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Benowitz KM, Allan CW, Jaworski CC, Sanderson MJ, Diaz F, Chen X, Matzkin LM. Fundamental Patterns of Structural Evolution Revealed by Chromosome-Length Genomes of Cactophilic Drosophila. Genome Biol Evol 2024; 16:evae191. [PMID: 39228294 PMCID: PMC11411373 DOI: 10.1093/gbe/evae191] [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: 06/21/2023] [Revised: 08/22/2024] [Accepted: 08/26/2024] [Indexed: 09/05/2024] Open
Abstract
A thorough understanding of adaptation and speciation requires model organisms with both a history of ecological and phenotypic study as well as a complete set of genomic resources. In particular, high-quality genome assemblies of ecological model organisms are needed to assess the evolution of genome structure and its role in adaptation and speciation. Here, we generate new genomes of cactophilic Drosophila, a crucial model clade for understanding speciation and ecological adaptation in xeric environments. We generated chromosome-level genome assemblies and complete annotations for seven populations across Drosophila mojavensis, Drosophila arizonae, and Drosophila navojoa. We use these data first to establish the most robust phylogeny for this clade to date, and to assess patterns of molecular evolution across the phylogeny, showing concordance with a priori hypotheses regarding adaptive genes in this system. We then show that structural evolution occurs at constant rate across the phylogeny, varies by chromosome, and is correlated with molecular evolution. These results advance the understanding of the D. mojavensis clade by demonstrating core evolutionary genetic patterns and integrating those patterns to generate new gene-level hypotheses regarding adaptation. Our data are presented in a new public database (cactusflybase.arizona.edu), providing one of the most in-depth resources for the analysis of inter- and intraspecific evolutionary genomic data. Furthermore, we anticipate that the patterns of structural evolution identified here will serve as a baseline for future comparative studies to identify the factors that influence the evolution of genome structure across taxa.
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Affiliation(s)
- Kyle M Benowitz
- Department of Entomology, University of Arizona, Tucson, AZ, USA
| | - Carson W Allan
- Department of Entomology, University of Arizona, Tucson, AZ, USA
| | | | - Michael J Sanderson
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ, USA
| | - Fernando Diaz
- Department of Entomology, University of Arizona, Tucson, AZ, USA
| | - Xingsen Chen
- Department of Entomology, University of Arizona, Tucson, AZ, USA
| | - Luciano M Matzkin
- Department of Entomology, University of Arizona, Tucson, AZ, USA
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ, USA
- BIO5 Institute, University of Arizona, Tucson, AZ, USA
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2
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Olito C, Ponnikas S, Hansson B, Abbott JK. Consequences of partially recessive deleterious genetic variation for the evolution of inversions suppressing recombination between sex chromosomes1. Evolution 2024; 78:1499-1510. [PMID: 38853722 DOI: 10.1093/evolut/qpae060] [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: 09/07/2023] [Revised: 03/26/2024] [Accepted: 04/25/2024] [Indexed: 06/11/2024]
Abstract
The evolution of suppressed recombination between sex chromosomes is widely hypothesized to be driven by sexually antagonistic selection (SA), where tighter linkage between the sex-determining gene(s) and nearby SA loci is favored when it couples male-beneficial alleles to the proto-Y chromosome, and female-beneficial alleles to the proto-X. Although difficult to test empirically, the SA selection hypothesis overshadows several alternatives, including an incomplete but often-repeated "sheltering" hypothesis which suggests that expansion of the sex-linked region (SLR) reduces the homozygous expression of deleterious mutations at selected loci. Here, we use population genetic models to evaluate the consequences of partially recessive deleterious mutational variation for the evolution of otherwise neutral chromosomal inversions expanding the SLR on proto-Y chromosomes. Both autosomal and SLR-expanding inversions face a race against time: lightly-loaded inversions are initially beneficial, but eventually become deleterious as they accumulate new mutations, after which their chances of fixing become negligible. In contrast, initially unloaded inversions eventually become neutral as their deleterious load reaches the same equilibrium as non-inverted haplotypes. Despite the differences in inheritance and indirect selection, SLR-expanding inversions exhibit similar evolutionary dynamics to autosomal inversions over many biologically plausible parameter conditions. Differences emerge when the population average mutation load is quite high; in this case large autosomal inversions that are lucky enough to be mutation-free can rise to intermediate to high frequencies where selection in homozygotes becomes important (Y-linked inversions never appear as homozygous karyotypes); conditions requiring either high mutation rates, highly recessive deleterious mutations, weak selection, or a combination thereof.
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Affiliation(s)
- Colin Olito
- Department of Biology, Lund University, Lund, Sweden
| | - Suvi Ponnikas
- Department of Biology, Lund University, Lund, Sweden
| | - Bengt Hansson
- Department of Biology, Lund University, Lund, Sweden
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3
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Mackintosh C, Scott MF, Reuter M, Pomiankowski A. Locally adaptive inversions in structured populations. Genetics 2024; 227:iyae073. [PMID: 38709495 DOI: 10.1093/genetics/iyae073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2024] [Revised: 04/05/2024] [Accepted: 04/16/2024] [Indexed: 05/07/2024] Open
Abstract
Inversions have been proposed to facilitate local adaptation, by linking together locally coadapted alleles at different loci. Prior work addressing this question theoretically has considered the spread of inversions in "continent-island" scenarios in which there is a unidirectional flow of maladapted migrants into the island population. In this setting, inversions capturing locally adaptive haplotypes are most likely to invade when selection is weak, because stronger local selection (i) more effectively purges maladaptive alleles and (ii) generates linkage disequilibrium between adaptive alleles, thus lessening the advantage of inversions. We show this finding only holds under limited conditions by studying the establishment of inversions in a more general two-deme model, which explicitly considers the dynamics of allele frequencies in both populations linked by bidirectional migration. In this model, the level of symmetry between demes can be varied from complete asymmetry (continent-island) to complete symmetry. For symmetric selection and migration, strong selection increases the allele frequency divergence between demes thereby increasing the frequency of maladaptive alleles in migrants, favoring inversions-the opposite of the pattern seen in the asymmetric continent-island scenario. We also account for the likelihood that a new inversion captures an adaptive haplotype in the first instance. When considering the combined process of capture and invasion in "continent island" and symmetric scenarios, relatively strong selection increases inversion establishment probability. Migration must also be low enough that the inversion is likely to capture an adaptive allele combination, but not so low as to eliminate the inversion's advantage. Overall, our analysis suggests that inversions are likely to harbor larger effect alleles that experience relatively strong selection.
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Affiliation(s)
- Carl Mackintosh
- Department of Genetics, Evolution, and Environment, University College London, Gower Street, London WC1E 6BT, UK
- CoMPLEX, University College London, Gower Street, London WC1E 6BT, UK
- CNRS, UMR7144 Adaptation et Diversité en Milieu Marin, Station Biologique de Roscoff, Roscoff 29680, France
- Sorbonne Universités, UPMC Université Paris VI, Roscoff 29680, France
| | - Michael F Scott
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK
| | - Max Reuter
- Department of Genetics, Evolution, and Environment, University College London, Gower Street, London WC1E 6BT, UK
| | - Andrew Pomiankowski
- Department of Genetics, Evolution, and Environment, University College London, Gower Street, London WC1E 6BT, UK
- CoMPLEX, University College London, Gower Street, London WC1E 6BT, UK
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4
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Jay P, Jeffries D, Hartmann FE, Véber A, Giraud T. Why do sex chromosomes progressively lose recombination? Trends Genet 2024; 40:564-579. [PMID: 38677904 DOI: 10.1016/j.tig.2024.03.005] [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: 10/17/2023] [Revised: 03/18/2024] [Accepted: 03/19/2024] [Indexed: 04/29/2024]
Abstract
Progressive recombination loss is a common feature of sex chromosomes. Yet, the evolutionary drivers of this phenomenon remain a mystery. For decades, differences in trait optima between sexes (sexual antagonism) have been the favoured hypothesis, but convincing evidence is lacking. Recent years have seen a surge of alternative hypotheses to explain progressive extensions and maintenance of recombination suppression: neutral accumulation of sequence divergence, selection of nonrecombining fragments with fewer deleterious mutations than average, sheltering of recessive deleterious mutations by linkage to heterozygous alleles, early evolution of dosage compensation, and constraints on recombination restoration. Here, we explain these recent hypotheses and dissect their assumptions, mechanisms, and predictions. We also review empirical studies that have brought support to the various hypotheses.
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Affiliation(s)
- Paul Jay
- Center for GeoGenetics, University of Copenhagen, Copenhagen, Denmark; Université Paris-Saclay, CNRS, AgroParisTech, Laboratoire Ecologie Systématique et Evolution, UMR 8079, Bâtiment 680, 12 route RD128, 91190 Gif-sur-Yvette, France.
| | - Daniel Jeffries
- Division of Evolutionary Ecology, Institute of Ecology and Evolution, University of Bern, 3012 Bern, Switzerland
| | - Fanny E Hartmann
- Université Paris-Saclay, CNRS, AgroParisTech, Laboratoire Ecologie Systématique et Evolution, UMR 8079, Bâtiment 680, 12 route RD128, 91190 Gif-sur-Yvette, France
| | - Amandine Véber
- Université Paris Cité, CNRS, MAP5, F-75006 Paris, France
| | - Tatiana Giraud
- Université Paris-Saclay, CNRS, AgroParisTech, Laboratoire Ecologie Systématique et Evolution, UMR 8079, Bâtiment 680, 12 route RD128, 91190 Gif-sur-Yvette, France
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5
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Justen HC, Easton WE, Delmore KE. Mapping seasonal migration in a songbird hybrid zone -- heritability, genetic correlations, and genomic patterns linked to speciation. Proc Natl Acad Sci U S A 2024; 121:e2313442121. [PMID: 38648483 PMCID: PMC11067064 DOI: 10.1073/pnas.2313442121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2023] [Accepted: 03/19/2024] [Indexed: 04/25/2024] Open
Abstract
Seasonal migration is a widespread behavior relevant for adaptation and speciation, yet knowledge of its genetic basis is limited. We leveraged advances in tracking and sequencing technologies to bridge this gap in a well-characterized hybrid zone between songbirds that differ in migratory behavior. Migration requires the coordinated action of many traits, including orientation, timing, and wing morphology. We used genetic mapping to show these traits are highly heritable and genetically correlated, explaining how migration has evolved so rapidly in the past and suggesting future responses to climate change may be possible. Many of these traits mapped to the same genomic regions and small structural variants indicating the same, or tightly linked, genes underlie them. Analyses integrating transcriptomic data indicate cholinergic receptors could control multiple traits. Furthermore, analyses integrating genomic differentiation further suggested genes underlying migratory traits help maintain reproductive isolation in this hybrid zone.
