DOCSLIB.ORG

Admixture Can Readily Lead to the Formation of Supergenes Paul Jay, Thomas Aubier, Mathieu Joron

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Admixture Can Readily Lead to the Formation of Supergenes Paul Jay, Thomas Aubier, Mathieu Joron Admixture can readily lead to the formation of supergenes Paul Jay, Thomas Aubier, Mathieu Joron To cite this version: Paul Jay, Thomas Aubier, Mathieu Joron. Admixture can readily lead to the formation of supergenes. 2021. hal-03101072 HAL Id: hal-03101072 https://hal.archives-ouvertes.fr/hal-03101072 Preprint submitted on 6 Jan 2021 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. bioRxiv preprint doi: https://doi.org/10.1101/2020.11.19.389577; this version posted November 19, 2020. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY-NC-ND 4.0 International license. Admixture can readily lead to the formation of supergenes Paul Jay1 *, Thomas G. Aubier1,2 *, and Mathieu Joron1 1CEFE, CNRS, Université de Montpellier, Université Paul Valery, Montpellier 3, EPHE, IRD, Montpellier, France 2Department of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, Switzerland *These authors contributed equally. Supergenes are genetic architectures allowing the segregation of populations (6,8, 10, 17, 18). Inversions suppress recombi- alternative combinations of alleles underlying complex pheno- nation in heterozygotes, and are therefore prone to capture types. The co-segregation of sets of alleles at linked loci is deter- and accumulate deleterious mutations (18–20). This reces- mined by polymorphic chromosomal rearrangements suppress- sive mutational load may generate balancing selection and ing recombination locally. Supergenes are involved in many contribute to polymorphism at supergenes (18). Neverthe- complex polymorphisms, including sexual, color or behavioral less, while the maintenance of supergene alleles is theoret- polymorphisms in numerous plants, fungi, mammals, fish, and ically well understood, how these differentiated functional insects. Despite a long history of empirical and theoretical re- search, the genetic origin of supergenes remains poorly under- haplotypes arise remains a challenging question (21–24) stood. Here, using a population genetic two-island model, we The difficulty of solving the origin of supergenes can be ap- explore how the evolution of overdominant chromosomal inver- preciated using the metaphor of the fitness landscape intro- sions may lead to the formation of supergenes. We show that the duced by Wright (25). A population harbouring a supergene evolution of inversions in differentiated populations connected can be seen as a population with several non-recombining by gene flow leads to an increase in frequency of poorly adapted, haplotypes underlying distinct phenotypes corresponding to immigrant haplotypes. When inversions are associated with re- alternative fitness peaks. The separation of fitness peaks cessive fitness cost hampering their fixation (such as a muta- in this model implies the existence of epistatic interac- tional load), this results in the formation of supergenes. These tions; supergene haplotypes link together co-adapted alle- results provide a realistic scenario for the evolution of super- les, and recombinant haplotypes thus display poor fitness genes and inversion polymorphisms in general, and bring new (16, 22, 23, 26). To reach this situation, a polymorphic pop- light into the importance of admixture in the formation of new genetic architectures. ulation may have evolved from a monomorphic populations. This implies a peak shift, across a fitness valley, forming dif- Polymorphism | Genome evolution | Inversion | Load | Overdominance | Pop- ferentiated haplotypes which do not reach fixation and thus ulation genetic model segregate under balancing selection with an ancestral form. Correspondence: [email protected] Peak shifts may occur via genetic drift (‘shifting balance the- Discrete polymorphisms are widespread in nature. Besides ory’ (25)), via varying selective conditions (27), via major the ubiquitous polymorphism of sexual and mating types effect mutations (23), or when mutation rate and population (1,2), classic examples of discrete polymorphisms involving size are high (28). Nevertheless, the processes underlying multiple functional loci include polymorphic immune sys- peak shifts do not explain the maintenance of ancestral and tems in vertebrates (3–5), and color polymorphisms in several derived adaptive strategies in a polymorphism. birds (6–8), insects (9–11), snails (12, 13) and lizards (14). The puzzle of the origin and the maintenance of polymor- Supergenes are genetic architectures which are often found to phisms at supergenes rests on the antagonistic effects of re- underlie discrete polymorphisms by preventing the formation combination on the evolution of new combination of co- of intermediate maladapted