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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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2
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Mayekar HV, Rajpurohit S. No single rescue recipe: genome complexities modulate insect response to climate change. CURRENT OPINION IN INSECT SCIENCE 2024; 64:101220. [PMID: 38848812 DOI: 10.1016/j.cois.2024.101220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Revised: 04/08/2024] [Accepted: 05/31/2024] [Indexed: 06/09/2024]
Abstract
Declines in insect populations have gained formidable attention. Given their crucial role in the ecosystem, the causes of declining insect populations must be investigated. However, the insect clade has been associated with low extinction and high diversification rates. It is unlikely that insects underwent mass extinctions in the past. However, the pace of current climate change could make insect populations vulnerable to extinction. We propose genome size (GS) and transposable elements (TEs) to be rough estimates to assess extinction risk. Larger GS and/or proliferating TEs have been associated with adaptation in rapid climate change scenarios. We speculate that unstable, stressful environmental conditions are strongly associated with GS and TE expansion, which could be further correlated with adaptations. Alternately, stressful conditions trigger TE bursts that are not purged in smaller populations. GS and TE loads could be indicators of small effective populations in the wild, likely experiencing bottlenecks or drastic climatic perturbations, which calls for an urgent assessment of extinction risk.
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Affiliation(s)
- Harshad Vijay Mayekar
- Biological and Life Sciences, School of Arts of Sciences, Ahmedabad University, Ahmedabad 380009, India.
| | - Subhash Rajpurohit
- Biological and Life Sciences, School of Arts of Sciences, Ahmedabad University, Ahmedabad 380009, India.
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3
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Flynn JM, Yamashita YM. The implications of satellite DNA instability on cellular function and evolution. Semin Cell Dev Biol 2024; 156:152-159. [PMID: 37852904 DOI: 10.1016/j.semcdb.2023.10.005] [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: 04/26/2023] [Revised: 09/21/2023] [Accepted: 10/11/2023] [Indexed: 10/20/2023]
Abstract
Abundant tandemly repeated satellite DNA is present in most eukaryotic genomes. Previous limitations including a pervasive view that it was uninteresting junk DNA, combined with challenges in studying it, are starting to dissolve - and recent studies have found important functions for satellite DNAs. The observed rapid evolution and implied instability of satellite DNA now has important significance for their functions and maintenance within the genome. In this review, we discuss the processes that lead to satellite DNA copy number instability, and the importance of mechanisms to manage the potential negative effects of instability. Satellite DNA is vulnerable to challenges during replication and repair, since it forms difficult-to-process secondary structures and its homology within tandem arrays can result in various types of recombination. Satellite DNA instability may be managed by DNA or chromatin-binding proteins ensuring proper nuclear localization and repair, or by proteins that process aberrant structures that satellite DNAs tend to form. We also discuss the pattern of satellite DNA mutations from recent mutation accumulation (MA) studies that have tracked changes in satellite DNA for up to 1000 generations with minimal selection. Finally, we highlight examples of satellite evolution from studies that have characterized satellites across millions of years of Drosophila fruit fly evolution, and discuss possible ways that selection might act on the satellite DNA composition.
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Affiliation(s)
- Jullien M Flynn
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA; Howard Hughes Medical Institute, Cambridge, MA, USA.
| | - Yukiko M Yamashita
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA; Howard Hughes Medical Institute, Cambridge, MA, USA; Massachusetts Institute of Technology, Cambridge, MA, USA.
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4
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Cang FA, Welles SR, Wong J, Ziaee M, Dlugosch KM. Genome size variation and evolution during invasive range expansion in an introduced plant. Evol Appl 2024; 17:e13624. [PMID: 38283607 PMCID: PMC10810172 DOI: 10.1111/eva.13624] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Revised: 11/03/2023] [Accepted: 11/13/2023] [Indexed: 01/30/2024] Open
Abstract
Plants demonstrate exceptional variation in genome size across species, and their genome sizes can also vary dramatically across individuals and populations within species. This aspect of genetic variation can have consequences for traits and fitness, but few studies attributed genome size differentiation to ecological and evolutionary processes. Biological invasions present particularly useful natural laboratories to infer selective agents that might drive genome size shifts across environments and population histories. Here, we test hypotheses for the evolutionary causes of genome size variation across 14 invading populations of yellow starthistle, Centaurea solstitialis, in California, United States. We use a survey of genome sizes and trait variation to ask: (1) Is variation in genome size associated with developmental trait variation? (2) Are genome sizes smaller toward the leading edge of the expansion, consistent with selection for "colonizer" traits? Or alternatively, does genome size increase toward the leading edge of the expansion, consistent with predicted consequences of founder effects and drift? (3) Finally, are genome sizes smaller at higher elevations, consistent with selection for shorter development times? We found that 2C DNA content varied 1.21-fold among all samples, and was associated with flowering time variation, such that plants with larger genomes reproduced later, with lower lifetime capitula production. Genome sizes increased toward the leading edge of the invasion, but tended to decrease at higher elevations, consistent with genetic drift during range expansion but potentially strong selection for smaller genomes and faster development time at higher elevations. These results demonstrate how genome size variation can contribute to traits directly tied to reproductive success, and how selection and drift can shape that variation. We highlight the influence of genome size on dynamics underlying a rapid range expansion in a highly problematic invasive plant.
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Affiliation(s)
- F. Alice Cang
- Department of Ecology and Evolutionary BiologyUniversity of ArizonaTucsonArizonaUSA
| | - Shana R. Welles
- Department of Ecology and Evolutionary BiologyUniversity of ArizonaTucsonArizonaUSA
- Utah Valley UniversityOremUtahUSA
| | - Jenny Wong
- Department of Ecology and Evolutionary BiologyUniversity of ArizonaTucsonArizonaUSA
| | - Maia Ziaee
- Department of Ecology and Evolutionary BiologyUniversity of ArizonaTucsonArizonaUSA
- Mills CollegeOaklandCaliforniaUSA
| | - Katrina M. Dlugosch
- Department of Ecology and Evolutionary BiologyUniversity of ArizonaTucsonArizonaUSA
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5
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Wong HWS, Holman L. Pleiotropic fitness effects across sexes and ages in the Drosophila genome and transcriptome. Evolution 2023; 77:2642-2655. [PMID: 37738246 DOI: 10.1093/evolut/qpad163] [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: 05/30/2023] [Revised: 08/20/2023] [Accepted: 09/19/2023] [Indexed: 09/24/2023]
Abstract
Selection varies between categories of individuals, with far-reaching ramifications: Sex-specific selection can impede or accelerate adaptation, and differences in selection between young and old individuals are ultimately responsible for senescence. Here, we measure early- and late-life fitness in adults of both sexes from the Drosophila genetic reference panel and perform quantitative genetic and transcriptomic analyses. Fitness was heritable, showed positive pleiotropy across sexes and age classes, and appeared to be influenced by very large numbers of loci with small effects plus a smaller number with moderate effects. Most loci affected male and female fitness in the same direction; relatively few candidate sexually antagonistic loci were found, though these were enriched on the X chromosome as predicted by theory. The expression level of many genes showed an opposite correlation with fitness in males and females, consistent with unresolved sexual conflict over transcription. The load of deleterious mutations correlated negatively with fitness across genotypes, and we found some evidence for the mutation accumulation (but not the antagonistic pleiotropy) theory of aging.
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Affiliation(s)
- Heidi W S Wong
- School of Biosciences, University of Melbourne, Parkville, VIC, Australia
| | - Luke Holman
- School of Applied Sciences, Edinburgh Napier University, Edinburgh, United Kingdom
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Earhart ML, Blanchard TS, Morrison PR, Strowbridge N, Penman RJ, Brauner CJ, Schulte PM, Baker DW. Identification of upper thermal thresholds during development in the endangered Nechako white sturgeon with management implications for a regulated river. CONSERVATION PHYSIOLOGY 2023; 11:coad032. [PMID: 37228298 PMCID: PMC10205467 DOI: 10.1093/conphys/coad032] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Revised: 04/20/2023] [Accepted: 04/27/2023] [Indexed: 05/27/2023]
Abstract
Climate change-induced warming effects are already evident in river ecosystems, and projected increases in temperature will continue to amplify stress on fish communities. In addition, many rivers globally are impacted by dams, which have many negative effects on fishes by altering flow, blocking fish passage, and changing sediment composition. However, in some systems, dams present an opportunity to manage river temperature through regulated releases of cooler water. For example, there is a government mandate for Kenney dam operators in the Nechako river, British Columbia, Canada, to maintain river temperature <20°C in July and August to protect migrating sockeye salmon (Oncorhynchus nerka). However, there is another endangered fish species inhabiting the same river, Nechako white sturgeon (Acipenser transmontanus), and it is unclear if these current temperature regulations, or timing of the regulations, are suitable for spawning and developing sturgeon. In this study, we aimed to identify upper thermal thresholds in white sturgeon embryos and larvae to investigate if exposure to current river temperatures are playing a role in recruitment failure. We incubated embryos and yolk-sac larvae in three environmentally relevant temperatures (14, 18 and 21°C) throughout development to identify thermal thresholds across different levels of biological organization. Our results demonstrate upper thermal thresholds at 21°C across physiological measurements in embryo and yolk-sac larvae white sturgeon. Before hatch, both embryo survival and metabolic rate were reduced at 21°C. After hatch, sublethal consequences continued at 21°C because larval sturgeon had decreased thermal plasticity and a dampened transcriptional response during development. In recent years, the Nechako river has reached 21°C by the end of June, and at this temperature, a decrease in sturgeon performance is evident in most of the traits measured. As such, the thermal thresholds identified here suggest current temperature regulations may not be suitable for developing white sturgeon and future recruitment.
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Affiliation(s)
- Madison L Earhart
- Corresponding author: Department of Zoology, University of British Columbia, 6270 University Blvd. Vancouver, BC V6T 1Z4, Canada. . Tel.: 204-799-9338
| | - Tessa S Blanchard
- Department of Zoology, University of British Columbia, 6270 University Blvd. Vancouver, BC V6T 1Z4, Canada
| | - Phillip R Morrison
- Department of Zoology, University of British Columbia, 6270 University Blvd. Vancouver, BC V6T 1Z4, Canada
- Department of Resource Management and Protection, and Biology Department, Vancouver Island University, 900 Fifth Street Nanaimo, BC V9R 5S5, Canada
| | - Nicholas Strowbridge
- Department of Zoology, University of British Columbia, 6270 University Blvd. Vancouver, BC V6T 1Z4, Canada
- School of Biodiversity, One Health, & Veterinary Medicine, College of Medical, Veterinary & Life Sciences, University of Glasgow, 464 Bearsden Rd, Bearsden, Glasgow G61 1QH, UK
| | - Rachael J Penman
- Department of Zoology, University of British Columbia, 6270 University Blvd. Vancouver, BC V6T 1Z4, Canada
- Instreams fisheries research, 2323 Boundary Rd Unit 115, Vancouver, BC V5M 4V8, Canada
| | - Colin J Brauner
- Department of Zoology, University of British Columbia, 6270 University Blvd. Vancouver, BC V6T 1Z4, Canada
| | - Patricia M Schulte
- Department of Zoology, University of British Columbia, 6270 University Blvd. Vancouver, BC V6T 1Z4, Canada
| | - Daniel W Baker
- Department of Fisheries and Aquaculture, Vancouver Island University, 900 Fifth Street, Nanaimo, BC V9R 5S5, Canada
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Boman J, Arnqvist G. Larger genomes show improved buffering of adult fitness against environmental stress in seed beetles. Biol Lett 2023; 19:20220450. [PMID: 36693428 PMCID: PMC9873469 DOI: 10.1098/rsbl.2022.0450] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Our general understanding of the evolution of genome size (GS) is incomplete, and it has long been clear that GS does not reflect organismal complexity. Here, we assess the hypothesis that larger genomes may allow organisms to better cope with environmental variation. It is, for example, possible that genome expansion due to proliferation of transposable elements or gene duplications may affect the ability to regulate and fine-tune transcriptional profiles. We used 18 populations of the seed beetle Callosobruchus maculatus, which differ in GS by up to 4.5%, and exposed adults and juveniles to environmental stress in a series of experiments where stage-specific fitness was assayed. We found that populations with larger genomes were indeed better buffered against environmental stress for adult, but not for juvenile, fitness. The genetic correlation across populations between GS and canalization of adult fitness is consistent with a role for natural selection in the evolution of GS.
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Affiliation(s)
- Jesper Boman
- Evolutionary Biology, Department of Ecology and Genetics, Uppsala University, Uppsala, Sweden
| | - Göran Arnqvist
- Animal Ecology, Department of Ecology and Genetics, Uppsala University, Uppsala, Sweden
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8
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Pincheira‐Donoso D, Harvey LP, Johnson JV, Hudson D, Finn C, Goodyear LEB, Guirguis J, Hyland EM, Hodgson DJ. Genome size does not influence extinction risk in the world's amphibians. Funct Ecol 2022. [DOI: 10.1111/1365-2435.14247] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
| | - Lilly P. Harvey
- School of Science and Technology Nottingham Trent University Nottingham UK
| | - Jack V. Johnson
- School of Biological Sciences Queen's University Belfast Belfast UK
| | - Dave Hudson
- Centre for Ecology and Conservation, College of Life and Environmental Sciences University of Exeter Penryn UK
| | - Catherine Finn
- School of Biological Sciences Queen's University Belfast Belfast UK
| | | | - Jacinta Guirguis
- School of Biological Sciences Queen's University Belfast Belfast UK
| | - Edel M. Hyland
- School of Biological Sciences Queen's University Belfast Belfast UK
| | - Dave J. Hodgson
- Centre for Ecology and Conservation, College of Life and Environmental Sciences University of Exeter Penryn UK
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9
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Nguyen A, Wang W, Chong E, Chatla K, Bachtrog D. Transposable element accumulation drives size differences among polymorphic Y Chromosomes in Drosophila. Genome Res 2022; 32:1074-1088. [PMID: 35501131 DOI: 10.1101/gr.275996.121] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Accepted: 04/15/2022] [Indexed: 11/24/2022]
Abstract
Y Chromosomes of many species are gene poor and show low levels of nucleotide variation, yet often display high amounts of structural diversity. Dobzhansky cataloged several morphologically distinct Y Chromosomes in Drosophila pseudoobscura that differ in size and shape, but the molecular causes of their dramatic size differences are unclear. Here we use cytogenetics and long-read sequencing to study the sequence content of polymorphic Y Chromosomes in D. pseudoobscura We show that Y Chromosomes differ almost 2-fold in size, ranging from 30 to 60 Mb. Most of this size difference is caused by a handful of active transposable elements (TEs) that have recently expanded on the largest Y Chromosome, with different elements being responsible for Y expansion on differently sized D. pseudoobscura Y's. We show that Y Chromosomes differ in their heterochromatin enrichment, expression of Y-enriched TEs, and also influence expression of dozens of autosomal and X-linked genes. The same helitron element that showed the most drastic amplification on the largest Y in D. pseudoobscura independently amplified on a polymorphic large Y Chromosome in D. affinis, suggesting that some TEs are inherently more prone to become deregulated on Y Chromosomes.
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Stelzer CP, Pichler M, Hatheuer A. Linking genome size variation to population phenotypic variation within the rotifer, Brachionus asplanchnoidis. Commun Biol 2021; 4:596. [PMID: 34011946 PMCID: PMC8134563 DOI: 10.1038/s42003-021-02131-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Accepted: 04/19/2021] [Indexed: 11/17/2022] Open
Abstract
Eukaryotic organisms usually contain much more genomic DNA than expected from their biological complexity. In explaining this pattern, selection-based hypotheses suggest that genome size evolves through selection acting on correlated life history traits, implicitly assuming the existence of phenotypic effects of (extra) genomic DNA that are independent of its information content. Here, we present conclusive evidence of such phenotypic effects within a well-mixed natural population that shows heritable variation in genome size. We found that genome size is positively correlated with body size, egg size, and embryonic development time in a population of the monogonont rotifer Brachionus asplanchnoidis. The effect on embryonic development time was mediated partly by an indirect effect (via egg size), and a direct effect, the latter indicating an increased replication cost of the larger amounts of DNA during mitosis. Our results suggest that selection-based change of genome size can operate in this population, provided it is strong enough to overcome drift or mutational change of genome size.
