1
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Courret C, Wei X, Larracuente AM. New perspectives on the causes and consequences of male meiotic drive. Curr Opin Genet Dev 2023; 83:102111. [PMID: 37704518 PMCID: PMC10842977 DOI: 10.1016/j.gde.2023.102111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Revised: 08/07/2023] [Accepted: 08/09/2023] [Indexed: 09/15/2023]
Abstract
Gametogenesis is vulnerable to selfish genetic elements that bias their transmission to the next generation by cheating meiosis. These so-called meiotic drivers are widespread in plants, animals, and fungi and can impact genome evolution. Here, we summarize recent progress on the causes and consequences of meiotic drive in males, where selfish elements attack vulnerabilities in spermatogenesis. Advances in genomics provide new insights into the organization and dynamics of driving chromosomes in natural populations. Common themes, including small RNAs, gene duplications, and heterochromatin, emerged from these studies. Interdisciplinary approaches combining evolutionary genomics with molecular and cell biology are beginning to unravel the mysteries of drive and suppression mechanisms. These approaches also provide insights into fundamental processes in spermatogenesis and chromatin regulation.
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Affiliation(s)
- Cécile Courret
- Department of Biology, University of Rochester, Rochester, NY 14627, USA. https://twitter.com/@CecileCourret
| | - Xiaolu Wei
- Department of Biology, University of Rochester, Rochester, NY 14627, USA. https://twitter.com/@xiaolu_wei
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2
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Asad M, Liu D, Chen J, Yang G. Applications of gene drive systems for population suppression of insect pests. BULLETIN OF ENTOMOLOGICAL RESEARCH 2022; 112:724-733. [PMID: 36043456 DOI: 10.1017/s0007485322000268] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Population suppression is an effective way for controlling insect pests and disease vectors, which cause significant damage to crop and spread contagious diseases to plants, animals and humans. Gene drive systems provide innovative opportunities for the insect pests population suppression by driving genes that impart fitness costs on populations of pests or disease vectors. Different gene-drive systems have been developed in insects and applied for their population suppression. Here, different categories of gene drives such as meiotic drive (MD), under-dominance (UD), homing endonuclease-based gene drive (HEGD) and especially the CRISPR/Cas9-based gene drive (CCGD) were reviewed, including the history, types, process and mechanisms. Furthermore, the advantages and limitations of applying different gene-drive systems to suppress the insect population were also summarized. This review provides a foundation for developing a specific gene-drive system for insect population suppression.
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Affiliation(s)
- Muhammad Asad
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Institute of Applied Ecology, Fujian Agriculture and Forestry University, Fuzhou 350002, China
- Joint International Research Laboratory of Ecological Pest Control, Ministry of Education, Fuzhou 350002, China
- Key Laboratory of Integrated Pest Management for Fujian-Taiwan Crops, Ministry of Agriculture, Fuzhou 350002, China
- Key Laboratory of Green Pest Control, Fujian Province University, Fuzhou 350002, China
| | - Dan Liu
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Institute of Applied Ecology, Fujian Agriculture and Forestry University, Fuzhou 350002, China
- Joint International Research Laboratory of Ecological Pest Control, Ministry of Education, Fuzhou 350002, China
- Key Laboratory of Integrated Pest Management for Fujian-Taiwan Crops, Ministry of Agriculture, Fuzhou 350002, China
- Key Laboratory of Green Pest Control, Fujian Province University, Fuzhou 350002, China
| | - Jing Chen
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Institute of Applied Ecology, Fujian Agriculture and Forestry University, Fuzhou 350002, China
- Joint International Research Laboratory of Ecological Pest Control, Ministry of Education, Fuzhou 350002, China
- Key Laboratory of Integrated Pest Management for Fujian-Taiwan Crops, Ministry of Agriculture, Fuzhou 350002, China
- Key Laboratory of Green Pest Control, Fujian Province University, Fuzhou 350002, China
| | - Guang Yang
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Institute of Applied Ecology, Fujian Agriculture and Forestry University, Fuzhou 350002, China
- Joint International Research Laboratory of Ecological Pest Control, Ministry of Education, Fuzhou 350002, China
