1
|
Olasege BS, Oh ZY, Tahir MS, Porto-Neto LR, Hayes BJ, Fortes MRS. Genomic regions and biological pathways associated with sex-limited reproductive traits in bovine species. J Anim Sci 2024; 102:skae085. [PMID: 38545844 PMCID: PMC11135212 DOI: 10.1093/jas/skae085] [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: 10/31/2023] [Accepted: 03/25/2024] [Indexed: 05/30/2024] Open
Abstract
Many animal species exhibit sex-limited traits, where certain phenotypes are exclusively expressed in one sex. Yet, the genomic regions that contribute to these sex-limited traits in males and females remain a subject of debate. Reproductive traits are ideal phenotypes to study sexual differences since they are mostly expressed in a sex-limited way. Therefore, this study aims to use local correlation analyses to identify genomic regions and biological pathways significantly associated with male and female sex-limited traits in two distinct cattle breeds (Brahman [BB] and Tropical Composite [TC]). We used the Correlation Scan method to perform local correlation analysis on 42 trait pairs consisting of six female and seven male reproductive traits recorded on ~1,000 animals for each sex in each breed. To pinpoint a specific region associated with these sex-limited reproductive traits, we investigated the genomic region(s) consistently identified as significant across the 42 trait pairs in each breed. The genes found in the identified regions were subjected to Quantitative Trait Loci (QTL) colocalization, QTL enrichment analyses, and functional analyses to gain biological insight into sexual differences. We found that the genomic regions associated with the sex-limited reproductive phenotypes are widely distributed across all the chromosomes. However, no single region across the genome was associated with all the 42 reproductive trait pairs in the two breeds. Nevertheless, we found a region on the X-chromosome to be most significant for 80% to 90% (BB: 33 and TC: 38) of the total 42 trait pairs. A considerable number of the genes in this region were regulatory genes. By considering only genomic regions that were significant for at least 50% of the 42 trait pairs, we observed more regions spread across the autosomes and the X-chromosome. All genomic regions identified were highly enriched for trait-specific QTL linked to sex-limited traits (percentage of normal sperm, metabolic weight, average daily gain, carcass weight, age at puberty, etc.). The gene list created from these identified regions was enriched for biological pathways that contribute to the observed differences between sexes. Our results demonstrate that genomic regions associated with male and female sex-limited reproductive traits are distributed across the genome. Yet, chromosome X seems to exert a relatively larger effect on the phenotypic variation observed between the sexes.
Collapse
Affiliation(s)
- Babatunde S Olasege
- The University of Queensland, School of Chemistry and Molecular Biosciences, Saint Lucia Campus, Brisbane, QLD, 4072, Australia
- Ag and Food, CSIRO Agriculture and Food, Saint Lucia, QLD, 4067, Australia
| | - Zhen Yin Oh
- The University of Queensland, School of Chemistry and Molecular Biosciences, Saint Lucia Campus, Brisbane, QLD, 4072, Australia
| | - Muhammad S Tahir
- The University of Queensland, School of Chemistry and Molecular Biosciences, Saint Lucia Campus, Brisbane, QLD, 4072, Australia
- Ag and Food, CSIRO Agriculture and Food, Saint Lucia, QLD, 4067, Australia
| | | | - Ben J Hayes
- The University of Queensland, Queensland Alliance for Agriculture and Food Innovation (QAAFI), Saint Lucia Campus, Brisbane, QLD, 4072, Australia
| | - Marina R S Fortes
- The University of Queensland, School of Chemistry and Molecular Biosciences, Saint Lucia Campus, Brisbane, QLD, 4072, Australia
- The University of Queensland, Queensland Alliance for Agriculture and Food Innovation (QAAFI), Saint Lucia Campus, Brisbane, QLD, 4072, Australia
| |
Collapse
|
2
|
Singh A, Hasan A, Agrawal AF. An investigation of the sex-specific genetic architecture of fitness in Drosophila melanogaster. Evolution 2023; 77:2015-2028. [PMID: 37329263 DOI: 10.1093/evolut/qpad107] [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: 08/04/2022] [Revised: 05/14/2023] [Accepted: 06/13/2023] [Indexed: 06/19/2023]
Abstract
In dioecious populations, the sexes employ divergent reproductive strategies to maximize fitness and, as a result, genetic variants can affect fitness differently in males and females. Moreover, recent studies have highlighted an important role of the mating environment in shaping the strength and direction of sex-specific selection. Here, we measure adult fitness for each sex of 357 lines from the Drosophila Synthetic Population Resource in two different mating environments. We analyze the data using three different approaches to gain insight into the sex-specific genetic architecture for fitness: classical quantitative genetics, genomic associations, and a mutational burden approach. The quantitative genetics analysis finds that on average segregating genetic variation in this population has concordant fitness effects both across the sexes and across mating environments. We do not find specific genomic regions with strong associations with either sexually antagonistic (SA) or sexually concordant (SC) fitness effects, yet there is modest evidence of an excess of genomic regions with weak associations, with both SA and SC fitness effects. Our examination of mutational burden indicates stronger selection against indels and loss-of-function variants in females than in males.
Collapse
Affiliation(s)
- Amardeep Singh
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, ON, Canada
| | - Asad Hasan
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, ON, Canada
| | - Aneil F Agrawal
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, ON, Canada
| |
Collapse
|
3
|
Reid JM. Intrinsic emergence and modulation of sex-specific dominance reversals in threshold traits. Evolution 2022; 76:1924-1941. [PMID: 35803581 PMCID: PMC9541474 DOI: 10.1111/evo.14563] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Revised: 06/24/2022] [Accepted: 06/30/2022] [Indexed: 01/22/2023]
Abstract
Sex-specific dominance reversals (SSDRs) in fitness-related traits, where heterozygotes' phenotypes resemble those of alternative homozygotes in females versus males, can simultaneously maintain genetic variation in fitness and resolve sexual conflict and thereby shape key evolutionary outcomes. However, the full implications of SSDRs will depend on how they arise and the resulting potential for evolutionary, ecological and environmental modulation. Recent field and laboratory studies have demonstrated SSDRs in threshold(-like) traits with dichotomous or competitive phenotypic outcomes, implying that such traits could promote the emergence of SSDRs. However, such possibilities have not been explicitly examined. I show how phenotypic SSDRs can readily emerge in threshold traits given genetic architectures involving large-effect loci alongside sexual dimorphism in the mean and variance in polygenic liability. I also show how multilocus SSDRs can arise in line-cross experiments, especially given competitive reproductive systems that generate nonlinear fitness outcomes. SSDRs can consequently emerge in threshold(-like) traits as functions of sexual antagonism, sexual dimorphism and reproductive systems, even with purely additive underlying genetic effects. Accordingly, I identify theoretical and empirical advances that are now required to discern the basis and occurrence of SSDRs in nature, probe forms of (co-)evolutionary, ecological and environmental modulation, and evaluate net impacts on sexual conflict.