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Affiliation(s)
| | - Maria Pichler
- University of Innsbruck, Mondseestr. 9, 5310, Mondsee, Austria
| | - Anita Hatheuer
- University of Innsbruck, Mondseestr. 9, 5310, Mondsee, Austria
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11
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Brown EJ, Nguyen AH, Bachtrog D. The Drosophila Y Chromosome Affects Heterochromatin Integrity Genome-Wide. Mol Biol Evol 2021; 37:2808-2824. [PMID: 32211857 PMCID: PMC7530609 DOI: 10.1093/molbev/msaa082] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The Drosophila Y chromosome is gene poor and mainly consists of silenced, repetitive DNA. Nonetheless, the Y influences expression of hundreds of genes genome-wide, possibly by sequestering key components of the heterochromatin machinery away from other positions in the genome. To test the influence of the Y chromosome on the genome-wide chromatin landscape, we assayed the genomic distribution of histone modifications associated with gene activation (H3K4me3) or heterochromatin (H3K9me2 and H3K9me3) in fruit flies with varying sex chromosome complements (X0, XY, and XYY males; XX and XXY females). Consistent with the general deficiency of active chromatin modifications on the Y, we find that Y gene dose has little influence on the genomic distribution of H3K4me3. In contrast, both the presence and the number of Y chromosomes strongly influence genome-wide enrichment patterns of repressive chromatin modifications. Highly repetitive regions such as the pericentromeres, the dot, and the Y chromosome (if present) are enriched for heterochromatic modifications in wildtype males and females, and even more strongly in X0 flies. In contrast, the additional Y chromosome in XYY males and XXY females diminishes the heterochromatic signal in these normally silenced, repeat-rich regions, which is accompanied by an increase in expression of Y-linked repeats. We find hundreds of genes that are expressed differentially between individuals with aberrant sex chromosome karyotypes, many of which also show sex-biased expression in wildtype Drosophila. Thus, Y chromosomes influence heterochromatin integrity genome-wide, and differences in the chromatin landscape of males and females may also contribute to sex-biased gene expression and sexual dimorphisms.
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Affiliation(s)
- Emily J Brown
- Department of Integrative Biology, University of California Berkeley, Berkeley, CA
| | - Alison H Nguyen
- Department of Integrative Biology, University of California Berkeley, Berkeley, CA
| | - Doris Bachtrog
- Department of Integrative Biology, University of California Berkeley, Berkeley, CA
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12
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Shindo Y, Amodeo AA. Excess histone H3 is a competitive Chk1 inhibitor that controls cell-cycle remodeling in the early Drosophila embryo. Curr Biol 2021; 31:2633-2642.e6. [PMID: 33848457 DOI: 10.1016/j.cub.2021.03.035] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Revised: 02/08/2021] [Accepted: 03/10/2021] [Indexed: 12/31/2022]
Abstract
The DNA damage checkpoint is crucial to protect genome integrity.1,2 However, the early embryos of many metazoans sacrifice this safeguard to allow for rapid cleavage divisions that are required for speedy development. At the mid-blastula transition (MBT), embryos switch from rapid cleavage divisions to slower, patterned divisions with the addition of gap phases and acquisition of DNA damage checkpoints. The timing of the MBT is dependent on the nuclear-to-cytoplasmic (N/C ratio)3-7 and the activation of the checkpoint kinase, Chk1.8-17 How Chk1 activity is coupled to the N/C ratio has remained poorly understood. Here, we show that dynamic changes in histone H3 availability in response to the increasing N/C ratio control Chk1 activity and thus time the MBT in the Drosophila embryo. We show that excess H3 in the early cycles interferes with cell-cycle slowing independent of chromatin incorporation. We find that the N-terminal tail of H3 acts as a competitive inhibitor of Chk1 in vitro and reduces Chk1 activity in vivo. Using a H3-tail mutant that has reduced Chk1 inhibitor activity, we show that the amount of available Chk1 sites in the H3 pool controls the dynamics of cell-cycle progression. Mathematical modeling quantitatively supports a mechanism where titration of H3 during early cleavage cycles regulates Chk1-dependent cell-cycle slowing. This study defines Chk1 regulation by H3 as a key mechanism that coordinates cell-cycle remodeling with developmental progression.
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Affiliation(s)
- Yuki Shindo
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA; Department of Biological Sciences, Dartmouth College, Hanover, NH 03755, USA
| | - Amanda A Amodeo
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA; Department of Biological Sciences, Dartmouth College, Hanover, NH 03755, USA.
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13
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Glazier DS. Genome Size Covaries More Positively with Propagule Size than Adult Size: New Insights into an Old Problem. BIOLOGY 2021; 10:270. [PMID: 33810583 PMCID: PMC8067107 DOI: 10.3390/biology10040270] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Revised: 03/18/2021] [Accepted: 03/23/2021] [Indexed: 12/17/2022]
Abstract
The body size and (or) complexity of organisms is not uniformly related to the amount of genetic material (DNA) contained in each of their cell nuclei ('genome size'). This surprising mismatch between the physical structure of organisms and their underlying genetic information appears to relate to variable accumulation of repetitive DNA sequences, but why this variation has evolved is little understood. Here, I show that genome size correlates more positively with egg size than adult size in crustaceans. I explain this and comparable patterns observed in other kinds of animals and plants as resulting from genome size relating strongly to cell size in most organisms, which should also apply to single-celled eggs and other reproductive propagules with relatively few cells that are pivotal first steps in their lives. However, since body size results from growth in cell size or number or both, it relates to genome size in diverse ways. Relationships between genome size and body size should be especially weak in large organisms whose size relates more to cell multiplication than to cell enlargement, as is generally observed. The ubiquitous single-cell 'bottleneck' of life cycles may affect both genome size and composition, and via both informational (genotypic) and non-informational (nucleotypic) effects, many other properties of multicellular organisms (e.g., rates of growth and metabolism) that have both theoretical and practical significance.
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14
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Verberk WC, Atkinson D, Hoefnagel KN, Hirst AG, Horne CR, Siepel H. Shrinking body sizes in response to warming: explanations for the temperature-size rule with special emphasis on the role of oxygen. Biol Rev Camb Philos Soc 2021; 96:247-268. [PMID: 32959989 PMCID: PMC7821163 DOI: 10.1111/brv.12653] [Citation(s) in RCA: 102] [Impact Index Per Article: 34.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Revised: 08/28/2020] [Accepted: 08/28/2020] [Indexed: 01/04/2023]
Abstract
Body size is central to ecology at levels ranging from organismal fecundity to the functioning of communities and ecosystems. Understanding temperature-induced variations in body size is therefore of fundamental and applied interest, yet thermal responses of body size remain poorly understood. Temperature-size (T-S) responses tend to be negative (e.g. smaller body size at maturity when reared under warmer conditions), which has been termed the temperature-size rule (TSR). Explanations emphasize either physiological mechanisms (e.g. limitation of oxygen or other resources and temperature-dependent resource allocation) or the adaptive value of either a large body size (e.g. to increase fecundity) or a short development time (e.g. in response to increased mortality in warm conditions). Oxygen limitation could act as a proximate factor, but we suggest it more likely constitutes a selective pressure to reduce body size in the warm: risks of oxygen limitation will be reduced as a consequence of evolution eliminating genotypes more prone to oxygen limitation. Thus, T-S responses can be explained by the 'Ghost of Oxygen-limitation Past', whereby the resulting (evolved) T-S responses safeguard sufficient oxygen provisioning under warmer conditions, reflecting the balance between oxygen supply and demands experienced by ancestors. T-S responses vary considerably across species, but some of this variation is predictable. Body-size reductions with warming are stronger in aquatic taxa than in terrestrial taxa. We discuss whether larger aquatic taxa may especially face greater risks of oxygen limitation as they grow, which may be manifested at the cellular level, the level of the gills and the whole-organism level. In contrast to aquatic species, terrestrial ectotherms may be less prone to oxygen limitation and prioritize early maturity over large size, likely because overwintering is more challenging, with concomitant stronger end-of season time constraints. Mechanisms related to time constraints and oxygen limitation are not mutually exclusive explanations for the TSR. Rather, these and other mechanisms may operate in tandem. But their relative importance may vary depending on the ecology and physiology of the species in question, explaining not only the general tendency of negative T-S responses but also variation in T-S responses among animals differing in mode of respiration (e.g. water breathers versus air breathers), genome size, voltinism and thermally associated behaviour (e.g. heliotherms).
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Affiliation(s)
- Wilco C.E.P. Verberk
- Department of Animal Ecology and Physiology, Institute for Water and Wetland ResearchRadboud UniversityHeyendaalseweg 1356525 AJNijmegenThe Netherlands
| | - David Atkinson
- Department of Evolution, Ecology and BehaviourUniversity of LiverpoolLiverpoolL69 7ZBU.K.
| | - K. Natan Hoefnagel
- Department of Animal Ecology and Physiology, Institute for Water and Wetland ResearchRadboud UniversityHeyendaalseweg 1356525 AJNijmegenThe Netherlands
- Faculty of Science and Engineering, Ocean Ecosystems — Energy and Sustainability Research Institute GroningenUniversity of GroningenNijenborgh 79747 AGGroningenThe Netherlands
| | - Andrew G. Hirst
- School of Environmental SciencesUniversity of LiverpoolLiverpoolL69 3GPU.K.
- Centre for Ocean Life, DTU AquaTechnical University of DenmarkLyngbyDenmark
| | - Curtis R. Horne
- School of Environmental SciencesUniversity of LiverpoolLiverpoolL69 3GPU.K.
| | - Henk Siepel
- Department of Animal Ecology and Physiology, Institute for Water and Wetland ResearchRadboud UniversityHeyendaalseweg 1356525 AJNijmegenThe Netherlands
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15
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16
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Sun Q, Perez-Rathke A, Czajkowsky DM, Shao Z, Liang J. High-resolution single-cell 3D-models of chromatin ensembles during Drosophila embryogenesis. Nat Commun 2021; 12:205. [PMID: 33420075 PMCID: PMC7794469 DOI: 10.1038/s41467-020-20490-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Accepted: 12/02/2020] [Indexed: 01/29/2023] Open
Abstract
Single-cell chromatin studies provide insights into how chromatin structure relates to functions of individual cells. However, balancing high-resolution and genome wide-coverage remains challenging. We describe a computational method for the reconstruction of large 3D-ensembles of single-cell (sc) chromatin conformations from population Hi-C that we apply to study embryogenesis in Drosophila. With minimal assumptions of physical properties and without adjustable parameters, our method generates large ensembles of chromatin conformations via deep-sampling. Our method identifies specific interactions, which constitute 5-6% of Hi-C frequencies, but surprisingly are sufficient to drive chromatin folding, giving rise to the observed Hi-C patterns. Modeled sc-chromatins quantify chromatin heterogeneity, revealing significant changes during embryogenesis. Furthermore, >50% of modeled sc-chromatin maintain topologically associating domains (TADs) in early embryos, when no population TADs are perceptible. Domain boundaries become fixated during development, with strong preference at binding-sites of insulator-complexes upon the midblastula transition. Overall, high-resolution 3D-ensembles of sc-chromatin conformations enable further in-depth interpretation of population Hi-C, improving understanding of the structure-function relationship of genome organization.
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Affiliation(s)
- Qiu Sun
- Shanghai Center for System Biomedicine, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Alan Perez-Rathke
- Department of Bioengineering, University of Illinois at Chicago, SEO, MC-063, Chicago, IL, 60607-7052, USA
| | - Daniel M Czajkowsky
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Zhifeng Shao
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China.
| | - Jie Liang
- Department of Bioengineering, University of Illinois at Chicago, SEO, MC-063, Chicago, IL, 60607-7052, USA.
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17
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Mao Y, Zhang N, Nie Y, Zhang X, Li X, Huang Y. Genome Size of 17 Species From Caelifera (Orthoptera) and Determination of Internal Standards With Very Large Genome Size in Insecta. Front Physiol 2020; 11:567125. [PMID: 33192564 PMCID: PMC7642767 DOI: 10.3389/fphys.2020.567125] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Accepted: 09/24/2020] [Indexed: 12/31/2022] Open
Abstract
Comparative studies of insect genome size show that Orthoptera is a unique group of Insecta with a significantly enlarged genome. To determine a suitable internal standard for a large genome and to compare the effects of different internal standards on estimates of genome size, we used four internal standards to estimate nuclear DNA content in nine insect species with large genomes. The results showed that the combination of two internal standards, Locusta migratoria (♂1C = 6.20 pg, ♀1C = 6.60 pg) and Periplaneta americana♂ (1C = 3.41 pg), was suitable for estimating large genome of Caelifera by flow cytometry. Using these two internal standards, we estimated the genome sizes of 17 species of Caelifera (12 genera in Acrididae, 2 genera in Pamphagidae, 1 genus in Pyrgomorphidae) using flow cytometry. Genomes ranged from 6.57 pg (Shirakiacris shirakii) to 18.64 pg (Bryodemella holdereri), the largest described in insects to date. These species showed significant genomic dimorphism based on sex: females had a 0.56 pg larger genome than males on average, which might be due to the sex chromosome determinism mechanism of X0(♂)/XX(♀). To test the results obtained by flow cytometry, we used k-mers of Illumina sequencing data to gauge the C-value of Calliptamus abbreviatus and Haplotropis brunneriana. The results of the two methods are slightly different. Genomes were estimated to be about 0.28 and 0.26 pg smaller, respectively, than the flow cytometry values. Furthermore, we also reconstructed the evolutionary relationships of these taxa and discuss the genome size evolution in a phylogenetic framework.
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Affiliation(s)
| | | | | | | | | | - Yuan Huang
- College of Life Sciences, Shaanxi Normal University, Xi’an, China
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18
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Bugg WS, Yoon GR, Schoen AN, Laluk A, Brandt C, Anderson WG, Jeffries KM. Effects of acclimation temperature on the thermal physiology in two geographically distinct populations of lake sturgeon ( Acipenser fulvescens). CONSERVATION PHYSIOLOGY 2020; 8:coaa087. [PMID: 34603733 PMCID: PMC7526614 DOI: 10.1093/conphys/coaa087] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 08/12/2020] [Accepted: 08/20/2020] [Indexed: 05/31/2023]
Abstract
Temperature is one of the most important abiotic factors regulating development and biological processes in ectotherms. By 2050, climate change may result in temperature increases of 2.1-3.4°C in Manitoba, Canada. Lake sturgeon, Acipenser fulvescens, from both northern and southern populations in Manitoba were acclimated to 16, 20 and 24°C for 30 days, after which critical thermal maximum (CTmax) trials were conducted to investigate their thermal plasticity. We also examined the effects of temperature on morphological and physiological indices. Acclimation temperature significantly influenced the CTmax, body mass, hepatosomatic index, metabolic rate and the mRNA expression of transcripts involved in the cellular response to heat shock and hypoxia (HSP70, HSP90a, HSP90b, HIF-1α) in the gill of lake sturgeon. Population significantly affected the above phenotypes, as well as the mRNA expression of Na+/K+ ATPase-α1 and the hepatic glutathione peroxidase enzyme activity. The southern population had an average CTmax that was 0.71 and 0.45°C higher than the northern population at 20 and 24°C, respectively. Immediately following CTmax trials, mRNA expression of HSP90a and HIF-1α was positively correlated with individual CTmax of lake sturgeon across acclimation treatments and populations (r = 0.7, r = 0.62, respectively; P < 0.0001). Lake sturgeon acclimated to 20 and 24°C had decreased hepatosomatic indices (93 and 244% reduction, respectively; P < 0.0001) and metabolic suppression (27.7 and 42.1% reduction, respectively; P < 0.05) when compared to sturgeon acclimated to 16°C, regardless of population. Glutathione peroxidase activity and mRNA expression Na+/K+ ATPase-α1 were elevated in the northern relative to the southern population. Acclimation to 24°C also induced mortality in both populations when compared to sturgeon acclimated to 16 and 20°C. Thus, increased temperatures have wide-ranging population-specific physiological consequences for lake sturgeon across biological levels of organization.