- Key Laboratory of Integrated Pest Management for Fujian-Taiwan Crops, Ministry of Agriculture, Fuzhou 350002, China
- Key Laboratory of Green Pest Control, Fujian Province University, Fuzhou 350002, China
- Ministerial and Provincial Joint Innovation Centre for Safety Production of Cross-Strait Crops, Fujian Agriculture and Forestry University, Fuzhou 350002, China
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3
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Navarro-Dominguez B, Chang CH, Brand CL, Muirhead CA, Presgraves DC, Larracuente AM. Epistatic selection on a selfish Segregation Distorter supergene - drive, recombination, and genetic load. eLife 2022; 11:e78981. [PMID: 35486424 PMCID: PMC9122502 DOI: 10.7554/elife.78981] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2022] [Accepted: 04/20/2022] [Indexed: 11/13/2022] Open
Abstract
Meiotic drive supergenes are complexes of alleles at linked loci that together subvert Mendelian segregation resulting in preferential transmission. In males, the most common mechanism of drive involves the disruption of sperm bearing one of a pair of alternative alleles. While at least two loci are important for male drive-the driver and the target-linked modifiers can enhance drive, creating selection pressure to suppress recombination. In this work, we investigate the evolution and genomic consequences of an autosomal, multilocus, male meiotic drive system, Segregation Distorter (SD) in the fruit fly, Drosophila melanogaster. In African populations, the predominant SD chromosome variant, SD-Mal, is characterized by two overlapping, paracentric inversions on chromosome arm 2R and nearly perfect (~100%) transmission. We study the SD-Mal system in detail, exploring its components, chromosomal structure, and evolutionary history. Our findings reveal a recent chromosome-scale selective sweep mediated by strong epistatic selection for haplotypes carrying Sd, the main driving allele, and one or more factors within the double inversion. While most SD-Mal chromosomes are homozygous lethal, SD-Mal haplotypes can recombine with other, complementing haplotypes via crossing over, and with wildtype chromosomes via gene conversion. SD-Mal chromosomes have nevertheless accumulated lethal mutations, excess non-synonymous mutations, and excess transposable element insertions. Therefore, SD-Mal haplotypes evolve as a small, semi-isolated subpopulation with a history of strong selection. These results may explain the evolutionary turnover of SD haplotypes in different populations around the world and have implications for supergene evolution broadly.
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Affiliation(s)
| | - Ching-Ho Chang
- Department of Biology, University of RochesterRochesterUnited States
| | - Cara L Brand
- Department of Biology, University of RochesterRochesterUnited States
| | - Christina A Muirhead
- Department of Biology, University of RochesterRochesterUnited States
- Ronin InstituteMontclairUnited States
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4
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Kelemen RK, Elkrewi M, Lindholm AK, Vicoso B. Novel patterns of expression and recruitment of new genes on the t-haplotype, a mouse selfish chromosome. Proc Biol Sci 2022; 289:20211985. [PMID: 35135349 PMCID: PMC8826135 DOI: 10.1098/rspb.2021.1985] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
The t-haplotype of mice is a classical model for autosomal transmission distortion. A largely non-recombining variant of the proximal region of chromosome 17, it is transmitted to more than 90% of the progeny of heterozygous males through the disabling of sperm carrying a standard chromosome. While extensive genetic and functional work has shed light on individual genes involved in drive, much less is known about the evolution and function of the rest of its hundreds of genes. Here, we characterize the sequence and expression of dozens of t-specific transcripts and of their chromosome 17 homologues. Many genes showed reduced expression of the t-allele, but an equal number of genes showed increased expression of their t-copy, consistent with increased activity or a newly evolved function. Genes on the t-haplotype had a significantly higher non-synonymous substitution rate than their homologues on the standard chromosome, with several genes harbouring dN/dS ratios above 1. Finally, the t-haplotype has acquired at least two genes from other chromosomes, which show high and tissue-specific expression. These results provide a first overview of the gene content of this selfish element, and support a more dynamic evolutionary scenario than expected of a large genomic region with almost no recombination.
