1
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Deon GA, Dos Santos RZ, Sassi FDMC, Moreira-Filho O, Vicari MR, Porto-Foresti F, Utsunomia R, Cioffi MDB. The role of satellite DNAs in the chromosomal rearrangements and the evolution of the rare XY1Y2 sex system in Harttia (Siluriformes: Loricariidae). J Hered 2024; 115:541-551. [PMID: 38757192 DOI: 10.1093/jhered/esae028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2024] [Accepted: 05/15/2024] [Indexed: 05/18/2024] Open
Abstract
The underlying processes behind the formation, evolution, and long-term maintenance of multiple sex chromosomes have been largely neglected. Among vertebrates, fishes represent the group with the highest diversity of multiple sex chromosome systems and, with six instances, the Neotropical fish genus Harttia stands out by presenting the most remarkable diversity. However, although the origin mechanism of their sex chromosome systems is well discussed, little is known about the importance of some repetitive DNA classes in the differentiation of multiple systems. In this work, by employing a combination of cytogenetic and genomic procedures, we evaluated the satellite DNA composition of H. carvalhoi with a focus on their role in the evolution, structure, and differentiation process of the rare XY1Y2 multiple-sex chromosome system. The genome of H. carvalhoi contains a total of 28 satellite DNA families, with the A + T content ranging between 38.1% and 68.1% and the predominant presence of long satellites. The in situ hybridization experiments detected 15 satellite DNAs with positive hybridization signals mainly on centromeric and pericentromeric regions of almost all chromosomes or clustered on a few pairs. Five of them presented clusters on X, Y1, and/or Y2 sex chromosomes which were therefore selected for comparative hybridization in the other three congeneric species. We found several conserved satellites accumulated on sex chromosomes and also in regions that were involved in chromosomal rearrangements. Our results provide a new contribution of satellitome studies in multiple sex chromosome systems in fishes and represent the first satellitome study for a Siluriformes species.
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Affiliation(s)
- Geize Aparecida Deon
- Departamento de Genética e Evolução, Universidade Federal de São Carlos, São Carlos, São Paulo, Brazil
| | - Rodrigo Zeni Dos Santos
- Departamento de Ciências Biológicas, Faculdade de Ciências, Universidade Estadual Paulista, Bauru, São Paulo, Brazil
| | | | - Orlando Moreira-Filho
- Departamento de Genética e Evolução, Universidade Federal de São Carlos, São Carlos, São Paulo, Brazil
| | - Marcelo Ricardo Vicari
- Departamento de Biologia Estrutural, Molecular e Genética, Universidade Estadual de Ponta Grossa, Ponta Grossa, Paraná, Brazil
| | - Fábio Porto-Foresti
- Departamento de Ciências Biológicas, Faculdade de Ciências, Universidade Estadual Paulista, Bauru, São Paulo, Brazil
| | - Ricardo Utsunomia
- Departamento de Ciências Biológicas, Faculdade de Ciências, Universidade Estadual Paulista, Bauru, São Paulo, Brazil
| | - Marcelo de Bello Cioffi
- Departamento de Genética e Evolução, Universidade Federal de São Carlos, São Carlos, São Paulo, Brazil
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2
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Jia H, Tan S, Cai Y, Guo Y, Shen J, Zhang Y, Ma H, Zhang Q, Chen J, Qiao G, Ruan J, Zhang YE. Low-input PacBio sequencing generates high-quality individual fly genomes and characterizes mutational processes. Nat Commun 2024; 15:5644. [PMID: 38969648 PMCID: PMC11226609 DOI: 10.1038/s41467-024-49992-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Accepted: 06/20/2024] [Indexed: 07/07/2024] Open
Abstract
Long-read sequencing, exemplified by PacBio, revolutionizes genomics, overcoming challenges like repetitive sequences. However, the high DNA requirement ( > 1 µg) is prohibitive for small organisms. We develop a low-input (100 ng), low-cost, and amplification-free library-generation method for PacBio sequencing (LILAP) using Tn5-based tagmentation and DNA circularization within one tube. We test LILAP with two Drosophila melanogaster individuals, and generate near-complete genomes, surpassing preexisting single-fly genomes. By analyzing variations in these two genomes, we characterize mutational processes: complex transpositions (transposon insertions together with extra duplications and/or deletions) prefer regions characterized by non-B DNA structures, and gene conversion of transposons occurs on both DNA and RNA levels. Concurrently, we generate two complete assemblies for the endosymbiotic bacterium Wolbachia in these flies and similarly detect transposon conversion. Thus, LILAP promises a broad PacBio sequencing adoption for not only mutational studies of flies and their symbionts but also explorations of other small organisms or precious samples.
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Affiliation(s)
- Hangxing Jia
- Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.
| | - Shengjun Tan
- Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.
| | - Yingao Cai
- Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Yanyan Guo
- Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Jieyu Shen
- Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Yaqiong Zhang
- Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Huijing Ma
- Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Qingzhu Zhang
- Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Jinfeng Chen
- University of Chinese Academy of Sciences, Beijing, China
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Gexia Qiao
- Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Jue Ruan
- Shenzhen Branch, Guangdong Laboratory of Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture and Rural Affairs, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, China.
| | - Yong E Zhang
- Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.
- University of Chinese Academy of Sciences, Beijing, China.
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3
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Srivastav SP, Feschotte C, Clark AG. Rapid evolution of piRNA clusters in the Drosophila melanogaster ovary. Genome Res 2024; 34:711-724. [PMID: 38749655 PMCID: PMC11216404 DOI: 10.1101/gr.278062.123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Accepted: 05/07/2024] [Indexed: 05/28/2024]
Abstract
The piRNA pathway is a highly conserved mechanism to repress transposable element (TE) activity in the animal germline via a specialized class of small RNAs called piwi-interacting RNAs (piRNAs). piRNAs are produced from discrete genomic regions called piRNA clusters (piCs). Although the molecular processes by which piCs function are relatively well understood in Drosophila melanogaster, much less is known about the origin and evolution of piCs in this or any other species. To investigate piC origin and evolution, we use a population genomic approach to compare piC activity and sequence composition across eight geographically distant strains of D. melanogaster with high-quality long-read genome assemblies. We perform annotations of ovary piCs and genome-wide TE content in each strain. Our analysis uncovers extensive variation in piC activity across strains and signatures of rapid birth and death of piCs. Most TEs inferred to be recently active show an enrichment of insertions into old and large piCs, consistent with the previously proposed "trap" model of piC evolution. In contrast, a small subset of active LTR families is enriched for the formation of new piCs, suggesting that these TEs have higher proclivity to form piCs. Thus, our findings uncover processes leading to the origin of piCs. We propose that piC evolution begins with the emergence of piRNAs from individual insertions of a few select TE families prone to seed new piCs that subsequently expand by accretion of insertions from most other TE families during evolution to form larger "trap" clusters. Our study shows that TEs themselves are the major force driving the rapid evolution of piCs.
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Affiliation(s)
- Satyam P Srivastav
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York 14853, USA
| | - Cédric Feschotte
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York 14853, USA
| | - Andrew G Clark
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York 14853, USA
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4
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Shukla HG, Chakraborty M, Emerson J. Genetic variation in recalcitrant repetitive regions of the Drosophila melanogaster genome. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.11.598575. [PMID: 38915508 PMCID: PMC11195212 DOI: 10.1101/2024.06.11.598575] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/26/2024]
Abstract
Many essential functions of organisms are encoded in highly repetitive genomic regions, including histones involved in DNA packaging, centromeres that are core components of chromosome segregation, ribosomal RNA comprising the protein translation machinery, telomeres that ensure chromosome integrity, piRNA clusters encoding host defenses against selfish elements, and virtually the entire Y chromosome. These regions, formed by highly similar tandem arrays, pose significant challenges for experimental and informatic study, impeding sequence-level descriptions essential for understanding genetic variation. Here, we report the assembly and variation analysis of such repetitive regions in Drosophila melanogaster, offering significant improvements to the existing community reference assembly. Our work successfully recovers previously elusive segments, including complete reconstructions of the histone locus and the pericentric heterochromatin of the X chromosome, spanning the Stellate locus to the distal flank of the rDNA cluster. To infer structural changes in these regions where alignments are often not practicable, we introduce landmark anchors based on unique variants that are putatively orthologous. These regions display considerable structural variation between different D. melanogaster strains, exhibiting differences in copy number and organization of homologous repeat units between haplotypes. In the histone cluster, although we observe minimal genetic exchange indicative of crossing over, the variation patterns suggest mechanisms such as unequal sister chromatid exchange. We also examine the prevalence and scale of concerted evolution in the histone and Stellate clusters and discuss the mechanisms underlying these observed patterns.
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Affiliation(s)
- Harsh G. Shukla
- Department of Ecology and Evolutionary Biology, University of California Irvine, Irvine, California 92697, USA
- Graduate Program in Mathematical, Computational and Systems Biology, University of California Irvine, Irvine, California 92697, USA
| | - Mahul Chakraborty
- Department of Biology, Texas A&M University, College Station, Texas 77843, USA
| | - J.J. Emerson
- Department of Ecology and Evolutionary Biology, University of California Irvine, Irvine, California 92697, USA
- Center for Complex Biological Systems, University of California Irvine, Irvine, California 92697, USA
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5
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Fingerhut JM, Lannes R, Whitfield TW, Thiru P, Yamashita YM. Co-transcriptional splicing facilitates transcription of gigantic genes. PLoS Genet 2024; 20:e1011241. [PMID: 38870220 PMCID: PMC11207136 DOI: 10.1371/journal.pgen.1011241] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2024] [Revised: 06/26/2024] [Accepted: 05/31/2024] [Indexed: 06/15/2024] Open
Abstract
Although introns are typically tens to thousands of nucleotides, there are notable exceptions. In flies as well as humans, a small number of genes contain introns that are more than 1000 times larger than typical introns, exceeding hundreds of kilobases (kb) to megabases (Mb). It remains unknown why gigantic introns exist and how cells overcome the challenges associated with their transcription and RNA processing. The Drosophila Y chromosome contains some of the largest genes identified to date: multiple genes exceed 4Mb, with introns accounting for over 99% of the gene span. Here we demonstrate that co-transcriptional splicing of these gigantic Y-linked genes is important to ensure successful transcription: perturbation of splicing led to the attenuation of transcription, leading to a failure to produce mature mRNA. Cytologically, defective splicing of the Y-linked gigantic genes resulted in disorganization of transcripts within the nucleus suggestive of entanglement of transcripts, likely resulting from unspliced long RNAs. We propose that co-transcriptional splicing maintains the length of nascent transcripts of gigantic genes under a critical threshold, preventing their entanglement and ensuring proper gene expression. Our study reveals a novel biological significance of co-transcriptional splicing.
