneum, including 3152 novel lncRNAs and 1364 known lncRNAs. These lncRNAs have few exons and transcripts, and are short in length. During development, they exhibited nine different expression patterns. Functionally, they can act either by targeting messenger RNAs (1813 lncRNAs) and lncRNAs (45 lncRNAs) or as micro RNA (miRNA) precursors (46 lncRNAs). LncRNAs were observed to target the metabolic enzymes of glycolysis, TCA cycle and amino acids, demonstrating that lncRNAs control metabolism by regulating metabolic enzymes. Moreover, lncRNAs were shown to participate in cell differentiation and development via their targets. As miRNA precursors, lncRNAs could participate in the ecdysone signaling pathway. This study provides comprehensive information for lncRNAs of T. castaneum, and will promote functional analysis and target identification of lncRNAs in the insect.
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Affiliation(s)
- Liu Yang
- School of Life Sciences, Jiangsu University, Zhenjiang, Jiangsu Province, 212013, China
| | - You-Wei Wang
- School of Life Sciences, Jiangsu University, Zhenjiang, Jiangsu Province, 212013, China
| | - Yao-Yao Lu
- Jiangsu Key Laboratory for Biodiversity and Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, 210023, China
| | - Bin Li
- Jiangsu Key Laboratory for Biodiversity and Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, 210023, China
| | - Ke-Ping Chen
- School of Life Sciences, Jiangsu University, Zhenjiang, Jiangsu Province, 212013, China
| | - Cheng-Jun Li
- School of Life Sciences, Jiangsu University, Zhenjiang, Jiangsu Province, 212013, China
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69
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Campos TL, Korhonen PK, Hofmann A, Gasser RB, Young ND. Harnessing model organism genomics to underpin the machine learning-based prediction of essential genes in eukaryotes - Biotechnological implications. Biotechnol Adv 2021; 54:107822. [PMID: 34461202 DOI: 10.1016/j.biotechadv.2021.107822] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Revised: 08/17/2021] [Accepted: 08/24/2021] [Indexed: 12/17/2022]
Abstract
The availability of high-quality genomes and advances in functional genomics have enabled large-scale studies of essential genes in model eukaryotes, including the 'elegant worm' (Caenorhabditis elegans; Nematoda) and the 'vinegar fly' (Drosophila melanogaster; Arthropoda). However, this is not the case for other, much less-studied organisms, such as socioeconomically important parasites, for which functional genomic platforms usually do not exist. Thus, there is a need to develop innovative techniques or approaches for the prediction, identification and investigation of essential genes. A key approach that could enable the prediction of such genes is machine learning (ML). Here, we undertake an historical review of experimental and computational approaches employed for the characterisation of essential genes in eukaryotes, with a particular focus on model ecdysozoans (C. elegans and D. melanogaster), and discuss the possible applicability of ML-approaches to organisms such as socioeconomically important parasites. We highlight some recent results showing that high-performance ML, combined with feature engineering, allows a reliable prediction of essential genes from extensive, publicly available 'omic data sets, with major potential to prioritise such genes (with statistical confidence) for subsequent functional genomic validation. These findings could 'open the door' to fundamental and applied research areas. Evidence of some commonality in the essential gene-complement between these two organisms indicates that an ML-engineering approach could find broader applicability to ecdysozoans such as parasitic nematodes or arthropods, provided that suitably large and informative data sets become/are available for proper feature engineering, and for the robust training and validation of algorithms. This area warrants detailed exploration to, for example, facilitate the identification and characterisation of essential molecules as novel targets for drugs and vaccines against parasitic diseases. This focus is particularly important, given the substantial impact that such diseases have worldwide, and the current challenges associated with their prevention and control and with drug resistance in parasite populations.
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Affiliation(s)
- Tulio L Campos
- Department of Veterinary Biosciences, Melbourne Veterinary School, The University of Melbourne, Parkville, Victoria 3010, Australia; Bioinformatics Core Facility, Instituto Aggeu Magalhães, Fundação Oswaldo Cruz (IAM-Fiocruz), Recife, Pernambuco, Brazil
| | - Pasi K Korhonen
- Department of Veterinary Biosciences, Melbourne Veterinary School, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Andreas Hofmann
- Department of Veterinary Biosciences, Melbourne Veterinary School, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Robin B Gasser
- Department of Veterinary Biosciences, Melbourne Veterinary School, The University of Melbourne, Parkville, Victoria 3010, Australia.
| | - Neil D Young
- Department of Veterinary Biosciences, Melbourne Veterinary School, The University of Melbourne, Parkville, Victoria 3010, Australia.
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70
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Modeling Notch-Induced Tumor Cell Survival in the Drosophila Ovary Identifies Cellular and Transcriptional Response to Nuclear NICD Accumulation. Cells 2021; 10:cells10092222. [PMID: 34571871 PMCID: PMC8465586 DOI: 10.3390/cells10092222] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Revised: 08/02/2021] [Accepted: 08/23/2021] [Indexed: 12/26/2022] Open
Abstract
Notch is a conserved developmental signaling pathway that is dysregulated in many cancer types, most often through constitutive activation. Tumor cells with nuclear accumulation of the active Notch receptor, NICD, generally exhibit enhanced survival while patients experience poorer outcomes. To understand the impact of NICD accumulation during tumorigenesis, we developed a tumor model using the Drosophila ovarian follicular epithelium. Using this system we demonstrated that NICD accumulation contributed to larger tumor growth, reduced apoptosis, increased nuclear size, and fewer incidents of DNA damage without altering ploidy. Using bulk RNA sequencing we identified key genes involved in both a pre- and post- tumor response to NICD accumulation. Among these are genes involved in regulating double-strand break repair, chromosome organization, metabolism, like raptor, which we experimentally validated contributes to early Notch-induced tumor growth. Finally, using single-cell RNA sequencing we identified follicle cell-specific targets in NICD-overexpressing cells which contribute to DNA repair and negative regulation of apoptosis. This valuable tumor model for nuclear NICD accumulation in adult Drosophila follicle cells has allowed us to better understand the specific contribution of nuclear NICD accumulation to cell survival in tumorigenesis and tumor progression.
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71
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Pimsler ML, Hjelmen CE, Jonika MM, Sharma A, Fu S, Bala M, Sze SH, Tomberlin JK, Tarone AM. Sexual Dimorphism in Growth Rate and Gene Expression Throughout Immature Development in Wild Type Chrysomya rufifacies (Diptera: Calliphoridae) Macquart. Front Ecol Evol 2021. [DOI: 10.3389/fevo.2021.696638] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Reliability of forensic entomology analyses to produce relevant information to a given case requires an understanding of the underlying arthropod population(s) of interest and the factors contributing to variability. Common traits for analyses are affected by a variety of genetic and environmental factors. One trait of interest in forensic investigations has been species-specific temperature-dependent growth rates. Recent work indicates sexual dimorphism may be important in the analysis of such traits and related genetic markers of age. However, studying sexual dimorphic patterns of gene expression throughout immature development in wild-type insects can be difficult due to a lack of genetic tools, and the limits of most sex-determination mechanisms. Chrysomya rufifacies, however, is a particularly tractable system to address these issues as it has a monogenic sex determination system, meaning females have only a single-sex of offspring throughout their life. Using modified breeding procedures (to ensure single-female egg clutches) and transcriptomics, we investigated sexual dimorphism in development rate and gene expression. Females develop slower than males (9 h difference from egg to eclosion respectively) even at 30°C, with an average egg-to-eclosion time of 225 h for males and 234 h for females. Given that many key genes rely on sex-specific splicing for the development and maintenance of sexually dimorphic traits, we used a transcriptomic approach to identify different expression of gene splice variants. We find that 98.4% of assembled nodes exhibited sex-specific, stage-specific, to sex-by-stage specific patterns of expression. However, the greatest signal in the expression data is differentiation by developmental stage, indicating that sexual dimorphism in gene expression during development may not be investigatively important and that markers of age may be relatively independent of sex. Subtle differences in these gene expression patterns can be detected as early as 4 h post-oviposition, and 12 of these nodes demonstrate homology with key Drosophila sex determination genes, providing clues regarding the distinct sex determination mechanism of C. rufifacies. Finally, we validated the transcriptome analyses through qPCR and have identified five genes that are developmentally informative within and between sexes.
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72
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Pazhenkova EA, Lukhtanov VA. Genomic introgression from a distant congener in the Levant fritillary butterfly, Melitaea acentria. Mol Ecol 2021; 30:4819-4832. [PMID: 34288183 DOI: 10.1111/mec.16085] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Revised: 07/14/2021] [Accepted: 07/15/2021] [Indexed: 12/12/2022]
Abstract
Introgressive hybridization is more common in nature than previously thought, and its role and creative power in evolution is hotly discussed but not completely understood. Introgression occurs more frequently in sympatry between recently diverged taxa, or when the speciation process has not yet been completed. However, there are relatively few documented cases of hybridization that erodes reproductive barriers between distantly related species. Here, we use whole genome and mitochondrial data to examine how introgression from a distant congener affects pattern of genetic differentiation in the Levant fritillary butterfly Melitaea acentria. We show that this local taxon has evolved as a peripatric geographic isolate of the widespread Melitaea persea, and that there has been significant unidirectional gene flow from the sympatric, nonclosely related Melitaea didyma to M. acentria. We found direct evidence of ongoing sporadic hybridization between M. didyma and M. acentria, which are separated by at least 5 million years of independent evolution. Elevated differentiation and lower level of introgression on the sex Z chromosome compared to autosomes suggest that the Z chromosome has accumulated loci acting as intrinsic postzygotic barriers. Our results show that introgression from M. didyma has been an additional source of nucleotide diversity in the M. acentria population, providing material for drift and selection.
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Affiliation(s)
- Elena A Pazhenkova
- Department of Entomology, St. Petersburg State University, St. Petersburg, Russia.,Department of Karyosystematics, Zoological Institute of Russian Academy of Sciences, St. Petersburg, Russia
| | - Vladimir A Lukhtanov
- Department of Karyosystematics, Zoological Institute of Russian Academy of Sciences, St. Petersburg, Russia
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73
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Grob S. Three-dimensional chromosome organization in flowering plants. Brief Funct Genomics 2021; 19:83-91. [PMID: 31680170 DOI: 10.1093/bfgp/elz024] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Revised: 09/02/2019] [Accepted: 09/03/2019] [Indexed: 12/20/2022] Open
Abstract
Research on plant three-dimensional (3D) genome architecture made rapid progress over the past 5 years. Numerous Hi-C interaction data sets were generated in a wide range of plant species, allowing for a comprehensive overview on 3D chromosome folding principles in the plant kingdom. Plants lack important genes reported to be vital for chromosome folding in animals. However, similar 3D structures such as topologically associating domains and chromatin loops were identified. Recent studies in Arabidopsis thaliana revealed how chromosomal regions are positioned within the nucleus by determining their association with both, the nuclear periphery and the nucleolus. Additionally, many plant species exhibit high-frequency interactions among KNOT entangled elements, which are associated with safeguarding the genome from invasive DNA elements. Many of the recently published Hi-C data sets were generated to aid de novo genome assembly and remain to date little explored. These data sets represent a valuable resource for future comparative studies, which may lead to a more profound understanding of the evolution of 3D chromosome organization in plants.