phenotypes. Supergenes are gen- adapted alleles. On the one hand, recombination can promote erally formed by polymorphic chromosomal rearrangements peak shifts by bringing into linkage beneficial mutations that that suppress recombination among linked loci. Suppressed arose on different chromatids. On the other hand, recom- recombination is thought to facilitate the evolution of alterna- bination can mix up alternative combinations of alleles and tive combinations of co-adapted alleles (15). Such combina- thus hamper the formation of new differentiated haplotypes tions are assumed to evolve as a result of selection favoring (29). Therefore, recombination can promote the evolution of alternative evolutionary strategies (16). new adaptive strategies, but is also a homogenizing force that The maintenance of polymorphism is a key feature of su- inhibits their maintenance in a polymorphism (23, 30). As pergenes. Yet one would expect that the best evolutionary a corollary, reduced recombination, caused by chromosomal strategy, determined by a combination of alleles (i.e. a hap- rearrangements or by tight linkage between adaptive loci, can lotype), should eventually fix in populations via selection. In allow the maintenance of alternative haplotypes, but may also nature, supergene alleles have been shown to be maintained prevent peak shift and the formation of differentiated haplo- by balancing selection, in particular by negative frequency- types. dependent selection taking the form of disassortative mate Because of this dual effect of recombination, polymorphism choice (17) or heterozygote advantage (7,8, 18). Indeed, su- is unlikely to be maintained during the process of peak shift pergene alleles are often associated with chromosomal inver- (28). Nonetheless, the evolution of supergene haplotypes sions that seem to harbour recessive deleterious mutations, as may occur in situations where rearrangements reducing re- suggested by the lack of inversions homozygotes in natural combination occur after peak shifts. Indeed, a solution to bioRxiv preprint doi: https://doi.org/10.1101/2020.11.19.389577; this version posted November 19, 2020. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY-NC-ND 4.0 International license. this paradox may involve the evolution of alternative super- between population is likely to lead to the formation of a su- gene haplotypes in either (i) different genomic regions or (ii) pergene, suggesting that admixture may play an important different taxa (15, 31, 32). In this later case, haplotypes be- role in the formation of new genetic architectures. In par- longing to the same population recombine normally, but not ticular, we show that the formation of a supergene strongly with haplotypes from the other population. Alternative strate- depends on the interaction between frequency-dependent ef- gies encoded by differentiated haplotypes can readily evolve fects of recombination and of overdominance. in separated populations if they experience variation in selec- tive pressure, and the same rationale applies for alternative Methods haplotypes evolving in distinct genomic regions, for instance following a duplication. By the way of genomic transloca- Purpose. We investigate the conditions under which chro- tion or migration between population (admixture), the differ- mosomal inversions spread in neighboring populations under ent haplotypes may be grouped respectively (i) in the same disruptive selection, and how it associates with the forma- genomic region or (ii) in the same population. If these haplo- tion of supergenes underlying the maintenance of discrete types are not recombining, for instance because one of them polymorphisms. We define a supergene as a genetic archi- has experienced a chromosomal inversion, and if some form tecture maintaining under balancing selection multiple non- of balancing selection maintains them in coexistence, they recombining haplotypes encoding alternative discrete pheno- may form a supergene. types. Polymorphisms at supergene is thus maintained over the long term by evolutionary forces balancing
Load more

Recommended publications
  • A Supergene-Linked Estrogen Receptor Drives Alternative Phenotypes in a Polymorphic Songbird