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Affiliation(s)
- Jaclyn M. Fingerhut
- Whitehead Institute for Biomedical Research, Cambridge, Massachusetts, United States of America
- Howard Hughes Medical Institute, Cambridge, Massachusetts, United States of America
| | - Romain Lannes
- Whitehead Institute for Biomedical Research, Cambridge, Massachusetts, United States of America
| | - Troy W. Whitfield
- Whitehead Institute for Biomedical Research, Cambridge, Massachusetts, United States of America
| | - Prathapan Thiru
- Whitehead Institute for Biomedical Research, Cambridge, Massachusetts, United States of America
| | - Yukiko M. Yamashita
- Whitehead Institute for Biomedical Research, Cambridge, Massachusetts, United States of America
- Howard Hughes Medical Institute, Cambridge, Massachusetts, United States of America
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
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6
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Brand CL, Oliver GT, Farkas IZ, Buszczak M, Levine MT. Recurrent Duplication and Diversification of a Vital DNA Repair Gene Family Across Drosophila. Mol Biol Evol 2024; 41:msae113. [PMID: 38865490 PMCID: PMC11210505 DOI: 10.1093/molbev/msae113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Revised: 05/30/2024] [Accepted: 06/04/2024] [Indexed: 06/14/2024] Open
Abstract
Maintaining genome integrity is vital for organismal survival and reproduction. Essential, broadly conserved DNA repair pathways actively preserve genome integrity. However, many DNA repair proteins evolve adaptively. Ecological forces like UV exposure are classically cited drivers of DNA repair evolution. Intrinsic forces like repetitive DNA, which also imperil genome integrity, have received less attention. We recently reported that a Drosophila melanogaster-specific DNA satellite array triggered species-specific, adaptive evolution of a DNA repair protein called Spartan/MH. The Spartan family of proteases cleave hazardous, covalent crosslinks that form between DNA and proteins ("DNA-protein crosslink repair"). Appreciating that DNA satellites are both ubiquitous and universally fast-evolving, we hypothesized that satellite DNA turnover spurs adaptive evolution of DNA-protein crosslink repair beyond a single gene and beyond the D. melanogaster lineage. This hypothesis predicts pervasive Spartan gene family diversification across Drosophila species. To study the evolutionary history of the Drosophila Spartan gene family, we conducted population genetic, molecular evolution, phylogenomic, and tissue-specific expression analyses. We uncovered widespread signals of positive selection across multiple Spartan family genes and across multiple evolutionary timescales. We also detected recurrent Spartan family gene duplication, divergence, and gene loss. Finally, we found that ovary-enriched parent genes consistently birthed functionally diverged, testis-enriched daughter genes. To account for Spartan family diversification, we introduce a novel mechanistic model of antagonistic coevolution that links DNA satellite evolution and adaptive regulation of Spartan protease activity. This framework promises to accelerate our understanding of how DNA repeats drive recurrent evolutionary innovation to preserve genome integrity.
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Affiliation(s)
- Cara L Brand
- Department of Biology and Epigenetics Institute, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Genevieve T Oliver
- Department of Biology and Epigenetics Institute, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Isabella Z Farkas
- Department of Biology and Epigenetics Institute, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Michael Buszczak
- Department of Molecular Biology and Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Mia T Levine
- Department of Biology and Epigenetics Institute, University of Pennsylvania, Philadelphia, PA 19104, USA
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7
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Nanni A, Titus-McQuillan J, Bankole KS, Pardo-Palacios F, Signor S, Vlaho S, Moskalenko O, Morse A, Rogers RL, Conesa A, McIntyre LM. Nucleotide-level distance metrics to quantify alternative splicing implemented in TranD. Nucleic Acids Res 2024; 52:e28. [PMID: 38340337 PMCID: PMC10954468 DOI: 10.1093/nar/gkae056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Revised: 11/29/2023] [Accepted: 01/18/2024] [Indexed: 02/12/2024] Open
Abstract
Advances in affordable transcriptome sequencing combined with better exon and gene prediction has motivated many to compare transcription across the tree of life. We develop a mathematical framework to calculate complexity and compare transcript models. Structural features, i.e. intron retention (IR), donor/acceptor site variation, alternative exon cassettes, alternative 5'/3' UTRs, are compared and the distance between transcript models is calculated with nucleotide level precision. All metrics are implemented in a PyPi package, TranD and output can be used to summarize splicing patterns for a transcriptome (1GTF) and between transcriptomes (2GTF). TranD output enables quantitative comparisons between: annotations augmented by empirical RNA-seq data and the original transcript models; transcript model prediction tools for longread RNA-seq (e.g. FLAIR versus Isoseq3); alternate annotations for a species (e.g. RefSeq vs Ensembl); and between closely related species. In C. elegans, Z. mays, D. melanogaster, D. simulans and H. sapiens, alternative exons were observed more frequently in combination with an alternative donor/acceptor than alone. Transcript models in RefSeq and Ensembl are linked and both have unique transcript models with empirical support. D. melanogaster and D. simulans, share many transcript models and long-read RNAseq data suggests that both species are under-annotated. We recommend combined references.
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Affiliation(s)
- Adalena Nanni
- Department of Molecular Genetics and Microbiology, University of Florida, Gainesville, FL 32611, USA
- University of Florida Genetics Institute, University of Florida, Gainesville, FL 32611, USA
| | - James Titus-McQuillan
- University of North Carolina at Charlotte Department of Bioinformatics and Genomics Charlotte, NC, USA
| | - Kinfeosioluwa S Bankole
- Department of Molecular Genetics and Microbiology, University of Florida, Gainesville, FL 32611, USA
- University of Florida Genetics Institute, University of Florida, Gainesville, FL 32611, USA
| | | | - Sarah Signor
- Department of Biological Sciences, North Dakota State University, Fargo, ND, USA
| | - Srna Vlaho
- Department of Biological Sciences, University of Southern California, Los Angeles, CA, USA
| | - Oleksandr Moskalenko
- University of Florida Research Computing, University of Florida, Gainesville, FL 32611, USA
| | - Alison M Morse
- Department of Molecular Genetics and Microbiology, University of Florida, Gainesville, FL 32611, USA
- University of Florida Genetics Institute, University of Florida, Gainesville, FL 32611, USA
| | - Rebekah L Rogers
- University of North Carolina at Charlotte Department of Bioinformatics and Genomics Charlotte, NC, USA
| | - Ana Conesa
- Institute for Integrative Systems Biology. Spanish National Research Council, Paterna, Spain
| | - Lauren M McIntyre
- Department of Molecular Genetics and Microbiology, University of Florida, Gainesville, FL 32611, USA
- University of Florida Genetics Institute, University of Florida, Gainesville, FL 32611, USA
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8
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Pianezza R, Scarpa A, Narayanan P, Signor S, Kofler R. Spoink, a LTR retrotransposon, invaded D. melanogaster populations in the 1990s. PLoS Genet 2024; 20:e1011201. [PMID: 38530818 DOI: 10.1371/journal.pgen.1011201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Accepted: 02/27/2024] [Indexed: 03/28/2024] Open
Abstract
During the last few centuries D. melanogaster populations were invaded by several transposable elements, the most recent of which was thought to be the P-element between 1950 and 1980. Here we describe a novel TE, which we named Spoink, that has invaded D. melanogaster. It is a 5216nt LTR retrotransposon of the Ty3/gypsy superfamily. Relying on strains sampled at different times during the last century we show that Spoink invaded worldwide D. melanogaster populations after the P-element between 1983 and 1993. This invasion was likely triggered by a horizontal transfer from the D. willistoni group, much as the P-element. Spoink is probably silenced by the piRNA pathway in natural populations and about 1/3 of the examined strains have an insertion into a canonical piRNA cluster such as 42AB. Given the degree of genetic investigation of D. melanogaster it is perhaps surprising that Spoink was able to invade unnoticed.
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Affiliation(s)
- Riccardo Pianezza
- Institut für Populationsgenetik, Vetmeduni Vienna, Vienna, Austria
- Vienna Graduate School of Population Genetics, Vetmeduni Vienna, Vienna, Austria
| | - Almorò Scarpa
- Institut für Populationsgenetik, Vetmeduni Vienna, Vienna, Austria
- Vienna Graduate School of Population Genetics, Vetmeduni Vienna, Vienna, Austria
| | - Prakash Narayanan
- Biological Sciences, North Dakota State University, Fargo, North Dakota, United States of America
| | - Sarah Signor
- Biological Sciences, North Dakota State University, Fargo, North Dakota, United States of America
| | - Robert Kofler
- Institut für Populationsgenetik, Vetmeduni Vienna, Vienna, Austria
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9
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Courret C, Larracuente AM. High levels of intra-strain structural variation in Drosophila simulans X pericentric heterochromatin. Genetics 2023; 225:iyad176. [PMID: 37768175 PMCID: PMC10697818 DOI: 10.1093/genetics/iyad176] [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: 08/12/2023] [Revised: 08/12/2023] [Accepted: 09/14/2023] [Indexed: 09/29/2023] Open
Abstract
Large genome structural variations can impact genome regulation and integrity. Repeat-rich regions like pericentric heterochromatin are vulnerable to structural rearrangements although we know little about how often these rearrangements occur over evolutionary time. Repetitive genome regions are particularly difficult to study with genomic approaches, as they are missing from most genome assemblies. However, cytogenetic approaches offer a direct way to detect large rearrangements involving pericentric heterochromatin. Here, we use a cytogenetic approach to reveal large structural rearrangements associated with the X pericentromeric region of Drosophila simulans. These rearrangements involve large blocks of satellite DNA-the 500-bp and Rsp-like satellites-which colocalize in the X pericentromeric heterochromatin. We find that this region is polymorphic not only among different strains, but between isolates of the same strain from different labs, and even within individual isolates. On the one hand, our observations raise questions regarding the potential impact of such variation at the phenotypic level and our ability to control for such genetic variability. On the other hand, this highlights the very rapid turnover of the pericentric heterochromatin most likely associated with genomic instability of the X pericentromere. It represents a unique opportunity to study the dynamics of pericentric heterochromatin, the evolution of associated satellites on a very short time scale, and to better understand how structural variation arises.