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Affiliation(s)
- Hannah C. Justen
- Biology Department, Texas Agricultural and Mechanical University, TAMUCollege Station, TX3528
| | - Wendy E. Easton
- Environment and Climate Change Canada, Canadian Wildlife Service-Pacific Region, Delta, BCV4K 3N2, Canada
| | - Kira E. Delmore
- Biology Department, Texas Agricultural and Mechanical University, TAMUCollege Station, TX3528
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6
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Wooldridge B, Orland C, Enbody E, Escalona M, Mirchandani C, Corbett-Detig R, Kapp JD, Fletcher N, Cox-Ammann K, Raimondi P, Shapiro B. Limited genomic signatures of population collapse in the critically endangered black abalone (Haliotis cracherodii). Mol Ecol 2024:e17362. [PMID: 38682494 DOI: 10.1111/mec.17362] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2024] [Revised: 04/05/2024] [Accepted: 04/09/2024] [Indexed: 05/01/2024]
Abstract
The black abalone, Haliotis cracherodii, is a large, long-lived marine mollusc that inhabits rocky intertidal habitats along the coast of California and Mexico. In 1985, populations were impacted by a bacterial disease known as withering syndrome (WS) that wiped out >90% of individuals, leading to the closure of all U.S. black abalone fisheries since 1993. Current conservation strategies include restoring diminished populations by translocating healthy individuals. However, population collapse on this scale may have dramatically lowered genetic diversity and strengthened geographic differentiation, making translocation-based recovery contentious. Additionally, the current prevalence of WS remains unknown. To address these uncertainties, we sequenced and analysed the genomes of 133 black abalone individuals from across their present range. We observed no spatial genetic structure among black abalone, with the exception of a single chromosomal inversion that increases in frequency with latitude. Outside the inversion, genetic differentiation between sites is minimal and does not scale with either geographic distance or environmental dissimilarity. Genetic diversity appears uniformly high across the range. Demographic inference does indicate a severe population bottleneck beginning just 15 generations in the past, but this decline is short lived, with present-day size far exceeding the pre-bottleneck status quo. Finally, we find the bacterial agent of WS is equally present across the sampled range, but only in 10% of individuals. The lack of population genetic structure, uniform diversity and prevalence of WS bacteria indicates that translocation could be a valid and low-risk means of population restoration for black abalone species' recovery.
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Affiliation(s)
- Brock Wooldridge
- Ecology and Evolutionary Biology Department, University of California Santa Cruz, Santa Cruz, California, USA
- Howard Hughes Medical Institute, University of California Santa Cruz, Santa Cruz, California, USA
| | - Chloé Orland
- Ecology and Evolutionary Biology Department, University of California Santa Cruz, Santa Cruz, California, USA
| | - Erik Enbody
- Department of Biomolecular Engineering, University of California Santa Cruz, Santa Cruz, California, USA
| | - Merly Escalona
- Department of Biomolecular Engineering, University of California Santa Cruz, Santa Cruz, California, USA
| | - Cade Mirchandani
- Department of Biomolecular Engineering, University of California Santa Cruz, Santa Cruz, California, USA
| | - Russell Corbett-Detig
- Department of Biomolecular Engineering, University of California Santa Cruz, Santa Cruz, California, USA
- Genomics Institute, University of California Santa Cruz, Santa Cruz, California, USA
| | - Joshua D Kapp
- Ecology and Evolutionary Biology Department, University of California Santa Cruz, Santa Cruz, California, USA
| | - Nathaniel Fletcher
- Ecology and Evolutionary Biology Department, University of California Santa Cruz, Santa Cruz, California, USA
| | - Karah Cox-Ammann
- Ecology and Evolutionary Biology Department, University of California Santa Cruz, Santa Cruz, California, USA
| | - Peter Raimondi
- Ecology and Evolutionary Biology Department, University of California Santa Cruz, Santa Cruz, California, USA
| | - Beth Shapiro
- Ecology and Evolutionary Biology Department, University of California Santa Cruz, Santa Cruz, California, USA
- Howard Hughes Medical Institute, University of California Santa Cruz, Santa Cruz, California, USA
- Genomics Institute, University of California Santa Cruz, Santa Cruz, California, USA
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7
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Soboleva ES, Kirilenko KM, Fedorova VS, Kokhanenko AA, Artemov GN, Sharakhov IV. Two Nested Inversions in the X Chromosome Differentiate the Dominant Malaria Vectors in Europe, Anopheles atroparvus and Anopheles messeae. INSECTS 2024; 15:312. [PMID: 38786868 PMCID: PMC11122324 DOI: 10.3390/insects15050312] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2024] [Revised: 04/22/2024] [Accepted: 04/23/2024] [Indexed: 05/25/2024]
Abstract
The Maculipennis subgroup of malaria mosquitoes includes both dominant malaria vectors and non-vectors in Eurasia. Understanding the genetic factors, particularly chromosomal inversions, that differentiate Anopheles species can provide valuable insights for vector control strategies. Although autosomal inversions between the species in this subgroup have been characterized based on the chromosomal banding patterns, the number and positions of rearrangements in the X chromosome remain unclear due to the divergent banding patterns. Here, we identified two large X chromosomal inversions, approximately 13 Mb and 10 Mb in size, using fluorescence in situ hybridization. The inversion breakpoint regions were mapped by hybridizing 53 gene markers with polytene chromosomes of An. messeae. The DNA probes were designed based on gene sequences from the annotated An. atroparvus genome. The two nested inversions resulted in five syntenic blocks. Only two small syntenic blocks, which encompass 181 annotated genes in the An. atroparvus genome, changed their position and orientation in the X chromosome. The analysis of the An. atroparvus genome revealed an enrichment of gene ontology terms associated with immune system and mating behavior in the rearranged syntenic blocks. Additionally, the enrichment of DNA transposons was found in sequences homologous to three of the four breakpoint regions. This study demonstrates the successful application of the physical genome mapping approach to identify rearrangements that differentiate species in insects with polytene chromosomes.
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Affiliation(s)
- Evgenia S. Soboleva
- Laboratory of Ecology, Genetics and Environmental Protection, Tomsk State University, 36 Lenin Avenue, Tomsk 634050, Russia
| | - Kirill M. Kirilenko
- Laboratory of Ecology, Genetics and Environmental Protection, Tomsk State University, 36 Lenin Avenue, Tomsk 634050, Russia
| | - Valentina S. Fedorova
- Laboratory of Ecology, Genetics and Environmental Protection, Tomsk State University, 36 Lenin Avenue, Tomsk 634050, Russia
| | - Alina A. Kokhanenko
- Laboratory of Ecology, Genetics and Environmental Protection, Tomsk State University, 36 Lenin Avenue, Tomsk 634050, Russia
| | - Gleb N. Artemov
- Laboratory of Ecology, Genetics and Environmental Protection, Tomsk State University, 36 Lenin Avenue, Tomsk 634050, Russia
| | - Igor V. Sharakhov
- Laboratory of Ecology, Genetics and Environmental Protection, Tomsk State University, 36 Lenin Avenue, Tomsk 634050, Russia
- Department of Entomology, the Fralin Life Sciences Institute, Virginia Polytechnic Institute and State University, 360 West Campus Drive, Blacksburg, VA 24061, USA
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8
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Poikela N, Laetsch DR, Hoikkala V, Lohse K, Kankare M. Chromosomal Inversions and the Demography of Speciation in Drosophila montana and Drosophila flavomontana. Genome Biol Evol 2024; 16:evae024. [PMID: 38482698 PMCID: PMC10972691 DOI: 10.1093/gbe/evae024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/30/2024] [Indexed: 04/01/2024] Open
Abstract
Chromosomal inversions may play a central role in speciation given their ability to locally reduce recombination and therefore genetic exchange between diverging populations. We analyzed long- and short-read whole-genome data from sympatric and allopatric populations of 2 Drosophila virilis group species, Drosophila montana and Drosophila flavomontana, to understand if inversions have contributed to their divergence. We identified 3 large alternatively fixed inversions on the X chromosome and one on each of the autosomes 4 and 5. A comparison of demographic models estimated for inverted and noninverted (colinear) chromosomal regions suggests that these inversions arose before the time of the species split. We detected a low rate of interspecific gene flow (introgression) from D. montana to D. flavomontana, which was further reduced inside inversions and was lower in allopatric than in sympatric populations. Together, these results suggest that the inversions were already present in the common ancestral population and that gene exchange between the sister taxa was reduced within inversions both before and after the onset of species divergence. Such ancestrally polymorphic inversions may foster speciation by allowing the accumulation of genetic divergence in loci involved in adaptation and reproductive isolation inside inversions early in the speciation process, while gene exchange at colinear regions continues until the evolving reproductive barriers complete speciation. The overlapping X inversions are particularly good candidates for driving the speciation process of D. montana and D. flavomontana, since they harbor strong genetic incompatibilities that were detected in a recent study of experimental introgression.