Collapse
Affiliation(s)
- Jane M. Reid
- Centre for Biodiversity DynamicsNTNUTrondheimNorway,School of Biological SciencesUniversity of AberdeenAberdeenUK
| |
Collapse
|
4
|
Meisel RP. Ecology and the evolution of sex chromosomes. J Evol Biol 2022; 35:1601-1618. [PMID: 35950939 DOI: 10.1111/jeb.14074] [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: 12/17/2021] [Revised: 07/15/2022] [Accepted: 07/21/2022] [Indexed: 11/29/2022]
Abstract
Sex chromosomes are common features of animal genomes, often carrying a sex determination gene responsible for initiating the development of sexually dimorphic traits. The specific chromosome that serves as the sex chromosome differs across taxa as a result of fusions between sex chromosomes and autosomes, along with sex chromosome turnover-autosomes becoming sex chromosomes and sex chromosomes 'reverting' back to autosomes. In addition, the types of genes on sex chromosomes frequently differ from the autosomes, and genes on sex chromosomes often evolve faster than autosomal genes. Sex-specific selection pressures, such as sexual antagonism and sexual selection, are hypothesized to be responsible for sex chromosome turnovers, the unique gene content of sex chromosomes and the accelerated evolutionary rates of genes on sex chromosomes. Sex-specific selection has pronounced effects on sex chromosomes because their sex-biased inheritance can tilt the balance of selection in favour of one sex. Despite the general consensus that sex-specific selection affects sex chromosome evolution, most population genetic models are agnostic as to the specific sources of these sex-specific selection pressures, and many of the details about the effects of sex-specific selection remain unresolved. Here, I review the evidence that ecological factors, including variable selection across heterogeneous environments and conflicts between sexual and natural selection, can be important determinants of sex-specific selection pressures that shape sex chromosome evolution. I also explain how studying the ecology of sex chromosome evolution can help us understand important and unresolved aspects of both sex chromosome evolution and sex-specific selection.
Collapse
Affiliation(s)
- Richard P Meisel
- Department of Biology and Biochemistry, University of Houston, Houston, Texas, USA
| |
Collapse
|
5
|
Geeta Arun M, Chechi TS, Meena R, Bhosle SD, Srishti, Prasad NG. Investigating the interaction between inter-locus and intra-locus sexual conflict using hemiclonal analysis in Drosophila melanogaster. BMC Ecol Evol 2022; 22:38. [PMID: 35346023 PMCID: PMC8962633 DOI: 10.1186/s12862-022-01992-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Accepted: 03/15/2022] [Indexed: 12/02/2022] Open
Abstract
Background Divergence in the evolutionary interests of males and females leads to sexual conflict. Traditionally, sexual conflict has been classified into two types: inter-locus sexual conflict (IeSC) and intra-locus sexual conflict (IaSC). IeSC is modeled as a conflict over outcomes of intersexual reproductive interactions mediated by loci that are sex-limited in their effects. IaSC is thought to be a product of selection acting in opposite directions in males and females on traits with a common underlying genetic basis. While in their canonical formalisms IaSC and IeSC are mutually exclusive, there is growing support for the idea that the two may interact. Empirical evidence for such interactions, however, is limited. Results Here, we investigated the interaction between IeSC and IaSC in Drosophila melanogaster. Using hemiclonal analysis, we sampled 39 hemigenomes from a laboratory-adapted population of D. melanogaster. We measured the contribution of each hemigenome to adult male and female fitness at three different intensities of IeSC, obtained by varying the operational sex ratio. Subsequently, we estimated the intensity of IaSC at each sex ratio by calculating the intersexual genetic correlation (rw,g,mf) for fitness and the proportion of sexually antagonistic fitness-variation. We found that the intersexual genetic correlation for fitness was positive at all three sex ratios. Additionally, at male biased and equal sex ratios the rw,g,mf was higher, and the proportion of sexually antagonistic fitness variation lower, relative to the female biased sex ratio, although this trend was not statistically significant. Conclusion Our results indicate a statistically non-significant trend suggesting that increasing the strength of IeSC ameliorates IaSC in the population. Supplementary Information The online version contains supplementary material available at 10.1186/s12862-022-01992-0.
Collapse
Affiliation(s)
- Manas Geeta Arun
- Department of Biological Sciences, Indian Institute of Science Education and Research Mohali, Sector 81, SAS Nagar, Mohali, Punjab, 140306, India
| | - Tejinder Singh Chechi
- Department of Biological Sciences, Indian Institute of Science Education and Research Mohali, Sector 81, SAS Nagar, Mohali, Punjab, 140306, India
| | - Rakesh Meena
- Department of Biological Sciences, Indian Institute of Science Education and Research Mohali, Sector 81, SAS Nagar, Mohali, Punjab, 140306, India
| | - Shradha Dattaraya Bhosle
- Department of Biochemistry, Dr. Babasaheb Ambedkar Marathwada University, University Campus, Jaisigpura, Aurangabad, Maharashtra, 431004, India
| | - Srishti
- Department of Biological Sciences, Indian Institute of Science Education and Research Mohali, Sector 81, SAS Nagar, Mohali, Punjab, 140306, India
| | - Nagaraj Guru Prasad
- Department of Biological Sciences, Indian Institute of Science Education and Research Mohali, Sector 81, SAS Nagar, Mohali, Punjab, 140306, India.
| |
Collapse
|
6
|
Janicke T, Chapuis E, Meconcelli S, Bonel N, Delahaie B, David P. Environmental effects on the genetic architecture of fitness components in a simultaneous hermaphrodite. J Anim Ecol 2021; 91:124-137. [PMID: 34652857 DOI: 10.1111/1365-2656.13607] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Accepted: 10/04/2021] [Indexed: 12/01/2022]
Abstract
Understanding how environmental change affects genetic variances and covariances of reproductive traits is key to formulate firm predictions on evolutionary responses. This is particularly true for sex-specific variance in reproductive success, which has been argued to affect how populations can adapt to environmental change. Our current knowledge on the impact of environmental stress on sex-specific genetic architecture of fitness components is still limited and restricted to separate-sexed organisms. However, hermaphroditism is widespread across animals and may entail interesting peculiarities with respect to genetic constraints imposed on the evolution of male and female reproduction. We explored how food restriction affects the genetic variance-covariance (G) matrix of body size and reproductive success of the simultaneously hermaphroditic freshwater snail Physa acuta. Our results provide strong evidence that the imposed environmental stress elevated the opportunity for selection in both sex functions. However, the G-matrix remained largely stable across the tested food treatments. Importantly, our results provide no support for cross-sex genetic correlations suggesting no strong evolutionary coupling of male and female reproductive traits. We discuss potential implications for the adaptation to changing environments and highlight the need for more quantitative genetic studies on male and female fitness components in simultaneous hermaphrodites.