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Affiliation(s)
- Cécile Courret
- Department of Biology, University of Rochester, Rochester, NY 14627, USA
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10
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Hopkins BR, Angus-Henry A, Kim BY, Carlisle JA, Thompson A, Kopp A. Decoupled evolution of the Sex Peptide gene family and Sex Peptide Receptor in Drosophilidae. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.29.547128. [PMID: 37425821 PMCID: PMC10327216 DOI: 10.1101/2023.06.29.547128] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/11/2023]
Abstract
Across internally fertilising species, males transfer ejaculate proteins that trigger wide-ranging changes in female behaviour and physiology. Much theory has been developed to explore the drivers of ejaculate protein evolution. The accelerating availability of high-quality genomes now allows us to test how these proteins are evolving at fine taxonomic scales. Here, we use genomes from 264 species to chart the evolutionary history of Sex Peptide (SP), a potent regulator of female post-mating responses in Drosophila melanogaster. We infer that SP first evolved in the Drosophilinae subfamily and has followed markedly different evolutionary trajectories in different lineages. Outside of the Sophophora-Lordiphosa, SP exists largely as a single-copy gene with independent losses in several lineages. Within the Sophophora-Lordiphosa, the SP gene family has repeatedly and independently expanded. Up to seven copies, collectively displaying extensive sequence variation, are present in some species. Despite these changes, SP expression remains restricted to the male reproductive tract. Alongside, we document considerable interspecific variation in the presence and morphology of seminal microcarriers that, despite the critical role SP plays in microcarrier assembly in D. melanogaster, appear to be independent of changes in the presence/absence or sequence of SP. We end by providing evidence that SP's evolution is decoupled from that of its receptor, SPR, in which we detect no evidence of correlated diversifying selection. Collectively, our work describes the divergent evolutionary trajectories that a novel gene has taken following its origin and finds a surprisingly weak coevolutionary signal between a supposedly sexually antagonistic protein and its receptor.
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Affiliation(s)
- Ben R. Hopkins
- Department of Evolution and Ecology, University of California – Davis, CA, USA
| | - Aidan Angus-Henry
- Department of Evolution and Ecology, University of California – Davis, CA, USA
| | | | - Jolie A. Carlisle
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY, USA
| | - Ammon Thompson
- Department of Evolution and Ecology, University of California – Davis, CA, USA
| | - Artyom Kopp
- Department of Evolution and Ecology, University of California – Davis, CA, USA
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11
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Lai EC, Vogan AA. Proliferation and dissemination of killer meiotic drive loci. Curr Opin Genet Dev 2023; 82:102100. [PMID: 37625205 PMCID: PMC10900872 DOI: 10.1016/j.gde.2023.102100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Revised: 07/20/2023] [Accepted: 07/22/2023] [Indexed: 08/27/2023]
Abstract
Killer meiotic drive elements are selfish genetic entities that manipulate the sexual cycle to promote their own inheritance via destructive means. Two broad classes are sperm killers, typical of animals and plants, and spore killers, which are present in ascomycete fungi. Killer meiotic drive systems operate via toxins that destroy or disable meiotic products bearing the alternative allele. To avoid suicidal autotargeting, cells that bear these selfish elements must either lack the toxin target, or express an antidote. Historically, these systems were presumed to require large nonrecombining haplotypes to link multiple functional interacting loci. However, recent advances on fungal spore killers reveal that numerous systems are enacted by single genes, and similar molecular genetic studies in Drosophila pinpoint individual loci that distort gamete sex. Notably, many meiotic drivers duplicate readily, forming gene families that can have complex interactions within and between species, and providing substrates for their rapid functional diversification. Here, we summarize the known families of meiotic drivers in fungi and fruit flies, and highlight shared principles about their evolution and proliferation that promote the spread of these noxious genes.
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Affiliation(s)
- Eric C Lai
- Developmental Biology Program, Sloan Kettering Institute, 430 East 67th St, ROC-10, New York, NY 10065, USA.
| | - Aaron A Vogan
- Institute of Organismal Biology, Uppsala University, Norbyvägen 18D, Uppsala 752 36, Sweden.
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12
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Fablet M, Salces-Ortiz J, Jacquet A, Menezes BF, Dechaud C, Veber P, Rebollo R, Vieira C. A Quantitative, Genome-Wide Analysis in Drosophila Reveals Transposable Elements' Influence on Gene Expression Is Species-Specific. Genome Biol Evol 2023; 15:evad160. [PMID: 37652057 PMCID: PMC10492446 DOI: 10.1093/gbe/evad160] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Revised: 08/21/2023] [Accepted: 08/25/2023] [Indexed: 09/02/2023] Open
Abstract
Transposable elements (TEs) are parasite DNA sequences that are able to move and multiply along the chromosomes of all genomes. They can be controlled by the host through the targeting of silencing epigenetic marks, which may affect the chromatin structure of neighboring sequences, including genes. In this study, we used transcriptomic and epigenomic high-throughput data produced from ovarian samples of several Drosophila melanogaster and Drosophila simulans wild-type strains, in order to finely quantify the influence of TE insertions on gene RNA levels and histone marks (H3K9me3 and H3K4me3). Our results reveal a stronger epigenetic effect of TEs on ortholog genes in D. simulans compared with D. melanogaster. At the same time, we uncover a larger contribution of TEs to gene H3K9me3 variance within genomes in D. melanogaster, which is evidenced by a stronger correlation of TE numbers around genes with the levels of this chromatin mark in D. melanogaster. Overall, this work contributes to the understanding of species-specific influence of TEs within genomes. It provides a new light on the considerable natural variability provided by TEs, which may be associated with contrasted adaptive and evolutionary potentials.
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Affiliation(s)
- Marie Fablet
- Laboratoire de Biométrie et Biologie Evolutive, Université de Lyon; Université Lyon 1; CNRS; UMR 5558, Villeurbanne, France
- Institut Universitaire de France (IUF), Paris, France
| | - Judit Salces-Ortiz
- Laboratoire de Biométrie et Biologie Evolutive, Université de Lyon; Université Lyon 1; CNRS; UMR 5558, Villeurbanne, France
| | - Angelo Jacquet
- Laboratoire de Biométrie et Biologie Evolutive, Université de Lyon; Université Lyon 1; CNRS; UMR 5558, Villeurbanne, France
| | - Bianca F Menezes
- Laboratoire de Biométrie et Biologie Evolutive, Université de Lyon; Université Lyon 1; CNRS; UMR 5558, Villeurbanne, France
| | - Corentin Dechaud
- Institut de Génomique Fonctionnelle de Lyon, Univ Lyon, CNRS UMR 5242, Ecole Normale Supérieure de Lyon, Université Claude Bernard Lyon 1, Lyon, France
| | - Philippe Veber
- Laboratoire de Biométrie et Biologie Evolutive, Université de Lyon; Université Lyon 1; CNRS; UMR 5558, Villeurbanne, France
| | - Rita Rebollo
- Univ Lyon, INRAE, INSA-Lyon, BF2I, UMR 203, Villeurbanne, France
| | - Cristina Vieira
- Laboratoire de Biométrie et Biologie Evolutive, Université de Lyon; Université Lyon 1; CNRS; UMR 5558, Villeurbanne, France
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13
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Vedanayagam J, Lin CJ, Papareddy R, Nodine M, Flynt AS, Wen J, Lai EC. Regulatory logic of endogenous RNAi in silencing de novo genomic conflicts. PLoS Genet 2023; 19:e1010787. [PMID: 37343034 DOI: 10.1371/journal.pgen.1010787] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Accepted: 05/17/2023] [Indexed: 06/23/2023] Open
Abstract
Although the biological utilities of endogenous RNAi (endo-RNAi) have been largely elusive, recent studies reveal its critical role in the non-model fruitfly Drosophila simulans to suppress selfish genes, whose unchecked activities can severely impair spermatogenesis. In particular, hairpin RNA (hpRNA) loci generate endo-siRNAs that suppress evolutionary novel, X-linked, meiotic drive loci. The consequences of deleting even a single hpRNA (Nmy) in males are profound, as such individuals are nearly incapable of siring male progeny. Here, comparative genomic analyses of D. simulans and D. melanogaster mutants of the core RNAi factor dcr-2 reveal a substantially expanded network of recently-emerged hpRNA-target interactions in the former species. The de novo hpRNA regulatory network in D. simulans provides insight into molecular strategies that underlie hpRNA emergence and their potential roles in sex chromosome conflict. In particular, our data support the existence of ongoing rapid evolution of Nmy/Dox-related networks, and recurrent targeting of testis HMG Box loci by hpRNAs. Importantly, the impact of the endo-RNAi network on gene expression flips the convention for regulatory networks, since we observe strong derepression of targets of the youngest hpRNAs, but only mild effects on the targets of the oldest hpRNAs. These data suggest that endo-RNAi are especially critical during incipient stages of intrinsic sex chromosome conflicts, and that continual cycles of distortion and resolution may contribute to speciation.
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Affiliation(s)
- Jeffrey Vedanayagam
- Developmental Biology Program, Sloan Kettering Institute, New York, New York, United States of America
| | - Ching-Jung Lin
- Developmental Biology Program, Sloan Kettering Institute, New York, New York, United States of America
- Weill Graduate School of Medical Sciences, Weill Cornell Medical College, New York, New York, United States of America
| | - Ranjith Papareddy
- Gregor Mendel Institute (GMI), Austrian Academy of Sciences, Vienna Biocenter (VBC), Austria
| | - Michael Nodine
- Gregor Mendel Institute (GMI), Austrian Academy of Sciences, Vienna Biocenter (VBC), Austria
| | - Alex S Flynt
- Cellular and Molecular Biology, University of Southern Mississippi, Hattiesburg, Mississippi, United States of America
| | - Jiayu Wen
- Division of Genome Sciences and Cancer, The John Curtin School of Medical Research The Australian National University, Canberra, Australia
| | - Eric C Lai
- Developmental Biology Program, Sloan Kettering Institute, New York, New York, United States of America
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14
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Vedanayagam J, Herbette M, Mudgett H, Lin CJ, Lai CM, McDonough-Goldstein C, Dorus S, Loppin B, Meiklejohn C, Dubruille R, Lai EC. Essential and recurrent roles for hairpin RNAs in silencing de novo sex chromosome conflict in Drosophila simulans. PLoS Biol 2023; 21:e3002136. [PMID: 37289846 DOI: 10.1371/journal.pbio.3002136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Accepted: 04/21/2023] [Indexed: 06/10/2023] Open
Abstract
Meiotic drive loci distort the normally equal segregation of alleles, which benefits their own transmission even in the face of severe fitness costs to their host organism. However, relatively little is known about the molecular identity of meiotic drivers, their strategies of action, and mechanisms that can suppress their activity. Here, we present data from the fruitfly Drosophila simulans that address these questions. We show that a family of de novo, protamine-derived X-linked selfish genes (the Dox gene family) is silenced by a pair of newly emerged hairpin RNA (hpRNA) small interfering RNA (siRNA)-class loci, Nmy and Tmy. In the w[XD1] genetic background, knockout of nmy derepresses Dox and MDox in testes and depletes male progeny, whereas knockout of tmy causes misexpression of PDox genes and renders males sterile. Importantly, genetic interactions between nmy and tmy mutant alleles reveal that Tmy also specifically maintains male progeny for normal sex ratio. We show the Dox loci are functionally polymorphic within D. simulans, such that both nmy-associated sex ratio bias and tmy-associated sterility can be rescued by wild-type X chromosomes bearing natural deletions in different Dox family genes. Finally, using tagged transgenes of Dox and PDox2, we provide the first experimental evidence Dox family genes encode proteins that are strongly derepressed in cognate hpRNA mutants. Altogether, these studies support a model in which protamine-derived drivers and hpRNA suppressors drive repeated cycles of sex chromosome conflict and resolution that shape genome evolution and the genetic control of male gametogenesis.