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Affiliation(s)
- Reka K. Kelemen
- Institute of Science and Technology Austria, Am Campus, 1, 3400 Klosterneuburg, Austria
| | - Marwan Elkrewi
- Institute of Science and Technology Austria, Am Campus, 1, 3400 Klosterneuburg, Austria
| | - Anna K. Lindholm
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Winterthurerstrasse, 190, 8057 Zurich, Switzerland
| | - Beatriz Vicoso
- Institute of Science and Technology Austria, Am Campus, 1, 3400 Klosterneuburg, Austria
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5
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Fuller ZL, Koury SA, Leonard CJ, Young RE, Ikegami K, Westlake J, Richards S, Schaeffer SW, Phadnis N. Extensive Recombination Suppression and Epistatic Selection Causes Chromosome-Wide Differentiation of a Selfish Sex Chromosome in Drosophila pseudoobscura. Genetics 2020; 216:205-226. [PMID: 32732371 PMCID: PMC7463281 DOI: 10.1534/genetics.120.303460] [Citation(s) in RCA: 13] [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: 06/19/2020] [Accepted: 07/27/2020] [Indexed: 11/18/2022] Open
Abstract
Sex-Ratio (SR) chromosomes are selfish X-chromosomes that distort Mendelian segregation and are commonly associated with inversions. These chromosomal rearrangements suppress recombination with Standard (ST) X-chromosomes and are hypothesized to maintain multiple alleles important for distortion in a single large haplotype. Here, we conduct a multifaceted study of the multiply inverted Drosophila pseudoobscura SR chromosome to understand the evolutionary history, genetic architecture, and present-day dynamics that shape this enigmatic selfish chromosome. The D. pseudoobscura SR chromosome has three nonoverlapping inversions of the right arm of the metacentric X-chromosome: basal, medial, and terminal. We find that 23 of 29 Mb of the D. pseudoobscuraX-chromosome right arm is highly differentiated between the Standard and SR arrangements, including a 6.6 Mb collinear region between the medial and terminal inversions. Although crossing-over is heavily suppressed on this chromosome arm, we discover it is not completely eliminated, with measured rates indicating recombination suppression alone cannot explain patterns of differentiation or the near-perfect association of the three SR chromosome inversions in nature. We then demonstrate the ancient basal and medial inversions of the SR chromosome contain genes sufficient to cause weak distortion. In contrast, the younger terminal inversion cannot distort by itself, but contains at least one modifier gene necessary for full manifestation of strong sex chromosome distortion. By parameterizing population genetic models for chromosome-wide linkage disequilibrium with our experimental results, we infer that strong selection acts to maintain the near-perfect association of SR chromosome inversions in present-day populations. Based on comparative genomic analyses, direct recombination experiments, segregation distortion assays, and population genetic modeling, we conclude the combined action of suppressed recombination and strong, ongoing, epistatic selection shape the D. pseudoobscura SR arrangement into a highly differentiated chromosome.
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Affiliation(s)
- Zachary L Fuller
- Department of Biology, The Pennsylvania State University, University Park, Pennsylvania 16802
- Department of Biological Sciences, Columbia University, New York, New York 10027
| | - Spencer A Koury
- School of Biological Sciences, University of Utah, Salt Lake City, Utah 84112
| | | | - Randee E Young
- School of Biological Sciences, University of Utah, Salt Lake City, Utah 84112
- Department of Genetics, University of Wisconsin, Madison, Wisconsin 53706
| | - Kobe Ikegami
- School of Biological Sciences, University of Utah, Salt Lake City, Utah 84112
| | - Jonathan Westlake
- Department of Biology, The Pennsylvania State University, University Park, Pennsylvania 16802
| | - Stephen Richards
- Human Genome Sequencing Center, Baylor College of Medicine, 1 Baylor Plaza, Houston, Texas 77030
| | - Stephen W Schaeffer
- Department of Biology, The Pennsylvania State University, University Park, Pennsylvania 16802
| | - Nitin Phadnis
- School of Biological Sciences, University of Utah, Salt Lake City, Utah 84112
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6
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Bravo Núñez MA, Sabbarini IM, Eide LE, Unckless RL, Zanders SE. Atypical meiosis can be adaptive in outcrossed Schizosaccharomyces pombe due to wtf meiotic drivers. eLife 2020; 9:57936. [PMID: 32790622 PMCID: PMC7426094 DOI: 10.7554/elife.57936] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Accepted: 07/21/2020] [Indexed: 01/11/2023] Open
Abstract
Killer meiotic drivers are genetic parasites that destroy ‘sibling’ gametes lacking the driver allele. The fitness costs of drive can lead to selection of unlinked suppressors. This suppression could involve evolutionary tradeoffs that compromise gametogenesis and contribute to infertility. Schizosaccharomyces pombe, an organism containing numerous gamete (spore)-killing wtf drivers, offers a tractable system to test this hypothesis. Here, we demonstrate that in scenarios analogous to outcrossing, wtf drivers generate a fitness landscape in which atypical spores, such as aneuploids and diploids, are advantageous. In this context, wtf drivers can decrease the fitness costs of mutations that disrupt meiotic fidelity and, in some circumstances, can even make such mutations beneficial. Moreover, we find that S. pombe isolates vary greatly in their ability to make haploid spores, with some isolates generating up to 46% aneuploid or diploid spores. This work empirically demonstrates the potential for meiotic drivers to shape the evolution of gametogenesis.