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Affiliation(s)
- Stefan Grob
- Institute of Plant and Microbial Biology, University of Zurich, Zollikerstrasse 107, 8008 Zurich, Switzerland
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74
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Cong Q, Shen J, Zhang J, Li W, Kinch LN, Calhoun JV, Warren AD, Grishin NV. Genomics Reveals the Origins of Historical Specimens. Mol Biol Evol 2021; 38:2166-2176. [PMID: 33502509 PMCID: PMC8097301 DOI: 10.1093/molbev/msab013] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Centuries of zoological studies have amassed billions of specimens in collections worldwide. Genomics of these specimens promises to reinvigorate biodiversity research. However, because DNA degrades with age in historical specimens, it is a challenge to obtain genomic data for them and analyze degraded genomes. We developed experimental and computational protocols to overcome these challenges and applied our methods to resolve a series of long-standing controversies involving a group of butterflies. We deduced the geographical origins of several historical specimens of uncertain provenance that are at the heart of these debates. Here, genomics tackles one of the greatest problems in zoology: countless old specimens that serve as irreplaceable embodiments of species concepts cannot be confidently assigned to extant species or population due to the lack of diagnostic morphological features and clear documentation of the collection locality. The ability to determine where they were collected will resolve many on-going disputes. More broadly, we show the utility of applying genomics to historical museum specimens to delineate the boundaries of species and populations, and to hypothesize about genotypic determinants of phenotypic traits.
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Affiliation(s)
- Qian Cong
- Eugene McDermott Center for Human Growth and Development, University of Texas Southwestern Medical Center, Dallas, TX, USA.,Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Jinhui Shen
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Jing Zhang
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Wenlin Li
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Lisa N Kinch
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX, USA.,Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - John V Calhoun
- McGuire Center for Lepidoptera and Biodiversity, Florida Museum of Natural History, University of Florida, Gainesville, FL, USA
| | - Andrew D Warren
- McGuire Center for Lepidoptera and Biodiversity, Florida Museum of Natural History, University of Florida, Gainesville, FL, USA
| | - Nick V Grishin
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX, USA.,Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, TX, USA.,Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX, USA
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75
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Wang XF, Yang SA, Gong S, Chang CH, Portilla JM, Chatterjee D, Irianto J, Bao H, Huang YC, Deng WM. Polyploid mitosis and depolyploidization promote chromosomal instability and tumor progression in a Notch-induced tumor model. Dev Cell 2021; 56:1976-1988.e4. [PMID: 34146466 DOI: 10.1016/j.devcel.2021.05.017] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Revised: 03/18/2021] [Accepted: 05/27/2021] [Indexed: 02/07/2023]
Abstract
Ploidy variation is a cancer hallmark and is frequently associated with poor prognosis in high-grade cancers. Using a Drosophila solid-tumor model where oncogenic Notch drives tumorigenesis in a transition-zone microenvironment in the salivary gland imaginal ring, we find that the tumor-initiating cells normally undergo endoreplication to become polyploid. Upregulation of Notch signaling, however, induces these polyploid transition-zone cells to re-enter mitosis and undergo tumorigenesis. Growth and progression of the transition-zone tumor are fueled by a combination of polyploid mitosis, endoreplication, and depolyploidization. Both polyploid mitosis and depolyploidization are error prone, resulting in chromosomal copy-number variation and polyaneuploidy. Comparative RNA-seq and epistasis analysis reveal that the DNA-damage response genes, also active during meiosis, are upregulated in these tumors and are required for the ploidy-reduction division. Together, these findings suggest that polyploidy and associated cell-cycle variants are critical for increased tumor-cell heterogeneity and genome instability during cancer progression.
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Affiliation(s)
- Xian-Feng Wang
- Department of Biochemistry and Molecular Biology, Tulane University Louisiana Center Research Center, New Orleans, LA 70112, USA
| | - Sheng-An Yang
- Department of Biological Science, Florida State University, Tallahassee, FL 32306, USA
| | - Shangyu Gong
- Department of Biochemistry and Molecular Biology, Tulane University Louisiana Center Research Center, New Orleans, LA 70112, USA
| | - Chih-Hsuan Chang
- Department of Biochemistry and Molecular Biology, Tulane University Louisiana Center Research Center, New Orleans, LA 70112, USA
| | - Juan Martin Portilla
- Department of Biological Science, Florida State University, Tallahassee, FL 32306, USA
| | - Deeptiman Chatterjee
- Department of Biochemistry and Molecular Biology, Tulane University Louisiana Center Research Center, New Orleans, LA 70112, USA
| | - Jerome Irianto
- Department of Biomedical Sciences, Florida State University College of Medicine, Tallahassee, FL 32306, USA
| | - Hongcun Bao
- Department of Biochemistry and Molecular Biology, Tulane University Louisiana Center Research Center, New Orleans, LA 70112, USA
| | - Yi-Chun Huang
- Department of Biochemistry and Molecular Biology, Tulane University Louisiana Center Research Center, New Orleans, LA 70112, USA
| | - Wu-Min Deng
- Department of Biochemistry and Molecular Biology, Tulane University Louisiana Center Research Center, New Orleans, LA 70112, USA; Department of Biological Science, Florida State University, Tallahassee, FL 32306, USA.
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76
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Yu T, Huang X, Dou S, Tang X, Luo S, Theurkauf WE, Lu J, Weng Z. A benchmark and an algorithm for detecting germline transposon insertions and measuring de novo transposon insertion frequencies. Nucleic Acids Res 2021; 49:e44. [PMID: 33511407 PMCID: PMC8096211 DOI: 10.1093/nar/gkab010] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Revised: 12/28/2020] [Accepted: 01/06/2021] [Indexed: 02/01/2023] Open
Abstract
Transposons are genomic parasites, and their new insertions can cause instability and spur the evolution of their host genomes. Rapid accumulation of short-read whole-genome sequencing data provides a great opportunity for studying new transposon insertions and their impacts on the host genome. Although many algorithms are available for detecting transposon insertions, the task remains challenging and existing tools are not designed for identifying de novo insertions. Here, we present a new benchmark fly dataset based on PacBio long-read sequencing and a new method TEMP2 for detecting germline insertions and measuring de novo ‘singleton’ insertion frequencies in eukaryotic genomes. TEMP2 achieves high sensitivity and precision for detecting germline insertions when compared with existing tools using both simulated data in fly and experimental data in fly and human. Furthermore, TEMP2 can accurately assess the frequencies of de novo transposon insertions even with high levels of chimeric reads in simulated datasets; such chimeric reads often occur during the construction of short-read sequencing libraries. By applying TEMP2 to published data on hybrid dysgenic flies inflicted by de-repressed P-elements, we confirmed the continuous new insertions of P-elements in dysgenic offspring before they regain piRNAs for P-element repression. TEMP2 is freely available at Github: https://github.com/weng-lab/TEMP2.
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Affiliation(s)
- Tianxiong Yu
- Department of Thoracic Surgery, Clinical Translational Research Center, Shanghai Pulmonary Hospital, The School of Life Sciences and Technology, Tongji University, Shanghai 200092, China.,Program in Bioinformatics and Integrative Biology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Xiao Huang
- Department of Thoracic Surgery, Clinical Translational Research Center, Shanghai Pulmonary Hospital, The School of Life Sciences and Technology, Tongji University, Shanghai 200092, China
| | - Shengqian Dou
- State Key Laboratory of Protein and Plant Gene Research, Center for Bioinformatics, School of Life Sciences and Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China
| | - Xiaolu Tang
- State Key Laboratory of Protein and Plant Gene Research, Center for Bioinformatics, School of Life Sciences and Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China
| | - Shiqi Luo
- State Key Laboratory of Protein and Plant Gene Research, Center for Bioinformatics, School of Life Sciences and Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China
| | - William E Theurkauf
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Jian Lu
- State Key Laboratory of Protein and Plant Gene Research, Center for Bioinformatics, School of Life Sciences and Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China
| | - Zhiping Weng
- Department of Thoracic Surgery, Clinical Translational Research Center, Shanghai Pulmonary Hospital, The School of Life Sciences and Technology, Tongji University, Shanghai 200092, China.,Program in Bioinformatics and Integrative Biology, University of Massachusetts Medical School, Worcester, MA 01605, USA
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77
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Duchen P, Salamin N. A Cautionary Note on the Use of Genotype Callers in Phylogenomics. Syst Biol 2021; 70:844-854. [PMID: 33084875 PMCID: PMC8208803 DOI: 10.1093/sysbio/syaa081] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Revised: 10/02/2020] [Accepted: 10/02/2020] [Indexed: 12/13/2022] Open
Abstract
Next-generation-sequencing genotype callers are commonly used in studies to call variants from newly sequenced species. However, due to the current availability of genomic resources, it is still common practice to use only one reference genome for a given genus, or even one reference for an entire clade of a higher taxon. The problem with traditional genotype callers, such as the one from GATK, is that they are optimized for variant calling at the population level. However, when these callers are used at the phylogenetic level, the consequences for downstream analyses can be substantial. Here, we performed simulations to compare the performance between the genotype callers of GATK and ATLAS, and present their differences at various phylogenetic scales. We show that the genotype caller of GATK substantially underestimates the number of variants at the phylogenetic level, but not at the population level. We also found that the accuracy of heterozygote calls declines with increasing distance to the reference genome. We quantified this decline and found that it is very sharp in GATK, while ATLAS maintains high accuracy even at moderately divergent species from the reference. We further suggest that efforts should be taken towards acquiring more reference genomes per species, before pursuing high-scale phylogenomic studies. [ATLAS; efficiency of SNP calling; GATK; heterozygote calling; next-generation sequencing; reference genome; variant calling.].