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Affiliation(s)
- Jeffrey Vedanayagam
- Developmental Biology Program, Sloan-Kettering Institute, New York, New York, United States of America
| | - Marion Herbette
- Laboratoire de Biologie et Modélisation de la Cellule, École Normale Supérieure de Lyon CNRS UMR5239, Université Claude Bernard Lyon 1, Lyon, France
| | - Holly Mudgett
- School of Biological Sciences, University of Nebraska, Lincoln, Nebraska, United States of America
| | - Ching-Jung Lin
- Developmental Biology Program, Sloan-Kettering Institute, New York, New York, United States of America
- Weill Graduate School of Medical Sciences, Weill Cornell Medical College, New York, New York, United States of America
| | - Chun-Ming Lai
- Developmental Biology Program, Sloan-Kettering Institute, New York, New York, United States of America
| | | | - Stephen Dorus
- Center for Reproductive Evolution, Syracuse University, Syracuse, New York, United States of America
| | - Benjamin Loppin
- Laboratoire de Biologie et Modélisation de la Cellule, École Normale Supérieure de Lyon CNRS UMR5239, Université Claude Bernard Lyon 1, Lyon, France
| | - Colin Meiklejohn
- School of Biological Sciences, University of Nebraska, Lincoln, Nebraska, United States of America
| | - Raphaëlle Dubruille
- Laboratoire de Biologie et Modélisation de la Cellule, École Normale Supérieure de Lyon CNRS UMR5239, Université Claude Bernard Lyon 1, Lyon, France
| | - Eric C Lai
- Developmental Biology Program, Sloan-Kettering Institute, New York, New York, United States of America
- Weill Graduate School of Medical Sciences, Weill Cornell Medical College, New York, New York, United States of America
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15
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Srivastav S, Feschotte C, Clark AG. Rapid evolution of piRNA clusters in the Drosophila melanogaster ovary. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.08.539910. [PMID: 37214865 PMCID: PMC10197564 DOI: 10.1101/2023.05.08.539910] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Animal genomes are parasitized by a horde of transposable elements (TEs) whose mutagenic activity can have catastrophic consequences. The piRNA pathway is a conserved mechanism to repress TE activity in the germline via a specialized class of small RNAs associated with effector Piwi proteins called piwi-associated RNAs (piRNAs). piRNAs are produced from discrete genomic regions called piRNA clusters (piCs). While piCs are generally enriched for TE sequences and the molecular processes by which they are transcribed and regulated are relatively well understood in Drosophila melanogaster, much less is known about the origin and evolution of piCs in this or any other species. To investigate piC evolution, we use a population genomics approach to compare piC activity and sequence composition across 8 geographically distant strains of D. melanogaster with high quality long-read genome assemblies. We perform extensive annotations of ovary piCs and TE content in each strain and test predictions of two proposed models of piC evolution. The 'de novo' model posits that individual TE insertions can spontaneously attain the status of a small piC to generate piRNAs silencing the entire TE family. The 'trap' model envisions large and evolutionary stable genomic clusters where TEs tend to accumulate and serves as a long-term "memory" of ancient TE invasions and produce a great variety of piRNAs protecting against related TEs entering the genome. It remains unclear which model best describes the evolution of piCs. Our analysis uncovers extensive variation in piC activity across strains and signatures of rapid birth and death of piCs in natural populations. Most TE families inferred to be recently or currently active show an enrichment of strain-specific insertions into large piCs, consistent with the trap model. By contrast, only a small subset of active LTR retrotransposon families is enriched for the formation of strain-specific piCs, suggesting that these families have an inherent proclivity to form de novo piCs. Thus, our findings support aspects of both 'de novo' and 'trap' models of piC evolution. We propose that these two models represent two extreme stages along an evolutionary continuum, which begins with the emergence of piCs de novo from a few specific LTR retrotransposon insertions that subsequently expand by accretion of other TE insertions during evolution to form larger 'trap' clusters. Our study shows that piCs are evolutionarily labile and that TEs themselves are the major force driving the formation and evolution of piCs.
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Affiliation(s)
- Satyam Srivastav
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, USA
| | - Cédric Feschotte
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, USA
| | - Andrew G. Clark
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, USA
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16
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Cridland JM, Contino CE, Begun DJ. Selection and geography shape male reproductive tract transcriptomes in Drosophila melanogaster. Genetics 2023; 224:iyad034. [PMID: 36869688 PMCID: PMC10474930 DOI: 10.1093/genetics/iyad034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Revised: 01/25/2023] [Accepted: 02/20/2023] [Indexed: 03/05/2023] Open
Abstract
Transcriptome analysis of several animal clades suggests that male reproductive tract gene expression evolves quickly. However, the factors influencing the abundance and distribution of within-species variation, the ultimate source of interspecific divergence, are poorly known. Drosophila melanogaster, an ancestrally African species that has recently spread throughout the world and colonized the Americas in the last roughly 100 years, exhibits phenotypic and genetic latitudinal clines on multiple continents, consistent with a role for spatially varying selection in shaping its biology. Nevertheless, geographic expression variation in the Americas is poorly described, as is its relationship to African expression variation. Here, we investigate these issues through the analysis of two male reproductive tissue transcriptomes [testis and accessory gland (AG)] in samples from Maine (USA), Panama, and Zambia. We find dramatic differences between these tissues in differential expression between Maine and Panama, with the accessory glands exhibiting abundant expression differentiation and the testis exhibiting very little. Latitudinal expression differentiation appears to be influenced by the selection of Panama expression phenotypes. While the testis shows little latitudinal expression differentiation, it exhibits much greater differentiation than the accessory gland in Zambia vs American population comparisons. Expression differentiation for both tissues is non-randomly distributed across the genome on a chromosome arm scale. Interspecific expression divergence between D. melanogaster and D. simulans is discordant with rates of differentiation between D. melanogaster populations. Strongly heterogeneous expression differentiation across tissues and timescales suggests a complex evolutionary process involving major temporal changes in the way selection influences expression evolution in these organs.
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Affiliation(s)
- Julie M Cridland
- Department of Evolution and Ecology, University of California-Davis, Davis, CA 95616, USA
| | - Colin E Contino
- Department of Evolution and Ecology, University of California-Davis, Davis, CA 95616, USA
| | - David J Begun
- Department of Evolution and Ecology, University of California-Davis, Davis, CA 95616, USA
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17
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Wierzbicki F, Kofler R, Signor S. Evolutionary dynamics of piRNA clusters in Drosophila. Mol Ecol 2023; 32:1306-1322. [PMID: 34878692 DOI: 10.1111/mec.16311] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 11/24/2021] [Accepted: 12/01/2021] [Indexed: 12/21/2022]
Abstract
Small RNAs produced from transposable element (TE)-rich sections of the genome, termed piRNA clusters, are a crucial component in the genomic defence against selfish DNA. In animals, it is thought the invasion of a TE is stopped when a copy of the TE inserts into a piRNA cluster, triggering the production of cognate small RNAs that silence the TE. Despite this importance for TE control, little is known about the evolutionary dynamics of piRNA clusters, mostly because these repeat-rich regions are difficult to assemble and compare. Here, we establish a framework for studying the evolution of piRNA clusters quantitatively. Previously introduced quality metrics and a newly developed software for multiple alignments of repeat annotations (Manna) allow us to estimate the level of polymorphism segregating in piRNA clusters and the divergence among homologous piRNA clusters. By studying 20 conserved piRNA clusters in multiple assemblies of four Drosophila species, we show that piRNA clusters are evolving rapidly. While 70%-80% of the clusters are conserved within species, the clusters share almost no similarity between species as closely related as D. melanogaster and D. simulans. Furthermore, abundant insertions and deletions are segregating within the Drosophila species. We show that the evolution of clusters is mainly driven by large insertions of recently active TEs and smaller deletions mostly in older TEs. The effect of these forces is so rapid that homologous clusters often do not contain insertions from the same TE families.
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Affiliation(s)
- Filip Wierzbicki
- Institut für Populationsgenetik, Vetmeduni Vienna, Vienna, Austria
- Vienna Graduate School of Population Genetics, Vienna, Austria
| | - Robert Kofler
- Institut für Populationsgenetik, Vetmeduni Vienna, Vienna, Austria
| | - Sarah Signor
- Biological Sciences, North Dakota State University, Fargo, North Dakota, USA
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18
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Chang CH, Mejia Natividad I, Malik HS. Expansion and loss of sperm nuclear basic protein genes in Drosophila correspond with genetic conflicts between sex chromosomes. eLife 2023; 12:85249. [PMID: 36763410 PMCID: PMC9917458 DOI: 10.7554/elife.85249] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Accepted: 01/04/2023] [Indexed: 02/11/2023] Open
Abstract
Many animal species employ sperm nuclear basic proteins (SNBPs) or protamines to package sperm genomes tightly. SNBPs vary across animal lineages and evolve rapidly in mammals. We used a phylogenomic approach to investigate SNBP diversification in Drosophila species. We found that most SNBP genes in Drosophila melanogaster evolve under positive selection except for genes essential for male fertility. Unexpectedly, evolutionarily young SNBP genes are more likely to be critical for fertility than ancient, conserved SNBP genes. For example, CG30056 is dispensable for male fertility despite being one of three SNBP genes universally retained in Drosophila species. We found 19 independent SNBP gene amplification events that occurred preferentially on sex chromosomes. Conversely, the montium group of Drosophila species lost otherwise-conserved SNBP genes, coincident with an X-Y chromosomal fusion. Furthermore, SNBP genes that became linked to sex chromosomes via chromosomal fusions were more likely to degenerate or relocate back to autosomes. We hypothesize that autosomal SNBP genes suppress meiotic drive, whereas sex-chromosomal SNBP expansions lead to meiotic drive. X-Y fusions in the montium group render autosomal SNBPs dispensable by making X-versus-Y meiotic drive obsolete or costly. Thus, genetic conflicts between sex chromosomes may drive SNBP rapid evolution during spermatogenesis in Drosophila species.