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Affiliation(s)
| | | | - Lauren E Eide
- Stowers Institute for Medical Research, Kansas City, United States.,University of Missouri-Kansas City, Kansas City, United States
| | - Robert L Unckless
- Department of Molecular Biosciences, University of Kansas, Lawrence, United States
| | - Sarah E Zanders
- Stowers Institute for Medical Research, Kansas City, United States.,Department of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, United States
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7
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Keais GL, Lu S, Perlman SJ. Autosomal suppression and fitness costs of an old driving X chromosome in Drosophila testacea. J Evol Biol 2020; 33:619-628. [PMID: 31990433 DOI: 10.1111/jeb.13596] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Revised: 12/18/2019] [Accepted: 01/07/2020] [Indexed: 12/19/2022]
Abstract
Driving X chromosomes (XD s) bias their own transmission through males by killing Y-bearing gametes. These chromosomes can in theory spread rapidly in populations and cause extinction, but many are found as balanced polymorphisms or as "cryptic" XD s shut down by drive suppressors. The relative likelihood of these outcomes and the evolutionary pathways through which they come about are not well understood. An XD was recently discovered in the mycophagous fly, Drosophila testacea, presenting the opportunity to compare this XD with the well-studied XD of its sister species, Drosophila neotestacea. Comparing features of independently evolved XD s in young sister species is a promising avenue towards understanding how XD s and their counteracting forces change over time. In contrast to the XD of D. neotestacea, we find that the XD of D. testacea is old, with its origin predating the radiation of three species: D. testacea, D. neotestacea and their shared sister species, Drosophila orientacea. Motivated by the suggestion that older XD s should be more deleterious to carriers, we assessed the effect of the XD on both male and female fertility. Unlike what is known from D. neotestacea, we found a strong fitness cost in females homozygous for the XD in D. testacea: a large proportion of homozygous females failed to produce offspring after being housed with males for several days. Our male fertility experiments show that although XD male fertility is lower under sperm-depleting conditions, XD males have comparable fertility to males carrying a standard X chromosome under a free-mating regime, which may better approximate conditions in wild populations of D. testacea. Lastly, we demonstrate the presence of autosomal suppression of X chromosome drive. Our results provide support for a model of XD evolution where the dynamics of young XD s are governed by fitness consequences in males, whereas in older XD systems, both suppression and fitness consequences in females likely supersede male fitness costs.
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Affiliation(s)
- Graeme L Keais
- Department of Biology, University of Victoria, Victoria, BC, Canada.,Department of Botany, University of British Columbia, Vancouver, BC, Canada
| | - Sijia Lu
- Department of Biology, University of Victoria, Victoria, BC, Canada
| | - Steve J Perlman
- Department of Biology, University of Victoria, Victoria, BC, Canada
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8
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Courret C, Chang CH, Wei KHC, Montchamp-Moreau C, Larracuente AM. Meiotic drive mechanisms: lessons from Drosophila. Proc Biol Sci 2019; 286:20191430. [PMID: 31640520 DOI: 10.1098/rspb.2019.1430] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Meiotic drivers are selfish genetic elements that bias their transmission into gametes, often to the detriment of the rest of the genome. The resulting intragenomic conflicts triggered by meiotic drive create evolutionary arms races and shape genome evolution. The phenomenon of meiotic drive is widespread across taxa but is particularly prominent in the Drosophila genus. Recent studies in Drosophila have provided insights into the genetic origins of drivers and their molecular mechanisms. Here, we review the current literature on mechanisms of drive with an emphasis on sperm killers in Drosophila species. In these systems, meiotic drivers often evolve from gene duplications and targets are generally linked to heterochromatin. While dense in repetitive elements and difficult to study using traditional genetic and genomic approaches, recent work in Drosophila has made progress on the heterochromatic compartment of the genome. Although we still understand little about precise drive mechanisms, studies of male drive systems are converging on common themes such as heterochromatin regulation, small RNA pathways, and nuclear transport pathways. Meiotic drive systems are therefore promising models for discovering fundamental features of gametogenesis.