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Affiliation(s)
- William S Bugg
- Corresponding author: Department of Biological Sciences, University of Manitoba, 50 Sifton Road, Winnipeg, Manitoba, R3T 2N2, Canada.
| | - Gwangseok R Yoon
- Department of Biological Sciences, University of Manitoba, 50 Sifton Road, Winnipeg, Manitoba, R3T 2N2, Canada
| | | | - Andrew Laluk
- Department of Biological Sciences, University of Manitoba, 50 Sifton Road, Winnipeg, Manitoba, R3T 2N2, Canada
| | - Catherine Brandt
- Department of Biological Sciences, University of Manitoba, 50 Sifton Road, Winnipeg, Manitoba, R3T 2N2, Canada
| | - W Gary Anderson
- Department of Biological Sciences, University of Manitoba, 50 Sifton Road, Winnipeg, Manitoba, R3T 2N2, Canada
| | - Ken M Jeffries
- Department of Biological Sciences, University of Manitoba, 50 Sifton Road, Winnipeg, Manitoba, R3T 2N2, Canada
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19
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The genome of the marine monogonont rotifer Brachionus rotundiformis and insight into species-specific detoxification components in Brachionus spp. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY D-GENOMICS & PROTEOMICS 2020; 36:100714. [PMID: 32784096 DOI: 10.1016/j.cbd.2020.100714] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 07/22/2020] [Accepted: 07/26/2020] [Indexed: 11/20/2022]
Abstract
The monogonont rotifer Brachionus spp. have been widely used for ecotoxicological studies because of their advantages as one of the most suitable laboratory experimental species. In the present study, we obtained and assembled the whole genome sequence of the rotifer Brachionus rotundiformis, consisting of 13,612 annotated genes with 213 scaffolds and 58 Mb in total length. Focusing on ecotoxicological aspects, we conducted a comparative genome analysis on the gene families involved in detoxification, including four to six sulfotransferase gene families, seven uridine 5'-diphospho-glucuronosyltransferase gene families, and 58, 61, or 70 ATP-binding cassette genes in the genus Brachionus including Brachionus koreanus and Brachionus plicatilis. Our results suggest that these gene families have undergone a species- and/or lineage-specific evolution in response to the surrounding environmental pressure. Our genome resource for B. rotundiformis would be highly useful for future ecotoxicological studies and also provides a better understanding on the view of evolutionary mechanism of detoxification in the genus Brachionus spp.
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20
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Moura MN, Cardoso DC, Lima Baldez BC, Cristiano MP. Intraspecific variation in the karyotype length and genome size of fungus-farming ants (genus Mycetophylax), with remarks on procedures for the estimation of genome size in the Formicidae by flow cytometry. PLoS One 2020; 15:e0237157. [PMID: 32760102 PMCID: PMC7410318 DOI: 10.1371/journal.pone.0237157] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Accepted: 07/20/2020] [Indexed: 11/19/2022] Open
Abstract
Ants (Formicidae) present considerable diversity in chromosome numbers, which vary from n = 1 to n = 60, although this variation is not proportional to that in genome size, for which estimates range from 0.18 pg to 0.77 pg. Intraspecific variation in the chromosome number and karyotype structure has been reported among species, although the variation among populations of the same species has received much less attention, and there are few data on genome size. Here, we studied the karyotype length and genome size of different populations of the fungus-farming ants Mycetophylax conformis (Mayr, 1884) and Mycetophylax morschi (Emery, 1888). We also provide remarks on procedure for the estimation of ant genome size by Flow Cytometry (FCM) analysis. Chromosome number and morphology did not vary among the populations of M. conformis or the cytotypes of M. morschi, but karyotype length and genome size were significantly distinct among the populations of these ants. Our results on the variation in karyotype length and genome size among M. morschi and M. conformis populations reveal considerable diversity that would be largely overlooked by more traditional descriptions of karyotypes, which were also supported by the estimates of genome size obtained using flow cytometry. Changes in the amount of DNA reflect variation in the fine structure of the chromosomes, which may represent the first steps of karyotype evolution and may occur previously to any changes in the chromosome number.
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Affiliation(s)
- Mariana Neves Moura
- Programa de Pós-graduação em Ecologia, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil
| | - Danon Clemes Cardoso
- Departamento de Biodiversidade, Evolução e Meio Ambiente/ICEB, Universidade Federal de Ouro Preto, Ouro Preto, Minas Gerais, Brazil
| | - Brenda Carla Lima Baldez
- Programa de Pós-graduação em Ecologia de Biomas Tropicais, Universidade Federal de Ouro Preto, Ouro Preto, Minas Gerais, Brazil
| | - Maykon Passos Cristiano
- Departamento de Biodiversidade, Evolução e Meio Ambiente/ICEB, Universidade Federal de Ouro Preto, Ouro Preto, Minas Gerais, Brazil
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21
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Xiao H, Ye X, Xu H, Mei Y, Yang Y, Chen X, Yang Y, Liu T, Yu Y, Yang W, Lu Z, Li F. The genetic adaptations of fall armyworm Spodoptera frugiperda facilitated its rapid global dispersal and invasion. Mol Ecol Resour 2020; 20:1050-1068. [PMID: 32359007 DOI: 10.1111/1755-0998.13182] [Citation(s) in RCA: 66] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Revised: 04/24/2020] [Accepted: 04/27/2020] [Indexed: 12/31/2022]
Abstract
The fall armyworm (Spodoptera frugiperda) is a lepidopteran insect pest that causes huge economic losses. This notorious insect pest has rapidly spread over the world in the past few years. However, the mechanisms of rapid dispersal are not well understood. Here, we report a chromosome-level assembled genome of the fall armyworm, named the ZJ-version, using PacBio and Hi-C technology. The sequenced individual was a female collected from the Zhejiang province of China and had high heterozygosity. The assembled genome size of ZJ-version was 486 Mb, containing 361 contigs with an N50 of 1.13 Mb. Hi-C scaffolding further assembled the genome into 31 chromosomes and a portion of W chromosome, representing 97.4% of all contigs and resulted in a chromosome-level genome with scaffold N50 of 16.3 Mb. The sex chromosomes were identified by genome resequencing of a single male pupa and a single female pupa. About 28% of the genome was annotated as repeat sequences, and 22,623 protein-coding genes were identified. Comparative genomics revealed the expansion of the detoxification-associated gene families, chemoreception-associated gene families, nutrition metabolism and transport system gene families in the fall armyworm. Transcriptomic and phylogenetic analyses focused on these gene families revealed the potential roles of the genes in polyphagia and invasion of fall armyworm. The high-quality of the fall armyworm genome provides an important genomic resource for further explorations of the mechanisms of polyphagia and insecticide resistance, as well as for pest management of fall armyworm.
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Affiliation(s)
- Huamei Xiao
- Key Laboratory of Crop Growth and Development Regulation of Jiangxi Province, College of Life Sciences and Resource Environment, Yichun University, Yichun, China.,State Key Laboratory of Rice Biology & Ministry of Agricultural and Rural Affairs Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Insect Sciences, Zhejiang University, Hangzhou, China
| | - Xinhai Ye
- State Key Laboratory of Rice Biology & Ministry of Agricultural and Rural Affairs Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Insect Sciences, Zhejiang University, Hangzhou, China
| | - Hongxing Xu
- Institute of Plant Protection and Microbiology, Zhejiang Academy of Agricultural Sciences, Hangzhou, China
| | - Yang Mei
- State Key Laboratory of Rice Biology & Ministry of Agricultural and Rural Affairs Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Insect Sciences, Zhejiang University, Hangzhou, China
| | - Yi Yang
- State Key Laboratory of Rice Biology & Ministry of Agricultural and Rural Affairs Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Insect Sciences, Zhejiang University, Hangzhou, China
| | - Xi Chen
- State Key Laboratory of Rice Biology & Ministry of Agricultural and Rural Affairs Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Insect Sciences, Zhejiang University, Hangzhou, China
| | - Yajun Yang
- Institute of Plant Protection and Microbiology, Zhejiang Academy of Agricultural Sciences, Hangzhou, China
| | - Tao Liu
- Annoroad Gene Technology (Beijing) Co Ltd, Beijing, China
| | - Yongyi Yu
- Annoroad Gene Technology (Beijing) Co Ltd, Beijing, China
| | - Weifei Yang
- Annoroad Gene Technology (Beijing) Co Ltd, Beijing, China
| | - Zhongxian Lu
- Institute of Plant Protection and Microbiology, Zhejiang Academy of Agricultural Sciences, Hangzhou, China
| | - Fei Li
- State Key Laboratory of Rice Biology & Ministry of Agricultural and Rural Affairs Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Insect Sciences, Zhejiang University, Hangzhou, China
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22
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The Y chromosome may contribute to sex-specific ageing in Drosophila. Nat Ecol Evol 2020; 4:853-862. [PMID: 32313175 PMCID: PMC7274899 DOI: 10.1038/s41559-020-1179-5] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Accepted: 03/16/2020] [Indexed: 12/03/2022]
Abstract
Heterochromatin suppresses repetitive DNA, and a loss of heterochromatin has been observed in aged cells of several species, including humans and Drosophila. Males often contain substantially more heterochromatic DNA than females, due to the presence of a large, repeat-rich Y chromosome, and male flies generally have shorter average life spans than females. Here we show that repetitive DNA becomes de-repressed more rapidly in old male flies relative to females, and repeats on the Y chromosome are disproportionally mis-expressed during aging. This is associated with a loss of heterochromatin at repetitive elements during aging in male flies, and a general loss of repressive chromatin in aged males away from pericentromeric regions and the Y. By generating flies with different sex chromosome karyotypes (XXY females; X0 and XYY males), we show that repeat de-repression and average lifespan is correlated with the number of Y chromosomes. This suggests that sex-specific chromatin differences may contribute to sex-specific aging in flies.
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23
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van de Pol ILE, Flik G, Verberk WCEP. Triploidy in zebrafish larvae: Effects on gene expression, cell size and cell number, growth, development and swimming performance. PLoS One 2020; 15:e0229468. [PMID: 32119699 PMCID: PMC7051096 DOI: 10.1371/journal.pone.0229468] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Accepted: 02/06/2020] [Indexed: 12/14/2022] Open
Abstract
There is renewed interest in the regulation and consequences of cell size adaptations in studies on understanding the ecophysiology of ectotherms. Here we test if induction of triploidy, which increases cell size in zebrafish (Danio rerio), makes for a good model system to study consequences of cell size. Ideally, diploid and triploid zebrafish should differ in cell size, but should otherwise be comparable in order to be suitable as a model. We induced triploidy by cold shock and compared diploid and triploid zebrafish larvae under standard rearing conditions for differences in genome size, cell size and cell number, development, growth and swimming performance and expression of housekeeping genes and hsp70.1. Triploid zebrafish have larger but fewer cells, and the increase in cell size matched the increase in genome size (+ 50%). Under standard conditions, patterns in gene expression, ontogenetic development and larval growth were near identical between triploids and diploids. However, under demanding conditions (i.e. the maximum swimming velocity during an escape response), triploid larvae performed poorer than their diploid counterparts, especially after repeated stimuli to induce swimming. This result is consistent with the idea that larger cells have less capacity to generate energy, which becomes manifest during repeated physical exertion resulting in increased fatigue. Triploidy induction in zebrafish appears a valid method to increase specifically cell size and this provides a model system to test for consequences of cell size adaptation for the energy budget and swimming performance of this ectothermic vertebrate.
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Affiliation(s)
- Iris L. E. van de Pol
- Department of Animal Ecology and Physiology, Institute for Water and Wetland Research, Radboud University, Nijmegen, The Netherlands
- * E-mail:
| | - Gert Flik
- Department of Animal Ecology and Physiology, Institute for Water and Wetland Research, Radboud University, Nijmegen, The Netherlands
| | - Wilco C. E. P. Verberk
- Department of Animal Ecology and Physiology, Institute for Water and Wetland Research, Radboud University, Nijmegen, The Netherlands
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24
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The Genetic Basis of Natural Variation in Drosophila melanogaster Immune Defense against Enterococcus faecalis. Genes (Basel) 2020; 11:genes11020234. [PMID: 32098395 PMCID: PMC7074548 DOI: 10.3390/genes11020234] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Revised: 02/18/2020] [Accepted: 02/18/2020] [Indexed: 01/03/2023] Open
Abstract
Dissecting the genetic basis of natural variation in disease response in hosts provides insights into the coevolutionary dynamics of host-pathogen interactions. Here, a genome-wide association study of Drosophila melanogaster survival after infection with the Gram-positive entomopathogenic bacterium Enterococcus faecalis is reported. There was considerable variation in defense against E. faecalis infection among inbred lines of the Drosophila Genetics Reference Panel. We identified single nucleotide polymorphisms associated with six genes with a significant (p < 10-08, corresponding to a false discovery rate of 2.4%) association with survival, none of which were canonical immune genes. To validate the role of these genes in immune defense, their expression was knocked-down using RNAi and survival of infected hosts was followed, which confirmed a role for the genes krishah and S6k in immune defense. We further identified a putative role for the Bomanin gene BomBc1 (also known as IM23), in E. faecalis infection response. This study adds to the growing set of association studies for infection in Drosophila melanogaster and suggests that the genetic causes of variation in immune defense differ for different pathogens.
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25
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Hjelmen CE, Parrott JJ, Srivastav SP, McGuane AS, Ellis LL, Stewart AD, Johnston JS, Tarone AM. Effect of Phenotype Selection on Genome Size Variation in Two Species of Diptera. Genes (Basel) 2020; 11:genes11020218. [PMID: 32093067 PMCID: PMC7074110 DOI: 10.3390/genes11020218] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Revised: 02/11/2020] [Accepted: 02/15/2020] [Indexed: 11/16/2022] Open
Abstract
Genome size varies widely across organisms yet has not been found to be related to organismal complexity in eukaryotes. While there is no evidence for a relationship with complexity, there is evidence to suggest that other phenotypic characteristics, such as nucleus size and cell-cycle time, are associated with genome size, body size, and development rate. However, what is unknown is how the selection for divergent phenotypic traits may indirectly affect genome size. Drosophila melanogaster were selected for small and large body size for up to 220 generations, while Cochliomyia macellaria were selected for 32 generations for fast and slow development. Size in D. melanogaster significantly changed in terms of both cell-count and genome size in isolines, but only the cell-count changed in lines which were maintained at larger effective population sizes. Larger genome sizes only occurred in a subset of D. melanogaster isolines originated from flies selected for their large body size. Selection for development time did not change average genome size yet decreased the within-population variation in genome size with increasing generations of selection. This decrease in variation and convergence on a similar mean genome size was not in correspondence with phenotypic variation and suggests stabilizing selection on genome size in laboratory conditions.
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Affiliation(s)
- Carl E. Hjelmen
- Department of Entomology, Texas A&M University, College Station, TX 77843, USA; (J.J.P.); (S.P.S.); (A.S.M.); (L.L.E.); (J.S.J.); (A.M.T.)
- Department of Biology, Texas A&M University, College Station, TX 77843, USA
- Correspondence: or
| | - Jonathan J. Parrott
- Department of Entomology, Texas A&M University, College Station, TX 77843, USA; (J.J.P.); (S.P.S.); (A.S.M.); (L.L.E.); (J.S.J.); (A.M.T.)
- School of Mathematical and Natural Sciences, Arizona State University, Glendale, AZ 85306, USA
| | - Satyam P. Srivastav
- Department of Entomology, Texas A&M University, College Station, TX 77843, USA; (J.J.P.); (S.P.S.); (A.S.M.); (L.L.E.); (J.S.J.); (A.M.T.)
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA
| | - Alexander S. McGuane
- Department of Entomology, Texas A&M University, College Station, TX 77843, USA; (J.J.P.); (S.P.S.); (A.S.M.); (L.L.E.); (J.S.J.); (A.M.T.)
- Harris County Institute of Forensic Sciences, 1861 Old Spanish Trail, Houston, TX 77054, USA
| | - Lisa L. Ellis
- Department of Entomology, Texas A&M University, College Station, TX 77843, USA; (J.J.P.); (S.P.S.); (A.S.M.); (L.L.E.); (J.S.J.); (A.M.T.)