Collapse
Affiliation(s)
- Tim Janicke
- Centre d'Écologie Fonctionnelle et Évolutive, CNRS, Univ Montpellier, EPHE, IRD, Montpellier, France.,Applied Zoology, Technical University Dresden, Dresden, Germany
| | - Elodie Chapuis
- MIVEGEC, Univ Montpellier, CNRS, IRD, Montpellier, France
| | - Stefania Meconcelli
- Centre d'Écologie Fonctionnelle et Évolutive, CNRS, Univ Montpellier, EPHE, IRD, Montpellier, France.,Department of Life Sciences and Systems Biology, Università di Torino, Torino, Italy
| | - Nicolas Bonel
- Centre d'Écologie Fonctionnelle et Évolutive, CNRS, Univ Montpellier, EPHE, IRD, Montpellier, France.,Centro de Recursos Naturales Renovables de la Zona Semiárida (CERZOS-CCT-CONICET Bahía Blanca), Bahía Blanca, Argentina
| | - Boris Delahaie
- Department of Plant Sciences, University of Cambridge, Cambridge, UK
| | - Patrice David
- Centre d'Écologie Fonctionnelle et Évolutive, CNRS, Univ Montpellier, EPHE, IRD, Montpellier, France
| |
Collapse
|
7
|
Plesnar‐Bielak A, Łukasiewicz A. Sexual conflict in a changing environment. Biol Rev Camb Philos Soc 2021; 96:1854-1867. [PMID: 33960630 PMCID: PMC8518779 DOI: 10.1111/brv.12728] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Revised: 04/14/2021] [Accepted: 04/16/2021] [Indexed: 01/02/2023]
Abstract
Sexual conflict has extremely important consequences for various evolutionary processes including its effect on local adaptation and extinction probability during environmental change. The awareness that the intensity and dynamics of sexual conflict is highly dependent on the ecological setting of a population has grown in recent years, but much work is yet to be done. Here, we review progress in our understanding of the ecology of sexual conflict and how the environmental sensitivity of such conflict feeds back into population adaptivity and demography, which, in turn, determine a population's chances of surviving a sudden environmental change. We link two possible forms of sexual conflict - intralocus and interlocus sexual conflict - in an environmental context and identify major gaps in our knowledge. These include sexual conflict responses to fluctuating and oscillating environmental changes and its influence on the interplay between interlocus and intralocus sexual conflict, among others. We also highlight the need to move our investigations into more natural settings and to investigate sexual conflict dynamics in wild populations.
Collapse
Affiliation(s)
- Agata Plesnar‐Bielak
- Institute of Environmental Sciences, Faculty of BiologyJagiellonian Universityul. Gronostajowa 730‐387KrakówPoland
| | - Aleksandra Łukasiewicz
- Department of Environmental and Biological SciencesUniversity of Eastern FinlandPO Box 11180101JoensuuFinland
- Evolutionary Biology Group, Faculty of BiologyAdam Mickiewicz Universityul. Uniwersytetu Poznańskiego 661‐614PoznańPoland
| |
Collapse
|
8
|
Koch EL, Sbilordo SH, Guillaume F. Genetic variance in fitness and its cross‐sex covariance predict adaptation during experimental evolution. Evolution 2020; 74:2725-2740. [DOI: 10.1111/evo.14119] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Revised: 09/29/2020] [Accepted: 10/25/2020] [Indexed: 01/05/2023]
Affiliation(s)
- Eva L. Koch
- Department of Evolutionary Biology and Environmental Studies University of Zürich Winterthurerstr. 190 Zürich 8057 Switzerland
- Department of Animal and Plant Science University of Sheffield Western Bank Sheffield S10 2TN United Kingdom
| | - Sonja H. Sbilordo
- Department of Evolutionary Biology and Environmental Studies University of Zürich Winterthurerstr. 190 Zürich 8057 Switzerland
| | - Frédéric Guillaume
- Department of Evolutionary Biology and Environmental Studies University of Zürich Winterthurerstr. 190 Zürich 8057 Switzerland
| |
Collapse
|
9
|
Ruzicka F, Connallon T. Is the X chromosome a hot spot for sexually antagonistic polymorphisms? Biases in current empirical tests of classical theory. Proc Biol Sci 2020; 287:20201869. [PMID: 33081608 PMCID: PMC7661300 DOI: 10.1098/rspb.2020.1869] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Accepted: 09/21/2020] [Indexed: 12/16/2022] Open
Abstract
Females and males carry nearly identical genomes, which can constrain the evolution of sexual dimorphism and generate conditions that are favourable for maintaining sexually antagonistic (SA) polymorphisms, in which alleles beneficial for one sex are deleterious for the other. An influential theoretical prediction, by Rice (Rice 1984 Evolution38, 735-742), is that the X chromosome should be a 'hot spot' (i.e. enriched) for SA polymorphisms. While important caveats to Rice's theoretical prediction have since been highlighted (e.g. by Fry (2010) Evolution64, 1510-1516), several empirical studies appear to support it. Here, we show that current tests of Rice's theory-most of which are based on quantitative genetic measures of fitness (co)variance-are frequently biased towards detecting X-linked effects. We show that X-linked genes tend to contribute disproportionately to quantitative genetic patterns of SA fitness variation whether or not the X is enriched for SA polymorphisms. Population genomic approaches for detecting SA loci, including genome-wide association study of fitness and analyses of intersexual FST, are similarly biased towards detecting X-linked effects. In the light of our models, we critically re-evaluate empirical evidence for Rice's theory and discuss prospects for empirically testing it.
Collapse
|
10
|
Han CS. Density-dependent sex-biased development of macroptery in a water strider. Ecol Evol 2020; 10:9514-9521. [PMID: 32953079 PMCID: PMC7487258 DOI: 10.1002/ece3.6644] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Revised: 07/15/2020] [Accepted: 07/17/2020] [Indexed: 12/16/2022] Open
Abstract
In wing-polymorphic insects, wing morphs differ not only in dispersal capability but also in life history traits because of trade-offs between flight capability and reproduction. When the fitness benefits and costs of producing wings differ between males and females, sex-specific trade-offs can result in sex differences in the frequency of long-winged individuals. Furthermore, the social environment during development affects sex differences in wing development, but few empirical tests of this phenomenon have been performed to date. Here, I used the wing-dimorphic water strider Tenagogerris euphrosyne to test how rearing density and sex ratio affect the sex-specific development of long-winged dispersing morphs (i.e., sex-specific macroptery). I also used a full-sib, split-family breeding design to assess genetic effects on density-dependent, sex-specific macroptery. I reared water strider nymphs at either high or low densities and measured their wing development. I found that long-winged morphs developed more frequently in males than in females when individuals were reared in a high-density environment. However, the frequency of long-winged morphs was not biased according to sex when individuals were reared in a low-density environment. In addition, full-sib males and females showed similar macroptery incidence rates at low nymphal density, whereas the macroptery incidence rates differed between full-sib males and females at high nymphal density. Thus complex gene-by-environment-by-sex interactions may explain the density-specific levels of sex bias in macroptery, although this interpretation should be treated with some caution. Overall, my study provides empirical evidence for density-specific, sex-biased wing development. My findings suggest that social factors as well as abiotic factors can be important in determining sex-biased wing development in insects.
Collapse
Affiliation(s)
- Chang S. Han
- Department of BiologyKyung Hee UniversitySeoulKorea
| |
Collapse
|
11
|
García-Roa R, Garcia-Gonzalez F, Noble DWA, Carazo P. Temperature as a modulator of sexual selection. Biol Rev Camb Philos Soc 2020; 95:1607-1629. [PMID: 32691483 DOI: 10.1111/brv.12632] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 06/10/2020] [Accepted: 06/12/2020] [Indexed: 12/25/2022]
Abstract
A central question in ecology and evolution is to understand why sexual selection varies so much in strength across taxa; it has long been known that ecological factors are crucial to this. Temperature is a particularly salient abiotic ecological factor that modulates a wide range of physiological, morphological and behavioural traits, impacting individuals and populations at a global taxonomic scale. Furthermore, temperature exhibits substantial temporal variation (e.g. daily, seasonally and inter-seasonally), and hence for most species in the wild sexual selection will regularly unfold in a dynamic thermal environment. Unfortunately, studies have so far almost completely neglected the role of temperature as a modulator of sexual selection. Here, we outline the main pathways through which temperature can affect the intensity and form (i.e. mechanisms) of sexual selection, via: (i) direct effects on secondary sexual traits and preferences (i.e. trait variance, opportunity for selection and trait-fitness covariance), and (ii) indirect effects on key mating parameters, sex-specific reproductive costs/benefits, trade-offs, demography and correlated abiotic factors. Building upon this framework, we show that, by focusing exclusively on the first-order effects that environmental temperature has on traits linked with individual fitness and population viability, current global warming studies may be ignoring eco-evolutionary feedbacks mediated by sexual selection. Finally, we tested the general prediction that temperature modulates sexual selection by conducting a meta-analysis of available studies experimentally manipulating temperature and reporting effects on the variance of male/female reproductive success and/or traits under sexual selection. Our results show a clear association between temperature and sexual selection measures in both sexes. In short, we suggest that studying the feedback between temperature and sexual selection processes may be vital to developing a better understanding of variation in the strength of sexual selection in nature, and its consequences for population viability in response to environmental change (e.g. global warming).