    A supergene-linked estrogen receptor drives alternative phenotypes in a polymorphic songbird Jennifer R. Merritta,1, Kathleen E. Grogana, Wendy M. Zinzow-Kramera, Dan Sunb, Eric A. Ortlundc, Soojin V. Yib, and Donna L. Maneya aDepartment of Psychology, Emory University, Atlanta, GA 30322; bSchool of Biological Sciences, Georgia Institute of Technology, Atlanta, GA 30332; and cDepartment of Biochemistry, Emory University, Atlanta, GA 30322 Edited by Gene E. Robinson, University of Illinois at Urbana–Champaign, Urbana, IL, and approved July 8, 2020 (received for review June 3, 2020) Behavioral evolution relies on genetic changes, yet few behaviors tan-striped (TS) morph are homozygous for the standard ar- can be traced to specific genetic sequences in vertebrates. Here we rangement, ZAL2 (13, 14) (Fig. 1A). The rearrangement is provide experimental evidence showing that differentiation of a maintained in the population because of the species’ unique dis- single gene has contributed to the evolution of divergent behav- assortative mating system; nearly every breeding pair consists of ioral phenotypes in the white-throated sparrow, a common back- one individual of each morph (15). Because almost all WS birds yard songbird. In this species, a series of chromosomal inversions are heterozygous for ZAL2m (15, 16), this mating system keeps has formed a supergene that segregates with an aggressive phe- ZAL2m in a near-constant state of heterozygosity (Fig. 1B), pro- notype. The supergene has captured ESR1, the gene that encodes foundly suppressing recombination and causing it to differentiate estrogen receptor α (ERα); as a result, this gene is accumulating from ZAL2 (15, 17). changes that now distinguish the supergene allele from the stan- The rearranged region of ZAL2m in white-throated sparrows dard allele.
    [Show full text]
  • Stance As Nonself Initiates a Complex Cascade of Events Which
    JOURNAL OF SURGICAL RESEARCH 39, l72- 18 1 ( 1985) CURRENT RESEARCH REVIEW Major Histocompatibility Complex Regulation of the Immune Response DAVID H. GUTMANN, PH.D., AND JOHN E. NIEDERHUBER, M.D. Departments of Microbiology and Immunology and Surgery, The University of Michigan Medical School, Ann Arbor, Michigan 48109 Submitted for publication July 18, 1984 The ability of an organism to distinguish self from nonself is determined by a cluster of genes located in the major histocompatibility complex. Recent advances in molecular genetics and cellular immunology have begun to elucidate the mechanisms responsible for immune response regulation. In this review article, the genetic organization of the murine and human major histocompatibility complexes and the manner by which their gene products modulate immune responsiveness are discussed. 0 1985 Academic Press. Inc. INTRODUCTION ulate the immune response in several ways. Whether this regulation is their primary The body’s recognition of a foreign sub- function is not clear, as it seemspossible that stance as nonself initiates a complex cascade other as yet undiscovered levels of regulation of events which leads to an immune response. of the immune response may exist. Since Regulation of this immune response is con- much of our understanding of the role of the trolled by a cluster of tightly linked genes MHC in immune regulation has resulted encoded within the major histocompatibility from studies on the mouse MHC, the struc- complex (MHC) [ 1, 21. While the MHC was ture and function of both mouse and, when originally defined as the site for control of available, human MHC molecules will be graft rejection, it is now known that MHC discussed in this review.
    [Show full text]
  • Chromosomal Rearrangements Maintain a Polymorphic Supergene Controlling Butterfly Mimicry
    Published in which should be cited to refer to this work. Chromosomal rearrangements maintain a polymorphic supergene controlling butterfly mimicry Mathieu Joron1,2,3, Lise Frezal1*, Robert T. Jones4*, Nicola L. Chamberlain4, Siu F. Lee5, Christoph R. Haag6, Annabel Whibley1, Michel Becuwe2, Simon W. Baxter7, Laura Ferguson7, Paul A. Wilkinson4, Camilo Salazar8, Claire Davidson9, Richard Clark9, Michael A. Quail9, Helen Beasley9, Rebecca Glithero9, Christine Lloyd9, Sarah Sims9, Matthew C. Jones9, Jane Rogers9, Chris D. Jiggins7 & Richard H. ffrench-Constant4 Supergenes are tight clusters of loci that facilitate the co-segregation be tightly linked from the outset or whether the association between of adaptive variation, providing integrated control of complex elements can be acquired, either gradually or in a single mutational adaptive phenotypes1. Polymorphic supergenes, in which specific step7–10,16–19. Chromosomal rearrangements, which can bring genes into combinations of traits are maintained within a single population, closer physical association and influence local recombination, offer one were first described for ‘pin’ and ‘thrum’ floral types in Primula1 and route through which supergenes may be assembled from more loosely Fagopyrum2, but classic examples are also found in insect mimicry3–5 linked components7,8,17–19. Although there are many cases of poly- and snail morphology6. Understanding the evolutionary mechan- morphic inversions associated with adaptive variation12,20, variation is isms that generate these co-adapted gene sets, as well as the mode in most cases geographical, rather than being maintained within popula- of limiting the production of unfit recombinant forms, remains a tions, and effects on local adaptation are cumulative. In contrast, super- substantial challenge7–10.