- Department of Biology, Houston Baptist University, Houston, TX 77074, USA
| | | | - J. Spencer Johnston
- Department of Entomology, Texas A&M University, College Station, TX 77843, USA; (J.J.P.); (S.P.S.); (A.S.M.); (L.L.E.); (J.S.J.); (A.M.T.)
| | - Aaron M. Tarone
- Department of Entomology, Texas A&M University, College Station, TX 77843, USA; (J.J.P.); (S.P.S.); (A.S.M.); (L.L.E.); (J.S.J.); (A.M.T.)
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26
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Bonnet J, Lindeboom RGH, Pokrovsky D, Stricker G, Çelik MH, Rupp RAW, Gagneur J, Vermeulen M, Imhof A, Müller J. Quantification of Proteins and Histone Marks in Drosophila Embryos Reveals Stoichiometric Relationships Impacting Chromatin Regulation. Dev Cell 2019; 51:632-644.e6. [PMID: 31630981 DOI: 10.1016/j.devcel.2019.09.011] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Revised: 06/09/2019] [Accepted: 09/16/2019] [Indexed: 10/25/2022]
Abstract
Gene transcription in eukaryotes is regulated through dynamic interactions of a variety of different proteins with DNA in the context of chromatin. Here, we used mass spectrometry for absolute quantification of the nuclear proteome and methyl marks on selected lysine residues in histone H3 during two stages of Drosophila embryogenesis. These analyses provide comprehensive information about the absolute copy number of several thousand proteins and reveal unexpected relationships between the abundance of histone-modifying and -binding proteins and the chromatin landscape that they generate and interact with. For some histone modifications, the levels in Drosophila embryos are substantially different from those previously reported in tissue culture cells. Genome-wide profiling of H3K27 methylation during developmental progression and in animals with reduced PRC2 levels illustrates how mass spectrometry can be used for quantitatively describing and comparing chromatin states. Together, these data provide a foundation toward a quantitative understanding of gene regulation in Drosophila.
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Affiliation(s)
- Jacques Bonnet
- Max-Planck Institute of Biochemistry, Laboratory of Chromatin Biology, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Rik G H Lindeboom
- Radboud Institute for Molecular Life Sciences, Oncode Institute, Department of Molecular Biology, Radboud University, Geert Grooteplein 28, 6525 GA Nijmegen, the Netherlands
| | - Daniil Pokrovsky
- Institute for Molecular Biology, BioMedical Center, Faculty of Medicine, Ludwig-Maximilians-University Munich, Großhadernerstr. 9, 82152 Martinsried, Germany; Protein Analysis Unit, BioMedical Center, Faculty of Medicine, Ludwig-Maximilians-University Munich, Großhadernerstr. 9, 82152 Martinsried, Germany
| | - Georg Stricker
- Department of Informatics, Technical University of Munich, Boltzmannstr. 3, 85748 Garching, Germany
| | - Muhammed Hasan Çelik
- Department of Informatics, Technical University of Munich, Boltzmannstr. 3, 85748 Garching, Germany
| | - Ralph A W Rupp
- Institute for Molecular Biology, BioMedical Center, Faculty of Medicine, Ludwig-Maximilians-University Munich, Großhadernerstr. 9, 82152 Martinsried, Germany
| | - Julien Gagneur
- Department of Informatics, Technical University of Munich, Boltzmannstr. 3, 85748 Garching, Germany
| | - Michiel Vermeulen
- Radboud Institute for Molecular Life Sciences, Oncode Institute, Department of Molecular Biology, Radboud University, Geert Grooteplein 28, 6525 GA Nijmegen, the Netherlands.
| | - Axel Imhof
- Protein Analysis Unit, BioMedical Center, Faculty of Medicine, Ludwig-Maximilians-University Munich, Großhadernerstr. 9, 82152 Martinsried, Germany.
| | - Jürg Müller
- Max-Planck Institute of Biochemistry, Laboratory of Chromatin Biology, Am Klopferspitz 18, 82152 Martinsried, Germany.
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27
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Blommaert J, Riss S, Hecox-Lea B, Mark Welch DB, Stelzer CP. Small, but surprisingly repetitive genomes: transposon expansion and not polyploidy has driven a doubling in genome size in a metazoan species complex. BMC Genomics 2019; 20:466. [PMID: 31174483 PMCID: PMC6555955 DOI: 10.1186/s12864-019-5859-y] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Accepted: 05/29/2019] [Indexed: 02/01/2023] Open
Abstract
BACKGROUND The causes and consequences of genome size variation across Eukaryotes, which spans five orders of magnitude, have been hotly debated since before the advent of genome sequencing. Previous studies have mostly examined variation among larger taxonomic units (e.g., orders, or genera), while comparisons among closely related species are rare. Rotifers of the Brachionus plicatilis species complex exhibit a seven-fold variation in genome size and thus represent a unique opportunity to study such changes on a relatively short evolutionary timescale. Here, we sequenced and analysed the genomes of four species of this complex with nuclear DNA contents spanning 110-422 Mbp. To establish the likely mechanisms of genome size change, we analysed both sequencing read libraries and assemblies for signatures of polyploidy and repetitive element content. We also compared these genomes to that of B. calyciflorus, the closest relative with a sequenced genome (293 Mbp nuclear DNA content). RESULTS Despite the very large differences in genome size, we saw no evidence of ploidy level changes across the B. plicatilis complex. However, repetitive element content explained a large portion of genome size variation (at least 54%). The species with the largest genome, B. asplanchnoidis, has a strikingly high 44% repetitive element content, while the smaller B. plicatilis genomes contain between 14 and 25% repetitive elements. According to our analyses, the B. calyciflorus genome contains 39% repetitive elements, which is substantially higher than previously reported (21%), and suggests that high repetitive element load could be widespread in monogonont rotifers. CONCLUSIONS Even though the genome sizes of these species are at the low end of the metazoan spectrum, their genomes contain substantial amounts of repetitive elements. Polyploidy does not appear to play a role in genome size variations in these species, and these variations can be mostly explained by changes in repetitive element content. This contradicts the naïve expectation that small genomes are streamlined, or less complex, and that large variations in nuclear DNA content between closely related species are due to polyploidy.
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Affiliation(s)
- J. Blommaert
- Research Department for Limnology, University of Innsbruck, Mondsee, Austria
| | - S. Riss
- Research Department for Limnology, University of Innsbruck, Mondsee, Austria
| | - B. Hecox-Lea
- Josephine Bay Paul Center for Comparative Molecular Biology and Evolution, Marine Biological Laboratory, Woods Hole, MA USA
| | - D. B. Mark Welch
- Josephine Bay Paul Center for Comparative Molecular Biology and Evolution, Marine Biological Laboratory, Woods Hole, MA USA
| | - C. P. Stelzer
- Research Department for Limnology, University of Innsbruck, Mondsee, Austria
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28
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Panfilio KA, Vargas Jentzsch IM, Benoit JB, Erezyilmaz D, Suzuki Y, Colella S, Robertson HM, Poelchau MF, Waterhouse RM, Ioannidis P, Weirauch MT, Hughes DST, Murali SC, Werren JH, Jacobs CGC, Duncan EJ, Armisén D, Vreede BMI, Baa-Puyoulet P, Berger CS, Chang CC, Chao H, Chen MJM, Chen YT, Childers CP, Chipman AD, Cridge AG, Crumière AJJ, Dearden PK, Didion EM, Dinh H, Doddapaneni HV, Dolan A, Dugan S, Extavour CG, Febvay G, Friedrich M, Ginzburg N, Han Y, Heger P, Holmes CJ, Horn T, Hsiao YM, Jennings EC, Johnston JS, Jones TE, Jones JW, Khila A, Koelzer S, Kovacova V, Leask M, Lee SL, Lee CY, Lovegrove MR, Lu HL, Lu Y, Moore PJ, Munoz-Torres MC, Muzny DM, Palli SR, Parisot N, Pick L, Porter ML, Qu J, Refki PN, Richter R, Rivera-Pomar R, Rosendale AJ, Roth S, Sachs L, Santos ME, Seibert J, Sghaier E, Shukla JN, Stancliffe RJ, Tidswell O, Traverso L, van der Zee M, Viala S, Worley KC, Zdobnov EM, Gibbs RA, Richards S. Molecular evolutionary trends and feeding ecology diversification in the Hemiptera, anchored by the milkweed bug genome. Genome Biol 2019. [PMID: 30935422 DOI: 10.1101/201731] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/08/2023] Open
Abstract
BACKGROUND The Hemiptera (aphids, cicadas, and true bugs) are a key insect order, with high diversity for feeding ecology and excellent experimental tractability for molecular genetics. Building upon recent sequencing of hemipteran pests such as phloem-feeding aphids and blood-feeding bed bugs, we present the genome sequence and comparative analyses centered on the milkweed bug Oncopeltus fasciatus, a seed feeder of the family Lygaeidae. RESULTS The 926-Mb Oncopeltus genome is well represented by the current assembly and official gene set. We use our genomic and RNA-seq data not only to characterize the protein-coding gene repertoire and perform isoform-specific RNAi, but also to elucidate patterns of molecular evolution and physiology. We find ongoing, lineage-specific expansion and diversification of repressive C2H2 zinc finger proteins. The discovery of intron gain and turnover specific to the Hemiptera also prompted the evaluation of lineage and genome size as predictors of gene structure evolution. Furthermore, we identify enzymatic gains and losses that correlate with feeding biology, particularly for reductions associated with derived, fluid nutrition feeding. CONCLUSIONS With the milkweed bug, we now have a critical mass of sequenced species for a hemimetabolous insect order and close outgroup to the Holometabola, substantially improving the diversity of insect genomics. We thereby define commonalities among the Hemiptera and delve into how hemipteran genomes reflect distinct feeding ecologies. Given Oncopeltus's strength as an experimental model, these new sequence resources bolster the foundation for molecular research and highlight technical considerations for the analysis of medium-sized invertebrate genomes.
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Affiliation(s)
- Kristen A Panfilio
- Institute for Zoology: Developmental Biology, University of Cologne, Zülpicher Str. 47b, 50674, Cologne, Germany.
- School of Life Sciences, University of Warwick, Gibbet Hill Campus, Coventry, CV4 7AL, UK.
| | - Iris M Vargas Jentzsch
- Institute for Zoology: Developmental Biology, University of Cologne, Zülpicher Str. 47b, 50674, Cologne, Germany
| | - Joshua B Benoit
- Department of Biological Sciences, University of Cincinnati, Cincinnati, OH, 45221, USA
| | - Deniz Erezyilmaz
- Department of Biochemistry and Cell Biology and Center for Developmental Genetics, Stony Brook University, Stony Brook, NY, 11794, USA
- Present address: Department of Physiology, Anatomy and Genetics and Centre for Neural Circuits and Behaviour, University of Oxford, Oxford, OX1 3SR, UK
| | - Yuichiro Suzuki
- Department of Biological Sciences, Wellesley College, 106 Central St., Wellesley, MA, 02481, USA
| | - Stefano Colella
- Univ Lyon, INSA-Lyon, INRA, BF2I, UMR0203, F-69621, Villeurbanne, France
- Present address: LSTM, Laboratoire des Symbioses Tropicales et Méditerranéennes, INRA, IRD, CIRAD, SupAgro, University of Montpellier, Montpellier, France
| | - Hugh M Robertson
- Department of Entomology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | | | - Robert M Waterhouse
- Department of Genetic Medicine and Development and Swiss Institute of Bioinformatics, University of Geneva, 1211, Geneva, Switzerland
- Present address: Department of Ecology and Evolution, University of Lausanne, 1015, Lausanne, Switzerland
| | - Panagiotis Ioannidis
- Department of Genetic Medicine and Development and Swiss Institute of Bioinformatics, University of Geneva, 1211, Geneva, Switzerland
| | - Matthew T Weirauch
- Center for Autoimmune Genomics and Etiology, Division of Biomedical Informatics, and Division of Developmental Biology, Cincinnati Children's Hospital Medical Center, Department of Pediatrics, College of Medicine, University of Cincinnati, Cincinnati, OH, 45229, USA
| | - Daniel S T Hughes
- Human Genome Sequencing Center, Department of Human and Molecular Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
| | - Shwetha C Murali
- Human Genome Sequencing Center, Department of Human and Molecular Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
- Present address: Department of Genome Sciences, University of Washington School of Medicine, Seattle, WA, 98195, USA
- Present address: Howard Hughes Medical Institute, University of Washington, Seattle, WA, 98195, USA
| | - John H Werren
- Department of Biology, University of Rochester, Rochester, NY, 14627, USA
| | - Chris G C Jacobs
- Institute of Biology, Leiden University, Sylviusweg 72, 2333 BE, Leiden, Netherlands
- Max Planck Institute for Chemical Ecology, Hans-Knöll Strasse 8, 07745, Jena, Germany
| | - Elizabeth J Duncan
- Department of Biochemistry and Genomics Aotearoa, University of Otago, Dunedin, 9054, New Zealand
- School of Biology, Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, UK
| | - David Armisén
- Institut de Génomique Fonctionnelle de Lyon, Université de Lyon, Université Claude Bernard Lyon 1, CNRS UMR 5242, École Normale Supérieure de Lyon, 46 Allée d'Italie, 69364, Lyon, France
| | - Barbara M I Vreede
- Department of Ecology, Evolution and Behavior, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, 91904, Jerusalem, Israel
| | | | - Chloé S Berger
- Institut de Génomique Fonctionnelle de Lyon, Université de Lyon, Université Claude Bernard Lyon 1, CNRS UMR 5242, École Normale Supérieure de Lyon, 46 Allée d'Italie, 69364, Lyon, France
| | - Chun-Che Chang
- Department of Entomology/Institute of Biotechnology, College of Bioresources and Agriculture, National Taiwan University, Taipei, Taiwan
- Research Center for Developmental Biology and Regenerative Medicine, National Taiwan University, Taipei, Taiwan
| | - Hsu Chao
- Human Genome Sequencing Center, Department of Human and Molecular Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
| | - Mei-Ju M Chen
- National Agricultural Library, Beltsville, MD, 20705, USA
| | - Yen-Ta Chen
- Institute for Zoology: Developmental Biology, University of Cologne, Zülpicher Str. 47b, 50674, Cologne, Germany
| | | | - Ariel D Chipman
- Department of Ecology, Evolution and Behavior, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, 91904, Jerusalem, Israel
| | - Andrew G Cridge
- Department of Biochemistry and Genomics Aotearoa, University of Otago, Dunedin, 9054, New Zealand
| | - Antonin J J Crumière
- Institut de Génomique Fonctionnelle de Lyon, Université de Lyon, Université Claude Bernard Lyon 1, CNRS UMR 5242, École Normale Supérieure de Lyon, 46 Allée d'Italie, 69364, Lyon, France
| | - Peter K Dearden
- Department of Biochemistry and Genomics Aotearoa, University of Otago, Dunedin, 9054, New Zealand
| | - Elise M Didion
- Department of Biological Sciences, University of Cincinnati, Cincinnati, OH, 45221, USA
| | - Huyen Dinh
- Human Genome Sequencing Center, Department of Human and Molecular Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
| | - Harsha Vardhan Doddapaneni
- Human Genome Sequencing Center, Department of Human and Molecular Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
| | - Amanda Dolan
- Department of Biology, University of Rochester, Rochester, NY, 14627, USA
- Present address: School of Life Sciences, Rochester Institute of Technology, Rochester, NY, 14623, USA
| | - Shannon Dugan
- Human Genome Sequencing Center, Department of Human and Molecular Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
| | - Cassandra G Extavour
- Department of Organismic and Evolutionary Biology, Harvard University, 26 Oxford Street, Cambridge, MA, 02138, USA
- Department of Molecular and Cellular Biology, Harvard University, 26 Oxford Street, Cambridge, MA, 02138, USA
| | - Gérard Febvay
- Univ Lyon, INSA-Lyon, INRA, BF2I, UMR0203, F-69621, Villeurbanne, France
| | - Markus Friedrich
- Department of Biological Sciences, Wayne State University, Detroit, MI, 48202, USA
| | - Neta Ginzburg
- Department of Ecology, Evolution and Behavior, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, 91904, Jerusalem, Israel
| | - Yi Han
- Human Genome Sequencing Center, Department of Human and Molecular Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
| | - Peter Heger
- Institute for Genetics, University of Cologne, Zülpicher Straße 47a, 50674, Cologne, Germany