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Affiliation(s)
- Ching-Ho Chang
- Division of Basic Sciences, Fred Hutchinson Cancer Center, Seattle, United States
| | - Isabel Mejia Natividad
- Division of Basic Sciences, Fred Hutchinson Cancer Center, Seattle, United States.,Howard Hughes Medical Institute, Fred Hutchinson Cancer Center, Seattle, United States
| | - Harmit S Malik
- Division of Basic Sciences, Fred Hutchinson Cancer Center, Seattle, United States.,Howard Hughes Medical Institute, Fred Hutchinson Cancer Center, Seattle, United States
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19
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De Grassi A, Tritto P, Palumbo V, Bozzetti MP, Berloco MF. The Drosophila simulans Genome Lacks the crystal- Stellate System. Cells 2022; 11:cells11233725. [PMID: 36496985 PMCID: PMC9741089 DOI: 10.3390/cells11233725] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Revised: 11/08/2022] [Accepted: 11/16/2022] [Indexed: 11/24/2022] Open
Abstract
The cry-Ste system is a genetic interaction system between heterochromatin and euchromatin in Drosophila melanogaster, regulated via the piRNA pathway. Deregulation of this system leads to meiotic defects and male sterility. Although the cry-Ste system is peculiar to D. melanogaster, ancestors of Ste and Su(Ste) elements are present in the three closely related species, D. simulans, D. sechellia, and D. mauritiana. The birth, evolution, and maintenance of this genetic system in Drosophila melanogaster are of interest. We investigate the presence of sequences homologous to cry and Ste elements in the simulans complex and describe their chromosomal distribution. The organization and expression of cry- and Ste-like sequences were further characterized in the D. simulans genome. Our results allow us to conclude that the cry-Ste genetic interaction system is absent in the D. simulans genome.
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Affiliation(s)
- Anna De Grassi
- Dipartimento di Bioscienze, Biotecnologie e Ambiente, Università Degli Studi di Bari “Aldo Moro”, 70125 Bari, Italy
| | - Patrizia Tritto
- Dipartimento di Bioscienze, Biotecnologie e Ambiente, Università Degli Studi di Bari “Aldo Moro”, 70125 Bari, Italy
| | - Valeria Palumbo
- Dipartimento di Biologia e Biotecnologie “C. Darwin”, “ Sapienza”, Università di Roma, 00185 Roma, Italy
| | - Maria Pia Bozzetti
- Dipartimento di Scienze e Tecnologie Biologiche ed Ambientali, Università del Salento, 73100 Lecce, Italy
| | - Maria Francesca Berloco
- Dipartimento di Bioscienze, Biotecnologie e Ambiente, Università Degli Studi di Bari “Aldo Moro”, 70125 Bari, Italy
- Correspondence:
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20
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Castillo DM, McCormick B, Kean CM, Natesan S, Barbash DA. Testing the Drosophila maternal haploid gene for functional divergence and a role in hybrid incompatibility. G3 (BETHESDA, MD.) 2022; 12:jkac177. [PMID: 35876798 PMCID: PMC9434238 DOI: 10.1093/g3journal/jkac177] [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] [Subscribe] [Scholar Register] [Received: 06/18/2022] [Accepted: 07/06/2022] [Indexed: 11/14/2022]
Abstract
Crosses between Drosophila simulans females and Drosophila melanogaster males produce viable F1 sons and poorly viable F1 daughters. Unlike most hybrid incompatibilities, this hybrid incompatibility violates Haldane's rule, the observation that incompatibilities preferentially affect the heterogametic sex. Furthermore, it has a different genetic basis than hybrid lethality in the reciprocal cross, with the causal allele in Drosophila melanogaster being a large species-specific block of complex satellite DNA on its X chromosome known as the 359-bp satellite, rather than a protein-coding locus. The causal allele(s) in Drosophila simulans are unknown but likely involve maternally expressed genes or factors since the F1 females die during early embryogenesis. The maternal haploid (mh) gene is an intriguing candidate because it is expressed maternally and its protein product localizes to the 359-bp repeat. We found that this gene has diverged extensively between Drosophila melanogaster and Drosophila simulans. This observation led to the hypothesis that Drosophila melanogaster mh may have coevolved with the 359-bp repeat and that hybrid incompatibility thus results from the absence of a coevolved mh allele in Drosophila simulans. We tested for the functional divergence of mh by creating matched transformants of Drosophila melanogaster and Drosophila simulans orthologs in both Drosophila melanogaster and Drosophila simulans strains. Surprisingly, we find that Drosophila simulans mh fully complements the female sterile phenotype of Drosophila melanogaster mh mutations. Contrary to our hypothesis, we find no evidence that adding a Drosophila melanogaster mh gene to Drosophila simulans increases hybrid viability.
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Affiliation(s)
- Dean M Castillo
- Institute of Agriculture and Natural Resources, University of Nebraska, Lincoln, NE 68588, USA
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14850, USA
| | - Benjamin McCormick
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14850, USA
| | - Connor M Kean
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14850, USA
| | - Sahana Natesan
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14850, USA
| | - Daniel A Barbash
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14850, USA
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21
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Huang Y, Shukla H, Lee YCG. Species-specific chromatin landscape determines how transposable elements shape genome evolution. eLife 2022; 11:81567. [PMID: 35997258 PMCID: PMC9398452 DOI: 10.7554/elife.81567] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Accepted: 07/15/2022] [Indexed: 11/30/2022] Open
Abstract
Transposable elements (TEs) are selfish genetic parasites that increase their copy number at the expense of host fitness. The ‘success’, or genome-wide abundance, of TEs differs widely between species. Deciphering the causes for this large variety in TE abundance has remained a central question in evolutionary genomics. We previously proposed that species-specific TE abundance could be driven by the inadvertent consequences of host-direct epigenetic silencing of TEs—the spreading of repressive epigenetic marks from silenced TEs into adjacent sequences. Here, we compared this TE-mediated local enrichment of repressive marks, or ‘the epigenetic effect of TEs’, in six species in the Drosophila melanogaster subgroup to dissect step-by-step the role of such effect in determining genomic TE abundance. We found that TE-mediated local enrichment of repressive marks is prevalent and substantially varies across and even within species. While this TE-mediated effect alters the epigenetic states of adjacent genes, we surprisingly discovered that the transcription of neighboring genes could reciprocally impact this spreading. Importantly, our multi-species analysis provides the power and appropriate phylogenetic resolution to connect species-specific host chromatin regulation, TE-mediated epigenetic effects, the strength of natural selection against TEs, and genomic TE abundance unique to individual species. Our findings point toward the importance of host chromatin landscapes in shaping genome evolution through the epigenetic effects of a selfish genetic parasite. All the instructions required for life are encoded in the set of DNA present in a cell. It therefore seems natural to think that every bit of this genetic information should serve the organism. And yet most species carry parasitic ‘transposable’ sequences, or transposons, whose only purpose is to multiply and insert themselves at other positions in the genome. It is possible for cells to suppress these selfish elements. Chemical marks can be deposited onto the DNA to temporarily ‘silence’ transposons and prevent them from being able to move and replicate. However, this sometimes comes at a cost: the repressive chemical modifications can spread to nearby genes that are essential for the organism and perturb their function. Strangely, the prevalence of transposons varies widely across the tree of life. These sequences form the majority of the genome of certain species – in fact, they represent about half of the human genetic information. But their abundance is much lower in other organisms, forming a measly 6% of the genome of puffer fish for instance. Even amongst fruit fly species, the prevalence of transposable elements can range between 2% and 25%. What explains such differences? Huang et al. set out to examine this question through the lens of transposon silencing, systematically comparing how this process impacts nearby regions in six species of fruit flies. This revealed variations in the strength of the side effects associated with transposon silencing, resulting in different levels of perturbation on neighbouring genes. A stronger impact was associated with the species having fewer transposons in its genome, suggesting that an evolutionary pressure is at work to keep the abundance of transposons at a low level in these species. Further analyses showed that the genes which determine how silencing marks are distributed may also be responsible for the variations in the impact of transposon silencing. They could therefore be the ones driving differences in the abundance of transposons between species. Overall, this work sheds light on the complex mechanisms shaping the evolution of genomes, and it may help to better understand how transposons are linked to processes such as aging and cancer.
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Affiliation(s)
- Yuheng Huang
- Department of Ecology and Evolutionary Biology, University of California, Irvine, Irvine, United States
| | - Harsh Shukla
- Department of Ecology and Evolutionary Biology, University of California, Irvine, Irvine, United States
| | - Yuh Chwen G Lee
- Department of Ecology and Evolutionary Biology, University of California, Irvine, Irvine, United States
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22
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Fingerhut JM, Yamashita YM. The regulation and potential functions of intronic satellite DNA. Semin Cell Dev Biol 2022; 128:69-77. [PMID: 35469677 DOI: 10.1016/j.semcdb.2022.04.010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Revised: 04/11/2022] [Accepted: 04/12/2022] [Indexed: 12/15/2022]
Abstract
Satellite DNAs are arrays of tandem repeats found in the eukaryotic genome. They are mainly found in pericentromeric heterochromatin and have been believed to be mostly inert, leading satellite DNAs to be erroneously regarded as junk. Recent studies have started to elucidate the function of satellite DNA, yet little is known about the peculiar case where satellite DNA is found within the introns of protein coding genes, resulting in incredibly large introns, a phenomenon termed intron gigantism. Studies in Drosophila demonstrated that satellite DNA-containing introns are transcribed with the gene and require specialized mechanisms to overcome the burdens imposed by the extremely long stretches of repetitive DNA. Whether intron gigantism confers any benefit or serves any functional purpose for cells and/or organisms remains elusive. Here we review our current understanding of intron gigantism: where it is found, the challenges it imposes, how it is regulated and what purpose it may serve.
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Affiliation(s)
- Jaclyn M Fingerhut
- Whitehead Institute for Biomedical Research and Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA; Howard Hughes Medical Institute, Cambridge, MA, USA.
| | - Yukiko M Yamashita
- Whitehead Institute for Biomedical Research and Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA; Howard Hughes Medical Institute, Cambridge, MA, USA.
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Copy number changes in co-expressed odorant receptor genes enable selection for sensory differences in drosophilid species. Nat Ecol Evol 2022; 6:1343-1353. [PMID: 35864227 DOI: 10.1038/s41559-022-01830-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Accepted: 06/15/2022] [Indexed: 11/09/2022]
Abstract
Despite numerous examples of chemoreceptor gene family expansions and contractions, how these relate to modifications in the sensory neuron populations in which they are expressed remains unclear. Drosophila melanogaster's odorant receptor (Or) family is ideal for addressing this question because most Ors are expressed in distinct olfactory sensory neuron (OSN) types. Between-species changes in Or copy number may therefore indicate increases or reductions in the number of OSN populations. Here we investigated the Or67a subfamily, which exhibits copy number variation in D. melanogaster and its closest relatives: D. simulans, D. sechellia and D. mauritiana. These species' common ancestor had three Or67a paralogues that had already diverged adaptively. Following speciation, two Or67a paralogues were lost independently in D. melanogaster and D. sechellia, with ongoing positive selection shaping the intact genes. Unexpectedly, the functionally diverged Or67a paralogues in D. simulans are co-expressed in a single neuron population, which projects to a glomerulus homologous to that innervated by Or67a neurons in D. melanogaster. Thus, while sensory pathway neuroanatomy is conserved, independent selection on co-expressed receptors has contributed to species-specific peripheral coding. This work reveals a type of adaptive change largely overlooked for olfactory evolution, raising the possibility that similar processes influence other cases of insect Or co-expression.