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Affiliation(s)
- Cécile Courret
- Evolution Génome Comportement et Ecologie, CNRS, IRD, Université Paris-Sud, Université Paris-Saclay, Gif sur Yvette 91190, France
| | - Ching-Ho Chang
- Department of Biology, University of Rochester, Rochester, NY, USA
| | - Kevin H-C Wei
- Department of Integrative Biology, University of California, Berkley, CA, USA
| | - Catherine Montchamp-Moreau
- Evolution Génome Comportement et Ecologie, CNRS, IRD, Université Paris-Sud, Université Paris-Saclay, Gif sur Yvette 91190, France
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9
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Lea JK, Unckless RL. An assessment of the immune costs associated with meiotic drive elements in Drosophila. Proc Biol Sci 2019; 286:20191534. [PMID: 31530140 PMCID: PMC6784720 DOI: 10.1098/rspb.2019.1534] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2019] [Accepted: 08/28/2019] [Indexed: 12/13/2022] Open
Abstract
Most organisms are constantly adapting to pathogens and parasites that exploit their host for their own benefit. Less studied, but perhaps more ubiquitous, are intragenomic parasites or selfish genetic elements. These include transposable elements, selfish B chromosomes and meiotic drivers that promote their own replication without regard to fitness effects on hosts. Therefore, intragenomic parasites are also a constant evolutionary pressure on hosts. Gamete-killing meiotic drive elements are often associated with large chromosomal inversions that reduce recombination between the drive and wild-type chromosomes. This reduced recombination is thought to reduce the efficacy of selection on the drive chromosome and allow for the accumulation of deleterious mutations. We tested whether gamete-killing meiotic drive chromosomes were associated with reduced immune defence against two bacterial pathogens in three species of Drosophila. We found little evidence of reduced immune defence in lines with meiotic drive. One line carrying the Drosophila melanogaster autosomal Segregation Distorter did show reduced defence, but we were unable to attribute that reduced defence to either genotype or immune gene expression differences. Our results suggest that though gamete-killing meiotic drive chromosomes probably accumulate deleterious mutations, those mutations do not result in reduced capacity for immune defence.
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Affiliation(s)
| | - Robert L. Unckless
- Department of Molecular Biosciences, University of Kansas, Lawrence, KS 66045, USA
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10
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Mathé‐Hubert H, Kaech H, Hertaeg C, Jaenike J, Vorburger C. Nonrandom associations of maternally transmitted symbionts in insects: The roles of drift versus biased cotransmission and selection. Mol Ecol 2019; 28:5330-5346. [DOI: 10.1111/mec.15206] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Accepted: 07/29/2019] [Indexed: 12/31/2022]
Affiliation(s)
- Hugo Mathé‐Hubert
- Eawag Swiss Federal Institute of Aquatic Science and Technology Dübendorf Switzerland
| | - Heidi Kaech
- Eawag Swiss Federal Institute of Aquatic Science and Technology Dübendorf Switzerland
- Institute of Integrative Biology Department of Environmental Systems Science ETH Zürich Zürich Switzerland
| | - Corinne Hertaeg
- Eawag Swiss Federal Institute of Aquatic Science and Technology Dübendorf Switzerland
- Institute of Agricultural Sciences Department of Environmental Systems Science ETH Zürich Zürich Switzerland
| | - John Jaenike
- Department of Biology University of Rochester Rochester NY USA
| | - Christoph Vorburger
- Eawag Swiss Federal Institute of Aquatic Science and Technology Dübendorf Switzerland
- Institute of Integrative Biology Department of Environmental Systems Science ETH Zürich Zürich Switzerland
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11
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Pieper KE, Unckless RL, Dyer KA. A fast-evolving X-linked duplicate of importin-α2 is overexpressed in sex-ratio drive in Drosophila neotestacea. Mol Ecol 2018; 27:5165-5179. [PMID: 30411843 DOI: 10.1111/mec.14928] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Revised: 10/21/2018] [Accepted: 10/25/2018] [Indexed: 01/31/2023]
Abstract
Selfish genetic elements that manipulate gametogenesis to achieve a transmission advantage are known as meiotic drivers. Sex-ratio X chromosomes (SR) are meiotic drivers that prevent the maturation of Y-bearing sperm in male carriers to result in the production of mainly female progeny. The spread of an SR chromosome can affect host genetic diversity and genome evolution, and can even cause host extinction if it reaches sufficiently high prevalence. Meiotic drivers have evolved independently many times, though only in a few cases is the underlying genetic mechanism known. In this study we use a combination of transcriptomics and population genetics to identify widespread expression differences between the standard (ST) and sex-ratio (SR) X chromosomes of the fly Drosophila neotestacea. We found the X chromosome is enriched for differentially expressed transcripts and that many of these X-linked differentially expressed transcripts had elevated Ka /Ks values between ST and SR, indicative of potential functional differences. We identified a set of candidate transcripts, including a testis-specific, X-linked duplicate of the nuclear transport gene importin-α2 that is overexpressed in SR. We find suggestions of positive selection in the lineage leading to the duplicate and that its molecular evolutionary patterns are consistent with relaxed purifying selection in ST. As these patterns are consistent with involvement in the mechanism of drive in this species, this duplicate is a strong candidate worthy of further functional investigation. Nuclear transport may be a common target for genetic conflict, as the mechanism of the autosomal Segregation Distorter drive system in D. melanogaster involves the same pathway.