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Affiliation(s)
- Noora Poikela
- Department of Biological and Environmental Science, University of Jyväskylä, FI-40014, Jyväskylä, Finland
| | - Dominik R Laetsch
- Institute of Evolutionary Biology, University of Edinburgh, Edinburgh, UK
| | - Ville Hoikkala
- Department of Biological and Environmental Science, University of Jyväskylä, FI-40014, Jyväskylä, Finland
| | - Konrad Lohse
- Institute of Evolutionary Biology, University of Edinburgh, Edinburgh, UK
| | - Maaria Kankare
- Department of Biological and Environmental Science, University of Jyväskylä, FI-40014, Jyväskylä, Finland
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9
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Jay P, Aubier TG, Joron M. The interplay of local adaptation and gene flow may lead to the formation of supergenes. Mol Ecol 2024:e17297. [PMID: 38415327 DOI: 10.1111/mec.17297] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Revised: 12/28/2023] [Accepted: 01/10/2024] [Indexed: 02/29/2024]
Abstract
Supergenes are genetic architectures resulting in the segregation of alternative combinations of alleles underlying complex phenotypes. The co-segregation of alleles at linked loci is often facilitated by polymorphic chromosomal rearrangements suppressing recombination locally. Supergenes are involved in many complex polymorphisms, including sexual, colour or behavioural polymorphisms in numerous plants, fungi, mammals, fish, and insects. Despite a long history of empirical and theoretical research, the formation of supergenes remains poorly understood. Here, using a two-island population genetic model, we explore how gene flow and the evolution of overdominant chromosomal inversions may jointly lead to the formation of supergenes. We show that the evolution of inversions in differentiated populations, both under disruptive selection, leads to an increase in frequency of poorly adapted, immigrant haplotypes. Indeed, rare allelic combinations, such as immigrant haplotypes, are more frequently reshuffled by recombination than common allelic combinations, and therefore benefit from the recombination suppression generated by inversions. When an inversion capturing a locally adapted haplotype spreads but is associated with a fitness cost hampering its fixation (e.g. a recessive mutation load), the maintenance of a non-inverted haplotype in the population is enhanced; under certain conditions, the immigrant haplotype persists alongside the inverted local haplotype, while the standard local haplotype disappears. This establishes a stable, local polymorphism with two non-recombining haplotypes encoding alternative adaptive strategies, that is, a supergene. These results bring new light to the importance of local adaptation, overdominance, and gene flow in the formation of supergenes and inversion polymorphisms in general.
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Affiliation(s)
- Paul Jay
- Centre d'Ecologie Fonctionnelle et Evolutive (CEFE), Université de Montpellier, CNRS, EPHE, IRD, Montpellier, France
- Center for GeoGenetics, University of Copenhagen, Copenhagen, Denmark
| | - Thomas G Aubier
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, Switzerland
- Department of Biology, University of North Carolina, Chapel Hill, North Carolina, USA
- Centre de Recherche sur la Biodiversité et l'Environnement (CRBE), Université de Toulouse, CNRS, IRD, Toulouse INP, Université Toulouse 3 - Paul Sabatier (UT3), Toulouse, France
| | - Mathieu Joron
- Centre d'Ecologie Fonctionnelle et Evolutive (CEFE), Université de Montpellier, CNRS, EPHE, IRD, Montpellier, France
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10
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Wooldridge B, Orland C, Enbody E, Escalona M, Mirchandani C, Corbett-Detig R, Kapp JD, Fletcher N, Ammann K, Raimondi P, Shapiro B. Limited genomic signatures of population collapse in the critically endangered black abalone ( Haliotis cracherodii). BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.26.577275. [PMID: 38352393 PMCID: PMC10862700 DOI: 10.1101/2024.01.26.577275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/19/2024]
Abstract
The black abalone, Haliotis cracherodii, is a large, long-lived marine mollusc that inhabits rocky intertidal habitats along the coast of California and Mexico. In 1985, populations were impacted by a bacterial disease known as withering syndrome (WS) that wiped out >90% of individuals, leading to the species' designation as critically endangered. Current conservation strategies include restoring diminished populations by translocating healthy individuals. However, population collapse on this scale may have dramatically lowered genetic diversity and strengthened geographic differentiation, making translocation-based recovery contentious. Additionally, the current prevalence of WS is unknown. To address these uncertainties, we sequenced and analyzed the genomes of 133 black abalone individuals from across their present range. We observed no spatial genetic structure among black abalone, with the exception of a single chromosomal inversion that increases in frequency with latitude. Genetic divergence between sites is minimal, and does not scale with either geographic distance or environmental dissimilarity. Genetic diversity appears uniformly high across the range. Despite this, however, demographic inference confirms a severe population bottleneck beginning around the time of WS onset, highlighting the temporal offset that may occur between a population collapse and its potential impact on genetic diversity. Finally, we find the bacterial agent of WS is equally present across the sampled range, but only in 10% of individuals. The lack of genetic structure, uniform diversity, and prevalence of WS bacteria indicates that translocation could be a valid and low-risk means of population restoration for black abalone species' recovery.
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Affiliation(s)
- Brock Wooldridge
- Ecology and Evolutionary Biology Department, University of California Santa Cruz, Santa Cruz, CA, 95064 USA
- Howard Hughes Medical Institute, University of California Santa Cruz, Santa Cruz, CA, 95064, USA
| | - Chloé Orland
- Ecology and Evolutionary Biology Department, University of California Santa Cruz, Santa Cruz, CA, 95064 USA
| | - Erik Enbody
- Department of Biomolecular Engineering, University of California Santa Cruz, Santa Cruz, CA, 95064 USA
| | - Merly Escalona
- Department of Biomolecular Engineering, University of California Santa Cruz, Santa Cruz, CA, 95064 USA
| | - Cade Mirchandani
- Department of Biomolecular Engineering, University of California Santa Cruz, Santa Cruz, CA, 95064 USA
| | - Russell Corbett-Detig
- Department of Biomolecular Engineering, University of California Santa Cruz, Santa Cruz, CA, 95064 USA
- Genomics Institute, University of California Santa Cruz, Santa Cruz, CA, 95064 USA
| | - Joshua D Kapp
- Ecology and Evolutionary Biology Department, University of California Santa Cruz, Santa Cruz, CA, 95064 USA
| | - Nathaniel Fletcher
- Ecology and Evolutionary Biology Department, University of California Santa Cruz, Santa Cruz, CA, 95064 USA
| | - Karah Ammann
- Ecology and Evolutionary Biology Department, University of California Santa Cruz, Santa Cruz, CA, 95064 USA
| | - Peter Raimondi
- Ecology and Evolutionary Biology Department, University of California Santa Cruz, Santa Cruz, CA, 95064 USA
| | - Beth Shapiro
- Ecology and Evolutionary Biology Department, University of California Santa Cruz, Santa Cruz, CA, 95064 USA
- Howard Hughes Medical Institute, University of California Santa Cruz, Santa Cruz, CA, 95064, USA
- Genomics Institute, University of California Santa Cruz, Santa Cruz, CA, 95064 USA
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11
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Willink B, Tunström K, Nilén S, Chikhi R, Lemane T, Takahashi M, Takahashi Y, Svensson EI, Wheat CW. The genomics and evolution of inter-sexual mimicry and female-limited polymorphisms in damselflies. Nat Ecol Evol 2024; 8:83-97. [PMID: 37932383 PMCID: PMC10781644 DOI: 10.1038/s41559-023-02243-1] [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: 03/14/2023] [Accepted: 10/04/2023] [Indexed: 11/08/2023]
Abstract
Sex-limited morphs can provide profound insights into the evolution and genomic architecture of complex phenotypes. Inter-sexual mimicry is one particular type of sex-limited polymorphism in which a novel morph resembles the opposite sex. While inter-sexual mimics are known in both sexes and a diverse range of animals, their evolutionary origin is poorly understood. Here, we investigated the genomic basis of female-limited morphs and male mimicry in the common bluetail damselfly. Differential gene expression between morphs has been documented in damselflies, but no causal locus has been previously identified. We found that male mimicry originated in an ancestrally sexually dimorphic lineage in association with multiple structural changes, probably driven by transposable element activity. These changes resulted in ~900 kb of novel genomic content that is partly shared by male mimics in a close relative, indicating that male mimicry is a trans-species polymorphism. More recently, a third morph originated following the translocation of part of the male-mimicry sequence into a genomic position ~3.5 mb apart. We provide evidence of balancing selection maintaining male mimicry, in line with previous field population studies. Our results underscore how structural variants affecting a handful of potentially regulatory genes and morph-specific genes can give rise to novel and complex phenotypic polymorphisms.
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Affiliation(s)
- Beatriz Willink
- Department of Zoology, Stockholm University, Stockholm, Sweden.
- Department of Biological Sciences, National University of Singapore, Singapore, Singapore.
| | - Kalle Tunström
- Department of Zoology, Stockholm University, Stockholm, Sweden
| | - Sofie Nilén
- Department of Biology, Lund University, Lund, Sweden
| | - Rayan Chikhi
- Sequence Bioinformatics, Institut Pasteur, Université Paris Cité, Paris, France
| | - Téo Lemane
- University of Rennes, Inria, CNRS, IRISA, Rennes, France
| | - Michihiko Takahashi
- Graduate School of Life Sciences, Tohoku University, Sendai, Japan
- Graduate School of Agriculture, Kyoto University, Kyoto, Japan
| | - Yuma Takahashi
- Graduate School of Science, Chiba University, Chiba, Japan
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12
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Berdan EL, Barton NH, Butlin R, Charlesworth B, Faria R, Fragata I, Gilbert KJ, Jay P, Kapun M, Lotterhos KE, Mérot C, Durmaz Mitchell E, Pascual M, Peichel CL, Rafajlović M, Westram AM, Schaeffer SW, Johannesson K, Flatt T. How chromosomal inversions reorient the evolutionary process. J Evol Biol 2023; 36:1761-1782. [PMID: 37942504 DOI: 10.1111/jeb.14242] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Revised: 09/13/2023] [Accepted: 10/05/2023] [Indexed: 11/10/2023]
Abstract
Inversions are structural mutations that reverse the sequence of a chromosome segment and reduce the effective rate of recombination in the heterozygous state. They play a major role in adaptation, as well as in other evolutionary processes such as speciation. Although inversions have been studied since the 1920s, they remain difficult to investigate because the reduced recombination conferred by them strengthens the effects of drift and hitchhiking, which in turn can obscure signatures of selection. Nonetheless, numerous inversions have been found to be under selection. Given recent advances in population genetic theory and empirical study, here we review how different mechanisms of selection affect the evolution of inversions. A key difference between inversions and other mutations, such as single nucleotide variants, is that the fitness of an inversion may be affected by a larger number of frequently interacting processes. This considerably complicates the analysis of the causes underlying the evolution of inversions. We discuss the extent to which these mechanisms can be disentangled, and by which approach.