    [Show full text]
  • Supergene Evolution Triggered by the Introgression of a Chromosomal Inversion
    Report Supergene Evolution Triggered by the Introgression of a Chromosomal Inversion Graphical Abstract Authors Paul Jay, Annabel Whibley, Lise Frezal, ..., James Mallet, Kanchon K. Dasmahapatra, Mathieu Joron Correspondence [email protected] (P.J.), [email protected] (M.J.) In Brief Supergenes are genetic architectures underlying complex polymorphisms in many organisms. Jay et al. show that a supergene controlling mimicry polymorphism in a butterfly was formed by the introgression of a chromosomal inversion from another species. Their results emphasize the role of hybridization in the evolution of novel genetic architectures. Highlights d Chromosomal inversions underlie wing-pattern polymorphism in a Heliconius butterfly d Inversion was introgressed from another species, then maintained as a polymorphism d 1.3 Ma of evolution in separate taxa explains the divergence of supergene haplotypes d Introgression may play a key role in the formation of novel genetic architectures Jay et al., 2018, Current Biology 28, 1–7 June 4, 2018 ª 2018 Elsevier Ltd. https://doi.org/10.1016/j.cub.2018.04.072 Please cite this article in press as: Jay et al., Supergene Evolution Triggered by the Introgression of a Chromosomal Inversion, Current Biology (2018), https://doi.org/10.1016/j.cub.2018.04.072 Current Biology Report Supergene Evolution Triggered by the Introgression of a Chromosomal Inversion Paul Jay,1,* Annabel Whibley,2 Lise Frezal, 3 Marı´aA´ ngeles Rodrı´guez de Cara,1 Reuben W. Nowell,4 James Mallet,5 Kanchon K. Dasmahapatra,6 and
    [Show full text]
  • A Behavioral Polymorphism Caused by a Single Gene Inside a Supergene
    bioRxiv preprint doi: https://doi.org/10.1101/2020.01.13.897637; this version posted January 16, 2020. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY-NC 4.0 International license. Merritt et al., 13 JAN 2020 – preprint copy – bioRxiv A behavioral polymorphism caused by a single gene inside a supergene Jennifer R. Merritta,1, Kathleen E. Grogana, Wendy M. Zinzow-Kramera, Dan Sunb, Eric A. Ortlundc, Soojin V. Yib, Donna L. Maneya a Department of Psychology, Emory University, Atlanta, GA 30322 b School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA 30332 c Department of Biochemistry, Emory University, Atlanta, GA 30322 1 Correspondence: [email protected] Abstract Behavioral evolution relies on genetic changes, yet few social behaviors can be traced to specific genetic seQuences in vertebrates. Here, we show experimental evidence that differentiation of a single gene has contributed to divergent behavioral phenotypes in the white-throated sparrow, a common North American songbird. In this species, one of two alleles of ESR1, encoding estrogen receptor a (ERa), has been captured inside a differentiating supergene that segregates with an aggressive phenotype, such that ESR1 expression predicts aggression. Here, we show that the aggressive phenotype associated with the supergene is prevented by ESR1 knockdown in a single brain region. Next, we show that in a free-living population, aggression is predicted by allelic imbalance favoring the supergene allele. Cis-regulatory variation between the two alleles affects transcription factor binding sites, DNA methylation, and rates of transcription.