| | - Christopher J Holmes
- Department of Biological Sciences, University of Cincinnati, Cincinnati, OH, 45221, USA
| | - Thorsten Horn
- Institute for Zoology: Developmental Biology, University of Cologne, Zülpicher Str. 47b, 50674, Cologne, Germany
| | - Yi-Min Hsiao
- Department of Entomology/Institute of Biotechnology, College of Bioresources and Agriculture, National Taiwan University, Taipei, Taiwan
- Research Center for Developmental Biology and Regenerative Medicine, National Taiwan University, Taipei, Taiwan
| | - Emily C Jennings
- Department of Biological Sciences, University of Cincinnati, Cincinnati, OH, 45221, USA
| | - J Spencer Johnston
- Department of Entomology, Texas A&M University, College Station, TX, 77843, USA
| | - Tamsin E Jones
- Department of Organismic and Evolutionary Biology, Harvard University, 26 Oxford Street, Cambridge, MA, 02138, USA
| | - Jeffery W Jones
- Department of Biological Sciences, Wayne State University, Detroit, MI, 48202, USA
| | - Abderrahman Khila
- Institut de Génomique Fonctionnelle de Lyon, Université de Lyon, Université Claude Bernard Lyon 1, CNRS UMR 5242, École Normale Supérieure de Lyon, 46 Allée d'Italie, 69364, Lyon, France
| | - Stefan Koelzer
- Institute for Zoology: Developmental Biology, University of Cologne, Zülpicher Str. 47b, 50674, Cologne, Germany
| | | | - Megan Leask
- Department of Biochemistry and Genomics Aotearoa, University of Otago, Dunedin, 9054, New Zealand
| | - Sandra L Lee
- Human Genome Sequencing Center, Department of Human and Molecular Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
| | - Chien-Yueh Lee
- National Agricultural Library, Beltsville, MD, 20705, USA
| | - Mackenzie R Lovegrove
- Department of Biochemistry and Genomics Aotearoa, University of Otago, Dunedin, 9054, New Zealand
| | - Hsiao-Ling Lu
- Department of Entomology/Institute of Biotechnology, College of Bioresources and Agriculture, National Taiwan University, Taipei, Taiwan
- Research Center for Developmental Biology and Regenerative Medicine, National Taiwan University, Taipei, Taiwan
| | - Yong Lu
- Department of Entomology and Program in Molecular & Cell Biology, University of Maryland, College Park, MD, 20742, USA
| | - Patricia J Moore
- Department of Entomology, University of Georgia, 120 Cedar St., Athens, GA, 30602, USA
| | - Monica C Munoz-Torres
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Donna M Muzny
- Human Genome Sequencing Center, Department of Human and Molecular Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
| | - Subba R Palli
- Department of Entomology, College of Agriculture, Food and Environment, University of Kentucky, Lexington, KY, 40546, USA
| | - Nicolas Parisot
- Univ Lyon, INSA-Lyon, INRA, BF2I, UMR0203, F-69621, Villeurbanne, France
| | - Leslie Pick
- Department of Entomology and Program in Molecular & Cell Biology, University of Maryland, College Park, MD, 20742, USA
| | - Megan L Porter
- Department of Biology, University of Hawai'i at Mānoa, Honolulu, HI, 96822, USA
| | - Jiaxin Qu
- Human Genome Sequencing Center, Department of Human and Molecular Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
| | - Peter N Refki
- Institut de Génomique Fonctionnelle de Lyon, Université de Lyon, Université Claude Bernard Lyon 1, CNRS UMR 5242, École Normale Supérieure de Lyon, 46 Allée d'Italie, 69364, Lyon, France
- Present address: Department of Evolutionary Genetics, Max-Planck-Institut für Evolutionsbiologie, August-Thienemann-Straße 2, 24306, Plön, Germany
| | - Rose Richter
- Department of Biology, University of Rochester, Rochester, NY, 14627, USA
- Present address: Earthworks Institute, 185 Caroline Street, Rochester, NY, 14620, USA
| | - Rolando Rivera-Pomar
- Centro de Bioinvestigaciones, Universidad Nacional del Noroeste de Buenos Aires, Pergamino, Argentina
| | - Andrew J Rosendale
- Department of Biological Sciences, University of Cincinnati, Cincinnati, OH, 45221, USA
| | - Siegfried Roth
- Institute for Zoology: Developmental Biology, University of Cologne, Zülpicher Str. 47b, 50674, Cologne, Germany
| | - Lena Sachs
- Institute for Zoology: Developmental Biology, University of Cologne, Zülpicher Str. 47b, 50674, Cologne, Germany
| | - M Emília Santos
- Institut de Génomique Fonctionnelle de Lyon, Université de Lyon, Université Claude Bernard Lyon 1, CNRS UMR 5242, École Normale Supérieure de Lyon, 46 Allée d'Italie, 69364, Lyon, France
| | - Jan Seibert
- Institute for Zoology: Developmental Biology, University of Cologne, Zülpicher Str. 47b, 50674, Cologne, Germany
| | - Essia Sghaier
- Institut de Génomique Fonctionnelle de Lyon, Université de Lyon, Université Claude Bernard Lyon 1, CNRS UMR 5242, École Normale Supérieure de Lyon, 46 Allée d'Italie, 69364, Lyon, France
| | - Jayendra N Shukla
- Department of Entomology, College of Agriculture, Food and Environment, University of Kentucky, Lexington, KY, 40546, USA
- Present address: Department of Biotechnology, Central University of Rajasthan (CURAJ), NH-8, Bandarsindri, Ajmer, 305801, India
| | - Richard J Stancliffe
- Argelander-Institut für Astronomie, Universität Bonn, Auf dem Hügel 71, 53121, Bonn, Germany
- Present address: E. A. Milne Centre for Astrophysics, Department of Physics and Mathematics, University of Hull, Hull, HU6 7RX, UK
| | - Olivia Tidswell
- Department of Biochemistry and Genomics Aotearoa, University of Otago, Dunedin, 9054, New Zealand
- Present address: Department of Zoology, University of Cambridge, Cambridge, CB2 3DT, UK
| | - Lucila Traverso
- Centro Regional de Estudios Genómicos, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, La Plata, Argentina
| | - Maurijn van der Zee
- Institute of Biology, Leiden University, Sylviusweg 72, 2333 BE, Leiden, Netherlands
| | - Séverine Viala
- Institut de Génomique Fonctionnelle de Lyon, Université de Lyon, Université Claude Bernard Lyon 1, CNRS UMR 5242, École Normale Supérieure de Lyon, 46 Allée d'Italie, 69364, Lyon, France
| | - Kim C Worley
- Human Genome Sequencing Center, Department of Human and Molecular Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
| | - Evgeny M Zdobnov
- Department of Genetic Medicine and Development and Swiss Institute of Bioinformatics, University of Geneva, 1211, Geneva, Switzerland
| | - Richard A Gibbs
- Human Genome Sequencing Center, Department of Human and Molecular Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
| | - Stephen Richards
- Human Genome Sequencing Center, Department of Human and Molecular Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
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29
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Panfilio KA, Vargas Jentzsch IM, Benoit JB, Erezyilmaz D, Suzuki Y, Colella S, Robertson HM, Poelchau MF, Waterhouse RM, Ioannidis P, Weirauch MT, Hughes DST, Murali SC, Werren JH, Jacobs CGC, Duncan EJ, Armisén D, Vreede BMI, Baa-Puyoulet P, Berger CS, Chang CC, Chao H, Chen MJM, Chen YT, Childers CP, Chipman AD, Cridge AG, Crumière AJJ, Dearden PK, Didion EM, Dinh H, Doddapaneni HV, Dolan A, Dugan S, Extavour CG, Febvay G, Friedrich M, Ginzburg N, Han Y, Heger P, Holmes CJ, Horn T, Hsiao YM, Jennings EC, Johnston JS, Jones TE, Jones JW, Khila A, Koelzer S, Kovacova V, Leask M, Lee SL, Lee CY, Lovegrove MR, Lu HL, Lu Y, Moore PJ, Munoz-Torres MC, Muzny DM, Palli SR, Parisot N, Pick L, Porter ML, Qu J, Refki PN, Richter R, Rivera-Pomar R, Rosendale AJ, Roth S, Sachs L, Santos ME, Seibert J, Sghaier E, Shukla JN, Stancliffe RJ, Tidswell O, Traverso L, van der Zee M, Viala S, Worley KC, Zdobnov EM, Gibbs RA, Richards S. Molecular evolutionary trends and feeding ecology diversification in the Hemiptera, anchored by the milkweed bug genome. Genome Biol 2019; 20:64. [PMID: 30935422 PMCID: PMC6444547 DOI: 10.1186/s13059-019-1660-0] [Citation(s) in RCA: 74] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Accepted: 02/21/2019] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND The Hemiptera (aphids, cicadas, and true bugs) are a key insect order, with high diversity for feeding ecology and excellent experimental tractability for molecular genetics. Building upon recent sequencing of hemipteran pests such as phloem-feeding aphids and blood-feeding bed bugs, we present the genome sequence and comparative analyses centered on the milkweed bug Oncopeltus fasciatus, a seed feeder of the family Lygaeidae. RESULTS The 926-Mb Oncopeltus genome is well represented by the current assembly and official gene set. We use our genomic and RNA-seq data not only to characterize the protein-coding gene repertoire and perform isoform-specific RNAi, but also to elucidate patterns of molecular evolution and physiology. We find ongoing, lineage-specific expansion and diversification of repressive C2H2 zinc finger proteins. The discovery of intron gain and turnover specific to the Hemiptera also prompted the evaluation of lineage and genome size as predictors of gene structure evolution. Furthermore, we identify enzymatic gains and losses that correlate with feeding biology, particularly for reductions associated with derived, fluid nutrition feeding. CONCLUSIONS With the milkweed bug, we now have a critical mass of sequenced species for a hemimetabolous insect order and close outgroup to the Holometabola, substantially improving the diversity of insect genomics. We thereby define commonalities among the Hemiptera and delve into how hemipteran genomes reflect distinct feeding ecologies. Given Oncopeltus's strength as an experimental model, these new sequence resources bolster the foundation for molecular research and highlight technical considerations for the analysis of medium-sized invertebrate genomes.
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Affiliation(s)
- Kristen A Panfilio
- Institute for Zoology: Developmental Biology, University of Cologne, Zülpicher Str. 47b, 50674, Cologne, Germany.
- School of Life Sciences, University of Warwick, Gibbet Hill Campus, Coventry, CV4 7AL, UK.
| | - Iris M Vargas Jentzsch
- Institute for Zoology: Developmental Biology, University of Cologne, Zülpicher Str. 47b, 50674, Cologne, Germany
| | - Joshua B Benoit
- Department of Biological Sciences, University of Cincinnati, Cincinnati, OH, 45221, USA
| | - Deniz Erezyilmaz
- Department of Biochemistry and Cell Biology and Center for Developmental Genetics, Stony Brook University, Stony Brook, NY, 11794, USA
- Present address: Department of Physiology, Anatomy and Genetics and Centre for Neural Circuits and Behaviour, University of Oxford, Oxford, OX1 3SR, UK
| | - Yuichiro Suzuki
- Department of Biological Sciences, Wellesley College, 106 Central St., Wellesley, MA, 02481, USA
| | - Stefano Colella
- Univ Lyon, INSA-Lyon, INRA, BF2I, UMR0203, F-69621, Villeurbanne, France
- Present address: LSTM, Laboratoire des Symbioses Tropicales et Méditerranéennes, INRA, IRD, CIRAD, SupAgro, University of Montpellier, Montpellier, France
| | - Hugh M Robertson
- Department of Entomology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | | | - Robert M Waterhouse
- Department of Genetic Medicine and Development and Swiss Institute of Bioinformatics, University of Geneva, 1211, Geneva, Switzerland
- Present address: Department of Ecology and Evolution, University of Lausanne, 1015, Lausanne, Switzerland
| | - Panagiotis Ioannidis
- Department of Genetic Medicine and Development and Swiss Institute of Bioinformatics, University of Geneva, 1211, Geneva, Switzerland
| | - Matthew T Weirauch
- Center for Autoimmune Genomics and Etiology, Division of Biomedical Informatics, and Division of Developmental Biology, Cincinnati Children's Hospital Medical Center, Department of Pediatrics, College of Medicine, University of Cincinnati, Cincinnati, OH, 45229, USA
| | - Daniel S T Hughes
- Human Genome Sequencing Center, Department of Human and Molecular Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
| | - Shwetha C Murali
- Human Genome Sequencing Center, Department of Human and Molecular Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
- Present address: Department of Genome Sciences, University of Washington School of Medicine, Seattle, WA, 98195, USA
- Present address: Howard Hughes Medical Institute, University of Washington, Seattle, WA, 98195, USA
| | - John H Werren
- Department of Biology, University of Rochester, Rochester, NY, 14627, USA
| | - Chris G C Jacobs
- Institute of Biology, Leiden University, Sylviusweg 72, 2333 BE, Leiden, Netherlands
- Max Planck Institute for Chemical Ecology, Hans-Knöll Strasse 8, 07745, Jena, Germany
| | - Elizabeth J Duncan
- Department of Biochemistry and Genomics Aotearoa, University of Otago, Dunedin, 9054, New Zealand
- School of Biology, Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, UK
| | - David Armisén
- Institut de Génomique Fonctionnelle de Lyon, Université de Lyon, Université Claude Bernard Lyon 1, CNRS UMR 5242, École Normale Supérieure de Lyon, 46 Allée d'Italie, 69364, Lyon, France
| | - Barbara M I Vreede
- Department of Ecology, Evolution and Behavior, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, 91904, Jerusalem, Israel
| | | | - Chloé S Berger
- Institut de Génomique Fonctionnelle de Lyon, Université de Lyon, Université Claude Bernard Lyon 1, CNRS UMR 5242, École Normale Supérieure de Lyon, 46 Allée d'Italie, 69364, Lyon, France
| | - Chun-Che Chang
- Department of Entomology/Institute of Biotechnology, College of Bioresources and Agriculture, National Taiwan University, Taipei, Taiwan
- Research Center for Developmental Biology and Regenerative Medicine, National Taiwan University, Taipei, Taiwan
| | - Hsu Chao
- Human Genome Sequencing Center, Department of Human and Molecular Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
| | - Mei-Ju M Chen
- National Agricultural Library, Beltsville, MD, 20705, USA
| | - Yen-Ta Chen
- Institute for Zoology: Developmental Biology, University of Cologne, Zülpicher Str. 47b, 50674, Cologne, Germany
| | | | - Ariel D Chipman
- Department of Ecology, Evolution and Behavior, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, 91904, Jerusalem, Israel
| | - Andrew G Cridge
- Department of Biochemistry and Genomics Aotearoa, University of Otago, Dunedin, 9054, New Zealand
| | - Antonin J J Crumière
- Institut de Génomique Fonctionnelle de Lyon, Université de Lyon, Université Claude Bernard Lyon 1, CNRS UMR 5242, École Normale Supérieure de Lyon, 46 Allée d'Italie, 69364, Lyon, France
| | - Peter K Dearden
- Department of Biochemistry and Genomics Aotearoa, University of Otago, Dunedin, 9054, New Zealand
| | - Elise M Didion
- Department of Biological Sciences, University of Cincinnati, Cincinnati, OH, 45221, USA
| | - Huyen Dinh
- Human Genome Sequencing Center, Department of Human and Molecular Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
| | - Harsha Vardhan Doddapaneni
- Human Genome Sequencing Center, Department of Human and Molecular Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
| | - Amanda Dolan
- Department of Biology, University of Rochester, Rochester, NY, 14627, USA
- Present address: School of Life Sciences, Rochester Institute of Technology, Rochester, NY, 14623, USA
| | - Shannon Dugan
- Human Genome Sequencing Center, Department of Human and Molecular Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
| | - Cassandra G Extavour
- Department of Organismic and Evolutionary Biology, Harvard University, 26 Oxford Street, Cambridge, MA, 02138, USA
- Department of Molecular and Cellular Biology, Harvard University, 26 Oxford Street, Cambridge, MA, 02138, USA
| | - Gérard Febvay
- Univ Lyon, INSA-Lyon, INRA, BF2I, UMR0203, F-69621, Villeurbanne, France
| | - Markus Friedrich
- Department of Biological Sciences, Wayne State University, Detroit, MI, 48202, USA
| | - Neta Ginzburg
- Department of Ecology, Evolution and Behavior, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, 91904, Jerusalem, Israel
| | - Yi Han
- Human Genome Sequencing Center, Department of Human and Molecular Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
| | - Peter Heger
- Institute for Genetics, University of Cologne, Zülpicher Straße 47a, 50674, Cologne, Germany
| | - Christopher J Holmes
- Department of Biological Sciences, University of Cincinnati, Cincinnati, OH, 45221, USA
| | - Thorsten Horn
- Institute for Zoology: Developmental Biology, University of Cologne, Zülpicher Str. 47b, 50674, Cologne, Germany
| | - Yi-Min Hsiao
- Department of Entomology/Institute of Biotechnology, College of Bioresources and Agriculture, National Taiwan University, Taipei, Taiwan
- Research Center for Developmental Biology and Regenerative Medicine, National Taiwan University, Taipei, Taiwan
| | - Emily C Jennings