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Affiliation(s)
- Pablo Duchen
- Department of Computational Biology, University of Lausanne, Quartier Sorge, 1015 Lausanne, Switzerland
| | - Nicolas Salamin
- Department of Computational Biology, University of Lausanne, Quartier Sorge, 1015 Lausanne, Switzerland
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78
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Hoencamp C, Dudchenko O, Elbatsh AMO, Brahmachari S, Raaijmakers JA, van Schaik T, Sedeño Cacciatore Á, Contessoto VG, van Heesbeen RGHP, van den Broek B, Mhaskar AN, Teunissen H, St Hilaire BG, Weisz D, Omer AD, Pham M, Colaric Z, Yang Z, Rao SSP, Mitra N, Lui C, Yao W, Khan R, Moroz LL, Kohn A, St Leger J, Mena A, Holcroft K, Gambetta MC, Lim F, Farley E, Stein N, Haddad A, Chauss D, Mutlu AS, Wang MC, Young ND, Hildebrandt E, Cheng HH, Knight CJ, Burnham TLU, Hovel KA, Beel AJ, Mattei PJ, Kornberg RD, Warren WC, Cary G, Gómez-Skarmeta JL, Hinman V, Lindblad-Toh K, Di Palma F, Maeshima K, Multani AS, Pathak S, Nel-Themaat L, Behringer RR, Kaur P, Medema RH, van Steensel B, de Wit E, Onuchic JN, Di Pierro M, Lieberman Aiden E, Rowland BD. 3D genomics across the tree of life reveals condensin II as a determinant of architecture type. Science 2021; 372:984-989. [PMID: 34045355 PMCID: PMC8172041 DOI: 10.1126/science.abe2218] [Citation(s) in RCA: 125] [Impact Index Per Article: 41.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Accepted: 04/16/2021] [Indexed: 01/01/2023]
Abstract
We investigated genome folding across the eukaryotic tree of life. We find two types of three-dimensional (3D) genome architectures at the chromosome scale. Each type appears and disappears repeatedly during eukaryotic evolution. The type of genome architecture that an organism exhibits correlates with the absence of condensin II subunits. Moreover, condensin II depletion converts the architecture of the human genome to a state resembling that seen in organisms such as fungi or mosquitoes. In this state, centromeres cluster together at nucleoli, and heterochromatin domains merge. We propose a physical model in which lengthwise compaction of chromosomes by condensin II during mitosis determines chromosome-scale genome architecture, with effects that are retained during the subsequent interphase. This mechanism likely has been conserved since the last common ancestor of all eukaryotes.
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Affiliation(s)
- Claire Hoencamp
- Division of Gene Regulation, Netherlands Cancer Institute, 1066 CX Amsterdam, Netherlands
| | - Olga Dudchenko
- The Center for Genome Architecture, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
- Center for Theoretical Biological Physics, Rice University, Houston, TX 77005, USA
| | - Ahmed M O Elbatsh
- Division of Gene Regulation, Netherlands Cancer Institute, 1066 CX Amsterdam, Netherlands
| | | | - Jonne A Raaijmakers
- Division of Cell Biology, Oncode Institute, Netherlands Cancer Institute, 1066 CX Amsterdam, Netherlands
| | - Tom van Schaik
- Division of Gene Regulation, Oncode Institute, Netherlands Cancer Institute, 1066 CX Amsterdam, Netherlands
| | | | - Vinícius G Contessoto
- Center for Theoretical Biological Physics, Rice University, Houston, TX 77005, USA
- Department of Physics, Institute of Biosciences, Letters and Exact Sciences, São Paulo State University (UNESP), São José do Rio Preto - SP, 15054-000, Brazil
| | - Roy G H P van Heesbeen
- Division of Cell Biology, Oncode Institute, Netherlands Cancer Institute, 1066 CX Amsterdam, Netherlands
| | - Bram van den Broek
- BioImaging Facility, Netherlands Cancer Institute, 1066 CX Amsterdam, Netherlands
| | - Aditya N Mhaskar
- Division of Gene Regulation, Netherlands Cancer Institute, 1066 CX Amsterdam, Netherlands
| | - Hans Teunissen
- Division of Gene Regulation, Oncode Institute, Netherlands Cancer Institute, 1066 CX Amsterdam, Netherlands
| | - Brian Glenn St Hilaire
- The Center for Genome Architecture, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - David Weisz
- The Center for Genome Architecture, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Arina D Omer
- The Center for Genome Architecture, Baylor College of Medicine, Houston, TX 77030, USA
| | - Melanie Pham
- The Center for Genome Architecture, Baylor College of Medicine, Houston, TX 77030, USA
| | - Zane Colaric
- The Center for Genome Architecture, Baylor College of Medicine, Houston, TX 77030, USA
| | - Zhenzhen Yang
- Shanghai Institute for Advanced Immunochemical Studies, ShanghaiTech, Pudong 201210, China
| | - Suhas S P Rao
- The Center for Genome Architecture, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Structural Biology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Namita Mitra
- The Center for Genome Architecture, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Christopher Lui
- The Center for Genome Architecture, Baylor College of Medicine, Houston, TX 77030, USA
| | - Weijie Yao
- The Center for Genome Architecture, Baylor College of Medicine, Houston, TX 77030, USA
| | - Ruqayya Khan
- The Center for Genome Architecture, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Leonid L Moroz
- Whitney Laboratory and Department of Neuroscience, University of Florida, Gainesville, FL 32611, USA
| | - Andrea Kohn
- Whitney Laboratory and Department of Neuroscience, University of Florida, Gainesville, FL 32611, USA
| | - Judy St Leger
- Department of Biosciences, Cornell University College of Veterinary Medicine, Ithaca, NY 14853, USA
| | | | | | | | - Fabian Lim
- Department of Medicine and Molecular Biology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Emma Farley
- Department of Medicine and Molecular Biology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Nils Stein
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK Gatersleben), 06466 Seeland, Germany
- Center of Integrated Breeding Research (CiBreed), Department of Crop Sciences, Georg-August-University Göttingen, 37075 Göttingen, Germany
- UWA School of Agriculture and Environment, The University of Western Australia, Perth, WA 6009, Australia
| | - Alexander Haddad
- The Center for Genome Architecture, Baylor College of Medicine, Houston, TX 77030, USA
| | - Daniel Chauss
- National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Ayse Sena Mutlu
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Meng C Wang
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
- Huffington Center on Aging, Baylor College of Medicine, Houston, TX 77030, USA
- Howard Hughes Medical Institute, Baylor College of Medicine, Houston, TX 77030, USA
| | - Neil D Young
- Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Parkville, VIC 3010, Australia
| | - Evin Hildebrandt
- Avian Diseases and Oncology Laboratory, US Department of Agriculture, Agricultural Research Service, East Lansing, MI 48823, USA
| | - Hans H Cheng
- Avian Diseases and Oncology Laboratory, US Department of Agriculture, Agricultural Research Service, East Lansing, MI 48823, USA
| | | | - Theresa L U Burnham
- Department of Wildlife, Fish, and Conservation Biology, University of California, Davis, Davis, CA 95616, USA
- Coastal and Marine Institute and Department of Biology, San Diego State University, San Diego, CA 92106, USA
| | - Kevin A Hovel
- Coastal and Marine Institute and Department of Biology, San Diego State University, San Diego, CA 92106, USA
| | - Andrew J Beel
- Department of Structural Biology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Pierre-Jean Mattei
- Department of Structural Biology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Roger D Kornberg
- Department of Structural Biology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Wesley C Warren
- Department of Animal Sciences, University of Missouri, Columbia, MO 65211, USA
| | - Gregory Cary
- The Jackson Laboratory, Bar Harbor, ME 04609, USA
| | - José Luis Gómez-Skarmeta
- Centro Andaluz de Biología del Desarrollo CSIC, Universidad Pablo de Olavide, 41013 Sevilla, Spain
| | - Veronica Hinman
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA 15213, USA
| | - Kerstin Lindblad-Toh
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
- Science for Life Laboratory, Department of Medical Biochemistry and Microbiology, Uppsala University, 751 23 Uppsala, Sweden
| | - Federica Di Palma
- Department of Biological Sciences, University of East Anglia, Norwich NR4 7TJ, UK
| | - Kazuhiro Maeshima
- Genome Dynamics Laboratory, National Institute of Genetics, Mishima, Shizuoka 411-8540, Japan
- Department of Genetics, Sokendai (Graduate University for Advanced Studies), Mishima, Shizuoka 411-8540, Japan
| | - Asha S Multani
- Department of Genetics, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Sen Pathak
- Department of Genetics, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Liesl Nel-Themaat
- Department of Genetics, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Richard R Behringer
- Department of Genetics, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Parwinder Kaur
- UWA School of Agriculture and Environment, The University of Western Australia, Perth, WA 6009, Australia
| | - René H Medema
- Division of Cell Biology, Oncode Institute, Netherlands Cancer Institute, 1066 CX Amsterdam, Netherlands
| | - Bas van Steensel
- Division of Gene Regulation, Oncode Institute, Netherlands Cancer Institute, 1066 CX Amsterdam, Netherlands
| | - Elzo de Wit
- Division of Gene Regulation, Oncode Institute, Netherlands Cancer Institute, 1066 CX Amsterdam, Netherlands
| | - José N Onuchic
- Center for Theoretical Biological Physics, Rice University, Houston, TX 77005, USA
- Departments of Physics and Astronomy, Chemistry, and Biosciences, Rice University, Houston, TX 77005, USA
| | - Michele Di Pierro
- Center for Theoretical Biological Physics, Rice University, Houston, TX 77005, USA
- Department of Physics, Northeastern University, Boston, MA 02115, USA
| | - Erez Lieberman Aiden
- The Center for Genome Architecture, Baylor College of Medicine, Houston, TX 77030, USA.
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
- Center for Theoretical Biological Physics, Rice University, Houston, TX 77005, USA
- Shanghai Institute for Advanced Immunochemical Studies, ShanghaiTech, Pudong 201210, China
- UWA School of Agriculture and Environment, The University of Western Australia, Perth, WA 6009, Australia
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Benjamin D Rowland
- Division of Gene Regulation, Netherlands Cancer Institute, 1066 CX Amsterdam, Netherlands.
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79
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Campos TL, Korhonen PK, Young ND. Cross-Predicting Essential Genes between Two Model Eukaryotic Species Using Machine Learning. Int J Mol Sci 2021; 22:5056. [PMID: 34064595 PMCID: PMC8150380 DOI: 10.3390/ijms22105056] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2021] [Revised: 05/07/2021] [Accepted: 05/08/2021] [Indexed: 12/24/2022] Open
Abstract
Experimental studies of Caenorhabditis elegans and Drosophila melanogaster have contributed substantially to our understanding of molecular and cellular processes in metazoans at large. Since the publication of their genomes, functional genomic investigations have identified genes that are essential or non-essential for survival in each species. Recently, a range of features linked to gene essentiality have been inferred using a machine learning (ML)-based approach, allowing essentiality predictions within a species. Nevertheless, predictions between species are still elusive. Here, we undertake a comprehensive study using ML to discover and validate features of essential genes common to both C. elegans and D. melanogaster. We demonstrate that the cross-species prediction of gene essentiality is possible using a subset of features linked to nucleotide/protein sequences, protein orthology and subcellular localisation, single-cell RNA-seq, and histone methylation markers. Complementary analyses showed that essential genes are enriched for transcription and translation functions and are preferentially located away from heterochromatin regions of C. elegans and D. melanogaster chromosomes. The present work should enable the cross-prediction of essential genes between model and non-model metazoans.
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Affiliation(s)
- Tulio L. Campos
- Department of Veterinary Biosciences, Melbourne Veterinary School, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, VIC 3010, Australia; (T.L.C.); (P.K.K.)
- Bioinformatics Core Facility, Instituto Aggeu Magalhães, Fundação Oswaldo Cruz (IAM-Fiocruz), Recife 50740-465, PE, Brazil
| | - Pasi K. Korhonen
- Department of Veterinary Biosciences, Melbourne Veterinary School, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, VIC 3010, Australia; (T.L.C.); (P.K.K.)
| | - Neil D. Young
- Department of Veterinary Biosciences, Melbourne Veterinary School, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, VIC 3010, Australia; (T.L.C.); (P.K.K.)