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Kofler R, Nolte V, Schlötterer C. The transposition rate has little influence on the plateauing level of the P-element. Mol Biol Evol 2022; 39:6613335. [PMID: 35731857 PMCID: PMC9254008 DOI: 10.1093/molbev/msac141] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The popular trap model assumes that the invasions of transposable elements (TEs) in mammals and invertebrates are stopped by piRNAs that emerge after insertion of the TE into a piRNA cluster. It remains, however, still unclear which factors influence the dynamics of TE invasions. The activity of the TE (i.e., transposition rate) is one frequently discussed key factor. Here we take advantage of the temperature-dependent activity of the P-element, a widely studied eukaryotic TE, to test how TE activity affects the dynamics of a TE invasion. We monitored P-element invasion dynamics in experimental Drosophila simulans populations at hot and cold culture conditions. Despite marked differences in transposition rates, the P-element reached very similar copy numbers at both temperatures. The reduction of the insertion rate upon approaching the copy number plateau was accompanied by similar amounts of piRNAs against the P-element at both temperatures. Nevertheless, we also observed fewer P-element insertions in piRNA clusters than expected, which is not compatible with a simple trap model. The ping-pong cycle, which degrades TE transcripts, becomes typically active after the copy number plateaued. We generated a model, with few parameters, that largely captures the observed invasion dynamics. We conclude that the transposition rate has at the most only a minor influence on TE abundance, but other factors, such as paramutations or selection against TE insertions are shaping the TE composition.
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Affiliation(s)
- Robert Kofler
- Institut für Populationsgenetik, Vetmeduni Vienna, Veterinärplatz 1, 1210 Wien, Austria
| | - Viola Nolte
- Institut für Populationsgenetik, Vetmeduni Vienna, Veterinärplatz 1, 1210 Wien, Austria
| | - Christian Schlötterer
- Institut für Populationsgenetik, Vetmeduni Vienna, Veterinärplatz 1, 1210 Wien, Austria
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25
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Hanson MA, Lemaitre B. Repeated truncation of a modular antimicrobial peptide gene for neural context. PLoS Genet 2022; 18:e1010259. [PMID: 35714143 PMCID: PMC9246212 DOI: 10.1371/journal.pgen.1010259] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Revised: 06/30/2022] [Accepted: 05/17/2022] [Indexed: 12/29/2022] Open
Abstract
Antimicrobial peptides (AMPs) are host-encoded antibiotics that combat invading pathogens. These genes commonly encode multiple products as post-translationally cleaved polypeptides. Recent studies have highlighted roles for AMPs in neurological contexts suggesting functions for these defence molecules beyond infection. During our immune study characterizing the antimicrobial peptide gene Baramicin, we recovered multiple Baramicin paralogs in Drosophila melanogaster and other species, united by their N-terminal IM24 domain. Not all paralogs were immune-induced. Here, through careful dissection of the Baramicin family's evolutionary history, we find that paralogs lacking immune induction result from repeated events of duplication and subsequent truncation of the coding sequence from an immune-inducible ancestor. These truncations leave only the IM24 domain as the prominent gene product. Surprisingly, using mutation and targeted gene silencing we demonstrate that two such genes are adapted for function in neural contexts in D. melanogaster. We also show enrichment in the head for independent Baramicin genes in other species. The Baramicin evolutionary history reveals that the IM24 Baramicin domain is not strictly useful in an immune context. We thus provide a case study for how an AMP-encoding gene might play dual roles in both immune and non-immune processes via its multiple peptide products. As many AMP genes encode polypeptides, a full understanding of how immune effectors interact with the nervous system will require consideration of all their peptide products.
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Affiliation(s)
- Mark A. Hanson
- Global Health Institute, School of Life Science, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
- * E-mail:
| | - Bruno Lemaitre
- Global Health Institute, School of Life Science, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
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26
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Wei KHC, Mai D, Chatla K, Bachtrog D. Dynamics and Impacts of Transposable Element Proliferation in the Drosophila nasuta Species Group Radiation. Mol Biol Evol 2022; 39:msac080. [PMID: 35485457 PMCID: PMC9075770 DOI: 10.1093/molbev/msac080] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Transposable element (TE) mobilization is a constant threat to genome integrity. Eukaryotic organisms have evolved robust defensive mechanisms to suppress their activity, yet TEs can escape suppression and proliferate, creating strong selective pressure for host defense to adapt. This genomic conflict fuels a never-ending arms race that drives the rapid evolution of TEs and recurrent positive selection of genes involved in host defense; the latter has been shown to contribute to postzygotic hybrid incompatibility. However, how TE proliferation impacts genome and regulatory divergence remains poorly understood. Here, we report the highly complete and contiguous (N50 = 33.8-38.0 Mb) genome assemblies of seven closely related Drosophila species that belong to the nasuta species group-a poorly studied group of flies that radiated in the last 2 My. We constructed a high-quality de novo TE library and gathered germline RNA-seq data, which allowed us to comprehensively annotate and compare TE insertion patterns between the species, and infer the evolutionary forces controlling their spread. We find a strong negative association between TE insertion frequency and expression of genes nearby; this likely reflects survivor bias from reduced fitness impact of TEs inserting near lowly expressed, nonessential genes, with limited TE-induced epigenetic silencing. Phylogenetic analyses of insertions of 147 TE families reveal that 53% of them show recent amplification in at least one species. The most highly amplified TE is a nonautonomous DNA element (Drosophila INterspersed Element; DINE) which has gone through multiple bouts of expansions with thousands of full-length copies littered throughout each genome. Across all TEs, we find that TEs expansions are significantly associated with high expression in the expanded species consistent with suppression escape. Thus, whereas horizontal transfer followed by the invasion of a naïve genome has been highlighted to explain the long-term survival of TEs, our analysis suggests that evasion of host suppression of resident TEs is a major strategy to persist over evolutionary times. Altogether, our results shed light on the heterogenous and context-dependent nature in which TEs affect gene regulation and the dynamics of rampant TE proliferation amidst a recently radiated species group.
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Affiliation(s)
- Kevin H.-C. Wei
- Department of Integrative Biology, University of California Berkeley, Berkeley, CA 94720, USA
| | - Dat Mai
- Department of Integrative Biology, University of California Berkeley, Berkeley, CA 94720, USA
| | - Kamalakar Chatla
- Department of Integrative Biology, University of California Berkeley, Berkeley, CA 94720, USA
| | - Doris Bachtrog
- Department of Integrative Biology, University of California Berkeley, Berkeley, CA 94720, USA
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27
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Cross-species incompatibility between a DNA satellite and the Drosophila Spartan homolog poisons germline genome integrity. Curr Biol 2022; 32:2962-2971.e4. [DOI: 10.1016/j.cub.2022.05.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Revised: 04/06/2022] [Accepted: 05/05/2022] [Indexed: 12/19/2022]
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Storer JM, Hubley R, Rosen J, Smit AFA. Methodologies for the De novo Discovery of Transposable Element Families. Genes (Basel) 2022; 13:709. [PMID: 35456515 PMCID: PMC9025800 DOI: 10.3390/genes13040709] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Revised: 04/14/2022] [Accepted: 04/15/2022] [Indexed: 02/07/2023] Open
Abstract
The discovery and characterization of transposable element (TE) families are crucial tasks in the process of genome annotation. Careful curation of TE libraries for each organism is necessary as each has been exposed to a unique and often complex set of TE families. De novo methods have been developed; however, a fully automated and accurate approach to the development of complete libraries remains elusive. In this review, we cover established methods and recent developments in de novo TE analysis. We also present various methodologies used to assess these tools and discuss opportunities for further advancement of the field.
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Affiliation(s)
| | | | | | - Arian F. A. Smit
- Institute for Systems Biology, Seattle, WA 98109, USA; (J.M.S.); (R.H.); (J.R.)
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29
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Yi X, Liu J, Chen S, Wu H, Liu M, Xu Q, Lei L, Lee S, Zhang B, Kudrna D, Fan W, Wing RA, Wang X, Zhang M, Zhang J, Yang C, Chen N. Genome assembly of the JD17 soybean provides a new reference genome for comparative genomics. G3 (BETHESDA, MD.) 2022; 12:jkac017. [PMID: 35188189 PMCID: PMC8982393 DOI: 10.1093/g3journal/jkac017] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Accepted: 01/11/2022] [Indexed: 12/30/2022]
Abstract
Cultivated soybean (Glycine max) is an important source for protein and oil. Many elite cultivars with different traits have been developed for different conditions. Each soybean strain has its own genetic diversity, and the availability of more high-quality soybean genomes can enhance comparative genomic analysis for identifying genetic underpinnings for its unique traits. In this study, we constructed a high-quality de novo assembly of an elite soybean cultivar Jidou 17 (JD17) with chromosome contiguity and high accuracy. We annotated 52,840 gene models and reconstructed 74,054 high-quality full-length transcripts. We performed a genome-wide comparative analysis based on the reference genome of JD17 with 3 published soybeans (WM82, ZH13, and W05), which identified 5 large inversions and 2 large translocations specific to JD17, 20,984-46,912 presence-absence variations spanning 13.1-46.9 Mb in size. A total of 1,695,741-3,664,629 SNPs and 446,689-800,489 Indels were identified and annotated between JD17 and them. Symbiotic nitrogen fixation genes were identified and the effects from these variants were further evaluated. It was found that the coding sequences of 9 nitrogen fixation-related genes were greatly affected. The high-quality genome assembly of JD17 can serve as a valuable reference for soybean functional genomics research.