    [Show full text]
  • Mutation Accumulation in Chromosomal Inversions Maintains Wing Pattern Polymorphism in a Butterfly
    bioRxiv preprint doi: https://doi.org/10.1101/736504; this version posted August 15, 2019. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY-NC-ND 4.0 International license. Mutation accumulation in chromosomal inversions maintains wing pattern polymorphism in a butterfly Paul Jay1 *, Mathieu Chouteau1,2 *, Annabel Whibley3, Héloïse Bastide4, Violaine Llaurens4, Hugues Parrinello5, and Mathieu Joron1 1CEFE, CNRS, Université de Montpellier, Université Paul Valery, Montpellier 3, EPHE, IRD, Montpellier, France 2LEEISA, USR 63456, Université De Guyane, CNRS Guyane, IFREMER Guyane, 275 route de Montabo, 797334 Cayenne, French Guiana 3School of Biological Sciences, University of Auckland, Auckland, New Zealand 4ISYEB, UMR7205 CNRS-MNHN-9UPMC-EPHE, Muséum national d’Histoire naturelle, CP 50,45 rue Buffon, 75005 Paris, 10France. 5MGX, Biocampus Montpellier, CNRS, INSERM, Université Montpellier, Montpellier, France *These authors contributed equally. While natural selection favours the fittest genotype, polymor- The Amazonian butterfly Heliconius numata displays wing phisms are maintained over evolutionary timescales in numer- pattern polymorphism with up to seven morphs coexisting ous species. Why these long-lived polymorphisms are often as- within a single locality, each one engaged in warning color sociated with chromosomal rearrangements remains obscure. mimicry with distinct groups of toxic species. Adult morphs Combining genome assemblies, population genomic analyses, vary in mimicry protection against predators and in mating and fitness assays, we studied the factors maintaining multiple success via disassortative mate preferences (13, 16). Poly- mimetic morphs in the butterfly Heliconius numata.
    [Show full text]
  • Multiple Convergent Supergene Evolution Events in Mating-Type
    Multiple convergent supergene evolution events in mating-type chromosomes Sara Branco, Fantin Carpentier, Ricardo Rodriguez de la Vega, Hélène Badouin, Alodie Snirc, Stéphanie Le Prieur, Marco Coelho, Damien de Vienne, Fanny Hartmann, Dominik Begerow, et al. To cite this version: Sara Branco, Fantin Carpentier, Ricardo Rodriguez de la Vega, Hélène Badouin, Alodie Snirc, et al.. Multiple convergent supergene evolution events in mating-type chromosomes. Nature Communica- tions, Nature Publishing Group, 2018, 9 (1), pp.2000. 10.1038/s41467-018-04380-9. hal-01796609 HAL Id: hal-01796609 https://hal.archives-ouvertes.fr/hal-01796609 Submitted on 21 May 2018 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. ARTICLE DOI: 10.1038/s41467-018-04380-9 OPEN Multiple convergent supergene evolution events in mating-type chromosomes Sara Branco1,2, Fantin Carpentier1, Ricardo C. Rodríguez de la Vega 1, Hélène Badouin1,3, Alodie Snirc1, Stéphanie Le Prieur1, Marco A. Coelho4, Damien M. de Vienne3, Fanny E. Hartmann1, Dominik Begerow5, Michael E. Hood6 & Tatiana Giraud 1 Convergent adaptation provides unique insights into the predictability of evolution and ulti- 1234567890():,; mately into processes of biological diversification. Supergenes (beneficial gene linkage) are striking examples of adaptation, but little is known about their prevalence or evolution.