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80
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Palmateer CM, Moseley SC, Ray S, Brovero SG, Arbeitman MN. Analysis of cell-type-specific chromatin modifications and gene expression in Drosophila neurons that direct reproductive behavior. PLoS Genet 2021; 17:e1009240. [PMID: 33901168 PMCID: PMC8102012 DOI: 10.1371/journal.pgen.1009240] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 05/06/2021] [Accepted: 04/05/2021] [Indexed: 02/06/2023] Open
Abstract
Examining the role of chromatin modifications and gene expression in neurons is critical for understanding how the potential for behaviors are established and maintained. We investigate this question by examining Drosophila melanogaster fru P1 neurons that underlie reproductive behaviors in both sexes. We developed a method to purify cell-type-specific chromatin (Chromatag), using a tagged histone H2B variant that is expressed using the versatile Gal4/UAS gene expression system. Here, we use Chromatag to evaluate five chromatin modifications, at three life stages in both sexes. We find substantial changes in chromatin modification profiles across development and fewer differences between males and females. Additionally, we find chromatin modifications that persist in different sets of genes from pupal to adult stages, which may point to genes important for cell fate determination in fru P1 neurons. We generated cell-type-specific RNA-seq data sets, using translating ribosome affinity purification (TRAP). We identify actively translated genes in fru P1 neurons, revealing novel stage- and sex-differences in gene expression. We also find chromatin modification enrichment patterns that are associated with gene expression. Next, we use the chromatin modification data to identify cell-type-specific super-enhancer-containing genes. We show that genes with super-enhancers in fru P1 neurons differ across development and between the sexes. We validated that a set of genes are expressed in fru P1 neurons, which were chosen based on having a super-enhancer and TRAP-enriched expression in fru P1 neurons.
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Affiliation(s)
- Colleen M. Palmateer
- Department of Biomedical Sciences, Florida State University, College of Medicine, Tallahassee, Florida, United States of America
| | - Shawn C. Moseley
- Department of Biomedical Sciences, Florida State University, College of Medicine, Tallahassee, Florida, United States of America
| | - Surjyendu Ray
- Department of Biomedical Sciences, Florida State University, College of Medicine, Tallahassee, Florida, United States of America
| | - Savannah G. Brovero
- Department of Biomedical Sciences, Florida State University, College of Medicine, Tallahassee, Florida, United States of America
| | - Michelle N. Arbeitman
- Department of Biomedical Sciences, Florida State University, College of Medicine, Tallahassee, Florida, United States of America
- Program of Neuroscience, Florida State University, Tallahassee, Florida, United States of America
- * E-mail:
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81
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Li M, Zhao Q, Belloli R, Duffy CR, Cai HN. Insulator foci distance correlates with cellular and nuclear morphology in early Drosophila embryos. Dev Biol 2021; 476:189-199. [PMID: 33844976 DOI: 10.1016/j.ydbio.2021.03.022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Revised: 02/16/2021] [Accepted: 03/26/2021] [Indexed: 11/25/2022]
Abstract
The three-dimensional (3D) organization of the genome is highly dynamic, changing during development and varying across different tissues and cell types. Recent studies indicate that these changes alter regulatory interactions, leading to changes in gene expression. Despite its importance, the mechanisms that influence genomic organization remain poorly understood. We have previously identified a network of chromatin boundary elements, or insulators, in the Drosophila Antennapedia homeotic complex (ANT-C). These genomic elements interact with one another to tether chromatin loops that could block or promote enhancer-promoter interactions. To understand the function of these insulators, we assessed their interactions by measuring their 3D nuclear distance in developing animal tissues. Our data suggest that the ANT-C Hox complex might be in a folded or looped configuration rather than in a random or extended form. The architecture of the ANT-C complex, as read out by the pair-wise distance between insulators, undergoes a strong compression during late embryogenesis, coinciding with the reduction of cell and nuclear diameters due to continued cell divisions in post-cleavage cells. Our results suggest that genomic architecture and gene regulation may be influenced by cellular morphology and movement during development.
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Affiliation(s)
- Mo Li
- Department of Cellular Biology, University of Georgia, Athens GA, 30602, USA
| | - Qing Zhao
- Department of Cellular Biology, University of Georgia, Athens GA, 30602, USA
| | - Ryan Belloli
- Department of Cellular Biology, University of Georgia, Athens GA, 30602, USA
| | - Carly R Duffy
- Department of Cellular Biology, University of Georgia, Athens GA, 30602, USA
| | - Haini N Cai
- Department of Cellular Biology, University of Georgia, Athens GA, 30602, USA.
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82
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Clifton BD, Jimenez J, Kimura A, Chahine Z, Librado P, Sánchez-Gracia A, Abbassi M, Carranza F, Chan C, Marchetti M, Zhang W, Shi M, Vu C, Yeh S, Fanti L, Xia XQ, Rozas J, Ranz JM. Understanding the Early Evolutionary Stages of a Tandem Drosophilamelanogaster-Specific Gene Family: A Structural and Functional Population Study. Mol Biol Evol 2021; 37:2584-2600. [PMID: 32359138 PMCID: PMC7475035 DOI: 10.1093/molbev/msaa109] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Gene families underlie genetic innovation and phenotypic diversification. However, our understanding of the early genomic and functional evolution of tandemly arranged gene families remains incomplete as paralog sequence similarity hinders their accurate characterization. The Drosophila melanogaster-specific gene family Sdic is tandemly repeated and impacts sperm competition. We scrutinized Sdic in 20 geographically diverse populations using reference-quality genome assemblies, read-depth methodologies, and qPCR, finding that ∼90% of the individuals harbor 3-7 copies as well as evidence of population differentiation. In strains with reliable gene annotations, copy number variation (CNV) and differential transposable element insertions distinguish one structurally distinct version of the Sdic region per strain. All 31 annotated copies featured protein-coding potential and, based on the protein variant encoded, were categorized into 13 paratypes differing in their 3' ends, with 3-5 paratypes coexisting in any strain examined. Despite widespread gene conversion, the only copy present in all strains has functionally diverged at both coding and regulatory levels under positive selection. Contrary to artificial tandem duplications of the Sdic region that resulted in increased male expression, CNV in cosmopolitan strains did not correlate with expression levels, likely as a result of differential genome modifier composition. Duplicating the region did not enhance sperm competitiveness, suggesting a fitness cost at high expression levels or a plateau effect. Beyond facilitating a minimally optimal expression level, Sdic CNV acts as a catalyst of protein and regulatory diversity, showcasing a possible evolutionary path recently formed tandem multigene families can follow toward long-term consolidation in eukaryotic genomes.
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Affiliation(s)
- Bryan D Clifton
- Department of Ecology and Evolutionary Biology, University of California Irvine, Irvine, CA
| | - Jamie Jimenez
- Department of Ecology and Evolutionary Biology, University of California Irvine, Irvine, CA
| | - Ashlyn Kimura
- Department of Ecology and Evolutionary Biology, University of California Irvine, Irvine, CA
| | - Zeinab Chahine
- Department of Ecology and Evolutionary Biology, University of California Irvine, Irvine, CA
| | - Pablo Librado
- Laboratoire AMIS CNRS UMR 5288, Faculté de Médicine de Purpan, Université Paul Sabatier, Toulouse, France
| | - Alejandro Sánchez-Gracia
- Departament de Genètica, Microbiologia i Estadistica, Universitat de Barcelona, Barcelona, Spain.,Institut de Recerca de la Biodiversitat, Universitat de Barcelona, Barcelona, Spain
| | - Mashya Abbassi
- Department of Ecology and Evolutionary Biology, University of California Irvine, Irvine, CA
| | - Francisco Carranza
- Department of Ecology and Evolutionary Biology, University of California Irvine, Irvine, CA
| | - Carolus Chan
- Department of Ecology and Evolutionary Biology, University of California Irvine, Irvine, CA
| | - Marcella Marchetti
- Istituto Pasteur Italia, Fondazione Cenci-Bolognetti, Rome, Italy.,Department of Biology and Biotechnology "C. Darwin", Sapienza University of Rome, Rome, Italy
| | - Wanting Zhang
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei Province, China
| | - Mijuan Shi
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei Province, China
| | - Christine Vu
- Department of Ecology and Evolutionary Biology, University of California Irvine, Irvine, CA
| | - Shudan Yeh
- Department of Ecology and Evolutionary Biology, University of California Irvine, Irvine, CA.,Department of Life Sciences, National Central University, Taoyuan City, Zhongli District, Taiwan
| | - Laura Fanti
- Istituto Pasteur Italia, Fondazione Cenci-Bolognetti, Rome, Italy.,Department of Biology and Biotechnology "C. Darwin", Sapienza University of Rome, Rome, Italy
| | - Xiao-Qin Xia
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei Province, China
| | - Julio Rozas
- Departament de Genètica, Microbiologia i Estadistica, Universitat de Barcelona, Barcelona, Spain.,Institut de Recerca de la Biodiversitat, Universitat de Barcelona, Barcelona, Spain
| | - José M Ranz
- Department of Ecology and Evolutionary Biology, University of California Irvine, Irvine, CA
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83
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Spierer AN, Mossman JA, Smith SP, Crawford L, Ramachandran S, Rand DM. Natural variation in the regulation of neurodevelopmental genes modifies flight performance in Drosophila. PLoS Genet 2021; 17:e1008887. [PMID: 33735180 PMCID: PMC7971549 DOI: 10.1371/journal.pgen.1008887] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Accepted: 01/26/2021] [Indexed: 12/28/2022] Open
Abstract
The winged insects of the order Diptera are colloquially named for their most recognizable phenotype: flight. These insects rely on flight for a number of important life history traits, such as dispersal, foraging, and courtship. Despite the importance of flight, relatively little is known about the genetic architecture of flight performance. Accordingly, we sought to uncover the genetic modifiers of flight using a measure of flies’ reaction and response to an abrupt drop in a vertical flight column. We conducted a genome wide association study (GWAS) using 197 of the Drosophila Genetic Reference Panel (DGRP) lines, and identified a combination of additive and marginal variants, epistatic interactions, whole genes, and enrichment across interaction networks. Egfr, a highly pleiotropic developmental gene, was among the most significant additive variants identified. We functionally validated 13 of the additive candidate genes’ (Adgf-A/Adgf-A2/CG32181, bru1, CadN, flapper (CG11073), CG15236, flippy (CG9766), CREG, Dscam4, form3, fry, Lasp/CG9692, Pde6, Snoo), and introduce a novel approach to whole gene significance screens: PEGASUS_flies. Additionally, we identified ppk23, an Acid Sensing Ion Channel (ASIC) homolog, as an important hub for epistatic interactions. We propose a model that suggests genetic modifiers of wing and muscle morphology, nervous system development and function, BMP signaling, sexually dimorphic neural wiring, and gene regulation are all important for the observed differences flight performance in a natural population. Additionally, these results represent a snapshot of the genetic modifiers affecting drop-response flight performance in Drosophila, with implications for other insects. Insect flight is a widely recognizable phenotype of many winged insects, hence the name: flies. While fruit flies, or Drosophila melanogaster, are a genetically tractable model, flight performance is a highly integrative phenotype, and therefore challenging to identify comprehensively which genetic modifiers contribute to its genetic architecture. Accordingly, we screened 197 Drosophila Genetic Reference Panel lines for their ability to react and respond to an abrupt drop. Using several computational approaches, we identified additive, marginal, and epistatic variants, as well as whole genes and altered sub-networks of gene-gene and protein-protein interaction networks that contribute to variation in flight performance. More generally, we demonstrate the benefits of employing multiple methodologies to elucidate the genetic architecture of complex traits. Many variants and genes mapped to regions of the genome that affect neurodevelopment, wing and muscle development, and regulation of gene expression. We also introduce PEGASUS_flies, a Drosophila-adapted version of the PEGASUS platform first used in human studies, to infer gene-level significance of association based on the gene’s distribution of individual variant P-values. Our results contribute to the debate over the relative importance of individual, additive factors and epistatic, or higher order, interactions, in the mapping of genotype to phenotype.