Collapse
Affiliation(s)
- Roberto García-Roa
- Behaviour and Evolution, Ethology Lab, Cavanilles Institute of Biodiversity and Evolutionary Biology, University of Valencia, C/Catedrático José Beltrán 2, Paterna, Valencia, 46980, Spain
| | - Francisco Garcia-Gonzalez
- Doñana Biological Station, Spanish Research Council CSIC, c/Americo Vespucio, 26, Isla de la Cartuja, Sevilla, 41092, Spain.,Centre for Evolutionary Biology, School of Biological Sciences, The University of Western Australia, 35 Stirling Highway, Crawley, Western Australia, 6009, Australia
| | - Daniel W A Noble
- Ecology and Evolution Research Centre, School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, New South Wales, 2052, Australia.,Division of Ecology and Evolution, Research School of Biology, The Australian National University, Canberra, Australian Capital Territory, 2061, Australia
| | - Pau Carazo
- Behaviour and Evolution, Ethology Lab, Cavanilles Institute of Biodiversity and Evolutionary Biology, University of Valencia, C/Catedrático José Beltrán 2, Paterna, Valencia, 46980, Spain
| |
Collapse
|
12
|
Natural infection by the protozoan Leptomonas wallacei impacts the morphology, physiology, reproduction, and lifespan of the insect Oncopeltus fasciatus. Sci Rep 2019; 9:17468. [PMID: 31767875 PMCID: PMC6877526 DOI: 10.1038/s41598-019-53678-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Accepted: 11/05/2019] [Indexed: 11/20/2022] Open
Abstract
Trypanosomatids are protozoan parasites that infect thousands of globally dispersed hosts, potentially affecting their physiology. Several species of trypanosomatids are commonly found in phytophagous insects. Leptomonas wallacei is a gut-restricted insect trypanosomatid only retrieved from Oncopeltus fasciatus. The insects get infected by coprophagy and transovum transmission of L. wallacei cysts. The main goal of the present study was to investigate the effects of a natural infection by L. wallacei on the hemipteran insect O. fasciatus, by comparing infected and uninfected individuals in a controlled environment. The L. wallacei-infected individuals showed reduced lifespan and morphological alterations. Also, we demonstrated a higher infection burden in females than in males. The infection caused by L. wallacei reduced host reproductive fitness by negatively impacting egg load, oviposition, and eclosion, and promoting an increase in egg reabsorption. Moreover, we associated the egg reabsorption observed in infected females, with a decrease in the intersex gene expression. Finally, we suggest alterations in population dynamics induced by L. wallacei infection using a mathematical model. Collectively, our findings demonstrated that L. wallacei infection negatively affected the physiology of O. fasciatus, which suggests that L. wallacei potentially has a vast ecological impact on host population growth.
Collapse
|
13
|
Abbott J, Rios‐Cardenas O, Morris MR. Insights from intralocus tactical conflict: adaptive states, interactions with ecology and population divergence. OIKOS 2019. [DOI: 10.1111/oik.06264] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Affiliation(s)
- Jessica Abbott
- Section for Evolutionary Ecology, Dept of Biology, Univ. Of Lund Sölvegatan 37 SE‐223 62 Lund Swede
| | | | | |
Collapse
|
14
|
Matthews G, Hangartner S, Chapple DG, Connallon T. Quantifying maladaptation during the evolution of sexual dimorphism. Proc Biol Sci 2019; 286:20191372. [PMID: 31409252 DOI: 10.1098/rspb.2019.1372] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Females and males have distinct trait optima, resulting in selection for sexual dimorphism. However, most traits have strong cross-sex genetic correlations, which constrain evolutionary divergence between the sexes and lead to protracted periods of maladaptation during the evolution of sexual dimorphism. While such constraints are thought to be costly in terms of individual and population fitness, it remains unclear how severe such costs are likely to be. Building upon classical models for the 'cost of selection' in changing environments (sensu Haldane), we derived a theoretical expression for the analogous cost of evolving sexual dimorphism; this cost is a simple function of genetic (co)variances of female and male traits and sex differences in trait optima. We then conducted a comprehensive literature search, compiled quantitative genetic data from a diverse set of traits and populations, and used them to quantify costs of sexual dimorphism in the light of our model. For roughly 90% of traits, costs of sexual dimorphism appear to be modest, and comparable to the costs of fixing one or a few beneficial substitutions. For the remaining traits (approx. 10%), sexual dimorphism appears to carry a substantial cost-potentially orders of magnitude greater than costs of selection during adaptation to environmental changes.
Collapse
Affiliation(s)
- Genevieve Matthews
- School of Biological Sciences, Monash University, Clayton, Victoria 3800, Australia
| | - Sandra Hangartner
- School of Biological Sciences, Monash University, Clayton, Victoria 3800, Australia
| | - David G Chapple
- School of Biological Sciences, Monash University, Clayton, Victoria 3800, Australia
| | - Tim Connallon
- School of Biological Sciences, Monash University, Clayton, Victoria 3800, Australia.,Centre for Geometric Biology, Monash University, Clayton, Victoria 3800, Australia
| |
Collapse
|
15
|
De Lisle SP, Goedert D, Reedy AM, Svensson EI. Climatic factors and species range position predict sexually antagonistic selection across taxa. Philos Trans R Soc Lond B Biol Sci 2019; 373:rstb.2017.0415. [PMID: 30150216 DOI: 10.1098/rstb.2017.0415] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/21/2018] [Indexed: 01/31/2023] Open
Abstract
Sex differences in selection are ubiquitous in sexually reproducing organisms. When the genetic basis of traits is shared between the sexes, such sexually antagonistic selection (SAS) creates a potential constraint on adaptive evolution. Theory and laboratory experiments suggest that environmental variation and the degree of local adaptation may all affect the frequency and intensity of SAS. Here, we capitalize on a large database of over 700 spatially or temporally replicated estimates of sex-specific phenotypic selection from wild populations, combined with data on microclimates and geographical range information. We performed a meta-analysis to test three predictions from SAS theory, that selection becomes more concordant between males and females: (1) in more stressful environments, (2) in more variable environments and (3) closer to the edge of the species' range. We find partial empirical support for all three predictions. Within-study analyses indicate SAS decreases in extreme environments, as indicated by a relationship with maximum temperature, minimum precipitation and evaporative potential (PET). Across studies, we found that the average level of SAS at high latitudes was lower, where environmental conditions are typically less stable. Finally, we found evidence for reduced SAS in populations that are far from the centre of their geographical range. However, and notably, we also found some evidence of reduced average strength of selection in these populations, which is in contrast to predictions from classical theoretical models on range limit evolution. Our results suggest that environmental lability and species range position predictably influence sex-specific selection and sexual antagonism in the wild.This article is part of the theme issue 'Linking local adaptation with the evolution of sex differences'.