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Affiliation(s)
| | - Robert L Unckless
- Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas
| | - Kelly A Dyer
- Department of Genetics, University of Georgia, Athens, Georgia
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12
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Ross KG, Shoemaker D. Unexpected patterns of segregation distortion at a selfish supergene in the fire ant Solenopsis invicta. BMC Genet 2018; 19:101. [PMID: 30404617 PMCID: PMC6223060 DOI: 10.1186/s12863-018-0685-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Accepted: 10/12/2018] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND The Sb supergene in the fire ant Solenopsis invicta determines the form of colony social organization, with colonies whose inhabitants bear the element containing multiple reproductive queens and colonies lacking it containing only a single queen. Several features of this supergene - including suppressed recombination, presence of deleterious mutations, association with a large centromere, and "green-beard" behavior - suggest that it may be a selfish genetic element that engages in transmission ratio distortion (TRD), defined as significant departures in progeny allele frequencies from Mendelian inheritance ratios. We tested this possibility by surveying segregation ratios in embryo progenies of 101 queens of the "polygyne" social form (3512 embryos) using three supergene-linked markers and twelve markers outside the supergene. RESULTS Significant departures from Mendelian ratios were observed at the supergene loci in 3-5 times more progenies than expected in the absence of TRD and than found, on average, among non-supergene loci. Also, supergene loci displayed the greatest mean deviations from Mendelian ratios among all study loci, although these typically were modest. A surprising feature of the observed inter-progeny variation in TRD was that significant deviations involved not only excesses of supergene alleles but also similarly frequent excesses of the alternate alleles on the homologous chromosome. As expected given the common occurrence of such "drive reversal" in this system, alleles associated with the supergene gain no consistent transmission advantage over their alternate alleles at the population level. Finally, we observed low levels of recombination and incomplete gametic disequilibrium across the supergene, including between adjacent markers within a single inversion. CONCLUSIONS Our data confirm the prediction that the Sb supergene is a selfish genetic element capable of biasing its own transmission during reproduction, yet counterselection for suppressor loci evidently has produced an evolutionary stalemate in TRD between the variant homologous haplotypes on the "social chromosome". Evidence implicates prezygotic segregation distortion as responsible for the TRD we document, with "true" meiotic drive the most likely mechanism. Low levels of recombination and incomplete gametic disequilibrium across the supergene suggest that selection does not preserve a single uniform supergene haplotype responsible for inducing polygyny.
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Affiliation(s)
- Kenneth G. Ross
- Department of Entomology, University of Georgia, Athens, GA USA
| | - DeWayne Shoemaker
- Department of Entomology and Plant Pathology, University of Tennessee, Knoxville, TN USA
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13
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Svedberg J, Hosseini S, Chen J, Vogan AA, Mozgova I, Hennig L, Manitchotpisit P, Abusharekh A, Hammond TM, Lascoux M, Johannesson H. Convergent evolution of complex genomic rearrangements in two fungal meiotic drive elements. Nat Commun 2018; 9:4242. [PMID: 30315196 PMCID: PMC6185902 DOI: 10.1038/s41467-018-06562-x] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2018] [Accepted: 09/12/2018] [Indexed: 12/31/2022] Open
Abstract
Meiotic drive is widespread in nature. The conflict it generates is expected to be an important motor for evolutionary change and innovation. In this study, we investigated the genomic consequences of two large multi-gene meiotic drive elements, Sk-2 and Sk-3, found in the filamentous ascomycete Neurospora intermedia. Using long-read sequencing, we generated the first complete and well-annotated genome assemblies of large, highly diverged, non-recombining regions associated with meiotic drive elements. Phylogenetic analysis shows that, even though Sk-2 and Sk-3 are located in the same chromosomal region, they do not form sister clades, suggesting independent origins or at least a long evolutionary separation. We conclude that they have in a convergent manner accumulated similar patterns of tandem inversions and dense repeat clusters, presumably in response to similar needs to create linkage between genes causing drive and resistance.