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Affiliation(s)
- Adam N Spierer
- Department of Ecology and Evolutionary Biology, Brown University, Providence, Rhode Island, United States of America
| | - Jim A Mossman
- Department of Ecology and Evolutionary Biology, Brown University, Providence, Rhode Island, United States of America
- Center for Computational Molecular Biology, Brown University, Providence, Rhode Island, United States of America
| | - Samuel Pattillo Smith
- Department of Ecology and Evolutionary Biology, Brown University, Providence, Rhode Island, United States of America
- Center for Computational Molecular Biology, Brown University, Providence, Rhode Island, United States of America
| | - Lorin Crawford
- Center for Computational Molecular Biology, Brown University, Providence, Rhode Island, United States of America
- Microsoft Research New England, Cambridge, Massachusetts, United States of America
| | - Sohini Ramachandran
- Department of Ecology and Evolutionary Biology, Brown University, Providence, Rhode Island, United States of America
- Center for Computational Molecular Biology, Brown University, Providence, Rhode Island, United States of America
| | - David M Rand
- Department of Ecology and Evolutionary Biology, Brown University, Providence, Rhode Island, United States of America
- Center for Computational Molecular Biology, Brown University, Providence, Rhode Island, United States of America
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84
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Chakraborty M, Ramaiah A, Adolfi A, Halas P, Kaduskar B, Ngo LT, Jayaprasad S, Paul K, Whadgar S, Srinivasan S, Subramani S, Bier E, James AA, Emerson JJ. Hidden genomic features of an invasive malaria vector, Anopheles stephensi, revealed by a chromosome-level genome assembly. BMC Biol 2021; 19:28. [PMID: 33568145 PMCID: PMC7876825 DOI: 10.1186/s12915-021-00963-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Accepted: 01/19/2021] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND The mosquito Anopheles stephensi is a vector of urban malaria in Asia that recently invaded Africa. Studying the genetic basis of vectorial capacity and engineering genetic interventions are both impeded by limitations of a vector's genome assembly. The existing assemblies of An. stephensi are draft-quality and contain thousands of sequence gaps, potentially missing genetic elements important for its biology and evolution. RESULTS To access previously intractable genomic regions, we generated a reference-grade genome assembly and full transcript annotations that achieve a new standard for reference genomes of disease vectors. Here, we report novel species-specific transposable element (TE) families and insertions in functional genetic elements, demonstrating the widespread role of TEs in genome evolution and phenotypic variation. We discovered 29 previously hidden members of insecticide resistance genes, uncovering new candidate genetic elements for the widespread insecticide resistance observed in An. stephensi. We identified 2.4 Mb of the Y chromosome and seven new male-linked gene candidates, representing the most extensive coverage of the Y chromosome in any mosquito. By tracking full-length mRNA for > 15 days following blood feeding, we discover distinct roles of previously uncharacterized genes in blood metabolism and female reproduction. The Y-linked heterochromatin landscape reveals extensive accumulation of long-terminal repeat retrotransposons throughout the evolution and degeneration of this chromosome. Finally, we identify a novel Y-linked putative transcription factor that is expressed constitutively throughout male development and adulthood, suggesting an important role. CONCLUSION Collectively, these results and resources underscore the significance of previously hidden genomic elements in the biology of malaria mosquitoes and will accelerate the development of genetic control strategies of malaria transmission.
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Affiliation(s)
- Mahul Chakraborty
- Department of Ecology and Evolutionary Biology, University of California, Irvine, CA, 92697, USA
| | - Arunachalam Ramaiah
- Department of Ecology and Evolutionary Biology, University of California, Irvine, CA, 92697, USA
- Section of Cell and Developmental Biology, University of California, San Diego, La Jolla, CA, 92093-0335, USA
- Tata Institute for Genetics and Society, Center at inStem, Bangalore, Karnataka, 560065, India
| | - Adriana Adolfi
- Department of Microbiology & Molecular Genetics, University of California, Irvine, CA, 92697, USA
| | - Paige Halas
- Department of Microbiology & Molecular Genetics, University of California, Irvine, CA, 92697, USA
| | - Bhagyashree Kaduskar
- Section of Cell and Developmental Biology, University of California, San Diego, La Jolla, CA, 92093-0335, USA
- Tata Institute for Genetics and Society, Center at inStem, Bangalore, Karnataka, 560065, India
| | - Luna Thanh Ngo
- Department of Ecology and Evolutionary Biology, University of California, Irvine, CA, 92697, USA
| | - Suvratha Jayaprasad
- Institute of Bioinformatics and Applied Biotechnology, Bangalore, KA, 560100, India
| | - Kiran Paul
- Institute of Bioinformatics and Applied Biotechnology, Bangalore, KA, 560100, India
| | - Saurabh Whadgar
- Institute of Bioinformatics and Applied Biotechnology, Bangalore, KA, 560100, India
| | - Subhashini Srinivasan
- Tata Institute for Genetics and Society, Center at inStem, Bangalore, Karnataka, 560065, India
- Institute of Bioinformatics and Applied Biotechnology, Bangalore, KA, 560100, India
| | - Suresh Subramani
- Tata Institute for Genetics and Society, Center at inStem, Bangalore, Karnataka, 560065, India
- Section of Molecular Biology, University of California, San Diego, La Jolla, CA, 92093-0322, USA
- Tata Institute for Genetics and Society, University of California, San Diego, La Jolla, CA, 92093-0335, USA
| | - Ethan Bier
- Section of Cell and Developmental Biology, University of California, San Diego, La Jolla, CA, 92093-0335, USA
- Tata Institute for Genetics and Society, University of California, San Diego, La Jolla, CA, 92093-0335, USA
| | - Anthony A James
- Department of Microbiology & Molecular Genetics, University of California, Irvine, CA, 92697, USA
- Tata Institute for Genetics and Society, University of California, San Diego, La Jolla, CA, 92093-0335, USA
- Department of Molecular Biology & Biochemistry, University of California, Irvine, CA, 92697, USA
| | - J J Emerson
- Department of Ecology and Evolutionary Biology, University of California, Irvine, CA, 92697, USA.
- Center for Complex Biological Systems, University of California, Irvine, CA, 92697, USA.
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85
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Abstract
Wolbachia is a maternally transmitted bacterium that manipulates arthropod and nematode biology in myriad ways. The Wolbachia strain colonizing Drosophila melanogaster creates sperm-egg incompatibilities and protects its host against RNA viruses, making it a promising tool for vector control. Despite successful trials using Wolbachia-transfected mosquitoes for dengue control, knowledge of how Wolbachia and viruses jointly affect insect biology remains limited. Using the Drosophila melanogaster model, transcriptomics and gene expression network analyses revealed pathways with altered expression and splicing due to Wolbachia colonization and virus infection. Included are metabolic pathways previously unknown to be important for Wolbachia-host interactions. Additionally, Wolbachia-colonized flies exhibit a dampened transcriptomic response to virus infection, consistent with early blocking of virus replication. Finally, using Drosophila genetics, we show that Wolbachia and expression of nucleotide metabolism genes have interactive effects on virus replication. Understanding the mechanisms of pathogen blocking will contribute to the effective development of Wolbachia-mediated vector control programs.IMPORTANCE Recently developed arbovirus control strategies leverage the symbiotic bacterium Wolbachia, which spreads in insect populations and blocks viruses from replicating. While this strategy has been successful, details of how this "pathogen blocking" works are limited. Here, we use a combination of virus infections, fly genetics, and transcriptomics to show that Wolbachia and virus interact at host nucleotide metabolism pathways.
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86
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Abstract
A complete RNA-Seq analysis involves the use of several different tools, with substantial software and computational requirements. The Galaxy platform simplifies the execution of such bioinformatics analyses by embedding the needed tools in its web interface, while also providing reproducibility. Here, we describe how to perform a reference-based RNA-Seq analysis using Galaxy, from data upload to visualization and functional enrichment analysis of differentially expressed genes.
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Affiliation(s)
- Bérénice Batut
- Bioinformatics Group, Department of Computer Science, Albert-Ludwigs-University Freiburg, Freiburg, Germany
| | - Marius van den Beek
- Department of Biochemistry and Molecular Biology, Penn State University, University Park, PA, USA
| | - Maria A Doyle
- Research Computing Facility, Peter MacCallum Cancer Centre, Melbourne, VIC, Australia
- Sir Peter MacCallum Department of Oncology, The University of Melbourne, Melbourne, VIC, Australia
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87
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Zhang C, Seong KM, Sun W, Mittapalli O, Qiu B, Clark JM, Pittendrigh BR. The insulin signaling pathway in Drosophila melanogaster: A nexus revealing an "Achilles' heel" in DDT resistance. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2021; 171:104727. [PMID: 33357549 DOI: 10.1016/j.pestbp.2020.104727] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Revised: 09/28/2020] [Accepted: 10/10/2020] [Indexed: 06/12/2023]
Abstract
Insecticide resistance is an ongoing challenge in agriculture and disease vector control. Here, we demonstrate a novel strategy to attenuate resistance. We used genomics tools to target fundamental energy-associated pathways and identified a potential "Achilles' heel" for resistance, a resistance-associated protein that, upon inhibition, results in a substantial loss in the resistance phenotype. Specifically, we compared the gene expression profiles and structural variations of the insulin/insulin-like growth factor signaling (IIS) pathway genes in DDT-susceptible (91-C) and -resistant (91-R) Drosophila melanogaster (Drosophila) strains. A total of eight and seven IIS transcripts were up- and down-regulated, respectively, in 91-R compared to 91-C. A total of 114 nonsynonymous mutations were observed between 91-C and 91-R, of which 51.8% were fixed. Among the differentially expressed transcripts, phosphoenolpyruvate carboxykinase (PEPCK), down-regulated in 91-R, encoded the greatest number of amino acid changes, prompting us to perform PEPCK inhibitor-pesticide exposure bioassays. The inhibitor of PEPCK, hydrazine sulfate, resulted in a 161- to 218-fold decrease in the DDT resistance phenotype (91-R) and more than a 4- to 5-fold increase in susceptibility in 91-C. A second target protein, Glycogen synthase kinase 3β (GSK3β-PO), had one amino acid difference between 91-C and 91-R, and the corresponding transcript was also down-regulated in 91-R. A GSK3β-PO inhibitor, lithium chloride, likewise reduced the resistance but to a lesser extent than did hydrazine sulfate for PEPCK. We demonstrate the potential role of IIS genes in DDT resistance and the potential discovery of an "Achilles' heel" against pesticide resistance in this pathway.