- Department of Biological Sciences, University of Cincinnati, Cincinnati, OH, 45221, USA
| | - J Spencer Johnston
- Department of Entomology, Texas A&M University, College Station, TX, 77843, USA
| | - Tamsin E Jones
- Department of Organismic and Evolutionary Biology, Harvard University, 26 Oxford Street, Cambridge, MA, 02138, USA
| | - Jeffery W Jones
- Department of Biological Sciences, Wayne State University, Detroit, MI, 48202, USA
| | - Abderrahman Khila
- Institut de Génomique Fonctionnelle de Lyon, Université de Lyon, Université Claude Bernard Lyon 1, CNRS UMR 5242, École Normale Supérieure de Lyon, 46 Allée d'Italie, 69364, Lyon, France
| | - Stefan Koelzer
- Institute for Zoology: Developmental Biology, University of Cologne, Zülpicher Str. 47b, 50674, Cologne, Germany
| | | | - Megan Leask
- Department of Biochemistry and Genomics Aotearoa, University of Otago, Dunedin, 9054, New Zealand
| | - Sandra L Lee
- Human Genome Sequencing Center, Department of Human and Molecular Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
| | - Chien-Yueh Lee
- National Agricultural Library, Beltsville, MD, 20705, USA
| | - Mackenzie R Lovegrove
- Department of Biochemistry and Genomics Aotearoa, University of Otago, Dunedin, 9054, New Zealand
| | - Hsiao-Ling Lu
- Department of Entomology/Institute of Biotechnology, College of Bioresources and Agriculture, National Taiwan University, Taipei, Taiwan
- Research Center for Developmental Biology and Regenerative Medicine, National Taiwan University, Taipei, Taiwan
| | - Yong Lu
- Department of Entomology and Program in Molecular & Cell Biology, University of Maryland, College Park, MD, 20742, USA
| | - Patricia J Moore
- Department of Entomology, University of Georgia, 120 Cedar St., Athens, GA, 30602, USA
| | - Monica C Munoz-Torres
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Donna M Muzny
- Human Genome Sequencing Center, Department of Human and Molecular Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
| | - Subba R Palli
- Department of Entomology, College of Agriculture, Food and Environment, University of Kentucky, Lexington, KY, 40546, USA
| | - Nicolas Parisot
- Univ Lyon, INSA-Lyon, INRA, BF2I, UMR0203, F-69621, Villeurbanne, France
| | - Leslie Pick
- Department of Entomology and Program in Molecular & Cell Biology, University of Maryland, College Park, MD, 20742, USA
| | - Megan L Porter
- Department of Biology, University of Hawai'i at Mānoa, Honolulu, HI, 96822, USA
| | - Jiaxin Qu
- Human Genome Sequencing Center, Department of Human and Molecular Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
| | - Peter N Refki
- Institut de Génomique Fonctionnelle de Lyon, Université de Lyon, Université Claude Bernard Lyon 1, CNRS UMR 5242, École Normale Supérieure de Lyon, 46 Allée d'Italie, 69364, Lyon, France
- Present address: Department of Evolutionary Genetics, Max-Planck-Institut für Evolutionsbiologie, August-Thienemann-Straße 2, 24306, Plön, Germany
| | - Rose Richter
- Department of Biology, University of Rochester, Rochester, NY, 14627, USA
- Present address: Earthworks Institute, 185 Caroline Street, Rochester, NY, 14620, USA
| | - Rolando Rivera-Pomar
- Centro de Bioinvestigaciones, Universidad Nacional del Noroeste de Buenos Aires, Pergamino, Argentina
| | - Andrew J Rosendale
- Department of Biological Sciences, University of Cincinnati, Cincinnati, OH, 45221, USA
| | - Siegfried Roth
- Institute for Zoology: Developmental Biology, University of Cologne, Zülpicher Str. 47b, 50674, Cologne, Germany
| | - Lena Sachs
- Institute for Zoology: Developmental Biology, University of Cologne, Zülpicher Str. 47b, 50674, Cologne, Germany
| | - M Emília Santos
- Institut de Génomique Fonctionnelle de Lyon, Université de Lyon, Université Claude Bernard Lyon 1, CNRS UMR 5242, École Normale Supérieure de Lyon, 46 Allée d'Italie, 69364, Lyon, France
| | - Jan Seibert
- Institute for Zoology: Developmental Biology, University of Cologne, Zülpicher Str. 47b, 50674, Cologne, Germany
| | - Essia Sghaier
- Institut de Génomique Fonctionnelle de Lyon, Université de Lyon, Université Claude Bernard Lyon 1, CNRS UMR 5242, École Normale Supérieure de Lyon, 46 Allée d'Italie, 69364, Lyon, France
| | - Jayendra N Shukla
- Department of Entomology, College of Agriculture, Food and Environment, University of Kentucky, Lexington, KY, 40546, USA
- Present address: Department of Biotechnology, Central University of Rajasthan (CURAJ), NH-8, Bandarsindri, Ajmer, 305801, India
| | - Richard J Stancliffe
- Argelander-Institut für Astronomie, Universität Bonn, Auf dem Hügel 71, 53121, Bonn, Germany
- Present address: E. A. Milne Centre for Astrophysics, Department of Physics and Mathematics, University of Hull, Hull, HU6 7RX, UK
| | - Olivia Tidswell
- Department of Biochemistry and Genomics Aotearoa, University of Otago, Dunedin, 9054, New Zealand
- Present address: Department of Zoology, University of Cambridge, Cambridge, CB2 3DT, UK
| | - Lucila Traverso
- Centro Regional de Estudios Genómicos, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, La Plata, Argentina
| | - Maurijn van der Zee
- Institute of Biology, Leiden University, Sylviusweg 72, 2333 BE, Leiden, Netherlands
| | - Séverine Viala
- Institut de Génomique Fonctionnelle de Lyon, Université de Lyon, Université Claude Bernard Lyon 1, CNRS UMR 5242, École Normale Supérieure de Lyon, 46 Allée d'Italie, 69364, Lyon, France
| | - Kim C Worley
- Human Genome Sequencing Center, Department of Human and Molecular Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
| | - Evgeny M Zdobnov
- Department of Genetic Medicine and Development and Swiss Institute of Bioinformatics, University of Geneva, 1211, Geneva, Switzerland
| | - Richard A Gibbs
- Human Genome Sequencing Center, Department of Human and Molecular Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
| | - Stephen Richards
- Human Genome Sequencing Center, Department of Human and Molecular Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
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Hjelmen CE, Garrett MA, Holmes VR, Mynes M, Piron E, Johnston JS. Genome Size Evolution within and between the Sexes. J Hered 2019; 110:219-228. [PMID: 30476187 DOI: 10.1093/jhered/esy063] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Accepted: 11/21/2018] [Indexed: 02/02/2023] Open
Abstract
Genome sizes are known to vary between closely related species, but the patterns behind this variation have yet to be fully understood. Although this variation has been evaluated between species and within sexes, unknown is the extent to which this variation is driven by differentiation in sex chromosomes. To address this longstanding question, we examine the mode and tempo of genome size evolution for a total of 87 species of Drosophilidae, estimating and updating male genome size values for 44 of these species. We compare the evolution of genome size within each sex to the evolution of the differences between the sexes. Utilizing comparative phylogenetic methods, we find that male and female genome size evolution is largely a neutral process, reflective of phylogenetic relatedness between species, which supports the newly proposed accordion model for genome size change. When similarly analyzed, the difference between the sexes due to heteromorphic sex chromosomes is a dynamic process; the male-female genome size difference increases with time with or without known neo-Y events or complete loss of the Y. Observed instances of rapid change match theoretical expectations and known neo-Y and Y loss events in individual species.
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Affiliation(s)
- Carl E Hjelmen
- Department of Entomology, Texas A&M University, College Station, TX
| | - Margaret A Garrett
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX
| | - V Renee Holmes
- Department of Entomology, Texas A&M University, College Station, TX
| | - Melissa Mynes
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX
| | - Elizabeth Piron
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX
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31
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Johnston JS, Bernardini A, Hjelmen CE. Genome Size Estimation and Quantitative Cytogenetics in Insects. Methods Mol Biol 2019; 1858:15-26. [PMID: 30414107 DOI: 10.1007/978-1-4939-8775-7_2] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
With care, it is possible using flow cytometry to create a precise and accurate estimate of the genome size of an insect that is useful for genomics, genetics, molecular/cell biology, or systematics. Genome size estimation is a useful first step in a complete genome sequencing project. The number of sequencing reads required to produce a given level of coverage depends directly upon the 1C amount of DNA per cell, while an even more critical need is an accurate 1C genome size estimate to compare against the final assembly. Here we present a detailed protocol to estimate genome size using flow cytometry. Published genome size estimates should be submitted to genomesize.com so that they are available to all.
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Affiliation(s)
- J Spencer Johnston
- Department of Entomology, Texas A&M University, College Station, TX, USA
| | - Angelina Bernardini
- Interdisciplinary Program in Genetics, Texas A&M University, College Station, TX, USA
| | - Carl E Hjelmen
- Department of Entomology, Texas A&M University, College Station, TX, USA.
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32
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Baldwin-Brown JG, Weeks SC, Long AD. A New Standard for Crustacean Genomes: The Highly Contiguous, Annotated Genome Assembly of the Clam Shrimp Eulimnadia texana Reveals HOX Gene Order and Identifies the Sex Chromosome. Genome Biol Evol 2018; 10:143-156. [PMID: 29294012 PMCID: PMC5765565 DOI: 10.1093/gbe/evx280] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/23/2017] [Indexed: 02/06/2023] Open
Abstract
Vernal pool clam shrimp (Eulimnadia texana) are a promising model system due to their ease of lab culture, short generation time, modest sized genome, a somewhat rare stable androdioecious sex determination system, and a requirement to reproduce via desiccated diapaused eggs. We generated a highly contiguous genome assembly using 46× of PacBio long read data and 216× of Illumina short reads, and annotated using Illumina RNAseq obtained from adult males or hermaphrodites. Of the 120 Mb genome 85% is contained in the largest eight contigs, the smallest of which is 4.6 Mb. The assembly contains 98% of transcripts predicted via RNAseq. This assembly is qualitatively different from scaffolded Illumina assemblies: It is produced from long reads that contain sequence data along their entire length, and is thus gap free. The contiguity of the assembly allows us to order the HOX genes within the genome, identifying two loci that contain HOX gene orthologs, and which approximately maintain the order observed in other arthropods. We identified a partial duplication of the Antennapedia complex adjacent to the few genes homologous to the Bithorax locus. Because the sex chromosome of an androdioecious species is of special interest, we used existing allozyme and microsatellite markers to identify the E. texana sex chromosome, and find that it comprises nearly half of the genome of this species. Linkage patterns indicate that recombination is extremely rare and perhaps absent in hermaphrodites, and as a result the location of the sex determining locus will be difficult to refine using recombination mapping.
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Affiliation(s)
| | | | - Anthony D Long
- Department of Ecology and Evolutionary Biology, University of California Irvine
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33
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The Sleep Inbred Panel, a Collection of Inbred Drosophila melanogaster with Extreme Long and Short Sleep Duration. G3-GENES GENOMES GENETICS 2018; 8:2865-2873. [PMID: 29991508 PMCID: PMC6118319 DOI: 10.1534/g3.118.200503] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Understanding how genomic variation causes differences in observable phenotypes remains a major challenge in biology. It is difficult to trace the sequence of events originating from genomic variants to changes in transcriptional responses or protein modifications. Ideally, one would conduct experiments with individuals that are at either extreme of the trait of interest, but such resources are often not available. Further, advances in genome editing will enable testing of candidate polymorphisms individually and in combination. Here we have created a resource for the study of sleep with 39 inbred lines of Drosophila-the Sleep Inbred Panel (SIP). SIP lines have stable long- and short-sleeping phenotypes developed from naturally occurring polymorphisms. These lines are fully sequenced, enabling more accurate targeting for genome editing and transgenic constructs. This panel facilitates the study of intermediate transcriptional and proteomic correlates of sleep, and supports genome editing studies to verify polymorphisms associated with sleep duration.
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34
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Wu KJ, Kumar S, Serrano Negron YL, Harbison ST. Genotype Influences Day-to-Day Variability in Sleep in Drosophila melanogaster. Sleep 2018; 41:zsx205. [PMID: 29228366 PMCID: PMC6018780 DOI: 10.1093/sleep/zsx205] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Accepted: 10/27/2017] [Indexed: 12/22/2022] Open
Abstract
Patterns of sleep often vary among individuals. But sleep and activity may also vary within an individual, fluctuating in pattern across time. One possibility is that these daily fluctuations in sleep are caused by the underlying genotype of the individual. However, differences attributable to genetic causes are difficult to distinguish from environmental factors in outbred populations such as humans. We therefore employed Drosophila as a model of intra-individual variability in sleep using previously collected sleep and activity data from the Drosophila Genetic Reference Panel, a collection of wild-derived inbred lines. Individual flies had significant daily fluctuations in their sleep patterns, and these fluctuations were heritable. Using the standard deviation of sleep parameters as a metric, we conducted a genome-wide association study. We found 663 polymorphisms in 104 genes associated with daily fluctuations in sleep. We confirmed the effects of 12 candidate genes on the standard deviation of sleep parameters. Our results suggest that daily fluctuations in sleep patterns are due in part to gene activity.
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Affiliation(s)
- Katherine J Wu
- Laboratory of Systems Genetics, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD
| | - Shailesh Kumar
- Laboratory of Systems Genetics, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD
| | - Yazmin L Serrano Negron
- Laboratory of Systems Genetics, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD
| | - Susan T Harbison
- Laboratory of Systems Genetics, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD
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35
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Song Y, Marmion RA, Park JO, Biswas D, Rabinowitz JD, Shvartsman SY. Dynamic Control of dNTP Synthesis in Early Embryos. Dev Cell 2017; 42:301-308.e3. [PMID: 28735680 DOI: 10.1016/j.devcel.2017.06.013] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Revised: 05/13/2017] [Accepted: 06/16/2017] [Indexed: 02/06/2023]
Abstract
Exponential increase of cell numbers in early embryos requires large amounts of DNA precursors (deoxyribonucleoside triphosphates (dNTPs)). Little is understood about how embryos satisfy this demand. We examined dNTP metabolism in the early Drosophila embryo, in which gastrulation is preceded by 13 sequential nuclear cleavages within only 2 hr of fertilization. Surprisingly, despite the breakneck speed at which Drosophila embryos synthesize DNA, maternally deposited dNTPs can generate less than half of the genomes needed to reach gastrulation. The rest of the dNTPs are synthesized "on the go." The rate-limiting enzyme of dNTP synthesis, ribonucleotide reductase, is inhibited by endogenous levels of deoxyATP (dATP) present at fertilization and is activated as dATP is depleted via DNA polymerization. This feedback inhibition renders the concentration of dNTPs at gastrulation robust, with respect to large variations in maternal supplies, and is essential for normal progression of embryogenesis.