    [Show full text]
  • Simple Inheritance, Complex Regulation: Supergene‐Mediated
    Received: 15 January 2020 | Revised: 3 July 2020 | Accepted: 18 July 2020 DOI: 10.1111/mec.15581 ORIGINAL ARTICLE Simple inheritance, complex regulation: Supergene-mediated fire ant queen polymorphism Samuel V. Arsenault1 | Joanie T. King1,2 | Sasha Kay1 | Kip D. Lacy1,3 | Kenneth G. Ross1 | Brendan G. Hunt1 1Department of Entomology, University of Georgia, Athens, GA, USA Abstract 2Department of Entomology, Texas A&M The fire ant Solenopsis invicta exists in two alternate social forms: monogyne nests University, College Station, TX, USA contain a single reproductive queen and polygyne nests contain multiple reproduc- 3Laboratory of Social Evolution and Behavior, The Rockefeller University, New tive queens. This colony-level social polymorphism corresponds with individual dif- York, NY, USA ferences in queen physiology, queen dispersal patterns and worker discrimination Correspondence behaviours, all evidently regulated by an inversion-based supergene that spans more Samuel V. Arsenault, Kenneth G. Ross, than 13 Mb of a “social chromosome,” contains over 400 protein-coding genes and and Brendan G. Hunt, Department of Entomology, University of Georgia, Athens, rarely undergoes recombination. The specific mechanisms by which this supergene GA, USA. influences expression of the many distinctive features that characterize the alternate Email: [email protected]; [email protected]; [email protected] forms remain almost wholly unknown. To advance our understanding of these mech- anisms, we explore the effects of social chromosome genotype and natal colony so- Funding information Division of Integrative Organismal Systems, cial form on gene expression in queens sampled as they embarked on nuptial flights, Grant/Award Number: 1755130; Division using RNA-sequencing of brains and ovaries.
    [Show full text]
  • Avian Supergenes
    PERSPECTIVES EVOLUTION important role in generating biological diver- Lekking ruffs. From left to right, a female, an sity in taxa ranging from plants to humans. independent male, and a satellite male ruff. A third The mimetic wing patterns of butterflies are type of male ruff closely resembles the female. Recent Avian a particularly well-documented example of research has shed light on the genetic underpinnings of how supergenes can underlie complex ad- the ruff’s complex reproductive strategies (1, 2). aptations (4). However, knowledge of the supergenes genetic architecture of supergenes remains attraction and attempt to “steal” copula- limited, and the molecular mechanisms by tions. Faeder males (<1%) mimic females Genetic data reveal how which they can generate complex pheno- in their plumage and smaller size and also two complex bird mating types are unclear. The recent studies of the steal copulations. ruff (1, 2) and the white-throated sparrow (3) As Küpper et al. (1) and Lamichhaney et systems evolved provide critical advances to our understand- al. (2) now show, these three reproductive ing of these aspects of supergenes. behaviors and associated phenotypes are de- By Scott Taylor 1,2 and Leonardo Campagna1,2 Reduced recombination within super- termined by a ~4.5 Mb inversion located on genes is central to their evolution, allowing an autosome (see the figure). Independent s the extravagant displays of birds of multiple genes to be inherited as a single males carry two copies of the ancestral, non- paradise remind us, many birds go to linked unit and setting the stage for their inverted chromosome: They do not possess great lengths to pass their genes on coevolution.
    [Show full text]
  • Unravelling the Genes Forming the Wing Pattern Supergene in the Polymorphic Butterfy Heliconius Numata Suzanne V
    Saenko et al. EvoDevo (2019) 10:16 https://doi.org/10.1186/s13227-019-0129-2 EvoDevo RESEARCH Open Access Unravelling the genes forming the wing pattern supergene in the polymorphic butterfy Heliconius numata Suzanne V. Saenko1†, Mathieu Chouteau2†, Florence Piron‑Prunier1, Corinne Blugeon3, Mathieu Joron4 and Violaine Llaurens1* Abstract Background: Unravelling the genetic basis of polymorphic characters is central to our understanding of the ori‑ gins and diversifcation of living organisms. Recently, supergenes have been implicated in a wide range of complex polymorphisms, from adaptive colouration in butterfies and fsh to reproductive strategies in birds and plants. The concept of a supergene is now a hot topic in biology, and identifcation of its functional elements is needed to shed light on the evolution of highly divergent adaptive traits. Here, we apply diferent gene expression analyses to study the supergene P that controls polymorphism of mimetic wing colour patterns in the neotropical butterfy Heliconius numata. Results: We performed de novo transcriptome assembly and diferential expression analyses using high‑throughput Illumina RNA sequencing on developing wing discs of diferent H. numata morphs. Within the P interval, 30 and 17 of the 191 transcripts were expressed diferentially in prepupae and day‑1 pupae, respectively. Among these is the gene cortex, known to play a role in wing pattern formation in Heliconius and other Lepidoptera. Our in situ hybridization experiments confrmed the relationship between cortex expression and adult wing patterns. Conclusions: This study found the majority of genes in the P interval to be expressed in the developing wing discs during the critical stages of colour pattern formation, and detect drastic changes in expression patterns in multiple genes associated with structural variants.