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Affiliation(s)
- Can Zhang
- Department of Eco-Engineering, Guangdong Eco-Engineering Polytechnic, Guangzhou 510520, China; Department of Entomology, Michigan State University, East Lansing, MI 48824, USA
| | - Keon Mook Seong
- Department of Entomology, Michigan State University, East Lansing, MI 48824, USA; Department of Applied Biology, College of Ecology and Environment, Kyungpook National University, Sangju, Republic of Korea
| | - Weilin Sun
- Department of Entomology, Michigan State University, East Lansing, MI 48824, USA
| | | | - Baoli Qiu
- Department of Entomology, South China Agricultural University, Guangzhou 510640, China
| | - John M Clark
- Department of Veterinary and Animal Sciences, University of Massachusetts-Amherst, Amherst, MA, USA
| | - Barry R Pittendrigh
- Department of Entomology, Michigan State University, East Lansing, MI 48824, USA.
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88
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Kumar S, Tunc I, Tansey TR, Pirooznia M, Harbison ST. Identification of Genes Contributing to a Long Circadian Period in Drosophila Melanogaster. J Biol Rhythms 2020; 36:239-253. [PMID: 33274675 DOI: 10.1177/0748730420975946] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The endogenous circadian period of animals and humans is typically very close to 24 h. Individuals with much longer circadian periods have been observed, however, and in the case of humans, these deviations have health implications. Previously, we observed a line of Drosophila with a very long average period of 31.3 h for locomotor activity behavior. Preliminary mapping indicated that the long period did not map to known canonical clock genes but instead mapped to multiple chromosomes. Using RNA-Seq, we surveyed the whole transcriptome of fly heads from this line across time and compared it with a wild-type control. A three-way generalized linear model revealed that approximately two-thirds of the genes were expressed differentially among the two genotypes, while only one quarter of the genes varied across time. Using these results, we applied algorithms to search for genes that oscillated over 24 h, identifying genes not previously known to cycle. We identified 166 differentially expressed genes that overlapped with a previous Genome-wide Association Study (GWAS) of circadian behavior, strongly implicating them in the long-period phenotype. We tested mutations in 45 of these genes for their effect on the circadian period. Mutations in Alk, alph, CG10089, CG42540, CG6034, Kairos (CG6123), CG8768, klg, Lar, sick, and tinc had significant effects on the circadian period, with seven of these mutations increasing the circadian period of locomotor activity behavior. Genetic rescue of mutant Kairos restored the circadian period to wild-type levels, suggesting it has a critical role in determining period length in constant darkness.
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Affiliation(s)
- Shailesh Kumar
- Laboratory of Systems Genetics, Systems Biology Center, National Heart, Lung, and Blood Institute, Bethesda, Maryland
| | - Ilker Tunc
- Bioinformatics and Computational Biology Core, National Heart, Lung, and Blood Institute, Bethesda, Maryland
| | - Terry R Tansey
- Laboratory of Systems Genetics, Systems Biology Center, National Heart, Lung, and Blood Institute, Bethesda, Maryland
| | - Mehdi Pirooznia
- Bioinformatics and Computational Biology Core, National Heart, Lung, and Blood Institute, Bethesda, Maryland
| | - Susan T Harbison
- Laboratory of Systems Genetics, Systems Biology Center, National Heart, Lung, and Blood Institute, Bethesda, Maryland
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Pérez-Lluch S, Klein CC, Breschi A, Ruiz-Romero M, Abad A, Palumbo E, Bekish L, Arnan C, Guigó R. bsAS, an antisense long non-coding RNA, essential for correct wing development through regulation of blistered/DSRF isoform usage. PLoS Genet 2020; 16:e1009245. [PMID: 33370262 PMCID: PMC7793246 DOI: 10.1371/journal.pgen.1009245] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Revised: 01/08/2021] [Accepted: 11/03/2020] [Indexed: 12/13/2022] Open
Abstract
Natural Antisense Transcripts (NATs) are long non-coding RNAs (lncRNAs) that overlap coding genes in the opposite strand. NATs roles have been related to gene regulation through different mechanisms, including post-transcriptional RNA processing. With the aim to identify NATs with potential regulatory function during fly development, we generated RNA-Seq data in Drosophila developing tissues and found bsAS, one of the most highly expressed lncRNAs in the fly wing. bsAS is antisense to bs/DSRF, a gene involved in wing development and neural processes. bsAS plays a crucial role in the tissue specific regulation of the expression of the bs/DSRF isoforms. This regulation is essential for the correct determination of cell fate during Drosophila development, as bsAS knockouts show highly aberrant phenotypes. Regulation of bs isoform usage by bsAS is mediated by specific physical interactions between the promoters of these two genes, which suggests a regulatory mechanism involving the collision of RNA polymerases transcribing in opposite directions. Evolutionary analysis suggests that bsAS NAT emerged simultaneously to the long-short isoform structure of bs, preceding the emergence of wings in insects.
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Affiliation(s)
- Sílvia Pérez-Lluch
- Centre for Genomic Regulation (CRG), The Barcelona Institute for Science and Technology, Barcelona (BIST), Catalonia, Spain
| | - Cecilia C. Klein
- Centre for Genomic Regulation (CRG), The Barcelona Institute for Science and Technology, Barcelona (BIST), Catalonia, Spain
- Departament de Genètica, Microbiologia i Estadística, Facultat de Biologia and Institut de Biomedicina (IBUB), Universitat de Barcelona, Barcelona, Catalonia, Spain
| | - Alessandra Breschi
- Centre for Genomic Regulation (CRG), The Barcelona Institute for Science and Technology, Barcelona (BIST), Catalonia, Spain
| | - Marina Ruiz-Romero
- Centre for Genomic Regulation (CRG), The Barcelona Institute for Science and Technology, Barcelona (BIST), Catalonia, Spain
| | - Amaya Abad
- Centre for Genomic Regulation (CRG), The Barcelona Institute for Science and Technology, Barcelona (BIST), Catalonia, Spain
| | - Emilio Palumbo
- Centre for Genomic Regulation (CRG), The Barcelona Institute for Science and Technology, Barcelona (BIST), Catalonia, Spain
| | - Lyazzat Bekish
- Centre for Genomic Regulation (CRG), The Barcelona Institute for Science and Technology, Barcelona (BIST), Catalonia, Spain
| | - Carme Arnan
- Centre for Genomic Regulation (CRG), The Barcelona Institute for Science and Technology, Barcelona (BIST), Catalonia, Spain
| | - Roderic Guigó
- Centre for Genomic Regulation (CRG), The Barcelona Institute for Science and Technology, Barcelona (BIST), Catalonia, Spain
- Universitat Pompeu Fabra (UPF), Barcelona, Catalonia, Spain
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90
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Souto-Maior C, Serrano Negron YL, Harbison ST. Natural selection on sleep duration in Drosophila melanogaster. Sci Rep 2020; 10:20652. [PMID: 33244154 PMCID: PMC7691507 DOI: 10.1038/s41598-020-77680-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Accepted: 11/10/2020] [Indexed: 11/30/2022] Open
Abstract
Sleep is ubiquitous across animal species, but why it persists is not well understood. Here we observe natural selection act on Drosophila sleep by relaxing bi-directional artificial selection for extreme sleep duration for 62 generations. When artificial selection was suspended, sleep increased in populations previously selected for short sleep. Likewise, sleep decreased in populations previously selected for long sleep when artificial selection was relaxed. We measured the corresponding changes in the allele frequencies of genomic variants responding to artificial selection. The allele frequencies of these variants reversed course in response to relaxed selection, and for short sleepers, the changes exceeded allele frequency changes that would be expected under random genetic drift. These observations suggest that the variants are causal polymorphisms for sleep duration responding to natural selection pressure. These polymorphisms may therefore pinpoint the most important regions of the genome maintaining variation in sleep duration.
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Affiliation(s)
- Caetano Souto-Maior
- Laboratory of Systems Genetics, Systems Biology Center, National Heart Lung and Blood Institute, Bethesda, MD, USA
| | - Yazmin L Serrano Negron
- Laboratory of Systems Genetics, Systems Biology Center, National Heart Lung and Blood Institute, Bethesda, MD, USA
| | - Susan T Harbison
- Laboratory of Systems Genetics, Systems Biology Center, National Heart Lung and Blood Institute, Bethesda, MD, USA.
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91
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Finogenova K, Bonnet J, Poepsel S, Schäfer IB, Finkl K, Schmid K, Litz C, Strauss M, Benda C, Müller J. Structural basis for PRC2 decoding of active histone methylation marks H3K36me2/3. eLife 2020; 9:e61964. [PMID: 33211010 PMCID: PMC7725500 DOI: 10.7554/elife.61964] [Citation(s) in RCA: 59] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Accepted: 11/18/2020] [Indexed: 11/13/2022] Open
Abstract
Repression of genes by Polycomb requires that PRC2 modifies their chromatin by trimethylating lysine 27 on histone H3 (H3K27me3). At transcriptionally active genes, di- and tri-methylated H3K36 inhibit PRC2. Here, the cryo-EM structure of PRC2 on dinucleosomes reveals how binding of its catalytic subunit EZH2 to nucleosomal DNA orients the H3 N-terminus via an extended network of interactions to place H3K27 into the active site. Unmodified H3K36 occupies a critical position in the EZH2-DNA interface. Mutation of H3K36 to arginine or alanine inhibits H3K27 methylation by PRC2 on nucleosomes in vitro. Accordingly, Drosophila H3K36A and H3K36R mutants show reduced levels of H3K27me3 and defective Polycomb repression of HOX genes. The relay of interactions between EZH2, the nucleosomal DNA and the H3 N-terminus therefore creates the geometry that permits allosteric inhibition of PRC2 by methylated H3K36 in transcriptionally active chromatin.