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Affiliation(s)
- Emma L Berdan
- Bioinformatics Core, Department of Biostatistics, Harvard T. H. Chan School of Public Health, Boston, Massachusetts, USA
- Department of Marine Sciences, University of Gothenburg, Gothenburg, Sweden
| | - Nicholas H Barton
- Institute of Science and Technology Austria (ISTA), Klosterneuburg, Austria
| | - Roger Butlin
- Department of Marine Sciences, University of Gothenburg, Gothenburg, Sweden
- Ecology and Evolutionary Biology, School of Bioscience, The University of Sheffield, Sheffield, UK
| | - Brian Charlesworth
- Institute of Ecology and Evolution, School of Biological Sciences, University of Edinburgh, Edinburgh, UK
| | - Rui Faria
- CIBIO-InBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, Universidade do Porto, Vairão, Portugal
- BIOPOLIS Program in Genomics, Biodiversity and Land Planning, CIBIO, Vairão, Portugal
| | - Inês Fragata
- CHANGE - Global Change and Sustainability Institute/Animal Biology Department, cE3c - Center for Ecology, Evolution and Environmental Changes, Faculty of Sciences, University of Lisbon, Lisbon, Portugal
| | | | - Paul Jay
- Center for GeoGenetics, University of Copenhagen, Copenhagen, Denmark
| | - Martin Kapun
- Center for Anatomy and Cell Biology, Medical University of Vienna, Vienna, Austria
- Central Research Laboratories, Natural History Museum of Vienna, Vienna, Austria
| | - Katie E Lotterhos
- Department of Marine and Environmental Sciences, Northeastern University, Boston, Massachusetts, USA
| | - Claire Mérot
- UMR 6553 Ecobio, Université de Rennes, OSUR, CNRS, Rennes, France
| | - Esra Durmaz Mitchell
- Department of Biology, University of Fribourg, Fribourg, Switzerland
- Functional Genomics & Metabolism Research Unit, Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense M, Denmark
| | - Marta Pascual
- Departament de Genètica, Microbiologia i Estadística, Institut de Recerca de la Biodiversitat (IRBio), Universitat de Barcelona, Barcelona, Spain
| | - Catherine L Peichel
- Division of Evolutionary Ecology, Institute of Ecology and Evolution, University of Bern, Bern, Switzerland
| | - Marina Rafajlović
- Department of Marine Sciences, University of Gothenburg, Gothenburg, Sweden
- Linnaeus Centre for Marine Evolutionary Biology, University of Gothenburg, Gothenburg, Sweden
| | - Anja M Westram
- Institute of Science and Technology Austria (ISTA), Klosterneuburg, Austria
- Faculty of Biosciences and Aquaculture, Nord University, Bodø, Norway
| | - Stephen W Schaeffer
- Department of Biology, Pennsylvania State University, University Park, Pennsylvania, USA
| | - Kerstin Johannesson
- Linnaeus Centre for Marine Evolutionary Biology, University of Gothenburg, Gothenburg, Sweden
- Tjärnö Marine Laboratory, Department of Marine Sciences, University of Gothenburg, Strömstad, Sweden
| | - Thomas Flatt
- Department of Biology, University of Fribourg, Fribourg, Switzerland
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13
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Cheatle Jarvela AM, Wexler JR. Advances in genome sequencing reveal changes in gene content that contribute to arthropod macroevolution. Dev Genes Evol 2023; 233:59-76. [PMID: 37982820 DOI: 10.1007/s00427-023-00712-y] [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: 06/16/2023] [Accepted: 11/05/2023] [Indexed: 11/21/2023]
Abstract
Current sequencing technology allows for the relatively affordable generation of highly contiguous genomes. Technological advances have made it possible for researchers to investigate the consequences of diverse sorts of genomic variants, such as gene gain and loss. With the extraordinary number of high-quality genomes now available, we take stock of how these genomic variants impact phenotypic evolution. We take care to point out that the identification of genomic variants of interest is only the first step in understanding their impact. Painstaking lab or fieldwork is still required to establish causal relationships between genomic variants and phenotypic evolution. We focus mostly on arthropod research, as this phylum has an impressive degree of phenotypic diversity and is also the subject of much evolutionary genetics research. This article is intended to both highlight recent advances in the field and also to be a primer for learning about evolutionary genetics and genomics.
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Affiliation(s)
- Alys M Cheatle Jarvela
- Department of Entomology, University of Maryland, College Park, MD, USA.
- HHMI Janelia Research Campus, Ashburn, VA, USA.
| | - Judith R Wexler
- Department of Ecology, Evolution, and Behavior, The Hebrew University in Jerusalem, Jerusalem, Israel.
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14
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Euclide PT, Larson WA, Shi Y, Gruenthal K, Christensen KA, Seeb J, Seeb L. Conserved islands of divergence associated with adaptive variation in sockeye salmon are maintained by multiple mechanisms. Mol Ecol 2023. [PMID: 37695544 DOI: 10.1111/mec.17126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Revised: 08/01/2023] [Accepted: 08/14/2023] [Indexed: 09/12/2023]
Abstract
Local adaptation is facilitated by loci clustered in relatively few regions of the genome, termed genomic islands of divergence. The mechanisms that create and maintain these islands and how they contribute to adaptive divergence is an active research topic. Here, we use sockeye salmon as a model to investigate both the mechanisms responsible for creating islands of divergence and the patterns of differentiation at these islands. Previous research suggested that multiple islands contributed to adaptive radiation of sockeye salmon. However, the low-density genomic methods used by these studies made it difficult to fully elucidate the mechanisms responsible for islands and connect genotypes to adaptive variation. We used whole genome resequencing to genotype millions of loci to investigate patterns of genetic variation at islands and the mechanisms that potentially created them. We discovered 64 islands, including 16 clustered in four genomic regions shared between two isolated populations. Characterisation of these four regions suggested that three were likely created by structural variation, while one was created by processes not involving structural variation. All four regions were small (< 600 kb), suggesting low recombination regions do not have to span megabases to be important for adaptive divergence. Differentiation at islands was not consistently associated with established population attributes. In sum, the landscape of adaptive divergence and the mechanisms that create it are complex; this complexity likely helps to facilitate fine-scale local adaptation unique to each population.
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Affiliation(s)
- Peter T Euclide
- Department of Forestry and Natural Resources, Illinois-Indiana Sea Grant, Purdue University, West Lafayette, Indiana, USA
| | - Wesley A Larson
- National Oceanographic and Atmospheric Administration, National Marine Fisheries Service, Alaska Fisheries Science Center, Auke Bay Laboratories, Juneau, Alaska, USA
| | - Yue Shi
- College of Fisheries and Ocean Sciences, University of Alaska Fairbanks, Juneau, Alaska, USA
| | - Kristen Gruenthal
- Alaska Department of Fish and Game, Juneau, Alaska, USA
- Office of Applied Science, Wisconsin Department of Natural Resources, Wisconsin Cooperative Fishery Research Unit, College of Natural Resources, University of Wisconsin-Stevens Point, Stevens Point, Wisconsin, USA
| | - Kris A Christensen
- Department of Biology, University of Victoria, Victoria, British Columbia, Canada
| | - Jim Seeb
- School of Aquatic and Fishery Sciences, University of Washington, Seattle, Washington, USA
| | - Lisa Seeb
- School of Aquatic and Fishery Sciences, University of Washington, Seattle, Washington, USA
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15
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Johnson ZV, Hegarty BE, Gruenhagen GW, Lancaster TJ, McGrath PT, Streelman JT. Cellular profiling of a recently-evolved social behavior in cichlid fishes. Nat Commun 2023; 14:4891. [PMID: 37580322 PMCID: PMC10425353 DOI: 10.1038/s41467-023-40331-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Accepted: 07/21/2023] [Indexed: 08/16/2023] Open
Abstract
Social behaviors are diverse in nature, but it is unclear how conserved genes, brain regions, and cell populations generate this diversity. Here we investigate bower-building, a recently-evolved social behavior in cichlid fishes. We use single nucleus RNA-sequencing in 38 individuals to show signatures of recent behavior in specific neuronal populations, and building-associated rebalancing of neuronal proportions in the putative homolog of the hippocampal formation. Using comparative genomics across 27 species, we trace bower-associated genome evolution to a subpopulation of glia lining the dorsal telencephalon. We show evidence that building-associated neural activity and a departure from quiescence in this glial subpopulation together regulate hippocampal-like neuronal rebalancing. Our work links behavior-associated genomic variation to specific brain cell types and their functions, and suggests a social behavior has evolved through changes in glia.
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Affiliation(s)
- Zachary V Johnson
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, 30332, USA.
- Institute of Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA, 30332, USA.
- Department of Psychiatry and Behavioral Sciences, Emory University, Atlanta, GA, USA.
- Emory National Primate Research Center, Emory University, Atlanta, GA, USA.
| | - Brianna E Hegarty
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, 30332, USA
- Institute of Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA, 30332, USA
| | - George W Gruenhagen
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, 30332, USA
- Institute of Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA, 30332, USA
| | - Tucker J Lancaster
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, 30332, USA
- Institute of Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA, 30332, USA
| | - Patrick T McGrath
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, 30332, USA.
- Institute of Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA, 30332, USA.
| | - Jeffrey T Streelman
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, 30332, USA.
- Institute of Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA, 30332, USA.
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16
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Charlesworth B. The effects of inversion polymorphisms on patterns of neutral genetic diversity. Genetics 2023; 224:iyad116. [PMID: 37348059 PMCID: PMC10411593 DOI: 10.1093/genetics/iyad116] [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: 02/23/2023] [Revised: 02/23/2023] [Accepted: 06/11/2023] [Indexed: 06/24/2023] Open
Abstract
The strong reduction in the frequency of recombination in heterozygotes for an inversion and a standard gene arrangement causes the arrangements to become partially isolated genetically, resulting in sequence divergence between them and changes in the levels of neutral variability at nucleotide sites within each arrangement class. Previous theoretical studies on the effects of inversions on neutral variability have assumed either that the population is panmictic or that it is divided into 2 populations subject to divergent selection. Here, the theory is extended to a model of an arbitrary number of demes connected by migration, using a finite island model with the inversion present at the same frequency in all demes. Recursion relations for mean pairwise coalescent times are used to obtain simple approximate expressions for diversity and divergence statistics for an inversion polymorphism at equilibrium under recombination and drift, and for the approach to equilibrium following the sweep of an inversion to a stable intermediate frequency. The effects of an inversion polymorphism on patterns of linkage disequilibrium are also examined. The reduction in effective recombination rate caused by population subdivision can have significant effects on these statistics. The theoretical results are discussed in relation to population genomic data on inversion polymorphisms, with an emphasis on Drosophila melanogaster. Methods are proposed for testing whether or not inversions are close to recombination-drift equilibrium, and for estimating the rate of recombinational exchange in heterozygotes for inversions; difficulties involved in estimating the ages of inversions are also discussed.