Collapse
Affiliation(s)
- Stephen P De Lisle
- Evolutionary Ecology Unit, Department of Biology, Lund University, Sölvegatan 37, Lund 22362, Sweden
| | - Debora Goedert
- Department of Biological Sciences, Dartmouth College, Hanover, NH 03755, USA
| | - Aaron M Reedy
- Department of Biology, University of Virginia, Charlottesville, VA 22904, USA.,Department of Biological Sciences, Auburn University, Auburn, AL 36849, USA
| | - Erik I Svensson
- Evolutionary Ecology Unit, Department of Biology, Lund University, Sölvegatan 37, Lund 22362, Sweden
| |
Collapse
|
16
|
Svensson EI, Goedert D, Gómez-Llano MA, Spagopoulou F, Nava-Bolaños A, Booksmythe I. Sex differences in local adaptation: what can we learn from reciprocal transplant experiments? Philos Trans R Soc Lond B Biol Sci 2019; 373:rstb.2017.0420. [PMID: 30150219 DOI: 10.1098/rstb.2017.0420] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/07/2018] [Indexed: 12/13/2022] Open
Abstract
Local adaptation is of fundamental interest to evolutionary biologists. Traditionally, local adaptation has been studied using reciprocal transplant experiments to quantify fitness differences between residents and immigrants in pairwise transplants between study populations. Previous studies have detected local adaptation in some cases, but others have shown lack of adaptation or even maladaptation. Recently, the importance of different fitness components, such as survival and fecundity, to local adaptation have been emphasized. Here, we address another neglected aspect in studies of local adaptation: sex differences. Given the ubiquity of sexual dimorphism in life histories and phenotypic traits, this neglect is surprising, but may be partly explained by differences in research traditions and terminology in the fields of local adaptation and sexual selection. Studies that investigate differences in mating success between resident and immigrants across populations tend to be framed in terms of reproductive and behavioural isolation, rather than local adaptation. We briefly review the published literature that bridges these areas and suggest that reciprocal transplant experiments could benefit from quantifying both male and female fitness components. Such a more integrative research approach could clarify the role of sex differences in the evolution of local adaptations.This article is part of the theme issue 'Linking local adaptation with the evolution of sex differences'.
Collapse
Affiliation(s)
| | - Debora Goedert
- Department of Biological Sciences, Dartmouth College, Hanover, NH 03755, USA
| | | | - Foteini Spagopoulou
- Animal Ecology, Department of Ecology and Evolution, Uppsala University, 752 36 Uppsala, Sweden
| | - Angela Nava-Bolaños
- Departamento de Ecología Evolutiva, Instituto de Ecología, Universidad Nacional Autónoma de México, Apdo. Postal 70-275, Ciudad Universitaria, 04510 Ciudad de México, México.,Secretaría de Educación Abierta y Continua, Facultad de Ciencias, Universidad Nacional Autónoma de México, Avenida Universidad 3000, C.U., 04510 Ciudad de México, México
| | - Isobel Booksmythe
- School of Biological Sciences, Monash University, 3800 Victoria, Australia
| |
Collapse
|
17
|
Connallon T, Débarre F, Li XY. Linking local adaptation with the evolution of sex differences. Philos Trans R Soc Lond B Biol Sci 2019; 373:rstb.2017.0414. [PMID: 30150215 DOI: 10.1098/rstb.2017.0414] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/28/2018] [Indexed: 01/21/2023] Open
Abstract
Many conspicuous forms of evolutionary diversity occur within species. Two prominent examples include evolutionary divergence between populations differentially adapted to their local environments (local adaptation), and divergence between females and males in response to sex differences in selection (sexual dimorphism sensu lato). These two forms of diversity have inspired vibrant research programmes, yet these fields have largely developed in isolation from one another. Nevertheless, conceptual parallels between these research traditions are striking. Opportunities for local adaptation strike a balance between local selection, which promotes divergence, and gene flow-via dispersal and interbreeding between populations-which constrains it. Sex differences are similarly constrained by fundamental features of inheritance that mimic gene flow. Offspring of each sex inherit genes from same-sex and opposite-sex parents, leading to gene flow between each differentially selected half of the population, and raising the question of how sex differences arise and are maintained. This special issue synthesizes and extends emerging research at the interface between the research traditions of local adaptation and sex differences. Each field can promote understanding of the other, and interactions between local adaptation and sex differences can generate new empirical predictions about the evolutionary consequences of selection that varies across space, time, and between the sexes.This article is part of the theme issue 'Linking local adaptation with the evolution of sex differences'.
Collapse
Affiliation(s)
- Tim Connallon
- School of Biological Sciences, Monash University, Clayton, Victoria, Australia
| | - Florence Débarre
- CNRS, UMR 7241 Centre Interdisciplinaire de Recherche en Biologie (CIRB), Collège de France, Paris, France
| | - Xiang-Yi Li
- Department of Evolutionary Biology and Environmental Studies, University of Zürich, Winterthurerstrasse 190, 8057 Zürich, Switzerland
| |
Collapse
|
18
|
Martinossi‐Allibert I, Thilliez E, Arnqvist G, Berger D. Sexual selection, environmental robustness, and evolutionary demography of maladapted populations: A test using experimental evolution in seed beetles. Evol Appl 2019; 12:1371-1384. [PMID: 31417621 PMCID: PMC6691221 DOI: 10.1111/eva.12758] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Revised: 11/19/2018] [Accepted: 12/09/2018] [Indexed: 01/01/2023] Open
Abstract
Whether sexual selection impedes or aids adaptation has become an outstanding question in times of rapid environmental change and parallels the debate about how the evolution of individual traits impacts on population dynamics. The net effect of sexual selection on population viability results from a balance between genetic benefits of "good-genes" effects and costs of sexual conflict. Depending on how these facets of sexual selection are affected under environmental change, extinction of maladapted populations could be either avoided or accelerated. Here, we evolved seed beetles under three alternative mating regimes to disentangle the contributions of sexual selection, fecundity selection, and male-female coevolution to individual reproductive success and population fitness. We compared these contributions between the ancestral environment and two stressful environments (elevated temperature and a host plant shift). We found evidence that sexual selection on males had positive genetic effects on female fitness components across environments, supporting good-genes sexual selection. Interestingly, however, when males evolved under sexual selection with fecundity selection removed, they became more robust to both temperature and host plant stress compared to their conspecific females and males from the other evolution regimes that applied fecundity selection. We quantified the population-level consequences of this sex-specific adaptation and found evidence that the cost of sociosexual interactions in terms of reduced offspring production was higher in the regime applying only sexual selection to males. Moreover, the cost tended to be more pronounced at the elevated temperature to which males from the regime were more robust compared to their conspecific females. These results illustrate the tension between individual-level adaptation and population-level viability in sexually reproducing species and suggest that the relative efficacies of sexual selection and fecundity selection can cause inherent sex differences in environmental robustness that may impact demography of maladapted populations.