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Affiliation(s)
- Ksenia Finogenova
- Max Planck Institute of Biochemistry, Laboratory of Chromatin BiologyMartinsriedGermany
| | - Jacques Bonnet
- Max Planck Institute of Biochemistry, Laboratory of Chromatin BiologyMartinsriedGermany
| | - Simon Poepsel
- California Institute for Quantitative Biology (QB3), University of California, California Institute for Quantitative Biology (QB3), Molecular Biophysics and Integrative Bio-Imaging Division, Lawrence Berkeley National LaboratoryBerkeleyUnited States
- University of Cologne, Center for Molecular Medicine Cologne (CMMC), Faculty of Medicine and University Hospital CologneCologneGermany
- Cologne Excellence Cluster for Cellular Stress Responses in Ageing-Associated Diseases (CECAD), University of CologneCologneGermany
| | - Ingmar B Schäfer
- Max Planck Institute of Biochemistry, Department of Structural Cell BiologyMartinsriedGermany
| | - Katja Finkl
- Max Planck Institute of Biochemistry, Laboratory of Chromatin BiologyMartinsriedGermany
| | - Katharina Schmid
- Max Planck Institute of Biochemistry, Laboratory of Chromatin BiologyMartinsriedGermany
| | - Claudia Litz
- Max Planck Institute of Biochemistry, Laboratory of Chromatin BiologyMartinsriedGermany
| | - Mike Strauss
- Max Planck Institute of Biochemistry, cryoEM FacilityMartinsriedGermany
| | - Christian Benda
- Max Planck Institute of Biochemistry, Department of Structural Cell BiologyMartinsriedGermany
| | - Jürg Müller
- Max Planck Institute of Biochemistry, Laboratory of Chromatin BiologyMartinsriedGermany
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92
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Martin PC, Zabet NR. Dissecting the binding mechanisms of transcription factors to DNA using a statistical thermodynamics framework. Comput Struct Biotechnol J 2020; 18:3590-3605. [PMID: 33304457 PMCID: PMC7708957 DOI: 10.1016/j.csbj.2020.11.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Revised: 11/02/2020] [Accepted: 11/04/2020] [Indexed: 01/22/2023] Open
Abstract
Transcription Factors (TFs) bind to DNA and control activity of target genes. Here, we present ChIPanalyser, a user-friendly, versatile and powerful R/Bioconductor package predicting and modelling the binding of TFs to DNA. ChIPanalyser performs similarly to state-of-the-art tools, but is an explainable model and provides biological insights into binding mechanisms of TFs. We focused on investigating the binding mechanisms of three TFs that are known architectural proteins CTCF, BEAF-32 and su(Hw) in three Drosophila cell lines (BG3, Kc167 and S2). While CTCF preferentially binds only to a subset of high affinity sites located mainly in open chromatin, BEAF-32 binds to most of its high affinity binding sites available in open chromatin. In contrast, su(Hw) binds to both open chromatin and also partially closed chromatin. Most importantly, differences in TF binding profiles between cell lines for these TFs are mainly driven by differences in DNA accessibility and not by differences in TF concentrations between cell lines. Finally, we investigated binding of Hox TFs in Drosophila and found that Ubx binds only in open chromatin, while Abd-B and Dfd are capable to bind in both open and partially closed chromatin. Overall, our results show that TFs display different binding mechanisms and that our model is able to recapitulate their specific binding behaviour.
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Affiliation(s)
- Patrick C.N. Martin
- School of Life Sciences, University of Essex, Colchester CO4 3SQ, UK
- Biotech Research and Innovation Centre (BRIC), University of Copenhagen, DK-2200 Copenhagen, Denmark
| | - Nicolae Radu Zabet
- School of Life Sciences, University of Essex, Colchester CO4 3SQ, UK
- Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London E1 2AT, UK
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93
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Ferguson KB, Kursch-Metz T, Verhulst EC, Pannebakker BA. Hybrid Genome Assembly and Evidence-Based Annotation of the Egg Parasitoid and Biological Control Agent Trichogramma brassicae. G3 (BETHESDA, MD.) 2020; 10:3533-3540. [PMID: 32792343 PMCID: PMC7534424 DOI: 10.1534/g3.120.401344] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Accepted: 08/04/2020] [Indexed: 11/26/2022]
Abstract
Trichogramma brassicae (Bezdenko) are egg parasitoids that are used throughout the world as biological control agents and in laboratories as model species. Despite this ubiquity, few genetic resources exist beyond COI, ITS2, and RAPD markers. Aided by a Wolbachia infection, a wild-caught strain from Germany was reared for low heterozygosity and sequenced in a hybrid de novo strategy, after which several assembling strategies were evaluated. The best assembly, derived from a DBG2OLC-based pipeline, yielded a genome of 235 Mbp made up of 1,572 contigs with an N50 of 556,663 bp. Following a rigorous ab initio-, homology-, and evidence-based annotation, 16,905 genes were annotated and functionally described. As an example of the utility of the genome, a simple ortholog cluster analysis was performed with sister species T. pretiosum, revealing over 6000 shared clusters and under 400 clusters unique to each species. The genome and transcriptome presented here provides an essential resource for comparative genomics of the commercially relevant genus Trichogramma, but also for research into molecular evolution, ecology, and breeding of T. brassicae.
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Affiliation(s)
- Kim B Ferguson
- Wageningen University, Laboratory of Genetics, Wageningen, The Netherlands
| | - Tore Kursch-Metz
- Technische Universität Darmstadt, Department of Biology, Darmstadt, Germany
- AMW Nützlinge GmbH, Pfungstadt, Germany
| | - Eveline C Verhulst
- Wageningen University, Laboratory of Entomology, Wageningen, The Netherlands
| | - Bart A Pannebakker
- Wageningen University, Laboratory of Genetics, Wageningen, The Netherlands
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94
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Chang ZX, Ajayi OE, Guo DY, Wu QF. Genome-wide characterization and developmental expression profiling of long non-coding RNAs in Sogatella furcifera. INSECT SCIENCE 2020; 27:987-997. [PMID: 31264303 DOI: 10.1111/1744-7917.12707] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Revised: 05/16/2019] [Accepted: 06/13/2019] [Indexed: 06/09/2023]
Abstract
The genome-wide characterization of long non-coding RNA (lncRNA) in insects demonstrates their importance in fundamental biological processes. Essentially, an in-depth understanding of the functional repertoire of lncRNA in insects is pivotal to insect resources utilization and sustainable pest control. Using a custom bioinformatics pipeline, we identified 1861 lncRNAs encoded by 1852 loci in the Sogatella furcifera genome. We profiled lncRNA expression in different developmental stages and observed that the expression of lncRNAs is more highly temporally restricted compared to protein-coding genes. More up-regulated Sogatella furcifera lncRNA expressed in the embryo, 4th and 5th instars, suggesting that increased lncRNA levels may play a role in these developmental stages. We compared the relationship between the expression of Sogatella furcifera lncRNA and its nearest protein gene and found that lncRNAs were more correlated to their downstream coding neighbors on the opposite strand. Our genome-wide profiling of lncRNAs in Sogatella furcifera identifies exciting candidates for characterization of lncRNAs, and also provides information on lncRNA regulation during insect development.
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Affiliation(s)
- Zhao-Xia Chang
- Hefei National Laboratory for Physical Sciences at Microscale, School of Life Sciences, University of Science and Technology of China, Hefei, China
| | - Olugbenga Emmanuel Ajayi
- Hefei National Laboratory for Physical Sciences at Microscale, School of Life Sciences, University of Science and Technology of China, Hefei, China
| | - Dong-Yang Guo
- Hefei National Laboratory for Physical Sciences at Microscale, School of Life Sciences, University of Science and Technology of China, Hefei, China
| | - Qing-Fa Wu
- Hefei National Laboratory for Physical Sciences at Microscale, School of Life Sciences, University of Science and Technology of China, Hefei, China
- CAS Key Laboratory of Innate Immunity and Chronic Disease, University of Science and Technology of China, Hefei, China
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95
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Ren L, Shang Y, Yang L, Wang S, Wang X, Chen S, Bao Z, An D, Meng F, Cai J, Guo Y. Chromosome-level de novo genome assembly of Sarcophaga peregrina provides insights into the evolutionary adaptation of flesh flies. Mol Ecol Resour 2020; 21:251-262. [PMID: 32853451 DOI: 10.1111/1755-0998.13246] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Revised: 08/11/2020] [Accepted: 08/17/2020] [Indexed: 01/29/2023]
Abstract
Sarcophaga peregrina is considered to be of great ecological, medical and forensic significance, and has unusual biological characteristics such as an ovoviviparous reproductive pattern and adaptation to feed on carrion. The availability of a high-quality genome will help to further reveal the mechanisms underlying these charcateristics. Here we present a de novo-assembled genome at chromosome scale for S. peregrina. The final assembled genome was 560.31 Mb with contig N50 of 3.84 Mb. Hi-C scaffolding reliably anchored six pseudochromosomes, accounting for 97.76% of the assembled genome. Moreover, 45.70% of repeat elements were identified in the genome. A total of 14,476 protein-coding genes were functionally annotated, accounting for 92.14% of all predicted genes. Phylogenetic analysis indicated that S. peregrina and S. bullata diverged ~ 7.14 million years ago. Comparative genomic analysis revealed expanded and positively selected genes related to biological features that aid in clarifying its ovoviviparous reproduction and carrion-feeding adaptations, such as lipid metabolism, olfactory receptor activity, antioxidant enzymes, proteolysis and serine-type endopeptidase activity. Protein-coding genes associated with ovoviparity, such as yolk proteins, transferrin and acid sphingomyelinase, were identified. This study provides a valuable genomic resource for S. peregrina, and sheds insight into further revealing the underlying molecular mechanisms of adaptive evolution.
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Affiliation(s)
- Lipin Ren
- Department of Forensic Science, School of Basic Medical Sciences, Central South University, Changsha, China
| | - Yanjie Shang
- Department of Forensic Science, School of Basic Medical Sciences, Central South University, Changsha, China
| | - Li Yang
- Department of Forensic Science, School of Basic Medical Sciences, Central South University, Changsha, China
| | - Shiwen Wang
- Department of Forensic Science, School of Basic Medical Sciences, Xinjiang Medical University, Ürümqi, China
| | - Xiang Wang
- Institute of Cancer Stem Cell, Dalian Medical University, Dalian, Liaoning, China
| | - Shan Chen
- School of Ecological and Environmental Sciences, East China Normal University, Shanghai, China
| | | | - Dong An
- OE biotech Co. Ltd, Shanghai, China
| | - Fanming Meng
- Department of Forensic Science, School of Basic Medical Sciences, Central South University, Changsha, China
| | - Jifeng Cai
- Department of Forensic Science, School of Basic Medical Sciences, Central South University, Changsha, China
| | - Yadong Guo
- Department of Forensic Science, School of Basic Medical Sciences, Central South University, Changsha, China
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96
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Álvarez-Rendón JP, Riesgo-Escovar JR. Circadian and rhythmic-related behavioral co-morbidities of the diabetic state in Drosophila melanogaster. Gen Comp Endocrinol 2020; 295:113477. [PMID: 32240709 DOI: 10.1016/j.ygcen.2020.113477] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Revised: 03/25/2020] [Accepted: 03/28/2020] [Indexed: 12/12/2022]
Abstract
Circadian phenomena rule many activities of life on earth. Disruptions in circadian rhythmicity and rhythms have been recognized as a contributing factor for diseased states, for instance metabolic disruptions like diabetes. Diabetes develops as a consequence of faulty insulin pathway signaling, either by lack of insulin production (diabetes type I), or by loss of responsiveness in target tissues (diabetes type 2). In this work we use the model organism Drosophila melanogaster with three different mutant hypomorphic conditions at different levels of the insulin pathway. The insulin pathway is a very evolutionarily conserved pathway. We study these different diabetic conditions as a source of circadian rhythm abnormalities and circadian-related co-morbidities. We do so by studying circadian rhythmicity, activity, sleep and sleep structure, and feeding behavior. Results show that flies with impaired insulin signaling show circadian rhythm and rhythmic-related co-morbidities, especially female flies, as a consequence of the diabetic state. The most extreme disruptions occur in flies with impaired insulin receptor signaling, which stands at the beginning of the insulin pathway, in principle affecting most if not all aspects of this pathway. Our work shows that defective insulin signaling is a source of circadian rhythm and rhythmic related co-morbidities.