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Affiliation(s)
- Brian Charlesworth
- Institute of Ecology and Evolution, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3FL, UK
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17
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Villoutreix R, de Carvalho CF, Feder JL, Gompert Z, Nosil P. Disruptive selection and the evolution of discrete color morphs in Timema stick insects. SCIENCE ADVANCES 2023; 9:eabm8157. [PMID: 37000882 PMCID: PMC10065444 DOI: 10.1126/sciadv.abm8157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Accepted: 02/27/2023] [Indexed: 06/19/2023]
Abstract
A major unresolved issue in biology is why phenotypic and genetic variation is sometimes continuous, yet other times packaged into discrete units of diversity, such as morphs, ecotypes, and species. In theory, ecological discontinuities can impose strong disruptive selection that promotes the evolution of discrete forms, but direct tests of this hypothesis are lacking. Here, we show that Timema stick insects exhibit genetically determined color morphs that range from weakly to strongly discontinuous. Color data from nature and a manipulative field experiment demonstrate that greater morph differentiation is associated with shifts from host plants exhibiting more continuous color variation to those exhibiting greater coloration distance between green leaves and brown stems, the latter of which generates strong disruptive selection. Our results show how ecological factors can promote discrete variation, and we further present results on how this can have variable effects on the genetic differentiation that promotes speciation.
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Affiliation(s)
| | - Clarissa F. de Carvalho
- CEFE, Université Montpellier, CNRS, EPHE, IRD, Montpellier, France
- Departamento de Ecologia e Biologia Evolutiva, UNIFESP, Diadema 09972-270, Brazil
| | - Jeffrey L. Feder
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN 46556, USA
| | | | - Patrik Nosil
- CEFE, Université Montpellier, CNRS, EPHE, IRD, Montpellier, France
- Department of Biology, Utah State University, Logan, UT 84322, USA
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18
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Blacher P, De Gasperin O, Grasso G, Sarton-Lohéac S, Allemann R, Chapuisat M. Cryptic recessive lethality of a supergene controlling social organization in ants. Mol Ecol 2023; 32:1062-1072. [PMID: 36504171 DOI: 10.1111/mec.16821] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Revised: 11/23/2022] [Accepted: 12/05/2022] [Indexed: 12/14/2022]
Abstract
Supergenes are clusters of linked loci that control complex phenotypes, such as alternative forms of social organization in ants. Explaining the long-term maintenance of supergenes is challenging, particularly when the derived haplotype lacks homozygous lethality and causes gene drive. In the Alpine silver ant, Formica selysi, a large and ancient social supergene with two haplotypes, M and P, controls colony social organization. Single-queen colonies only contain MM females, while multiqueen colonies contain MP and PP females. The derived P haplotype, found only in multiqueen colonies, selfishly enhances its transmission through maternal effect killing, which could have led to its fixation. A population genetic model showed that a stable social polymorphism can only be maintained under a narrow set of conditions, which includes partial assortative mating by social form (which is known to occur in the wild), and low fitness of PP queens. With a combination of field and laboratory experiments, we show that the P haplotype has deleterious effects on female fitness. The survival rate of PP queens and workers was around half that of other genotypes. Moreover, P-carrying queens had lower fertility and fecundity compared to other queens. We discuss how cryptic lethal effects of the P haplotype help stabilize this ancient polymorphism.
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Affiliation(s)
- Pierre Blacher
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland
| | - Ornela De Gasperin
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland.,Red de Ecoetología, Instituto de Ecología A. C., Veracruz, Mexico
| | - Guglielmo Grasso
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland.,University of Manchester, Manchester, UK
| | - Solenn Sarton-Lohéac
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland
| | - Roxane Allemann
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland
| | - Michel Chapuisat
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland
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19
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Komata S, Yoda S, KonDo Y, Shinozaki S, Tamai K, Fujiwara H. Functional unit of supergene in female-limited Batesian mimicry of Papilio polytes. Genetics 2023; 223:iyac177. [PMID: 36454671 PMCID: PMC9910408 DOI: 10.1093/genetics/iyac177] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Revised: 11/14/2022] [Accepted: 11/14/2022] [Indexed: 12/05/2022] Open
Abstract
Supergenes are sets of genes and genetic elements that are inherited like a single gene and control complex adaptive traits, but their functional roles and units are poorly understood. In Papilio polytes, female-limited Batesian mimicry is thought to be regulated by a ∼130 kb inversion region (highly diversified region: HDR) containing 3 genes, UXT, U3X, and doublesex (dsx) which switches non-mimetic and mimetic types. To determine the functional unit, we here performed electroporation-mediated RNAi analyses (and further Crispr/Cas9 for UXT) of genes within and flanking the HDR in pupal hindwings. We first clarified that non-mimetic dsx-h had a function to form the non-mimetic trait in female and only dsx-H isoform 3 had an important function in the formation of mimetic traits. Next, we found that UXT was involved in making mimetic-type pale-yellow spots and adjacent gene sir2 in making red spots in hindwings, both of which refine more elaborate mimicry. Furthermore, downstream gene networks of dsx, U3X, and UXT screened by RNA sequencing showed that U3X upregulated dsx-H expression and repressed UXT expression. These findings demonstrate that a set of multiple genes, not only inside but also flanking HDR, can function as supergene members, which extends the definition of supergene unit than we considered before. Also, our results indicate that dsx functions as the switching gene and some other genes such as UXT and sir2 within the supergene unit work as the modifier gene.
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Affiliation(s)
- Shinya Komata
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Chiba 277-8562, Japan
| | - Shinichi Yoda
- NIBB Core Research Facilities, National Institute for Basic Biology, Okazaki, 444-8585, Japan
| | - Yûsuke KonDo
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Chiba 277-8562, Japan
| | - Souta Shinozaki
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Chiba 277-8562, Japan
| | - Kouki Tamai
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Chiba 277-8562, Japan
| | - Haruhiko Fujiwara
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Chiba 277-8562, Japan
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20
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Krysanov EY, Nagy B, Watters BR, Sember A, Simanovsky SA. Karyotype differentiation in the Nothobranchiusugandensis species group (Teleostei, Cyprinodontiformes), seasonal fishes from the east African inland plateau, in the context of phylogeny and biogeography. COMPARATIVE CYTOGENETICS 2023; 17:13-29. [PMID: 37305809 PMCID: PMC10252138 DOI: 10.3897/compcytogen.v7.i1.97165] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Accepted: 01/04/2023] [Indexed: 06/13/2023]
Abstract
The karyotype differentiation of the twelve known members of the Nothobranchiusugandensis Wildekamp, 1994 species group is reviewed and the karyotype composition of seven of its species is described herein for the first time using a conventional cytogenetic protocol. Changes in the architecture of eukaryotic genomes often have a major impact on processes underlying reproductive isolation, adaptation and diversification. African annual killifishes of the genus Nothobranchius Peters, 1868 (Teleostei: Nothobranchiidae), which are adapted to an extreme environment of ephemeral wetland pools in African savannahs, feature extensive karyotype evolution in small, isolated populations and thus are suitable models for studying the interplay between karyotype change and species evolution. The present investigation reveals a highly conserved diploid chromosome number (2n = 36) but a variable number of chromosomal arms (46-64) among members of the N.ugandensis species group, implying a significant role of pericentric inversions and/or other types of centromeric shift in the karyotype evolution of the group. When superimposed onto a phylogenetic tree based on molecular analyses of two mitochondrial genes the cytogenetic characteristics did not show any correlation with the phylogenetic relationships within the lineage. While karyotypes of many other Nothobranchius spp. studied to date diversified mainly via chromosome fusions and fissions, the N.ugandensis species group maintains stable 2n and the karyotype differentiation seems to be constrained to intrachromosomal rearrangements. Possible reasons for this difference in the trajectory of karyotype differentiation are discussed. While genetic drift seems to be a major factor in the fixation of chromosome rearrangements in Nothobranchius, future studies are needed to assess the impact of predicted multiple inversions on the genome evolution and species diversification within the N.ugandensis species group.
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Affiliation(s)
- Eugene Yu. Krysanov
- Severtsov Institute of Ecology and Evolution, Russian
Academy of Sciences, Leninsky Prospect 33, 119071, Moscow, RussiaSevertsov Institute of Ecology and Evolution, Russian Academy of
SciencesMoscowRussia
| | - Béla Nagy
- 15, voie de la Liberté, 77870, Vulaines sur Seine,
FranceUnaffiliatedVulaines sur SeineFrance
| | - Brian R. Watters
- 6141 Parkwood Drive, Nanaimo, British Columbia V9T 6A2,
Nanaimo, CanadaUnaffiliatedNanaimoCanada
| | - Alexandr Sember
- Laboratory of Fish Genetics, Institute of Animal
Physiology and Genetics, Czech Academy of Sciences, Rumburská 89, 27721, Liběchov, Czech
RepublicLaboratory of Fish Genetics, Institute of Animal Physiology and Genetics, Czech
Academy of SciencesLiběchovCzech Republic
| | - Sergey A. Simanovsky
- Severtsov Institute of Ecology and Evolution, Russian
Academy of Sciences, Leninsky Prospect 33, 119071, Moscow, RussiaSevertsov Institute of Ecology and Evolution, Russian Academy of
SciencesMoscowRussia
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21
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Campoy E, Puig M, Yakymenko I, Lerga-Jaso J, Cáceres M. Genomic architecture and functional effects of potential human inversion supergenes. Philos Trans R Soc Lond B Biol Sci 2022; 377:20210209. [PMID: 35694745 PMCID: PMC9189494 DOI: 10.1098/rstb.2021.0209] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Supergenes are involved in adaptation in multiple organisms, but they are little known in humans. Genomic inversions are the most common mechanism of supergene generation and maintenance. Here, we review the information about two large inversions that are the best examples of potential human supergenes. In addition, we do an integrative analysis of the newest data to understand better their functional effects and underlying genetic changes. We have found that the highly divergent haplotypes of the 17q21.31 inversion of approximately 1.5 Mb have multiple phenotypic associations, with consistent effects in brain-related traits, red and white blood cells, lung function, male and female characteristics and disease risk. By combining gene expression and nucleotide variation data, we also analysed the molecular differences between haplotypes, including gene duplications, amino acid substitutions and regulatory changes, and identify CRHR1, KANLS1 and MAPT as good candidates to be responsible for these phenotypes. The situation is more complex for the 8p23.1 inversion, where there is no clear genetic differentiation. However, the inversion is associated with several related phenotypes and gene expression differences that could be linked to haplotypes specific of one orientation. Our work, therefore, contributes to the characterization of both exceptional variants and illustrates the important role of inversions. This article is part of the theme issue 'Genomic architecture of supergenes: causes and evolutionary consequences'.