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Affiliation(s)
- Yonghyun Song
- The Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA
| | - Robert A Marmion
- The Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA
| | - Junyoung O Park
- The Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA; Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ 08544, USA
| | - Debopriyo Biswas
- The Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA
| | - Joshua D Rabinowitz
- The Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA; Department of Chemistry, Princeton University, Princeton, NJ 08544, USA
| | - Stanislav Y Shvartsman
- The Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA; Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ 08544, USA.
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Lower SS, Johnston JS, Stanger-Hall KF, Hjelmen CE, Hanrahan SJ, Korunes K, Hall D. Genome Size in North American Fireflies: Substantial Variation Likely Driven by Neutral Processes. Genome Biol Evol 2017; 9:1499-1512. [PMID: 28541478 PMCID: PMC5499882 DOI: 10.1093/gbe/evx097] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/24/2017] [Indexed: 12/11/2022] Open
Abstract
Eukaryotic genomes show tremendous size variation across taxa. Proximate explanations for genome size variation include differences in ploidy and amounts of noncoding DNA, especially repetitive DNA. Ultimate explanations include selection on physiological correlates of genome size such as cell size, which in turn influence body size, resulting in the often-observed correlation between body size and genome size. In this study, we examined body size and repetitive DNA elements in relationship to the evolution of genome size in North American representatives of a single beetle family, the Lampyridae (fireflies). The 23 species considered represent an excellent study system because of the greater than 5-fold range of genome sizes, documented here using flow cytometry, and the 3-fold range in body size, measured using pronotum width. We also identified common genomic repetitive elements using low-coverage sequencing. We found a positive relationship between genome size and repetitive DNA, particularly retrotransposons. Both genome size and these elements were evolving as expected given phylogenetic relatedness. We also tested whether genome size varied with body size and found no relationship. Together, our results suggest that genome size is evolving neutrally in fireflies.
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Affiliation(s)
| | | | | | | | | | | | - David Hall
- Department of Genetics, University of Georgia
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37
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Li L, Wunderlich Z. An Enhancer's Length and Composition Are Shaped by Its Regulatory Task. Front Genet 2017; 8:63. [PMID: 28588608 PMCID: PMC5440464 DOI: 10.3389/fgene.2017.00063] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Accepted: 05/08/2017] [Indexed: 12/02/2022] Open
Abstract
Enhancers drive the gene expression patterns required for virtually every process in metazoans. We propose that enhancer length and transcription factor (TF) binding site composition—the number and identity of TF binding sites—reflect the complexity of the enhancer's regulatory task. In development, we define regulatory task complexity as the number of fates specified in a set of cells at once. We hypothesize that enhancers with more complex regulatory tasks will be longer, with more, but less specific, TF binding sites. Larger numbers of binding sites can be arranged in more ways, allowing enhancers to drive many distinct expression patterns, and therefore cell fates, using a finite number of TF inputs. We compare ~100 enhancers patterning the more complex anterior-posterior (AP) axis and the simpler dorsal-ventral (DV) axis in Drosophila and find that the AP enhancers are longer with more, but less specific binding sites than the (DV) enhancers. Using a set of ~3,500 enhancers, we find enhancer length and TF binding site number again increase with increasing regulatory task complexity. Therefore, to be broadly applicable, computational tools to study enhancers must account for differences in regulatory task.
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Affiliation(s)
- Lily Li
- Department of Developmental and Cell Biology, University of California, IrvineIrvine, CA, United States
| | - Zeba Wunderlich
- Department of Developmental and Cell Biology, University of California, IrvineIrvine, CA, United States
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38
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Hughes KA, Leips J. Pleiotropy, constraint, and modularity in the evolution of life histories: insights from genomic analyses. Ann N Y Acad Sci 2017; 1389:76-91. [PMID: 27936291 PMCID: PMC5318229 DOI: 10.1111/nyas.13256] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Revised: 08/10/2016] [Accepted: 08/22/2016] [Indexed: 12/20/2022]
Abstract
Multicellular organisms display an enormous range of life history (LH) strategies and present an evolutionary conundrum; despite strong natural selection, LH traits are characterized by high levels of genetic variation. To understand the evolution of life histories and maintenance of this variation, the specific phenotypic effects of segregating alleles and the genetic networks in which they act need to be elucidated. In particular, the extent to which LH evolution is constrained by the pleiotropy of alleles contributing to LH variation is generally unknown. Here, we review recent empirical results that shed light on this question, with an emphasis on studies employing genomic analyses. While genome-scale analyses are increasingly practical and affordable, they face limitations of genetic resolution and statistical power. We describe new research approaches that we believe can produce new insights and evaluate their promise and applicability to different kinds of organisms. Two approaches seem particularly promising: experiments that manipulate selection in multiple dimensions and measure phenotypic and genomic response and analytical approaches that take into account genome-wide associations between markers and phenotypes, rather than applying a traditional marker-by-marker approach.
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Affiliation(s)
- Kimberly A. Hughes
- Department of Biological Science, Florida State University, Tallahassee, Florida
| | - Jeff Leips
- Department of Biological Sciences, University of Maryland, Baltimore County, Baltimore, Maryland
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39
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Wang L, Tang N, Gao X, Chang Z, Zhang L, Zhou G, Guo D, Zeng Z, Li W, Akinyemi IA, Yang H, Wu Q. Genome sequence of a rice pest, the white-backed planthopper (Sogatella furcifera). Gigascience 2017; 6:1-9. [PMID: 28369349 PMCID: PMC5437944 DOI: 10.1093/gigascience/giw004] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2016] [Revised: 10/10/2016] [Accepted: 11/15/2016] [Indexed: 11/16/2022] Open
Abstract
Background Sogatella furcifera is an important phloem sap-sucking and plant virus-transmitting migratory insect of rice. Because of its high reproductive potential, dispersal capability and transmission of plant viral diseases, S. furcifera causes considerable damage to rice grain production and has great economical and agricultural impacts. Comprehensive studies into ecological aspects and virus-host interactions of S. furcifera have been limited because of the lack of a well-assembled genome sequence. Findings A total of 241.3 Gb of raw reads from the whole genome of S. furcifera were generated by Illumina sequencing using different combinations of mate-pair and paired-end libraries from 17 insert libraries ranging between 180 bp and 40 kbp. The final genome assembly (0.72 Gb), with average N50 contig size of 70.7 kb and scaffold N50 of 1.18 Mb, covers 98.6 % of the estimated genome size of S. furcifera . Genome annotation, assisted by eight different developmental stages (embryos, 1 st -5 th instar nymphs, 5-day-old adults and 10-day-old adults), generated 21 254 protein-coding genes, which captured 99.59 % (247/248) of core CEGMA genes and 91.7 % (2453/2675) of BUSCO genes. Conclusions We report the first assembled and annotated whole genome sequence and transcriptome of S. furcifera . The assembled draft genome of S. furcifera will be a valuable resource for ecological and virus-host interaction studies of this pest.
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Affiliation(s)
- Lin Wang
- School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, China
| | - Nan Tang
- School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, China
| | - Xinlei Gao
- School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, China
| | - Zhaoxia Chang
- School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, China
| | - Liqin Zhang
- School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, China
| | - Guohui Zhou
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, College of Agriculture, South China Agricultural University, Guangzhou, Guangdong 510642, China
| | - Dongyang Guo
- School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, China
| | - Zhen Zeng
- School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, China
| | - Wenjie Li
- School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, China
| | - Ibukun A. Akinyemi
- School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, China
| | - Huanming Yang
- BGI–Shenzhen, Beishan Industrial Zone, Yantian District, Shenzhen 518083, China
| | - Qingfa Wu
- School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, China
- Chinese Academy of Sciences Key Laboratory of Innate Immunity and Chronic Disease, University of Science and Technology of China, Hefei, Anhui 230027, China
- Hefei National Laboratory for Physical Sciences at the Microscale, Bio-X Interdisciplinary Sciences, 443 Huang-Shan Road, Hefei, Anhui 230027, China
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Horváth B, Kalinka AT. Effects of larval crowding on quantitative variation for development time and viability in Drosophila melanogaster. Ecol Evol 2016; 6:8460-8473. [PMID: 28031798 PMCID: PMC5167028 DOI: 10.1002/ece3.2552] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Revised: 09/15/2016] [Accepted: 09/22/2016] [Indexed: 11/06/2022] Open
Abstract
Competition between individuals belonging to the same species is a universal feature of natural populations and is the process underpinning organismal adaptation. Despite its importance, still comparatively little is known about the genetic variation responsible for competitive traits. Here, we measured the phenotypic variation and quantitative genetics parameters for two fitness-related traits-egg-to-adult viability and development time-across a panel of Drosophila strains under varying larval densities. Both traits exhibited substantial genetic variation at all larval densities, as well as significant genotype-by-environment interactions (GEIs). GEI was attributable to changes in the rank order of reaction norms for both traits, and additionally to differences in the between-line variance for development time. The coefficient of genetic variation increased under stress conditions for development time, while it was higher at both high and low densities for viability. While development time also correlated negatively with fitness at high larval densities-meaning that fast developers have high fitness-there was no correlation with fitness at low density. This result suggests that GEI may be a common feature of fitness-related genetic variation and, further, that trait values under noncompetitive conditions could be poor indicators of individual fitness. The latter point could have significant implications for animal and plant breeding programs, as well as for conservation genetics.
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Affiliation(s)
- Barbara Horváth
- Institut für Populationsgenetik Veterinärmedizinische Universität Wien A-1210 Vienna Austria; Vienna Graduate School of Population Genetics, Veterinärmedizinische Universität Wien A-1210, Vienna Austria
| | - Alex T Kalinka
- Institut für Populationsgenetik Veterinärmedizinische Universität Wien A-1210 Vienna Austria
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41
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Horváth B, Betancourt AJ, Kalinka AT. A novel method for quantifying the rate of embryogenesis uncovers considerable genetic variation for the duration of embryonic development in Drosophila melanogaster. BMC Evol Biol 2016; 16:200. [PMID: 27717305 PMCID: PMC5054588 DOI: 10.1186/s12862-016-0776-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Accepted: 09/29/2016] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND Embryogenesis is a highly conserved, canalized process, and variation in the duration of embryogenesis (DOE), i.e., time from egg lay to hatching, has a potentially profound effect on the outcome of within- and between-species competition. There is both intra- and inter-specific variation in this trait, which may provide important fuel for evolutionary processes, particularly adaptation. However, while genetic variation underlying simpler morphological traits, or with large phenotypic effects is well described in the literature, less is known about the underlying genetics of traits, such as DOE, partly due to a lack of tools with which to study them. RESULTS Here, we establish a novel microscope-based assay to survey genetic variation for the duration of embryogenesis (DOE). First, to establish the potential importance of DOE in competitive fitness, we performed a set of experiments where we experimentally manipulated the time until hatching, and show that short hatching times result in priority effect in the form of improved larval competitive ability. We then use our assay to measure DOE for 43 strains from the Drosophila Genetic Reference Panel (DGRP). Our assay greatly simplifies the measurement of DOE, making it possible to precisely quantify this trait for 59,295 individual embryos (mean ± S.D. of 1103 ± 293 per DGRP strain, and 1002 ± 203 per control). We find extensive genetic variation in DOE, with a 15 % difference in rate between the slowest and fastest strains measured, and 89 % of phenotypic variation due to DGRP strain. Using sequence information from the DGRP, we perform a genome-wide association study, which suggests that some well-known developmental genes affect the speed of embryonic development. CONCLUSIONS We showed that the duration of embryogenesis (DOE) can be efficiently and precisely measured in Drosophila, and that the DGRP strains show remarkable variation in DOE. A genome-wide analysis suggests that some well-known developmental genes are potentially associated with DOE. Further functional assays, or transcriptomic analysis of embryos from the DGRP, can validate the role of our candidates in early developmental processes.
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Affiliation(s)
- Barbara Horváth
- Institut für Populationsgenetik, Veterinärmedizinische Universität Wien, Veterinärplatz 1, A-1210, Vienna, Austria. .,Vienna Graduate School of Population Genetics, Veterinärmedizinische Universität Wien, Veterinärplatz 1, Vienna, A-1210, Austria.
| | - Andrea J Betancourt
- Institut für Populationsgenetik, Veterinärmedizinische Universität Wien, Veterinärplatz 1, A-1210, Vienna, Austria
| | - Alex T Kalinka
- Institut für Populationsgenetik, Veterinärmedizinische Universität Wien, Veterinärplatz 1, A-1210, Vienna, Austria
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42
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Schubert I, Vu GTH. Genome Stability and Evolution: Attempting a Holistic View. TRENDS IN PLANT SCIENCE 2016; 21:749-757. [PMID: 27427334 DOI: 10.1016/j.tplants.2016.06.003] [Citation(s) in RCA: 94] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Revised: 06/06/2016] [Accepted: 06/15/2016] [Indexed: 05/02/2023]
Abstract
The reason why the DNA content, chromosome number and shape, and gene content of eukaryotic genomes vary independently remains a matter of speculation. The same is true for the questions of whether there is a general tendency for increase or decrease of genome size and chromosome number and whether genome size and/or chromosome number have an adaptive value and, if so, what this value is. Here we assume that three strategies of genome evolution (shrinkage, expansion, and equilibrium) have developed to find the optimal balance between genomic stability and plasticity. We suggest various modes of DNA double-strand break (DSB) repair in combination with whole-genome duplication (WGD) and dysploid chromosome number alteration to explain the different strategies of genome size and karyotype evolution.
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Affiliation(s)
- Ingo Schubert
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), D 06466 Gatersleben, Stadt Seeland, Germany.
| | - Giang T H Vu
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), D 06466 Gatersleben, Stadt Seeland, Germany
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43
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Arnqvist G, Sayadi A, Immonen E, Hotzy C, Rankin D, Tuda M, Hjelmen CE, Johnston JS. Genome size correlates with reproductive fitness in seed beetles. Proc Biol Sci 2016; 282:rspb.2015.1421. [PMID: 26354938 DOI: 10.1098/rspb.2015.1421] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The ultimate cause of genome size (GS) evolution in eukaryotes remains a major and unresolved puzzle in evolutionary biology. Large-scale comparative studies have failed to find consistent correlations between GS and organismal properties, resulting in the 'C-value paradox'. Current hypotheses for the evolution of GS are based either on the balance between mutational events and drift or on natural selection acting upon standing genetic variation in GS. It is, however, currently very difficult to evaluate the role of selection because within-species studies that relate variation in life-history traits to variation in GS are very rare. Here, we report phylogenetic comparative analyses of GS evolution in seed beetles at two distinct taxonomic scales, which combines replicated estimation of GS with experimental assays of life-history traits and reproductive fitness. GS showed rapid and bidirectional evolution across species, but did not show correlated evolution with any of several indices of the relative importance of genetic drift. Within a single species, GS varied by 4-5% across populations and showed positive correlated evolution with independent estimates of male and female reproductive fitness. Collectively, the phylogenetic pattern of GS diversification across and within species in conjunction with the pattern of correlated evolution between GS and fitness provide novel support for the tenet that natural selection plays a key role in shaping GS evolution.