Collapse
Affiliation(s)
| | - Emma Thilliez
- Department of Ecology and Genetics, Animal EcologyUppsala UniversityUppsalaSweden
| | - Göran Arnqvist
- Department of Ecology and Genetics, Animal EcologyUppsala UniversityUppsalaSweden
| | - David Berger
- Department of Ecology and Genetics, Animal EcologyUppsala UniversityUppsalaSweden
| |
Collapse
|
19
|
Connallon T, Matthews G. Cross-sex genetic correlations for fitness and fitness components: Connecting theoretical predictions to empirical patterns. Evol Lett 2019; 3:254-262. [PMID: 31171981 PMCID: PMC6546386 DOI: 10.1002/evl3.116] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Revised: 03/21/2019] [Accepted: 04/07/2019] [Indexed: 11/18/2022] Open
Abstract
Sex differences in morphology, physiology, development, and behavior are widespread, yet the sexes inherit nearly identical genomes, causing most traits to exhibit strong and positive cross‐sex genetic correlations. In contrast to most other traits, estimates of cross‐sex genetic correlations for fitness and fitness components (rW fm ) are generally low and occasionally negative, implying that a substantial fraction of standing genetic variation for fitness might be sexually antagonistic (i.e., alleles benefitting one sex harm the other). Nevertheless, while low values of rW fm are often regarded as consequences of sexually antagonistic selection, it remains unclear exactly how selection and variation in quantitative traits interact to determine the sign and magnitude of rW fm , making it difficult to relate empirical estimates of cross‐sex genetic correlations to the evolutionary processes that might shape them. We present simple univariate and multivariate quantitative genetic models that explicitly link patterns of sex‐specific selection and trait genetic variation to the cross‐sex genetic correlation for fitness. We show that rW fm provides an unreliable signal of sexually antagonistic selection for two reasons. First, rW fm is constrained to be less than the cross‐sex genetic correlation for traits affecting fitness, regardless of the nature of selection on the traits. Second, sexually antagonistic selection is an insufficient condition for generating negative cross‐sex genetic correlations for fitness. Instead, negative fitness correlations between the sexes (rW fm <0) can only emerge when selection is sexually antagonistic and the strength of directional selection on each sex is strong relative to the amount of shared additive genetic variation in female and male traits. These results imply that empirical tests of sexual antagonism that are based on estimates of rW fm will be conservative and underestimate its true scope. In light of these theoretical results, we revisit current data on rW fm and sex‐specific selection and find that they are consistent with the theory.
Collapse
Affiliation(s)
- Tim Connallon
- School of Biological Sciences, and Centre for Geometric Biology Monash University Clayton Victoria 3800 Australia
| | - Genevieve Matthews
- School of Biological Sciences, and Centre for Geometric Biology Monash University Clayton Victoria 3800 Australia
| |
Collapse
|
20
|
Fox RJ, Fromhage L, Jennions MD. Sexual selection, phenotypic plasticity and female reproductive output. Philos Trans R Soc Lond B Biol Sci 2019; 374:20180184. [PMID: 30966965 PMCID: PMC6365872 DOI: 10.1098/rstb.2018.0184] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/15/2018] [Indexed: 01/17/2023] Open
Abstract
In a rapidly changing environment, does sexual selection on males elevate a population's reproductive output? If so, does phenotypic plasticity enhance or diminish any such effect? We outline two routes by which sexual selection can influence the reproductive output of a population: a genetic correlation between male sexual competitiveness and female lifetime reproductive success; and direct effects of males on females' breeding success. We then discuss how phenotypic plasticity of sexually selected male traits and/or female responses (e.g. plasticity in mate choice), as the environment changes, might influence how sexual selection affects a population's reproductive output. Two key points emerge. First, condition-dependent expression of male sexual traits makes it likely that sexual selection increases female fitness if reproductively successful males disproportionately transfer genes that are under natural selection in both sexes, such as genes for foraging efficiency. Condition-dependence is a form of phenotypic plasticity if some of the variation in net resource acquisition and assimilation is attributable to the environment rather than solely genetic in origin. Second, the optimal allocation of resources into different condition-dependent traits depends on their marginal fitness gains. As male condition improves, this can therefore increase or, though rarely highlighted, actually decrease the expression of sexually selected traits. It is therefore crucial to understand how condition determines male allocation of resources to different sexually selected traits that vary in their immediate effects on female reproductive output (e.g. ornaments versus coercive behaviour). In addition, changes in the distribution of condition among males as the environment shifts could reduce phenotypic variance in certain male traits, thereby reducing the strength of sexual selection imposed by females. Studies of adaptive evolution under rapid environmental change should consider the possibility that phenotypic plasticity of sexually selected male traits, even if it elevates male fitness, could have a negative effect on female reproductive output, thereby increasing the risk of population extinction. This article is part of the theme issue 'The role of plasticity in phenotypic adaptation to rapid environmental change'.
Collapse
Affiliation(s)
- Rebecca J. Fox
- Division of Ecology and Evolution, Research School of Biology, Australian National University, Canberra, Australian Capital Territory 2601, Australia
| | - Lutz Fromhage
- Department of Biological and Environmental Science, University of Jyvaskyla, PO Box 35, Jyvaskyla 40014, Finland
| | - Michael D. Jennions
- Division of Ecology and Evolution, Research School of Biology, Australian National University, Canberra, Australian Capital Territory 2601, Australia
| |
Collapse
|
21
|
Martinossi-Allibert I, Rueffler C, Arnqvist G, Berger D. The efficacy of good genes sexual selection under environmental change. Proc Biol Sci 2019; 286:20182313. [PMID: 30963930 PMCID: PMC6408614 DOI: 10.1098/rspb.2018.2313] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Accepted: 01/10/2019] [Indexed: 11/12/2022] Open
Abstract
Sexual selection can promote adaptation if sexually selected traits are reliable indicators of genetic quality. Moreover, models of good genes sexual selection suggest that, by operating more strongly in males than in females, sexual selection may purge deleterious alleles from the population at a low demographic cost, offering an evolutionary benefit to sexually reproducing populations. Here, we investigate the effect of good genes sexual selection on adaptation following environmental change. We show that the strength of sexual selection is often weakened relative to fecundity selection, reducing the suggested benefit of sexual reproduction. This result is a consequence of incorporating a simple and general mechanistic basis for how sexual selection operates under different mating systems, rendering selection on males frequency-dependent and dynamic with respect to the degree of environmental change. Our model illustrates that incorporating the mechanism of selection is necessary to predict evolutionary outcomes and highlights the need to substantiate previous theoretical claims with further work on how sexual selection operates in changing environments.