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Affiliation(s)
- Xinxin Yi
- National Key Laboratory of Crop Genetic Improvement, Center of Integrative Biology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, Hubei, China
| | - Jing Liu
- National Key Laboratory of Crop Genetic Improvement, Center of Integrative Biology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, Hubei, China
- State Key Laboratory of Crop Stress Adaptation and Improvement, Henan University, Kaifeng 475004, Henan, China
| | - Shengcai Chen
- National Key Laboratory of Crop Genetic Improvement, Center of Integrative Biology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, Hubei, China
- State Key Laboratory of Crop Stress Adaptation and Improvement, Henan University, Kaifeng 475004, Henan, China
| | - Hao Wu
- National Key Laboratory of Crop Genetic Improvement, Center of Integrative Biology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, Hubei, China
| | - Min Liu
- National Key Laboratory of Crop Genetic Improvement, Center of Integrative Biology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, Hubei, China
| | - Qing Xu
- National Key Laboratory of Crop Genetic Improvement, Center of Integrative Biology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, Hubei, China
| | - Lingshan Lei
- National Key Laboratory of Crop Genetic Improvement, Center of Integrative Biology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, Hubei, China
| | - Seunghee Lee
- Arizona Genomics Institute and BIO5 Institute, School of Plant Sciences, University of Arizona, Tucson, AZ 85721, USA
| | - Bao Zhang
- State Key Laboratory of Crop Stress Adaptation and Improvement, Henan University, Kaifeng 475004, Henan, China
| | - Dave Kudrna
- Arizona Genomics Institute and BIO5 Institute, School of Plant Sciences, University of Arizona, Tucson, AZ 85721, USA
| | - Wei Fan
- National Key Laboratory of Crop Genetic Improvement, Center of Integrative Biology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, Hubei, China
- State Key Laboratory of Crop Stress Adaptation and Improvement, Henan University, Kaifeng 475004, Henan, China
| | - Rod A Wing
- Arizona Genomics Institute and BIO5 Institute, School of Plant Sciences, University of Arizona, Tucson, AZ 85721, USA
| | - Xuelu Wang
- State Key Laboratory of Crop Stress Adaptation and Improvement, Henan University, Kaifeng 475004, Henan, China
| | - Mengchen Zhang
- Institute of Food and Oil Crops, Hebei Academy of Agricultural and Forestry Sciences, Shijiazhuang 050031, Hebei, China
| | - Jianwei Zhang
- National Key Laboratory of Crop Genetic Improvement, Center of Integrative Biology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, Hubei, China
- Arizona Genomics Institute and BIO5 Institute, School of Plant Sciences, University of Arizona, Tucson, AZ 85721, USA
| | - Chunyan Yang
- Institute of Food and Oil Crops, Hebei Academy of Agricultural and Forestry Sciences, Shijiazhuang 050031, Hebei, China
| | - Nansheng Chen
- National Key Laboratory of Crop Genetic Improvement, Center of Integrative Biology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, Hubei, China
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC V5A 1S6, Canada
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30
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Chang CH, Gregory LE, Gordon KE, Meiklejohn CD, Larracuente AM. Unique structure and positive selection promote the rapid divergence of Drosophila Y chromosomes. eLife 2022; 11:e75795. [PMID: 34989337 PMCID: PMC8794474 DOI: 10.7554/elife.75795] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Accepted: 12/18/2021] [Indexed: 02/06/2023] Open
Abstract
Y chromosomes across diverse species convergently evolve a gene-poor, heterochromatic organization enriched for duplicated genes, LTR retrotransposons, and satellite DNA. Sexual antagonism and a loss of recombination play major roles in the degeneration of young Y chromosomes. However, the processes shaping the evolution of mature, already degenerated Y chromosomes are less well-understood. Because Y chromosomes evolve rapidly, comparisons between closely related species are particularly useful. We generated de novo long-read assemblies complemented with cytological validation to reveal Y chromosome organization in three closely related species of the Drosophila simulans complex, which diverged only 250,000 years ago and share >98% sequence identity. We find these Y chromosomes are divergent in their organization and repetitive DNA composition and discover new Y-linked gene families whose evolution is driven by both positive selection and gene conversion. These Y chromosomes are also enriched for large deletions, suggesting that the repair of double-strand breaks on Y chromosomes may be biased toward microhomology-mediated end joining over canonical non-homologous end-joining. We propose that this repair mechanism contributes to the convergent evolution of Y chromosome organization across organisms.
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Affiliation(s)
- Ching-Ho Chang
- Department of Biology, University of RochesterRochesterUnited States
| | - Lauren E Gregory
- Department of Biology, University of RochesterRochesterUnited States
| | - Kathleen E Gordon
- School of Biological Sciences, University of Nebraska-LincolnLincolnUnited States
| | - Colin D Meiklejohn
- School of Biological Sciences, University of Nebraska-LincolnLincolnUnited States
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31
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Affiliation(s)
| | - Francisco J. Ruiz-Ruano
- Department of Organismal Biology – Systematic Biology, Evolutionary Biology Centre, Uppsala University, Uppsala, Sweden
- School of Biological Sciences, Norwich Research Park University of East Anglia, Norwich, UK
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32
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33
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Rapid evolutionary dynamics of an expanding family of meiotic drive factors and their hpRNA suppressors. Nat Ecol Evol 2021; 5:1613-1623. [PMID: 34862477 PMCID: PMC8665063 DOI: 10.1038/s41559-021-01592-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Accepted: 10/19/2021] [Indexed: 11/25/2022]
Abstract
Meiotic drivers are a class of selfish genetic elements whose existence is frequently hidden due to concomitant suppressor systems. Accordingly, we know little of their evolutionary breadth and molecular mechanisms. Here, we trace the evolution of the Dox meiotic drive system in Drosophila simulans, which affects male-female balance (sex-ratio). Dox emerged via stepwise mobilization and acquisition of multiple D. melanogaster gene segments including from protamine, which mediates compaction of sperm chromatin. Moreover, we reveal novel Dox homologs and massive amplification of Dox superfamily genes on X chromosomes of its closest sisters D. mauritiana and D. sechellia. Emergence of Dox loci is tightly associated with 359-class satellite repeats that flank de novo genomic copies. In concert, we find coordinated diversification of autosomal hairpin RNA-class siRNA loci that target subsets of Dox superfamily genes. Overall, we reveal fierce genetic arms races between meiotic drive factors and siRNA suppressors associated with recent speciation.
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34
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Muirhead CA, Presgraves DC. Satellite DNA-mediated diversification of a sex-ratio meiotic drive gene family in Drosophila. Nat Ecol Evol 2021; 5:1604-1612. [PMID: 34489561 PMCID: PMC11188575 DOI: 10.1038/s41559-021-01543-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Accepted: 07/23/2021] [Indexed: 02/07/2023]
Abstract
Sex chromosomes are susceptible to the evolution of selfish meiotic drive elements that bias transmission and distort progeny sex ratios. Conflict between such sex-ratio drivers and the rest of the genome can trigger evolutionary arms races resulting in genetically suppressed 'cryptic' drive systems. The Winters cryptic sex-ratio drive system of Drosophila simulans comprises a driver, Distorter on the X (Dox) and an autosomal suppressor, Not much yang, a retroduplicate of Dox that suppresses via production of endogenous small interfering RNAs (esiRNAs). Here we report that over 22 Dox-like (Dxl) sequences originated, amplified and diversified over the ~250,000-year history of the three closely related species, D. simulans, D. mauritiana and D. sechellia. The Dxl sequences encode a rapidly evolving family of protamines. Dxl copy numbers amplified by ectopic exchange among euchromatic islands of satellite DNAs on the X chromosome and separately spawned four esiRNA-producing suppressors on the autosomes. Our results reveal the genomic consequences of evolutionary arms races and highlight complex interactions among different classes of selfish DNAs.
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Affiliation(s)
- Christina A Muirhead
- Department of Biology, University of Rochester, Rochester, NY, USA
- Ronin Institute, Montclair, NJ, USA
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35
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Abstract
Repeat-enriched genomic regions evolve rapidly and yet support strictly conserved functions like faithful chromosome transmission and the preservation of genome integrity. The leading resolution to this paradox is that DNA repeat-packaging proteins evolve adaptively to mitigate deleterious changes in DNA repeat copy number, sequence, and organization. Exciting new research has tested this model of coevolution by engineering evolutionary mismatches between adaptively evolving chromatin proteins of one species and the DNA repeats of a close relative. Here, we review these innovative evolution-guided functional analyses. The studies demonstrate that vital, chromatin-mediated cellular processes, including transposon suppression, faithful chromosome transmission, and chromosome retention depend on species-specific versions of chromatin proteins that package species-specific DNA repeats. In many cases, the ever-evolving repeats are selfish genetic elements, raising the possibility that chromatin is a battleground of intragenomic conflict.
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Affiliation(s)
- Cara L Brand
- Department of Biology and Epigenetics Institute, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA;
| | - Mia T Levine
- Department of Biology and Epigenetics Institute, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA;
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36
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Kim BY, Wang JR, Miller DE, Barmina O, Delaney E, Thompson A, Comeault AA, Peede D, D'Agostino ERR, Pelaez J, Aguilar JM, Haji D, Matsunaga T, Armstrong EE, Zych M, Ogawa Y, Stamenković-Radak M, Jelić M, Veselinović MS, Tanasković M, Erić P, Gao JJ, Katoh TK, Toda MJ, Watabe H, Watada M, Davis JS, Moyle LC, Manoli G, Bertolini E, Košťál V, Hawley RS, Takahashi A, Jones CD, Price DK, Whiteman N, Kopp A, Matute DR, Petrov DA. Highly contiguous assemblies of 101 drosophilid genomes. eLife 2021; 10:e66405. [PMID: 34279216 PMCID: PMC8337076 DOI: 10.7554/elife.66405] [Citation(s) in RCA: 72] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Accepted: 07/16/2021] [Indexed: 12/13/2022] Open
Abstract
Over 100 years of studies in Drosophila melanogaster and related species in the genus Drosophila have facilitated key discoveries in genetics, genomics, and evolution. While high-quality genome assemblies exist for several species in this group, they only encompass a small fraction of the genus. Recent advances in long-read sequencing allow high-quality genome assemblies for tens or even hundreds of species to be efficiently generated. Here, we utilize Oxford Nanopore sequencing to build an open community resource of genome assemblies for 101 lines of 93 drosophilid species encompassing 14 species groups and 35 sub-groups. The genomes are highly contiguous and complete, with an average contig N50 of 10.5 Mb and greater than 97% BUSCO completeness in 97/101 assemblies. We show that Nanopore-based assemblies are highly accurate in coding regions, particularly with respect to coding insertions and deletions. These assemblies, along with a detailed laboratory protocol and assembly pipelines, are released as a public resource and will serve as a starting point for addressing broad questions of genetics, ecology, and evolution at the scale of hundreds of species.