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Affiliation(s)
- Göran Arnqvist
- Animal Ecology, Department of Ecology and Genetics, Uppsala University, Norbyvägen 18D, Uppsala 75236, Sweden
| | - Ahmed Sayadi
- Animal Ecology, Department of Ecology and Genetics, Uppsala University, Norbyvägen 18D, Uppsala 75236, Sweden
| | - Elina Immonen
- Animal Ecology, Department of Ecology and Genetics, Uppsala University, Norbyvägen 18D, Uppsala 75236, Sweden
| | - Cosima Hotzy
- Evolutionary Biology, Department of Ecology and Genetics, Uppsala University, Norbyvägen 18D, Uppsala 75236, Sweden
| | - Daniel Rankin
- Institute of Evolutionary Biology and Environmental Studies, University of Zürich, Zürich, Switzerland
| | - Midori Tuda
- Laboratory of Insect Natural Enemies, Department of Bioresource Sciences, Kyushu University, Fukuoka 812-8581, Japan Institute of Biological Control, Faculty of Agriculture, Kyushu University, Fukuoka 812-8581, Japan
| | - Carl E Hjelmen
- Department of Entomology, Texas A&M University, College Station, TX 77843 2475, USA
| | - J Spencer Johnston
- Department of Entomology, Texas A&M University, College Station, TX 77843 2475, USA
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44
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Jeffery NW, Hultgren K, Chak STC, Gregory TR, Rubenstein DR. Patterns of genome size variation in snapping shrimp. Genome 2016; 59:393-402. [DOI: 10.1139/gen-2015-0206] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Although crustaceans vary extensively in genome size, little is known about how genome size may affect the ecology and evolution of species in this diverse group, in part due to the lack of large genome size datasets. Here we investigate interspecific, intraspecific, and intracolony variation in genome size in 39 species of Synalpheus shrimps, representing one of the largest genome size datasets for a single genus within crustaceans. We find that genome size ranges approximately 4-fold across Synalpheus with little phylogenetic signal, and is not related to body size. In a subset of these species, genome size is related to chromosome size, but not to chromosome number, suggesting that despite large genomes, these species are not polyploid. Interestingly, there appears to be 35% intraspecific genome size variation in Synalpheus idios among geographic regions, and up to 30% variation in Synalpheus duffyi genome size within the same colony.
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Affiliation(s)
- Nicholas W. Jeffery
- Department of Integrative Biology, University of Guelph, Guelph, ON N1G 2W1, Canada
| | - Kristin Hultgren
- Department of Biology, Seattle University, Seattle, WA 98122, USA
| | - Solomon Tin Chi Chak
- Virginia Institute of Marine Science, The College of William and Mary, Gloucester Point, VA 23062, USA
| | - T. Ryan Gregory
- Department of Integrative Biology, University of Guelph, Guelph, ON N1G 2W1, Canada
| | - Dustin R. Rubenstein
- Department of Ecology, Evolution and Environmental Biology, Columbia University, New York, NY 10027, USA
- Center for Integrative Animal Behavior, Columbia University, New York, NY 10027, USA
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45
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Mossman JA, Biancani LM, Zhu CT, Rand DM. Mitonuclear Epistasis for Development Time and Its Modification by Diet in Drosophila. Genetics 2016; 203:463-84. [PMID: 26966258 PMCID: PMC4858792 DOI: 10.1534/genetics.116.187286] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2016] [Accepted: 03/04/2016] [Indexed: 11/18/2022] Open
Abstract
Mitochondrial (mtDNA) and nuclear genes have to operate in a coordinated manner to maintain organismal function, and the regulation of this homeostasis presents a substantial source of potential epistatic (G × G) interactions. How these interactions shape the fitness landscape is poorly understood. Here we developed a novel mitonuclear epistasis model, using selected strains of the Drosophila Genetic Reference Panel (DGRP) and mitochondrial genomes from within Drosophila melanogaster and D. simulans to test the hypothesis that mtDNA × nDNA interactions influence fitness. In total we built 72 genotypes (12 nuclear backgrounds × 6 mtDNA haplotypes, with 3 from each species) to dissect the relationship between genotype and phenotype. Each genotype was assayed on four food environments. We found considerable variation in several phenotypes, including development time and egg-to-adult viability, and this variation was partitioned into genetic (G), environmental (E), and higher-order (G × G, G × E, and G × G × E) components. Food type had a significant impact on development time and also modified mitonuclear epistases, evidencing a broad spectrum of G × G × E across these genotypes. Nuclear background effects were substantial, followed by mtDNA effects and their G × G interaction. The species of mtDNA haplotype had negligible effects on phenotypic variation and there was no evidence that mtDNA variation has different effects on male and female fitness traits. Our results demonstrate that mitonuclear epistases are context dependent, suggesting the selective pressure acting on mitonuclear genotypes may vary with food environment in a genotype-specific manner.
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Affiliation(s)
- Jim A Mossman
- Department of Ecology and Evolutionary Biology, Brown University, Providence, Rhode Island 02912
| | - Leann M Biancani
- Department of Ecology and Evolutionary Biology, Brown University, Providence, Rhode Island 02912
| | - Chen-Tseh Zhu
- Department of Ecology and Evolutionary Biology, Brown University, Providence, Rhode Island 02912
| | - David M Rand
- Department of Ecology and Evolutionary Biology, Brown University, Providence, Rhode Island 02912
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46
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Kwon SY, Grisan V, Jang B, Herbert J, Badenhorst P. Genome-Wide Mapping Targets of the Metazoan Chromatin Remodeling Factor NURF Reveals Nucleosome Remodeling at Enhancers, Core Promoters and Gene Insulators. PLoS Genet 2016; 12:e1005969. [PMID: 27046080 PMCID: PMC4821604 DOI: 10.1371/journal.pgen.1005969] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Accepted: 03/10/2016] [Indexed: 12/20/2022] Open
Abstract
NURF is a conserved higher eukaryotic ISWI-containing chromatin remodeling complex that catalyzes ATP-dependent nucleosome sliding. By sliding nucleosomes, NURF is able to alter chromatin dynamics to control transcription and genome organization. Previous biochemical and genetic analysis of the specificity-subunit of Drosophila NURF (Nurf301/Enhancer of Bithorax (E(bx)) has defined NURF as a critical regulator of homeotic, heat-shock and steroid-responsive gene transcription. It has been speculated that NURF controls pathway specific transcription by co-operating with sequence-specific transcription factors to remodel chromatin at dedicated enhancers. However, conclusive in vivo demonstration of this is lacking and precise regulatory elements targeted by NURF are poorly defined. To address this, we have generated a comprehensive map of in vivo NURF activity, using MNase-sequencing to determine at base pair resolution NURF target nucleosomes, and ChIP-sequencing to define sites of NURF recruitment. Our data show that, besides anticipated roles at enhancers, NURF interacts physically and functionally with the TRF2/DREF basal transcription factor to organize nucleosomes downstream of active promoters. Moreover, we detect NURF remodeling and recruitment at distal insulator sites, where NURF functionally interacts with and co-localizes with DREF and insulator proteins including CP190 to establish nucleosome-depleted domains. This insulator function of NURF is most apparent at subclasses of insulators that mark the boundaries of chromatin domains, where multiple insulator proteins co-associate. By visualizing the complete repertoire of in vivo NURF chromatin targets, our data provide new insights into how chromatin remodeling can control genome organization and regulatory interactions.
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Affiliation(s)
- So Yeon Kwon
- Institute of Biomedical Research, University of Birmingham, Edgbaston, United Kingdom
| | - Valentina Grisan
- Institute of Biomedical Research, University of Birmingham, Edgbaston, United Kingdom
| | - Boyun Jang
- Institute of Biomedical Research, University of Birmingham, Edgbaston, United Kingdom
| | - John Herbert
- Institute of Biomedical Research, University of Birmingham, Edgbaston, United Kingdom
| | - Paul Badenhorst
- Institute of Biomedical Research, University of Birmingham, Edgbaston, United Kingdom
- * E-mail:
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47
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Svetec N, Cridland JM, Zhao L, Begun DJ. The Adaptive Significance of Natural Genetic Variation in the DNA Damage Response of Drosophila melanogaster. PLoS Genet 2016; 12:e1005869. [PMID: 26950216 PMCID: PMC4780809 DOI: 10.1371/journal.pgen.1005869] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2015] [Accepted: 01/22/2016] [Indexed: 01/15/2023] Open
Abstract
Despite decades of work, our understanding of the distribution of fitness effects of segregating genetic variants in natural populations remains largely incomplete. One form of selection that can maintain genetic variation is spatially varying selection, such as that leading to latitudinal clines. While the introduction of population genomic approaches to understanding spatially varying selection has generated much excitement, little successful effort has been devoted to moving beyond genome scans for selection to experimental analysis of the relevant biology and the development of experimentally motivated hypotheses regarding the agents of selection; it remains an interesting question as to whether the vast majority of population genomic work will lead to satisfying biological insights. Here, motivated by population genomic results, we investigate how spatially varying selection in the genetic model system, Drosophila melanogaster, has led to genetic differences between populations in several components of the DNA damage response. UVB incidence, which is negatively correlated with latitude, is an important agent of DNA damage. We show that sensitivity of early embryos to UVB exposure is strongly correlated with latitude such that low latitude populations show much lower sensitivity to UVB. We then show that lines with lower embryo UVB sensitivity also exhibit increased capacity for repair of damaged sperm DNA by the oocyte. A comparison of the early embryo transcriptome in high and low latitude embryos provides evidence that one mechanism of adaptive DNA repair differences between populations is the greater abundance of DNA repair transcripts in the eggs of low latitude females. Finally, we use population genomic comparisons of high and low latitude samples to reveal evidence that multiple components of the DNA damage response and both coding and non-coding variation likely contribute to adaptive differences in DNA repair between populations.
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Affiliation(s)
- Nicolas Svetec
- Department of Evolution and Ecology, University of California, Davis, Davis, California, United States of America
| | - Julie M. Cridland
- Department of Evolution and Ecology, University of California, Davis, Davis, California, United States of America
| | - Li Zhao
- Department of Evolution and Ecology, University of California, Davis, Davis, California, United States of America
| | - David J. Begun
- Department of Evolution and Ecology, University of California, Davis, Davis, California, United States of America
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48
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Romero-Soriano V, Burlet N, Vela D, Fontdevila A, Vieira C, García Guerreiro MP. Drosophila Females Undergo Genome Expansion after Interspecific Hybridization. Genome Biol Evol 2016; 8:556-61. [PMID: 26872773 PMCID: PMC4824032 DOI: 10.1093/gbe/evw024] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Genome size (or C-value) can present a wide range of values among eukaryotes. This variation has been attributed to differences in the amplification and deletion of different noncoding repetitive sequences, particularly transposable elements (TEs). TEs can be activated under different stress conditions such as interspecific hybridization events, as described for several species of animals and plants. These massive transposition episodes can lead to considerable genome expansions that could ultimately be involved in hybrid speciation processes. Here, we describe the effects of hybridization and introgression on genome size of Drosophila hybrids. We measured the genome size of two close Drosophila species, Drosophila buzzatii and Drosophila koepferae, their F1 offspring and the offspring from three generations of backcrossed hybrids; where mobilization of up to 28 different TEs was previously detected. We show that hybrid females indeed present a genome expansion, especially in the first backcross, which could likely be explained by transposition events. Hybrid males, which exhibit more variable C-values among individuals of the same generation, do not present an increased genome size. Thus, we demonstrate that the impact of hybridization on genome size can be detected through flow cytometry and is sex-dependent.
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Affiliation(s)
- Valèria Romero-Soriano
- Departament De Genètica I Microbiologia (Edifici C), Grup De Genòmica, Bioinformàtica I Biologia Evolutiva. Universitat Autònoma De Barcelona, Spain
| | - Nelly Burlet
- Laboratoire De Biométrie Et Biologie Evolutive, UMR5558, Université Lyon 1, Université Lyon, Villeurbanne, France
| | - Doris Vela
- Laboratorio De Genética Evolutiva, Pontificia Universidad Católica Del Ecuador, Quito, Ecuador
| | - Antonio Fontdevila
- Departament De Genètica I Microbiologia (Edifici C), Grup De Genòmica, Bioinformàtica I Biologia Evolutiva. Universitat Autònoma De Barcelona, Spain
| | - Cristina Vieira
- Laboratoire De Biométrie Et Biologie Evolutive, UMR5558, Université Lyon 1, Université Lyon, Villeurbanne, France
| | - María Pilar García Guerreiro
- Departament De Genètica I Microbiologia (Edifici C), Grup De Genòmica, Bioinformàtica I Biologia Evolutiva. Universitat Autònoma De Barcelona, Spain
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Cheng W, Lei J, Fox CW, Johnston JS, Zhu-Salzman K. Comparison of life history and genetic properties of cowpea bruchid strains and their response to hypoxia. JOURNAL OF INSECT PHYSIOLOGY 2015; 75:5-11. [PMID: 25733404 DOI: 10.1016/j.jinsphys.2015.02.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2014] [Revised: 02/22/2015] [Accepted: 02/24/2015] [Indexed: 06/04/2023]
Abstract
The cowpea bruchid (Callosobruchus maculatus) is the most important storage pest of grain legumes and comprises geographically distinct strains. Storage under a modified atmosphere with decreased O2 content represents an alternative to chemical fumigants for pest control of stored grains. In this study, we compared reproduction, development and survival, as well as genome size of bruchid strains from South India (SI), Burkina Faso (BF), Niger (CmNnC) and the United States (OH), reared on mung bean (Vigna radiata). Fecundity and egg-to-adult duration varied significantly among these strains. Notably, strain BF had the highest fecundity, and strain SI displayed the fastest development whereas strain OH was the slowest. Differences in adult lifespan among strains were only detected in unmated but not in the mated group. Genome size of SI females was significantly larger than that of OH females, and for all four strains, the female genomes were larger than those of their corresponding males. Furthermore, we studied effects of exposure to 1% O2+99% N2 on strains SI and BF. Mortality caused by hypoxia was influenced by not only developmental stage but also by insect strain. Eggs were most sensitive, particularly at the early stage, whereas the 3rd and 4th instar larvae were most tolerant and could survive up to 15 days of low O2. Strain SI was slightly more resistant than BF in egg and larval stages. Proteolytic activity prior to, during and after hypoxia treatment revealed remarkable metabolic plasticity of cowpea bruchids in response to modified atmosphere.
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Affiliation(s)
- Weining Cheng
- Key Laboratory of Integrated Pest Management on Crops in Northwestern Loess Plateau, Ministry of Agriculture, Northwest A&F University, Yangling, Shaanxi 712100, China; Department of Entomology, Texas A&M University, College Station, TX 77843, USA; Institute for Plant Genomics & Biotechnology, Texas A&M University, College Station, TX 77843, USA.
| | - Jiaxin Lei
- Department of Entomology, Texas A&M University, College Station, TX 77843, USA; Institute for Plant Genomics & Biotechnology, Texas A&M University, College Station, TX 77843, USA
| | - Charles W Fox
- Entomology Department, University of Kentucky, Lexington, KY 40546, USA
| | - J Spencer Johnston
- Department of Entomology, Texas A&M University, College Station, TX 77843, USA
| | - Keyan Zhu-Salzman
- Department of Entomology, Texas A&M University, College Station, TX 77843, USA; Institute for Plant Genomics & Biotechnology, Texas A&M University, College Station, TX 77843, USA.
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50
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Correlated variation and population differentiation in satellite DNA abundance among lines of Drosophila melanogaster. Proc Natl Acad Sci U S A 2014; 111:18793-8. [PMID: 25512552 DOI: 10.1073/pnas.1421951112] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Tandemly repeating satellite DNA elements in heterochromatin occupy a substantial portion of many eukaryotic genomes. Although often characterized as genomic parasites deleterious to the host, they also can be crucial for essential processes such as chromosome segregation. Adding to their interest, satellite DNA elements evolve at high rates; among Drosophila, closely related species often differ drastically in both the types and abundances of satellite repeats. However, due to technical challenges, the evolutionary mechanisms driving this rapid turnover remain unclear. Here we characterize natural variation in simple-sequence repeats of 2-10 bp from inbred Drosophila melanogaster lines derived from multiple populations, using a method we developed called k-Seek that analyzes unassembled Illumina sequence reads. In addition to quantifying all previously described satellite repeats, we identified many novel repeats of low to medium abundance. Many of the repeats show population differentiation, including two that are present in only some populations. Interestingly, the population structure inferred from overall satellite quantities does not recapitulate the expected population relationships based on the demographic history of D. melanogaster. We also find that some satellites of similar sequence composition are correlated across lines, revealing concerted evolution. Moreover, correlated satellites tend to be interspersed with each other, further suggesting that concerted change is partially driven by higher order structure. Surprisingly, we identified negative correlations among some satellites, suggesting antagonistic interactions. Our study demonstrates that current genome assemblies vastly underestimate the complexity, abundance, and variation of highly repetitive satellite DNA and presents approaches to understand their rapid evolutionary divergence.
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