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Affiliation(s)
- Elena Campoy
- Institut de Biotecnologia i de Biomedicina, Universitat Autònoma de Barcelona, Bellaterra (Barcelona), Spain
| | - Marta Puig
- Institut de Biotecnologia i de Biomedicina, Universitat Autònoma de Barcelona, Bellaterra (Barcelona), Spain.,Departament de Genètica i de Microbiologia, Universitat Autònoma de Barcelona, Bellaterra (Barcelona), Spain
| | - Illya Yakymenko
- Institut de Biotecnologia i de Biomedicina, Universitat Autònoma de Barcelona, Bellaterra (Barcelona), Spain
| | - Jon Lerga-Jaso
- Institut de Biotecnologia i de Biomedicina, Universitat Autònoma de Barcelona, Bellaterra (Barcelona), Spain
| | - Mario Cáceres
- Institut de Biotecnologia i de Biomedicina, Universitat Autònoma de Barcelona, Bellaterra (Barcelona), Spain.,ICREA, Barcelona, Spain
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22
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Stenløkk K, Saitou M, Rud-Johansen L, Nome T, Moser M, Árnyasi M, Kent M, Barson NJ, Lien S. The emergence of supergenes from inversions in Atlantic salmon. Philos Trans R Soc Lond B Biol Sci 2022; 377:20210195. [PMID: 35694753 PMCID: PMC9189505 DOI: 10.1098/rstb.2021.0195] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Accepted: 03/31/2022] [Indexed: 12/14/2022] Open
Abstract
Supergenes link allelic combinations into non-recombining units known to play an essential role in maintaining adaptive genetic variation. However, because supergenes can be maintained over millions of years by balancing selection and typically exhibit strong recombination suppression, both the underlying functional variants and how the supergenes are formed are largely unknown. Particularly, questions remain over the importance of inversion breakpoint sequences and whether supergenes capture pre-existing adaptive variation or accumulate this following recombination suppression. To investigate the process of supergene formation, we identified inversion polymorphisms in Atlantic salmon by assembling eleven genomes with nanopore long-read sequencing technology. A genome assembly from the sister species, brown trout, was used to determine the standard state of the inversions. We found evidence for adaptive variation through genotype-environment associations, but not for the accumulation of deleterious mutations. One young 3 Mb inversion segregating in North American populations has captured adaptive variation that is still segregating within the standard arrangement of the inversion, while some adaptive variation has accumulated after the inversion. This inversion and two others had breakpoints disrupting genes. Three multigene inversions with matched repeat structures at the breakpoints did not show any supergene signatures, suggesting that shared breakpoint repeats may obstruct supergene formation. This article is part of the theme issue 'Genomic architecture of supergenes: causes and evolutionary consequences'.
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Affiliation(s)
- Kristina Stenløkk
- Centre for Integrative Genetics (CIGENE) and Department of Animal and Aquacultural Sciences, Faculty of Biosciences, Norwegian University of Life Sciences, As, Norway
| | - Marie Saitou
- Centre for Integrative Genetics (CIGENE) and Department of Animal and Aquacultural Sciences, Faculty of Biosciences, Norwegian University of Life Sciences, As, Norway
| | - Live Rud-Johansen
- Centre for Integrative Genetics (CIGENE) and Department of Animal and Aquacultural Sciences, Faculty of Biosciences, Norwegian University of Life Sciences, As, Norway
| | - Torfinn Nome
- Centre for Integrative Genetics (CIGENE) and Department of Animal and Aquacultural Sciences, Faculty of Biosciences, Norwegian University of Life Sciences, As, Norway
| | - Michel Moser
- Centre for Integrative Genetics (CIGENE) and Department of Animal and Aquacultural Sciences, Faculty of Biosciences, Norwegian University of Life Sciences, As, Norway
| | - Mariann Árnyasi
- Centre for Integrative Genetics (CIGENE) and Department of Animal and Aquacultural Sciences, Faculty of Biosciences, Norwegian University of Life Sciences, As, Norway
| | - Matthew Kent
- Centre for Integrative Genetics (CIGENE) and Department of Animal and Aquacultural Sciences, Faculty of Biosciences, Norwegian University of Life Sciences, As, Norway
| | - Nicola Jane Barson
- Centre for Integrative Genetics (CIGENE) and Department of Animal and Aquacultural Sciences, Faculty of Biosciences, Norwegian University of Life Sciences, As, Norway
| | - Sigbjørn Lien
- Centre for Integrative Genetics (CIGENE) and Department of Animal and Aquacultural Sciences, Faculty of Biosciences, Norwegian University of Life Sciences, As, Norway
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23
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Komata S, Kajitani R, Itoh T, Fujiwara H. Genomic architecture and functional unit of mimicry supergene in female limited Batesian mimic Papilio butterflies. Philos Trans R Soc Lond B Biol Sci 2022; 377:20210198. [PMID: 35694751 PMCID: PMC9189499 DOI: 10.1098/rstb.2021.0198] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Accepted: 03/17/2022] [Indexed: 11/12/2022] Open
Abstract
It has long been suggested that dimorphic female-limited Batesian mimicry of two closely related Papilio butterflies, Papilio memnon and Papilio polytes, is controlled by supergenes. Whole-genome sequencing, genome-wide association studies and functional analyses have recently identified mimicry supergenes, including the doublesex (dsx) gene. Although supergenes of both the species are composed of highly divergent regions between mimetic and non-mimetic alleles and are located at the same chromosomal locus, they show critical differences in genomic architecture, particularly with or without an inversion: P. polytes has an inversion, but P. memnon does not. This review introduces and compares the detailed genomic structure of mimicry supergenes in two Papilio species, including gene composition, repetitive sequence composition, breakpoint/boundary site structure, chromosomal inversion and linkage disequilibrium. Expression patterns and functional analyses of the respective genes within or flanking the supergene suggest that dsx and other genes are involved in mimetic traits. In addition, structural comparison of the corresponding region for the mimicry supergene among further Papilio species suggests three scenarios for the evolution of the mimicry supergene between the two Papilio species. The structural features revealed in the Papilio mimicry supergene provide insight into the formation, maintenance and evolution of supergenes. This article is part of the theme issue 'Genomic architecture of supergenes: causes and evolutionary consequences'.
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Affiliation(s)
- Shinya Komata
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Chiba 277-8562, Japan
| | - Rei Kajitani
- School of Life Science and Technology, Tokyo Institute of Technology, Meguro-ku, Tokyo 152-8550, Japan
| | - Takehiko Itoh
- School of Life Science and Technology, Tokyo Institute of Technology, Meguro-ku, Tokyo 152-8550, Japan
| | - Haruhiko Fujiwara
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Chiba 277-8562, Japan
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24
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Jay P, Leroy M, Le Poul Y, Whibley A, Arias M, Chouteau M, Joron M. Association mapping of colour variation in a butterfly provides evidence that a supergene locks together a cluster of adaptive loci. Philos Trans R Soc Lond B Biol Sci 2022; 377:20210193. [PMID: 35694756 PMCID: PMC9189503 DOI: 10.1098/rstb.2021.0193] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Supergenes are genetic architectures associated with discrete and concerted variation in multiple traits. It has long been suggested that supergenes control these complex polymorphisms by suppressing recombination between sets of coadapted genes. However, because recombination suppression hinders the dissociation of the individual effects of genes within supergenes, there is still little evidence that supergenes evolve by tightening linkage between coadapted genes. Here, combining a landmark-free phenotyping algorithm with multivariate genome-wide association studies, we dissected the genetic basis of wing pattern variation in the butterfly Heliconius numata. We show that the supergene controlling the striking wing pattern polymorphism displayed by this species contains several independent loci associated with different features of wing patterns. The three chromosomal inversions of this supergene suppress recombination between these loci, supporting the hypothesis that they may have evolved because they captured beneficial combinations of alleles. Some of these loci are, however, associated with colour variations only in a subset of morphs where the phenotype is controlled by derived inversion forms, indicating that they were recruited after the formation of the inversions. Our study shows that supergenes and clusters of adaptive loci in general may form via the evolution of chromosomal rearrangements suppressing recombination between co-adapted loci but also via the subsequent recruitment of linked adaptive mutations. This article is part of the theme issue 'Genomic architecture of supergenes: causes and evolutionary consequences'.