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Affiliation(s)
- Jesper Svedberg
- Department of Organismal Biology, Uppsala University, Norbyvägen 18D, 752 36, Uppsala, Sweden
| | - Sara Hosseini
- Department of Organismal Biology, Uppsala University, Norbyvägen 18D, 752 36, Uppsala, Sweden
| | - Jun Chen
- Department of Ecology and Genetics, Science for Life Laboratory, Uppsala University, Norbyvägen 18D, 752 36, Uppsala, Sweden
| | - Aaron A Vogan
- Department of Organismal Biology, Uppsala University, Norbyvägen 18D, 752 36, Uppsala, Sweden
| | - Iva Mozgova
- Department of Plant Biology and Linnean Center for Plant Biology, Swedish University of Agricultural Sciences, PO-Box 7080, SE-75007, Uppsala, Sweden
- Institute of Microbiology of the Czech Academy of Sciences, Centre Algatech, Opatovický mlýn, CZ-37981, Třeboň, Czech Republic
| | - Lars Hennig
- Department of Plant Biology and Linnean Center for Plant Biology, Swedish University of Agricultural Sciences, PO-Box 7080, SE-75007, Uppsala, Sweden
| | | | - Anna Abusharekh
- School of Biological Sciences, Illinois State University, Normal, IL, 61790, USA
| | - Thomas M Hammond
- School of Biological Sciences, Illinois State University, Normal, IL, 61790, USA
| | - Martin Lascoux
- Department of Ecology and Genetics, Science for Life Laboratory, Uppsala University, Norbyvägen 18D, 752 36, Uppsala, Sweden
| | - Hanna Johannesson
- Department of Organismal Biology, Uppsala University, Norbyvägen 18D, 752 36, Uppsala, Sweden.
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14
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Complex History and Differentiation Patterns of the t-Haplotype, a Mouse Meiotic Driver. Genetics 2017; 208:365-375. [PMID: 29138255 PMCID: PMC5753869 DOI: 10.1534/genetics.117.300513] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2017] [Accepted: 11/07/2017] [Indexed: 11/18/2022] Open
Abstract
The t-haplotype, a mouse meiotic driver found on chromosome 17, has been a model for autosomal segregation distortion for close to a century, but several questions remain regarding its biology and evolutionary history. A recently published set of population genomics resources for wild mice includes several individuals heterozygous for the t-haplotype, which we use to characterize this selfish element at the genomic and transcriptomic level. Our results show that large sections of the t-haplotype have been replaced by standard homologous sequences, possibly due to occasional events of recombination, and that this complicates the inference of its history. As expected for a long genomic segment of very low recombination, the t-haplotype carries an excess of fixed nonsynonymous mutations compared to the standard chromosome. This excess is stronger for regions that have not undergone recent recombination, suggesting that occasional gene flow between the t and the standard chromosome may provide a mechanism to regenerate coding sequences that have accumulated deleterious mutations. Finally, we find that t-complex genes with altered expression largely overlap with deleted or amplified regions, and that carrying a t-haplotype alters the testis expression of genes outside of the t-complex, providing new leads into the pathways involved in the biology of this segregation distorter.
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15
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Fitness Costs and Variation in Transmission Distortion Associated with the Abnormal Chromosome 10 Meiotic Drive System in Maize. Genetics 2017; 208:297-305. [PMID: 29122827 DOI: 10.1534/genetics.117.300060] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Accepted: 10/02/2017] [Indexed: 01/03/2023] Open
Abstract
Meiotic drive describes a process whereby selfish genetic elements are transmitted at levels greater than Mendelian expectations. Maize abnormal chromosome 10 (Ab10) encodes a meiotic drive system that exhibits strong preferential segregation through female gametes. We performed transmission assays on nine Ab10 chromosomes from landraces and teosinte lines and found a transmission advantage of 62-79% in heterozygotes. Despite this transmission advantage, Ab10 is present at low frequencies in natural populations, suggesting that it carries large negative fitness consequences. We measured pollen transmission, the percentage of live pollen, seed production, and seed size to estimate several of the possible fitness effects of Ab10. We found no evidence that Ab10 affects pollen transmission, i.e., Ab10 and N10 pollen are transmitted equally from heterozygous fathers. However, at the diploid (sporophyte) level, both heterozygous and homozygous Ab10-I-MMR individuals show decreased pollen viability, decreased seed set, and decreased seed weight. The observed fitness costs can nearly but not entirely account for the observed frequencies of Ab10. Sequence analysis shows a surprising amount of molecular variation among Ab10 haplotypes, suggesting that there may be other phenotypic variables that contribute to the low but stable equilibrium frequencies.