Collapse
|
22
|
García‐Roa R, Chirinos V, Carazo P. The ecology of sexual conflict: Temperature variation in the social environment can drastically modulate male harm to females. Funct Ecol 2019. [DOI: 10.1111/1365-2435.13275] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Roberto García‐Roa
- Behaviour and Evolution Group, Ethology Lab, Cavanilles Institute of Biodiversity and Evolutionary Biology University of Valencia Valencia Spain
| | - Valeria Chirinos
- Behaviour and Evolution Group, Ethology Lab, Cavanilles Institute of Biodiversity and Evolutionary Biology University of Valencia Valencia Spain
| | - Pau Carazo
- Behaviour and Evolution Group, Ethology Lab, Cavanilles Institute of Biodiversity and Evolutionary Biology University of Valencia Valencia Spain
| |
Collapse
|
23
|
Duffy E, Archer CR, Sharma MD, Prus M, Joag RA, Radwan J, Wedell N, Hosken DJ. Wolbachia infection can bias estimates of intralocus sexual conflict. Ecol Evol 2019; 9:328-338. [PMID: 30680117 PMCID: PMC6342094 DOI: 10.1002/ece3.4744] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Revised: 09/30/2018] [Accepted: 11/01/2018] [Indexed: 12/19/2022] Open
Abstract
Males and females share most of their genome and develop many of the same traits. However, each sex frequently has different optimal values for these shared traits, creating intralocus sexual conflict. This conflict has been observed in wild and laboratory populations of insects and affects important evolutionary processes such as sexual selection, the maintenance of genetic variation, and possibly even speciation. Given the broad impacts of intralocus conflict, accurately detecting and measuring it is important. A common way to detect intralocus sexual conflict is to calculate the intersexual genetic correlation for fitness, with negative values suggesting conflict. Here, we highlight a potential confounder of this measure-cytoplasmic incompatibility caused by the intracellular parasite Wolbachia. Infection with Wolbachia can generate negative intersexual genetic correlations for fitness in insects, suggestive of intralocus sexual conflict. This is because cytoplasmic incompatibility reduces the fitness of uninfected females mated to infected males, while uninfected males will not suffer reductions in fitness if they mate with infected females and may even be fitter than infected males. This can lead to strong negative intersexual genetic correlations for fitness, mimicking intralocus conflict. We illustrate this issue using simulations and then present Drosophila simulans data that show how reproductive incompatibilities caused by Wolbachia infection can generate signals of intralocus sexual conflict. Given that Wolbachia infection in insect populations is pervasive, but populations usually contain both infected and uninfected individuals providing scope for cytoplasmic incompatibility, this is an important consideration for sexual conflict research but one which, to date, has been largely underappreciated.
Collapse
Affiliation(s)
- Eoin Duffy
- Institute of Environmental SciencesJagiellonian UniversityKrakowPoland
- Science and Engineering Research Support Facility (SERSF)University of ExeterPenrynUK
| | - C. Ruth Archer
- Science and Engineering Research Support Facility (SERSF)University of ExeterPenrynUK
| | - Manmohan Dev Sharma
- Science and Engineering Research Support Facility (SERSF)University of ExeterPenrynUK
| | - Monika Prus
- Institute of Environmental SciencesJagiellonian UniversityKrakowPoland
| | - Richa A. Joag
- Institute of Environmental SciencesJagiellonian UniversityKrakowPoland
- Science and Engineering Research Support Facility (SERSF)University of ExeterPenrynUK
| | - Jacek Radwan
- Institute of Environmental SciencesJagiellonian UniversityKrakowPoland
- Faculty of BiologyAdam Mickiewicz UniversityPoznańPoland
| | - Nina Wedell
- Science and Engineering Research Support Facility (SERSF)University of ExeterPenrynUK
| | - David J. Hosken
- Science and Engineering Research Support Facility (SERSF)University of ExeterPenrynUK
| |
Collapse
|
24
|
Wolak ME, Arcese P, Keller LF, Nietlisbach P, Reid JM. Sex‐specific additive genetic variances and correlations for fitness in a song sparrow (
Melospiza melodia
) population subject to natural immigration and inbreeding. Evolution 2018; 72:2057-2075. [DOI: 10.1111/evo.13575] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Accepted: 07/23/2018] [Indexed: 12/15/2022]
Affiliation(s)
- Matthew E. Wolak
- School of Biological SciencesUniversity of Aberdeen Aberdeen Scotland
- Department of Biological SciencesAuburn University Auburn Alabama 36849
| | - Peter Arcese
- Department of Forest and Conservation SciencesUniversity of British Columbia Vancouver British Columbia Canada
| | - Lukas F. Keller
- Department of Evolutionary Biology and Environmental StudiesUniversity of Zurich Winterthurerstrasse 190 CH‐8057 Zurich Switzerland
- Zoological MuseumUniversity of Zurich Karl‐Schmid‐Strasse 4 CH‐8006 Zurich Switzerland
| | - Pirmin Nietlisbach
- Department of Evolutionary Biology and Environmental StudiesUniversity of Zurich Winterthurerstrasse 190 CH‐8057 Zurich Switzerland
- Department of ZoologyUniversity of British Columbia Vancouver British Columbia Canada
| | - Jane M. Reid
- School of Biological SciencesUniversity of Aberdeen Aberdeen Scotland
| |
Collapse
|
25
|
Skwierzyńska AM, Radwan J, Plesnar‐Bielak A. Male-limited secondary sexual trait interacts with environment in determining female fitness. Evolution 2018; 72:1716-1722. [PMID: 29984827 PMCID: PMC6175437 DOI: 10.1111/evo.13551] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Revised: 06/27/2018] [Accepted: 06/30/2018] [Indexed: 12/16/2022]
Abstract
Selection for secondary sexual trait (SST) elaboration may increase intralocus sexual conflict over the optimal values of traits expressed from shared genomes. This conflict can reduce female fitness, and the resulting gender load can be exacerbated by environmental stress, with consequences for a population's ability to adapt to novel environments. However, how the evolution of SSTs interacts with environment in determining female fitness is not well understood. Here, we investigated this question using replicate lines of bulb mites selected for increased or decreased prevalence of a male SST-thickened legs used as weapons. The fitness of females from these lines was measured at a temperature to which the mites were adapted (24°C), as well as at two novel temperatures: 18°C and 28°C. We found the prevalence of the SST interacted with temperature in determining female fecundity. At 28°C, females from populations with high SST prevalence were less fecund than females from populations in which the SST was rare, but the reverse was true at 18°C. Thus, a novel environment does not universally depress female fitness more in populations with a high degree of sexually selected dimorphism. We discuss possible consequences of the interaction we detected for adaptation to novel environments.
Collapse
Affiliation(s)
| | - Jacek Radwan
- Institute of Environmental Biology, Faculty of BiologyAdam Mickiewicz UniversityPoznańPoland
| | - Agata Plesnar‐Bielak
- Institute of Environmental SciencesJagiellonian UniversityGronostajowa7, 30‐387KrakówPoland
| |
Collapse
|
26
|
Reid JM, Wolak ME. Is there indirect selection on female extra-pair reproduction through cross-sex genetic correlations with male reproductive fitness? Evol Lett 2018; 2:159-168. [PMID: 30283673 PMCID: PMC6121835 DOI: 10.1002/evl3.56] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Revised: 04/16/2018] [Accepted: 04/25/2018] [Indexed: 11/16/2022] Open
Abstract
One key hypothesis explaining the evolution and persistence of polyandry, and resulting female extra‐pair reproduction in socially monogamous systems, is that female propensity for extra‐pair reproduction is positively genetically correlated with male reproductive fitness and consequently experiences positive cross‐sex indirect selection. However, key genetic correlations have rarely been estimated, especially in free‐living populations experiencing natural (co)variation in reproductive strategies and fitness. We used long‐term life‐history and pedigree data from song sparrows (Melospiza melodia) to estimate the cross‐sex genetic correlation between female propensity for extra‐pair reproduction and adult male lifetime reproductive success, and thereby test a key hypothesis regarding mating system evolution. There was substantial additive genetic variance in both traits, providing substantial potential for indirect selection on female reproductive strategy. However, the cross‐sex genetic correlation was estimated to be close to zero. Such small correlations might arise because male reproductive success achieved through extra‐pair paternity was strongly positively genetically correlated with success achieved through within‐pair paternity, implying that the same successful males commonly sire offspring produced by polyandrous and monogamous females. Cross‐sex indirect selection may consequently have limited capacity to drive evolution of female extra‐pair reproduction, or hence underlying polyandry, in systems where multiple routes to paternity success exist.