    [Show full text]
  • The Chicken Major Histocompatibility Complex and Disease
    Animal Science Publications Animal Science 1998 The chicken major histocompatibility complex and disease Susan J. Lamont Iowa State University, [email protected] Follow this and additional works at: https://lib.dr.iastate.edu/ans_pubs Part of the Agriculture Commons, Animal Sciences Commons, Genetics Commons, and the Immunology and Infectious Disease Commons The complete bibliographic information for this item can be found at https://lib.dr.iastate.edu/ ans_pubs/855. For information on how to cite this item, please visit http://lib.dr.iastate.edu/ howtocite.html. This Article is brought to you for free and open access by the Animal Science at Iowa State University Digital Repository. It has been accepted for inclusion in Animal Science Publications by an authorized administrator of Iowa State University Digital Repository. For more information, please contact [email protected]. The chicken major histocompatibility complex and disease Abstract The chicken major histocompatibility complex (MHC), or B complex, consists of several clusters of highly polymorphic genes, some of which are associated with disease resistance. The class I and class II antigens resemble their mammalian counterparts in the encoded protein structure. The class IV region encodes the B blood group antigens, which are readily identified yb serological blood-typing. The class III region appears to be divided in chickens, with some elements that are MHC-linked and others that map elsewhere. In addition the Rfp-Y system, which bears a strong similarity to the MHC, maps to the opposite side of the nucleolar organiser region on the same microchromosome as the MHC. Each class of MHC genes is a potential candidate for a role in disease resistance.
    [Show full text]
  • A Supergene-Linked Estrogen Receptor Drives Alternative Phenotypes in a Polymorphic Songbird
    A supergene-linked estrogen receptor drives alternative phenotypes in a polymorphic songbird Jennifer R. Merritta,1, Kathleen E. Grogana, Wendy M. Zinzow-Kramera, Dan Sunb, Eric A. Ortlundc, Soojin V. Yib, and Donna L. Maneya aDepartment of Psychology, Emory University, Atlanta, GA 30322; bSchool of Biological Sciences, Georgia Institute of Technology, Atlanta, GA 30332; and cDepartment of Biochemistry, Emory University, Atlanta, GA 30322 Edited by Gene E. Robinson, University of Illinois at Urbana–Champaign, Urbana, IL, and approved July 8, 2020 (received for review June 3, 2020) Behavioral evolution relies on genetic changes, yet few behaviors tan-striped (TS) morph are homozygous for the standard ar- can be traced to specific genetic sequences in vertebrates. Here we rangement, ZAL2 (13, 14) (Fig. 1A). The rearrangement is provide experimental evidence showing that differentiation of a maintained in the population because of the species’ unique dis- single gene has contributed to the evolution of divergent behav- assortative mating system; nearly every breeding pair consists of ioral phenotypes in the white-throated sparrow, a common back- one individual of each morph (15). Because almost all WS birds yard songbird. In this species, a series of chromosomal inversions are heterozygous for ZAL2m (15, 16), this mating system keeps has formed a supergene that segregates with an aggressive phe- ZAL2m in a near-constant state of heterozygosity (Fig. 1B), pro- notype. The supergene has captured ESR1, the gene that encodes foundly suppressing recombination and causing it to differentiate estrogen receptor α (ERα); as a result, this gene is accumulating from ZAL2 (15, 17). changes that now distinguish the supergene allele from the stan- The rearranged region of ZAL2m in white-throated sparrows dard allele.
    [Show full text]