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16
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Paczolt KA, Reinhardt JA, Wilkinson GS. Contrasting patterns of X-chromosome divergence underlie multiple sex-ratio polymorphisms in stalk-eyed flies. J Evol Biol 2017; 30:1772-1784. [PMID: 28688201 DOI: 10.1111/jeb.13140] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Revised: 06/27/2017] [Accepted: 07/04/2017] [Indexed: 11/28/2022]
Abstract
Sex-linked segregation distorters cause offspring sex ratios to differ from equality. Theory predicts that such selfish alleles may either go to fixation and cause extinction, reach a stable polymorphism or initiate an evolutionary arms race with genetic modifiers. The extent to which a sex ratio distorter follows any of these trajectories in nature is poorly known. Here, we used X-linked sequence and simple tandem repeat data for three sympatric species of stalk-eyed flies (Teleopsis whitei and two cryptic species of T. dalmanni) to infer the evolution of distorting X chromosomes. By screening large numbers of field and recently laboratory-bred flies, we found no evidence of males with strongly female-biased sex ratio phenotypes (SR) in one species but high frequencies of SR males in the other two species. In the two species with SR males, we find contrasting patterns of X-chromosome evolution. T. dalmanni-1 shows chromosome-wide differences between sex-ratio (XSR ) and standard (XST ) X chromosomes consistent with a relatively old sex-ratio haplotype based on evidence including genetic divergence, an inversion polymorphism and reduced recombination among XSR chromosomes relative to XST chromosomes. In contrast, we found no evidence of genetic divergence on the X between males with female-biased and nonbiased sex ratios in T. whitei. Taken with previous studies that found evidence of genetic suppression of sex ratio distortion in this clade, our results illustrate that sex ratio modification in these flies is undergoing recurrent evolution with diverse genomic consequences.
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Affiliation(s)
- K A Paczolt
- Department of Biology, University of Maryland College Park, College Park, MD, USA
| | - J A Reinhardt
- Department of Biology, SUNY Geneseo, Geneseo, NY, USA
| | - G S Wilkinson
- Department of Biology, University of Maryland College Park, College Park, MD, USA
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17
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Keais GL, Hanson MA, Gowen BE, Perlman SJ. X chromosome drive in a widespread Palearctic woodland fly, Drosophila testacea. J Evol Biol 2017; 30:1185-1194. [PMID: 28402000 DOI: 10.1111/jeb.13089] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2017] [Revised: 03/20/2017] [Accepted: 04/04/2017] [Indexed: 12/27/2022]
Abstract
Selfish genes that bias their own transmission during meiosis can spread rapidly in populations, even if they contribute negatively to the fitness of their host. Driving X chromosomes provide a clear example of this type of selfish propagation. These chromosomes have important evolutionary and ecological consequences, and can be found in a broad range of taxa including plants, mammals and insects. Here, we report a new case of X chromosome drive (X drive) in a widespread woodland fly, Drosophila testacea. We show that males carrying the driving X (SR males) sire 80-100% female offspring and possess a diagnostic X chromosome haplotype that is perfectly associated with the sex ratio distortion phenotype. We find that the majority of sons produced by SR males are sterile and appear to lack a Y chromosome, suggesting that meiotic defects involving the Y chromosome may underlie X drive in this species. Abnormalities in sperm cysts of SR males reflect that some spermatids are failing to develop properly, confirming that drive is acting during gametogenesis. By screening wild-caught flies using progeny sex ratios and a diagnostic marker, we demonstrate that the driving X is present in wild populations at a frequency of ~ 10% and that suppressors of drive are segregating in the same population. The testacea species group appears to be a hot spot for X drive, and D. testacea is a promising model to compare driving X chromosomes in closely related species, some of which may even be younger than the chromosomes themselves.
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Affiliation(s)
- G L Keais
- Department of Biology, University of Victoria, Victoria, BC, Canada
| | - M A Hanson
- Department of Biology, University of Victoria, Victoria, BC, Canada
| | - B E Gowen
- Department of Biology, University of Victoria, Victoria, BC, Canada
| | - S J Perlman
- Department of Biology, University of Victoria, Victoria, BC, Canada
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