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Affiliation(s)
- Paul Jay
- CEFE, Université de Montpellier, CNRS, EPHE, IRD, 34293 Montpellier cedex 5, France
| | - Manon Leroy
- CEFE, Université de Montpellier, CNRS, EPHE, IRD, 34293 Montpellier cedex 5, France
| | - Yann Le Poul
- CEFE, Université de Montpellier, CNRS, EPHE, IRD, 34293 Montpellier cedex 5, France
| | - Annabel Whibley
- School of Biological Sciences, University of Auckland, Auckland 1010, New Zealand
| | - Mónica Arias
- CIRAD, UMR PHIM, F-34398 Montpellier, France.,PHIM, Univ Montpellier, CIRAD, INRAE, Institut Agro, IRD, CEDEX 5, 34398 Montpellier, France
| | - Mathieu Chouteau
- CEFE, Université de Montpellier, CNRS, EPHE, IRD, 34293 Montpellier cedex 5, France.,LEEISA, USR 63456, Université de Guyane, CNRS, IFREMER, 275 route de Montabo, 797334 Cayenne, French Guiana
| | - Mathieu Joron
- CEFE, Université de Montpellier, CNRS, EPHE, IRD, 34293 Montpellier cedex 5, France
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25
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Calboli FCF, Koskinen H, Nousianen A, Fraslin C, Houston RD, Kause A. Conserved QTL and chromosomal inversion affect resistance to columnaris disease in 2 rainbow trout ( Oncorhyncus mykiss) populations. G3 GENES|GENOMES|GENETICS 2022; 12:6603111. [PMID: 35666190 PMCID: PMC9339330 DOI: 10.1093/g3journal/jkac137] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Accepted: 05/26/2022] [Indexed: 11/20/2022]
Abstract
We present a comparative genetic analysis of the quantitative trait loci underlying resistance to warm water columnaris disease in 2 farmed rainbow trout (Oncorhynchus mykiss) populations. We provide evidence for the conservation of a major quantitative trait loci on Omy03, and the putative role played by a chromosomal rearrangement on Omy05. A total of 3,962 individuals from the 2 populations experienced a natural Flavobacterium columnare outbreak. Data for 25,823 genome-wide SNPs were generated for both cases (fatalities) and controls (survivors). FST and pairwise additive genetic relationships suggest that, despite being currently kept as separate broodstocks, the 2 populations are closely related. Association analyses identified a major quantitative trait loci on chromosome Omy03 and a second smaller quantitative trait loci on Omy05. Quantitative trait loci on Omy03 consistently explained 3–11% of genetic variation in both populations, whereas quantitative trait loci on Omy05 showed different degree of association across populations and sexes. The quantitative trait loci on Omy05 was found within a naturally occurring, 54.84 cM long inversion which is easy to tag due to a strong linkage disequilibrium between the 375 tagging SNPs. The ancestral haplotype on Omy05 was associated with decreased mortality. Genetic correlation between mortality in the 2 populations was estimated at 0.64, implying that the genetic basis of resistance is partly similar in the 2 populations. Our quantitative trait loci validation identifies markers that can be potentially used to complement breeding value evaluations to increase resistance against columnaris disease, and help to mitigate effects of climate change on aquaculture.
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Affiliation(s)
| | - Heikki Koskinen
- Natural Resources Institute Finland (LUKE) , FI-70210 Kuopio, Finland
| | - Antti Nousianen
- Natural Resources Institute Finland (LUKE) , FI-70210 Kuopio, Finland
| | - Clémence Fraslin
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh , Easter Bush EH25 9RG, UK
| | - Ross D Houston
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh , Easter Bush EH25 9RG, UK
| | - Antti Kause
- Natural Resources Institute Finland (LUKE) , FI-31600 Jokioinen, Finland
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26
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Abstract
Speciation is the process by which barriers to gene flow evolve between populations. Although we now know that speciation is largely driven by natural selection, knowledge of the agents of selection and the genetic and genomic mechanisms that facilitate divergence is required for a satisfactory theory of speciation. In this essay, we highlight three advances/problems in our understanding of speciation that have arisen from studies of the genes and genomic regions that underlie the evolution of reproductive isolation. First, we describe how the identification of “speciation” genes makes it possible to identify the agents of selection causing the evolution of reproductive isolation, while also noting that the link between the genetics of phenotypic divergence and intrinsic postzygotic reproductive barriers remains tenuous. Second, we discuss the important role of recombination suppressors in facilitating speciation with gene flow, but point out that the means and timing by which reproductive barriers become associated with recombination cold spots remains uncertain. Third, we establish the importance of ancient genetic variation in speciation, although we argue that the focus of speciation studies on evolutionarily young groups may bias conclusions in favor of ancient variation relative to new mutations.
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27
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Hager ER, Harringmeyer OS, Wooldridge TB, Theingi S, Gable JT, McFadden S, Neugeboren B, Turner KM, Jensen JD, Hoekstra HE. A chromosomal inversion contributes to divergence in multiple traits between deer mouse ecotypes. Science 2022; 377:399-405. [PMID: 35862520 PMCID: PMC9571565 DOI: 10.1126/science.abg0718] [Citation(s) in RCA: 35] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
How locally adapted ecotypes are established and maintained within a species is a long-standing question in evolutionary biology. Using forest and prairie ecotypes of deer mice (Peromyscus maniculatus), we characterized the genetic basis of variation in two defining traits-tail length and coat color-and discovered a 41-megabase chromosomal inversion linked to both. The inversion frequency is 90% in the dark, long-tailed forest ecotype; decreases across a habitat transition; and is absent from the light, short-tailed prairie ecotype. We implicate divergent selection in maintaining the inversion at frequencies observed in the wild, despite high levels of gene flow, and explore fitness benefits that arise from suppressed recombination within the inversion. We uncover a key role for a large, previously uncharacterized inversion in the evolution and maintenance of classic mammalian ecotypes.
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Affiliation(s)
- Emily R Hager
- Department of Molecular and Cellular Biology, Department of Organismic and Evolutionary Biology, Museum of Comparative Zoology, and Howard Hughes Medical Institute, Harvard University, Cambridge, MA 02138, USA
| | - Olivia S Harringmeyer
- Department of Molecular and Cellular Biology, Department of Organismic and Evolutionary Biology, Museum of Comparative Zoology, and Howard Hughes Medical Institute, Harvard University, Cambridge, MA 02138, USA
| | - T Brock Wooldridge
- Department of Molecular and Cellular Biology, Department of Organismic and Evolutionary Biology, Museum of Comparative Zoology, and Howard Hughes Medical Institute, Harvard University, Cambridge, MA 02138, USA
| | - Shunn Theingi
- Department of Molecular and Cellular Biology, Department of Organismic and Evolutionary Biology, Museum of Comparative Zoology, and Howard Hughes Medical Institute, Harvard University, Cambridge, MA 02138, USA
| | - Jacob T Gable
- Department of Molecular and Cellular Biology, Department of Organismic and Evolutionary Biology, Museum of Comparative Zoology, and Howard Hughes Medical Institute, Harvard University, Cambridge, MA 02138, USA
| | - Sade McFadden
- Department of Molecular and Cellular Biology, Department of Organismic and Evolutionary Biology, Museum of Comparative Zoology, and Howard Hughes Medical Institute, Harvard University, Cambridge, MA 02138, USA
| | - Beverly Neugeboren
- Department of Molecular and Cellular Biology, Department of Organismic and Evolutionary Biology, Museum of Comparative Zoology, and Howard Hughes Medical Institute, Harvard University, Cambridge, MA 02138, USA
| | - Kyle M Turner
- Department of Molecular and Cellular Biology, Department of Organismic and Evolutionary Biology, Museum of Comparative Zoology, and Howard Hughes Medical Institute, Harvard University, Cambridge, MA 02138, USA
| | - Jeffrey D Jensen
- School of Life Sciences, Arizona State University, Tempe, AZ 85287, USA
| | - Hopi E Hoekstra
- Department of Molecular and Cellular Biology, Department of Organismic and Evolutionary Biology, Museum of Comparative Zoology, and Howard Hughes Medical Institute, Harvard University, Cambridge, MA 02138, USA
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28
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Villoutreix R, de Carvalho CF, Gompert Z, Parchman TL, Feder JL, Nosil P. Testing for fitness epistasis in a transplant experiment identifies a candidate adaptive locus in Timema stick insects. Philos Trans R Soc Lond B Biol Sci 2022; 377:20200508. [PMID: 35634927 PMCID: PMC9149791 DOI: 10.1098/rstb.2020.0508] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Accepted: 12/18/2021] [Indexed: 07/20/2023] Open
Abstract
Identifying the genetic basis of adaptation is a central goal of evolutionary biology. However, identifying genes and mutations affecting fitness remains challenging because a large number of traits and variants can influence fitness. Selected phenotypes can also be difficult to know a priori, complicating top-down genetic approaches for trait mapping that involve crosses or genome-wide association studies. In such cases, experimental genetic approaches, where one maps fitness directly and attempts to infer the traits involved afterwards, can be valuable. Here, we re-analyse data from a transplant experiment involving Timema stick insects, where five physically clustered single-nucleotide polymorphisms associated with cryptic body coloration were shown to interact to affect survival. Our analysis covers a larger genomic region than past work and revealed a locus previously not identified as associated with survival. This locus resides near a gene, Punch (Pu), involved in pteridine pigments production, implying that it could be associated with an unmeasured coloration trait. However, by combining previous and newly obtained phenotypic data, we show that this trait is not eye or body coloration. We discuss the implications of our results for the discovery of traits, genes and mutations associated with fitness in other systems, as well as for supergene evolution. This article is part of the theme issue 'Genetic basis of adaptation and speciation: from loci to causative mutations'.
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Affiliation(s)
- Romain Villoutreix
- CEFE, Univ Montpellier, CNRS, EPHE, IRD, Univ Paul Valéry Montpellier 3, Montpellier 34293, France
| | | | | | | | - Jeffrey L. Feder
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN 46556, USA
| | - Patrik Nosil
- CEFE, Univ Montpellier, CNRS, EPHE, IRD, Univ Paul Valéry Montpellier 3, Montpellier 34293, France
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29
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Olito C, Ponnikas S, Hansson B, Abbott JK. Consequences of partially recessive deleterious genetic variation for the evolution of inversions suppressing recombination between sex chromosomes. Evolution 2022; 76:1320-1330. [PMID: 35482933 PMCID: PMC9324078 DOI: 10.1111/evo.14496] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Accepted: 03/15/2022] [Indexed: 01/21/2023]
Abstract
The evolution of suppressed recombination between sex chromosomes is widely hypothesized to be driven by sexually antagonistic selection (SA), where tighter linkage between the sex-determining gene(s) and nearby SA loci is favored when it couples male-beneficial alleles to the proto-Y chromosome, and female-beneficial alleles to the proto-X. Despite limited empirical evidence, the SA selection hypothesis overshadows several alternatives, including an incomplete but often-repeated "sheltering hypothesis" that suggests that expansion of the sex-linked region (SLR) reduces homozygous expression of partially recessive deleterious mutations at selected loci. Here, we use population genetic models to evaluate the consequences of deleterious mutational variation for the evolution of neutral chromosomal inversions expanding the SLR on proto-Y chromosomes. We find that SLR-expanding inversions face a race against time: lightly loaded inversions are initially beneficial, but eventually become deleterious as they accumulate new mutations, and must fix before this window of opportunity closes. The outcome of this race is strongly influenced by inversion size, the mutation rate, and the dominance coefficient of deleterious mutations. Yet, small inversions have elevated fixation probabilities relative to neutral expectations for biologically plausible parameter values. Our results demonstrate that deleterious genetic variation can plausibly drive recombination suppression in small steps and would be most consistent with empirical patterns of small evolutionary strata or gradual recombination arrest.