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Affiliation(s)
- Jessica Paloma Álvarez-Rendón
- Departamento de Neurobiología del Desarrollo y Neurofisiología, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Campus UNAM Juriquilla, 3001 Boulevard Juriquilla, Juriquilla, Querétaro, cp 76230, Mexico
| | - Juan Rafael Riesgo-Escovar
- Departamento de Neurobiología del Desarrollo y Neurofisiología, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Campus UNAM Juriquilla, 3001 Boulevard Juriquilla, Juriquilla, Querétaro, cp 76230, Mexico.
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97
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Huang J, Sun W, Seong KM, Mittapalli O, Ojo J, Coates B, Paige KN, Clark JM, Pittendrigh BR. Dietary antioxidant vitamin C influences the evolutionary path of insecticide resistance in Drosophila melanogaster. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2020; 168:104631. [PMID: 32711765 DOI: 10.1016/j.pestbp.2020.104631] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Revised: 06/03/2020] [Accepted: 06/09/2020] [Indexed: 06/11/2023]
Abstract
Herbivorous insects encounter a variety of toxic environmental substances ranging from ingested plant defensive compounds to human-introduced insecticidal agents. Dietary antioxidants are known to reduce the negative physiological impacts of toxins in mammalian systems through amelioration of reactive oxygen-related cellular damage. The analogous impacts to insects caused by multigenerational exposure to pesticides and the effects on adaptive responses within insect populations, however, are currently unknown. To address these research gaps, we used Drosophila as a model system to explore adaptive phenotypic responses to acute dichlorodiphenyltrichloroethane (DDT) exposure in the presence of the dietary antioxidant vitamin C and to examine the structural genomic consequences of this exposure. DDT resistance increased significantly among four replicates exposed to a low concentration of DDT for 10 generations. In contrast, dietary intake of vitamin C significantly reduced DDT resistance after mutigenerational exposure to the same concentration of DDT. As to the genomic consequences, no significant differences were predicted in overall nucleotide substitution rates across the genome between any of the treatments. Despite this, replicates exposed to a low concentration of DDT without vitamin C showed the highest number of synonymous and non-synonymous variants (3196 in total), followed by the DDT plus vitamin C (1174 in total), and vitamin C alone (728 in total) treatments. This study demonstrates the potential role of diet (specifically, antioxidant intake) on adaptive genome responses, and thus on the evolution of pesticide resistance within insect populations.
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Affiliation(s)
- Jingfei Huang
- College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, Fujian Province, China.
| | - Weilin Sun
- Department of Entomology, Michigan State University, East Lansing, MI, USA
| | - Keon Mook Seong
- Department of Applied Biology, College of Ecology and Environment, Kyungpook National University, Sangju, Republic of Korea
| | | | - James Ojo
- Department of Crop Production, Kwara State University, Malete, Ilorin, Nigeria
| | - Brad Coates
- USDA-ARS, Corn Insects & Crop Genetics Research Unit, Ames, IA, USA
| | - Ken N Paige
- Department of Evolution, Ecology & Behavior, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - John M Clark
- Department of Veterinary & Animal Science, University of Massachusetts, Amherst, MA, USA
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98
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Transcriptional signature of prion-induced neurotoxicity in a Drosophila model of transmissible mammalian prion disease. Biochem J 2020; 477:833-852. [PMID: 32108870 PMCID: PMC7054746 DOI: 10.1042/bcj20190872] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Revised: 01/14/2020] [Accepted: 01/31/2020] [Indexed: 12/11/2022]
Abstract
Prion diseases are fatal transmissible neurodegenerative conditions of humans and animals that arise through neurotoxicity induced by PrP misfolding. The cellular and molecular mechanisms of prion-induced neurotoxicity remain undefined. Understanding these processes will underpin therapeutic and control strategies for human and animal prion diseases, respectively. Prion diseases are difficult to study in their natural hosts and require the use of tractable animal models. Here we used RNA-Seq-based transcriptome analysis of prion-exposed Drosophila to probe the mechanism of prion-induced neurotoxicity. Adult Drosophila transgenic for pan neuronal expression of ovine PrP targeted to the plasma membrane exhibit a neurotoxic phenotype evidenced by decreased locomotor activity after exposure to ovine prions at the larval stage. Pathway analysis and quantitative PCR of genes differentially expressed in prion-infected Drosophila revealed up-regulation of cell cycle activity and DNA damage response, followed by down-regulation of eIF2 and mTOR signalling. Mitochondrial dysfunction was identified as the principal toxicity pathway in prion-exposed PrP transgenic Drosophila. The transcriptomic changes we observed were specific to PrP targeted to the plasma membrane since these prion-induced gene expression changes were not evident in similarly treated Drosophila transgenic for cytosolic pan neuronal PrP expression, or in non-transgenic control flies. Collectively, our data indicate that aberrant cell cycle activity, repression of protein synthesis and altered mitochondrial function are key events involved in prion-induced neurotoxicity, and correlate with those identified in mammalian hosts undergoing prion disease. These studies highlight the use of PrP transgenic Drosophila as a genetically well-defined tractable host to study mammalian prion biology.
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99
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Sigalova OM, Shaeiri A, Forneris M, Furlong EEM, Zaugg JB. Predictive features of gene expression variation reveal mechanistic link with differential expression. Mol Syst Biol 2020; 16:e9539. [PMID: 32767663 PMCID: PMC7411568 DOI: 10.15252/msb.20209539] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Revised: 06/26/2020] [Accepted: 06/30/2020] [Indexed: 12/22/2022] Open
Abstract
For most biological processes, organisms must respond to extrinsic cues, while maintaining essential gene expression programmes. Although studied extensively in single cells, it is still unclear how variation is controlled in multicellular organisms. Here, we used a machine-learning approach to identify genomic features that are predictive of genes with high versus low variation in their expression across individuals, using bulk data to remove stochastic cell-to-cell variation. Using embryonic gene expression across 75 Drosophila isogenic lines, we identify features predictive of expression variation (controlling for expression level), many of which are promoter-related. Genes with low variation fall into two classes reflecting different mechanisms to maintain robust expression, while genes with high variation seem to lack both types of stabilizing mechanisms. Applying this framework to humans revealed similar predictive features, indicating that promoter architecture is an ancient mechanism to control expression variation. Remarkably, expression variation features could also partially predict differential expression after diverse perturbations in both Drosophila and humans. Differential gene expression signatures may therefore be partially explained by genetically encoded gene-specific features, unrelated to the studied treatment.
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Affiliation(s)
- Olga M Sigalova
- Genome Biology UnitEuropean Molecular Biology Laboratory (EMBL)HeidelbergGermany
| | - Amirreza Shaeiri
- Structures and Computational Biology UnitEuropean Molecular Biology Laboratory (EMBL)HeidelbergGermany
| | - Mattia Forneris
- Genome Biology UnitEuropean Molecular Biology Laboratory (EMBL)HeidelbergGermany
| | - Eileen EM Furlong
- Genome Biology UnitEuropean Molecular Biology Laboratory (EMBL)HeidelbergGermany
| | - Judith B Zaugg
- Structures and Computational Biology UnitEuropean Molecular Biology Laboratory (EMBL)HeidelbergGermany
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100
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Kennedy T, Rinker D, Broadie K. Genetic background mutations drive neural circuit hyperconnectivity in a fragile X syndrome model. BMC Biol 2020; 18:94. [PMID: 32731855 PMCID: PMC7392683 DOI: 10.1186/s12915-020-00817-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Accepted: 06/19/2020] [Indexed: 01/03/2023] Open
Abstract
BACKGROUND Neural circuits are initially assembled during development when neurons synapse with potential partners and later refined as appropriate connections stabilize into mature synapses while inappropriate contacts are eliminated. Disruptions to this synaptogenic process impair connectivity optimization and can cause neurodevelopmental disorders. Intellectual disability (ID) and autism spectrum disorder (ASD) are often characterized by synaptic overgrowth, with the maintenance of immature or inappropriate synapses. Such synaptogenic defects can occur through mutation of a single gene, such as fragile X mental retardation protein (FMRP) loss causing the neurodevelopmental disorder fragile X syndrome (FXS). FXS represents the leading heritable cause of ID and ASD, but many other genes that play roles in ID and ASD have yet to be identified. RESULTS In a Drosophila FXS disease model, one dfmr150M null mutant stock exhibits previously unreported axonal overgrowths at developmental and mature stages in the giant fiber (GF) escape circuit. These excess axon projections contain both chemical and electrical synapse markers, indicating mixed synaptic connections. Extensive analyses show these supernumerary synapses connect known GF circuit neurons, rather than new, inappropriate partners, indicating hyperconnectivity within the circuit. Despite the striking similarities to well-characterized FXS synaptic defects, this new GF circuit hyperconnectivity phenotype is driven by genetic background mutations in this dfmr150M stock. Similar GF circuit synaptic overgrowth is not observed in independent dfmr1 null alleles. Bulked segregant analysis (BSA) was combined with whole genome sequencing (WGS) to identify the quantitative trait loci (QTL) linked to neural circuit hyperconnectivity. The results reveal 8 QTL associated with inappropriate synapse formation and maintenance in the dfmr150M mutant background. CONCLUSIONS Synaptogenesis is a complex, precisely orchestrated neurodevelopmental process with a large cohort of gene products coordinating the connectivity, synaptic strength, and excitatory/inhibitory balance between neuronal partners. This work identifies a number of genetic regions that contain mutations disrupting proper synaptogenesis within a particularly well-mapped neural circuit. These QTL regions contain potential new genes involved in synapse formation and refinement. Given the similarity of the synaptic overgrowth phenotype to known ID and ASD inherited conditions, identifying these genes should increase our understanding of these devastating neurodevelopmental disease states.
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Affiliation(s)
- Tyler Kennedy
- Department of Biological Sciences, Vanderbilt University and Medical Center, Nashville, TN, 37235, USA
| | - David Rinker
- Department of Biological Sciences, Vanderbilt University and Medical Center, Nashville, TN, 37235, USA
| | - Kendal Broadie
- Department of Biological Sciences, Vanderbilt University and Medical Center, Nashville, TN, 37235, USA.
- Department of Cell and Developmental Biology, Vanderbilt University and Medical Center, Nashville, TN, 37235, USA.
- Vanderbilt Brain Institute, Vanderbilt University and Medical Center, Nashville, TN, 37235, USA.
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