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Affiliation(s)
- Bernard Y Kim
- Department of Biology, Stanford UniversityStanfordUnited States
| | - Jeremy R Wang
- Department of Genetics, University of North CarolinaChapel HillUnited States
| | - Danny E Miller
- Department of Pediatrics, Division of Genetic Medicine, University of Washington and Seattle Children’s HospitalSeattleUnited States
| | - Olga Barmina
- Department of Evolution and Ecology, University of California DavisDavisUnited States
| | - Emily Delaney
- Department of Evolution and Ecology, University of California DavisDavisUnited States
| | - Ammon Thompson
- Department of Evolution and Ecology, University of California DavisDavisUnited States
| | - Aaron A Comeault
- School of Natural Sciences, Bangor UniversityBangorUnited Kingdom
| | - David Peede
- Biology Department, University of North CarolinaChapel HillUnited States
| | | | - Julianne Pelaez
- Department of Integrative Biology, University of California, BerkeleyBerkeleyUnited States
| | - Jessica M Aguilar
- Department of Integrative Biology, University of California, BerkeleyBerkeleyUnited States
| | - Diler Haji
- Department of Integrative Biology, University of California, BerkeleyBerkeleyUnited States
| | - Teruyuki Matsunaga
- Department of Integrative Biology, University of California, BerkeleyBerkeleyUnited States
| | | | - Molly Zych
- Molecular and Cellular Biology Program, University of WashingtonSeattleUnited States
| | - Yoshitaka Ogawa
- Department of Biological Sciences, Tokyo Metropolitan UniversityHachiojiJapan
| | | | - Mihailo Jelić
- Faculty of Biology, University of BelgradeBelgradeSerbia
| | | | - Marija Tanasković
- University of Belgrade, Institute for Biological Research "Siniša Stanković", National Institute of Republic of SerbiaBelgradeSerbia
| | - Pavle Erić
- University of Belgrade, Institute for Biological Research "Siniša Stanković", National Institute of Republic of SerbiaBelgradeSerbia
| | - Jian-Jun Gao
- School of Ecology and Environmental Science, Yunnan UniversityKunmingChina
| | - Takehiro K Katoh
- School of Ecology and Environmental Science, Yunnan UniversityKunmingChina
| | | | - Hideaki Watabe
- Biological Laboratory, Sapporo College, Hokkaido University of EducationSapporoJapan
| | - Masayoshi Watada
- Graduate School of Science and Engineering, Ehime UniversityMatsuyamaJapan
| | - Jeremy S Davis
- Department of Biology, University of KentuckyLexingtonUnited States
| | - Leonie C Moyle
- Department of Biology, Indiana UniversityBloomingtonUnited States
| | - Giulia Manoli
- Neurobiology and Genetics, Theodor Boveri Institute, Biocentre, University of WürzburgWürzburgGermany
| | - Enrico Bertolini
- Neurobiology and Genetics, Theodor Boveri Institute, Biocentre, University of WürzburgWürzburgGermany
| | - Vladimír Košťál
- Institute of Entomology, Biology Centre, Academy of Sciences of the Czech RepublicPragueCzech Republic
| | - R Scott Hawley
- Department of Molecular and Integrative Physiology, University of Kansas Medical Center, Stowers Institute for Medical ResearchKansas CityUnited States
| | - Aya Takahashi
- Department of Biological Sciences, Tokyo Metropolitan UniversityHachiojiJapan
| | - Corbin D Jones
- Biology Department, University of North CarolinaChapel HillUnited States
| | - Donald K Price
- School of Life Science, University of NevadaLas VegasUnited States
| | - Noah Whiteman
- Department of Integrative Biology, University of California, BerkeleyBerkeleyUnited States
| | - Artyom Kopp
- Department of Evolution and Ecology, University of California DavisDavisUnited States
| | - Daniel R Matute
- Biology Department, University of North CarolinaChapel HillUnited States
| | - Dmitri A Petrov
- Department of Biology, Stanford UniversityStanfordUnited States
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37
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Presgraves DC, Meiklejohn CD. Hybrid Sterility, Genetic Conflict and Complex Speciation: Lessons From the Drosophila simulans Clade Species. Front Genet 2021; 12:669045. [PMID: 34249091 PMCID: PMC8261240 DOI: 10.3389/fgene.2021.669045] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Accepted: 05/20/2021] [Indexed: 12/31/2022] Open
Abstract
The three fruitfly species of the Drosophila simulans clade- D. simulans, D. mauritiana, and D. sechellia- have served as important models in speciation genetics for over 40 years. These species are reproductively isolated by geography, ecology, sexual signals, postmating-prezygotic interactions, and postzygotic genetic incompatibilities. All pairwise crosses between these species conform to Haldane's rule, producing fertile F1 hybrid females and sterile F1 hybrid males. The close phylogenetic proximity of the D. simulans clade species to the model organism, D. melanogaster, has empowered genetic analyses of their species differences, including reproductive incompatibilities. But perhaps no phenotype has been subject to more continuous and intensive genetic scrutiny than hybrid male sterility. Here we review the history, progress, and current state of our understanding of hybrid male sterility among the D. simulans clade species. Our aim is to integrate the available information from experimental and population genetics analyses bearing on the causes and consequences of hybrid male sterility. We highlight numerous conclusions that have emerged as well as issues that remain unresolved. We focus on the special role of sex chromosomes, the fine-scale genetic architecture of hybrid male sterility, and the history of gene flow between species. The biggest surprises to emerge from this work are that (i) genetic conflicts may be an important general force in the evolution of hybrid incompatibility, (ii) hybrid male sterility is polygenic with contributions of complex epistasis, and (iii) speciation, even among these geographically allopatric taxa, has involved the interplay of gene flow, negative selection, and positive selection. These three conclusions are marked departures from the classical views of speciation that emerged from the modern evolutionary synthesis.
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Affiliation(s)
- Daven C. Presgraves
- Department of Biology, University of Rochester, Rochester, NY, United States
| | - Colin D. Meiklejohn
- School of Biological Sciences, University of Nebraska, Lincoln, NE, United States
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Durkin SM, Chakraborty M, Abrieux A, Lewald KM, Gadau A, Svetec N, Peng J, Kopyto M, Langer CB, Chiu JC, Emerson JJ, Zhao L. Behavioral and Genomic Sensory Adaptations Underlying the Pest Activity of Drosophila suzukii. Mol Biol Evol 2021; 38:2532-2546. [PMID: 33586767 PMCID: PMC8136512 DOI: 10.1093/molbev/msab048] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Studying how novel phenotypes originate and evolve is fundamental to the field of evolutionary biology as it allows us to understand how organismal diversity is generated and maintained. However, determining the basis of novel phenotypes is challenging as it involves orchestrated changes at multiple biological levels. Here, we aim to overcome this challenge by using a comparative species framework combining behavioral, gene expression, and genomic analyses to understand the evolutionary novel egg-laying substrate-choice behavior of the invasive pest species Drosophila suzukii. First, we used egg-laying behavioral assays to understand the evolution of ripe fruit oviposition preference in D. suzukii compared with closely related species D. subpulchrella and D. biarmipes as well as D. melanogaster. We show that D. subpulchrella and D. biarmipes lay eggs on both ripe and rotten fruits, suggesting that the transition to ripe fruit preference was gradual. Second, using two-choice oviposition assays, we studied how D. suzukii, D. subpulchrella, D. biarmipes, and D. melanogaster differentially process key sensory cues distinguishing ripe from rotten fruit during egg-laying. We found that D. suzukii's preference for ripe fruit is in part mediated through a species-specific preference for stiff substrates. Last, we sequenced and annotated a high-quality genome for D. subpulchrella. Using comparative genomic approaches, we identified candidate genes involved in D. suzukii's ability to seek out and target ripe fruits. Our results provide detail to the stepwise evolution of pest activity in D. suzukii, indicating important cues used by this species when finding a host, and the molecular mechanisms potentially underlying their adaptation to a new ecological niche.
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Affiliation(s)
- Sylvia M Durkin
- Laboratory of Evolutionary Genetics and Genomics, The Rockefeller University, New York, NY, USA
- Department of Integrative Biology and Museum of Vertebrate Zoology, University of California, Berkeley, Berkeley, CA, USA
| | - Mahul Chakraborty
- Department of Ecology and Evolutionary Biology, University of California, Irvine, CA, USA
| | - Antoine Abrieux
- Department of Entomology and Nematology, College of Agricultural and Environmental Sciences, University of California, Davis, Davis, CA, USA
| | - Kyle M Lewald
- Department of Entomology and Nematology, College of Agricultural and Environmental Sciences, University of California, Davis, Davis, CA, USA
| | - Alice Gadau
- Laboratory of Evolutionary Genetics and Genomics, The Rockefeller University, New York, NY, USA
| | - Nicolas Svetec
- Laboratory of Evolutionary Genetics and Genomics, The Rockefeller University, New York, NY, USA
| | - Junhui Peng
- Laboratory of Evolutionary Genetics and Genomics, The Rockefeller University, New York, NY, USA
| | - Miriam Kopyto
- Laboratory of Evolutionary Genetics and Genomics, The Rockefeller University, New York, NY, USA
| | - Christopher B Langer
- Laboratory of Evolutionary Genetics and Genomics, The Rockefeller University, New York, NY, USA
| | - Joanna C Chiu
- Department of Entomology and Nematology, College of Agricultural and Environmental Sciences, University of California, Davis, Davis, CA, USA
| | - J J Emerson
- Department of Ecology and Evolutionary Biology, University of California, Irvine, CA, USA
| | - Li Zhao
- Laboratory of Evolutionary Genetics and Genomics, The Rockefeller University, New York, NY, USA
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Liao Y, Zhang X, Chakraborty M, Emerson JJ. Topologically associating domains and their role in the evolution of genome structure and function in Drosophila. Genome Res 2021; 31:397-410. [PMID: 33563719 PMCID: PMC7919452 DOI: 10.1101/gr.266130.120] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2020] [Accepted: 12/24/2020] [Indexed: 12/18/2022]
Abstract
Topologically associating domains (TADs) were recently identified as fundamental units of three-dimensional eukaryotic genomic organization, although our knowledge of the influence of TADs on genome evolution remains preliminary. To study the molecular evolution of TADs in Drosophila species, we constructed a new reference-grade genome assembly and accompanying high-resolution TAD map for D. pseudoobscura Comparison of D. pseudoobscura and D. melanogaster, which are separated by ∼49 million years of divergence, showed that ∼30%-40% of their genomes retain conserved TADs. Comparative genomic analysis of 17 Drosophila species revealed that chromosomal rearrangement breakpoints are enriched at TAD boundaries but depleted within TADs. Additionally, genes within conserved TADs show lower expression divergence than those located in nonconserved TADs. Furthermore, we found that a substantial proportion of long genes (>50 kbp) in D. melanogaster (42%) and D. pseudoobscura (26%) constitute their own TADs, implying transcript structure may be one of the deterministic factors for TAD formation. By using structural variants (SVs) identified from 14 D. melanogaster strains, its three closest sibling species from the D. simulans species complex, and two obscura clade species, we uncovered evidence of selection acting on SVs at TAD boundaries, but with the nature of selection differing between SV types. Deletions are depleted at TAD boundaries in both divergent and polymorphic SVs, suggesting purifying selection, whereas divergent tandem duplications are enriched at TAD boundaries relative to polymorphism, suggesting they are adaptive. Our findings highlight how important TADs are in shaping the acquisition and retention of structural mutations that fundamentally alter genome organization.
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Affiliation(s)
- Yi Liao
- Department of Ecology and Evolutionary Biology, University of California, Irvine, California 92697, USA
| | - Xinwen Zhang
- Department of Ecology and Evolutionary Biology, University of California, Irvine, California 92697, USA
| | - Mahul Chakraborty
- Department of Ecology and Evolutionary Biology, University of California, Irvine, California 92697, USA
| | - J J Emerson
- Department of Ecology and Evolutionary Biology, University of California, Irvine, California 92697, USA.,Center for Complex Biological Systems, University of California, Irvine, California 92697, USA
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