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Affiliation(s)
- Colin Olito
- Department of BiologyLund UniversityLund22362Sweden
| | - Suvi Ponnikas
- Department of BiologyLund UniversityLund22362Sweden
- Current address: Ecology and Genetics Research UnitUniversity of OuluOulu90014Finland
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30
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Laurentino TG, Boileau N, Ronco F, Berner D. The ectodysplasin-A receptor is a candidate gene for lateral plate number variation in stickleback fish. G3 (BETHESDA, MD.) 2022; 12:jkac077. [PMID: 35377433 PMCID: PMC9157104 DOI: 10.1093/g3journal/jkac077] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Accepted: 03/28/2022] [Indexed: 02/04/2023]
Abstract
Variation in lateral plating in stickleback fish represents a classical example of rapid and parallel adaptation in morphology. The underlying genetic architecture involves polymorphism at the ectodysplasin-A gene (EDA). However, lateral plate number is influenced by additional loci that remain poorly characterized. Here, we search for such loci by performing genome-wide differentiation mapping based on pooled whole-genome sequence data from a European stickleback population variable in the extent of lateral plating, while tightly controlling for the phenotypic effect of EDA. This suggests a new candidate locus, the EDA receptor gene (EDAR), for which additional support is obtained by individual-level targeted Sanger sequencing and by comparing allele frequencies among natural populations. Overall, our study illustrates the power of pooled whole-genome sequencing for searching phenotypically relevant loci and opens opportunities for exploring the population genetics and ecological significance of a new candidate locus for stickleback armor evolution.
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Affiliation(s)
- Telma G Laurentino
- Department of Environmental Sciences, Zoology, University of Basel, 4051 Basel, Switzerland
- Department of Environmental Science, Policy, and Management, University of California, Berkeley, CA 94720, USA
| | - Nicolas Boileau
- Department of Environmental Sciences, Zoology, University of Basel, 4051 Basel, Switzerland
| | - Fabrizia Ronco
- Department of Environmental Sciences, Zoology, University of Basel, 4051 Basel, Switzerland
| | - Daniel Berner
- Department of Environmental Sciences, Zoology, University of Basel, 4051 Basel, Switzerland
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31
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Rieseberg L, Warschefsky E, O'Boyle B, Taberlet P, Ortiz-Barrientos D, Kane NC, Sibbett B. Editorial 2022. Mol Ecol 2021; 31:1-30. [PMID: 34957606 DOI: 10.1111/mec.16328] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Accepted: 12/10/2021] [Indexed: 11/30/2022]
Affiliation(s)
- Loren Rieseberg
- Department of Botany, University of British Columbia, Vancouver, British Columbia, Canada
| | | | | | - Pierre Taberlet
- Laboratoire d'Ecologie Alpine, CNRS UMR 5553, Université Univ. Grenoble Alpes, Grenoble Cedex 9, France
| | - Daniel Ortiz-Barrientos
- School of Biological Sciences, The University of Queenland, St. Lucia, Queensland, Australia
| | - Nolan C Kane
- University of Colorado at Boulder, Boulder, Colorado, USA
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32
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Guzmán NV, Kemppainen P, Monti D, Castillo ERD, Rodriguero MS, Sánchez-Restrepo AF, Cigliano MM, Confalonieri VA. Stable inversion clines in a grasshopper species group despite complex geographical history. Mol Ecol 2021; 31:1196-1215. [PMID: 34862997 DOI: 10.1111/mec.16305] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Revised: 11/24/2021] [Accepted: 11/29/2021] [Indexed: 11/27/2022]
Abstract
Chromosomal inversions are known to play roles in adaptation and differentiation in many species. They involve clusters of correlated genes (i.e., loci in linkage disequilibrium, LD) possibly associated with environmental variables. The grasshopper "species complex" Trimerotropis pallidipennis comprises several genetic lineages distributed from North to South America in arid and semi-arid high-altitude environments. The southernmost lineage, Trimerotropis sp., segregates for four to seven putative inversions that display clinal variation, possibly through adaptation to temperate environments. We analysed chromosomal, mitochondrial and genome-wide single nucleotide polymorphism data in 19 Trimerotropis sp. populations mainly distributed along two altitudinal gradients (MS and Ju). Populations across Argentina comprise two main chromosomally and genetically differentiated lineages: one distributed across the southernmost border of the "Andes Centrales," adding evidence for a differentiation hotspot in this area; and the other widely distributed in Argentina. Within the latter, network analytical approaches to LD found three clusters of correlated loci (LD-clusters), with inversion karyotypes explaining >79% of the genetic variation. Outlier loci associated with environmental variables mapped to two of these LD-clusters. Furthermore, despite the complex geographical history indicated by population genetic analyses, the clines in inversion karyotypes have remained stable for more than 20 generations, implicating their role in adaptation and differentiation within this lineage. We hypothesize that these clines could be the consequence of a coupling between extrinsic postzygotic barriers and spatially varying selection along environmental gradients resulting in a hybrid zone. These results provide a framework for future investigations about candidate genes implicated in rapid adaptation to new environments.
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Affiliation(s)
- Noelia V Guzmán
- Departamento de Ecología, Genética y Evolución, FCEyN, Universidad de Buenos Aires (UBA), IEGEBA (Consejo Nacional de Investigaciones Científicas y Tecnológicas (CONICET)/UBA), Ciudad Universitaria, Buenos Aires, Argentina
| | - Petri Kemppainen
- Ecological Genetics Research Unit, Organismal and Evolutionary Biology Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
| | - Daniela Monti
- Departamento de Ecología, Genética y Evolución, FCEyN, Universidad de Buenos Aires (UBA), IEGEBA (Consejo Nacional de Investigaciones Científicas y Tecnológicas (CONICET)/UBA), Ciudad Universitaria, Buenos Aires, Argentina
| | - Elio R D Castillo
- Laboratorio de Genética Evolutiva "Dr. Claudio J. Bidau", FCEQyN, Universidad Nacional de Misiones (UNaM), Instituto de Biología Subtropical (IBS) (CONICET/UNaM), LQH, Posadas, Misiones, Argentina
| | - Marcela S Rodriguero
- Departamento de Ecología, Genética y Evolución, FCEyN, Universidad de Buenos Aires (UBA), IEGEBA (Consejo Nacional de Investigaciones Científicas y Tecnológicas (CONICET)/UBA), Ciudad Universitaria, Buenos Aires, Argentina
| | - Andrés F Sánchez-Restrepo
- Departamento de Ecología, Genética y Evolución, FCEyN, Universidad de Buenos Aires (UBA), IEGEBA (Consejo Nacional de Investigaciones Científicas y Tecnológicas (CONICET)/UBA), Ciudad Universitaria, Buenos Aires, Argentina.,Fundación para el Estudio de Especies Invasivas (FuEDEI), Hurlingham, Buenos Aires, Argentina
| | - Maria Marta Cigliano
- Museo de La Plata, Centro de Estudios Parasitológicos y de Vectores (CEPAVE- CONICET/UNLP), Universidad Nacional de la Plata, Buenos Aires, Argentina
| | - Viviana A Confalonieri
- Departamento de Ecología, Genética y Evolución, FCEyN, Universidad de Buenos Aires (UBA), IEGEBA (Consejo Nacional de Investigaciones Científicas y Tecnológicas (CONICET)/UBA), Ciudad Universitaria, Buenos Aires, Argentina
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33
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Connallon T, Olito C. Natural selection and the distribution of chromosomal inversion lengths. Mol Ecol 2021; 31:3627-3641. [PMID: 34297880 DOI: 10.1111/mec.16091] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Revised: 07/16/2021] [Accepted: 07/19/2021] [Indexed: 11/28/2022]
Abstract
Chromosomal inversions contribute substantially to genome evolution, yet the processes governing their evolutionary dynamics remain poorly understood. Theory suggests that a readily measurable property of inversions-their length-can potentially affect their evolutionary fates. Emerging data on the lengths of polymorphic and fixed inversions may therefore provide clues to the evolutionary processes promoting inversion establishment. However, formal predictions for the distribution of inversion lengths remain incomplete, making empirical patterns difficult to interpret. We model the relation between inversion length and establishment probability for four inversion types: (1) neutral, (2) underdominant, (3) directly beneficial, and (4) indirectly beneficial, with selection favouring the latter because they capture locally adapted alleles at migration-selection balance and suppress recombination between them. We also consider how deleterious mutations affect the lengths of established inversions. We show that length distributions of common polymorphic and fixed inversions systematically differ among inversion types. Small rearrangements contribute the most to genome evolution under neutral and underdominant scenarios of selection, with the lengths of neutral inversion substitutions increasing, and those of underdominant substitutions decreasing, with effective population size. Among directly beneficial inversions, small rearrangements are preferentially fixed, whereas intermediate-to-large inversions are maintained as balanced polymorphisms via associative overdominance. Finally, inversions established under the local adaptation scenario are predominantly intermediate-to-large. Such inversions remain polymorphic or approach fixation within the local populations where they are favoured. Our models clarify how inversion length distributions relate to processes of inversion establishment, providing a platform for testing how natural selection shapes the evolution of genome structure.
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Affiliation(s)
- Tim Connallon
- School of Biological Sciences and Centre for Geometric Biology, Monash University, Clayton, Victoria, Australia
| | - Colin Olito
- Department of Biology, Section for Evolutionary Ecology, Lund University, Lund, Sweden
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