Collapse
Affiliation(s)
- Jane M Reid
- School of Biological Sciences University of Aberdeen Aberdeen United Kingdom
| | - Matthew E Wolak
- School of Biological Sciences University of Aberdeen Aberdeen United Kingdom.,Department of Biological Sciences Auburn University Auburn Alabama 36849
| |
Collapse
|
27
|
Lasne C, Hangartner SB, Connallon T, Sgrò CM. Cross‐sex genetic correlations and the evolution of sex‐specific local adaptation: Insights from classical trait clines in
Drosophila melanogaster. Evolution 2018; 72:1317-1327. [DOI: 10.1111/evo.13494] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Accepted: 04/03/2018] [Indexed: 01/02/2023]
Affiliation(s)
- Clémentine Lasne
- School of Biological Sciences Monash University Clayton Victoria 3800 Australia
| | | | - Tim Connallon
- School of Biological Sciences Monash University Clayton Victoria 3800 Australia
| | - Carla M. Sgrò
- School of Biological Sciences Monash University Clayton Victoria 3800 Australia
| |
Collapse
|
28
|
Han CS, Dingemanse NJ. Sex-dependent expression of behavioural genetic architectures and the evolution of sexual dimorphism. Proc Biol Sci 2018; 284:rspb.2017.1658. [PMID: 28978735 DOI: 10.1098/rspb.2017.1658] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2017] [Accepted: 08/21/2017] [Indexed: 12/12/2022] Open
Abstract
Empirical studies imply that sex-specific genetic architectures can resolve evolutionary conflicts between males and females, and thereby facilitate the evolution of sexual dimorphism. Sex-specificity of behavioural genetic architectures has, however, rarely been considered. Moreover, as the expression of genetic (co)variances is often environment-dependent, general inferences on sex-specific genetic architectures require estimates of quantitative genetics parameters under multiple conditions. We measured exploration and aggression in pedigreed populations of southern field crickets (Gryllus bimaculatus) raised on either naturally balanced (free-choice) or imbalanced (protein-deprived) diets. For each dietary condition, we measured for each behavioural trait (i) level of sexual dimorphism, (ii) level of sex-specificity of survival selection gradients, (iii) level of sex-specificity of additive genetic variance, and (iv) strength of the cross-sex genetic correlation. We report here evidence for sexual dimorphism in behaviour as well as sex-specificity in the expression of genetic (co)variances as predicted by theory. The additive genetic variances of exploration and aggression were significantly greater in males compared with females. Cross-sex genetic correlations were highly positive for exploration but deviating (significantly) from one for aggression; findings were consistent across dietary treatments. This suggests that genetic architectures characterize the sexually dimorphic focal behaviours across various key environmental conditions in the wild. Our finding also highlights that sexual conflict can be resolved by evolving sexually independent genetic architectures.
Collapse
Affiliation(s)
- Chang S Han
- Behavioural Ecology, Department of Biology, Ludwig-Maximilians University of Munich, Planegg-Martinsried, Germany
| | - Niels J Dingemanse
- Behavioural Ecology, Department of Biology, Ludwig-Maximilians University of Munich, Planegg-Martinsried, Germany
| |
Collapse
|
29
|
Cheng C, Kirkpatrick M. Environmental Plasticity in the Intersexual Correlation and Sex Bias of Gene Expression. J Hered 2018; 108:754-758. [PMID: 29036352 DOI: 10.1093/jhered/esx083] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Accepted: 09/22/2017] [Indexed: 11/13/2022] Open
Abstract
Intersexual genetic correlations are expected to constrain the evolution of sexual dimorphic traits, including the degree of sex-biased gene expression. Consistent with that expectation, studies in fruit flies and birds have reported that genes whose expression has a strong intersexual genetic correlation (rMF) show a lower level of sex-biased expression (SBE). However, it is known that both rMF and SBE can be affected by the environment. It is therefore unclear whether there is a consistent relationship between these 2 quantities across multiple environments. In this paper, we study this relationship in the African malaria mosquito Anopheles gambiae. We show that both rMF and SBE change between environments. The change in SBE across environments is significantly correlated with dN/dS: greater changes in SBE are associated with higher values of dN/dS. Furthermore, the relationship between rMF and SBE is sensitive to the environment. We conclude that this relationship is sufficiently plastic that environmental effects should be considered in future studies.
Collapse
Affiliation(s)
- Changde Cheng
- Department of Integrative Biology, University of Texas, Austin, TX 78712.,Department of Computational Biology, St. Jude Children's Research Hospital, Memphis, TN 38105
| | - Mark Kirkpatrick
- Department of Integrative Biology, University of Texas, Austin, TX 78712
| |
Collapse
|
30
|
Pennell TM, Holman L, Morrow EH, Field J. Building a new research framework for social evolution: intralocus caste antagonism. Biol Rev Camb Philos Soc 2018; 93:1251-1268. [PMID: 29341390 PMCID: PMC5896731 DOI: 10.1111/brv.12394] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2017] [Revised: 12/06/2017] [Accepted: 12/18/2017] [Indexed: 01/02/2023]
Abstract
The breeding and non‐breeding ‘castes’ of eusocial insects provide a striking example of role‐specific selection, where each caste maximises fitness through different morphological, behavioural and physiological trait values. Typically, queens are long‐lived egg‐layers, while workers are short‐lived, largely sterile foragers. Remarkably, the two castes are nevertheless produced by the same genome. The existence of inter‐caste genetic correlations is a neglected consequence of this shared genome, potentially hindering the evolution of caste dimorphism: alleles that increase the productivity of queens may decrease the productivity of workers and vice versa, such that each caste is prevented from reaching optimal trait values. A likely consequence of this ‘intralocus caste antagonism’ should be the maintenance of genetic variation for fitness and maladaptation within castes (termed ‘caste load’), analogous to the result of intralocus sexual antagonism. The aim of this review is to create a research framework for understanding caste antagonism, drawing in part upon conceptual similarities with sexual antagonism. By reviewing both the social insect and sexual antagonism literature, we highlight the current empirical evidence for caste antagonism, discuss social systems of interest, how antagonism might be resolved, and challenges for future research. We also introduce the idea that sexual and caste antagonism could interact, creating a three‐way antagonism over gene expression. This includes unpacking the implications of haplodiploidy for the outcome of this complex interaction.
Collapse
Affiliation(s)
- Tanya M Pennell
- College of Life and Environmental Sciences, University of Exeter, Penryn, Cornwall, TR10 9FE, UK
| | - Luke Holman
- School of Biosciences, University of Melbourne, Parkville, Victoria, 3052, Australia
| | - Edward H Morrow
- Evolution Behaviour and Environment Group, School of Life Sciences, University of Sussex, Falmer, East Sussex, BN1 9QG, UK
| | - Jeremy Field
- College of Life and Environmental Sciences, University of Exeter, Penryn, Cornwall, TR10 9FE, UK
| |
Collapse
|
31
|
Holman L, Jacomb F. The effects of stress and sex on selection, genetic covariance, and the evolutionary response. J Evol Biol 2017; 30:1898-1909. [PMID: 28763136 DOI: 10.1111/jeb.13149] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2017] [Revised: 07/02/2017] [Accepted: 07/06/2017] [Indexed: 12/26/2022]
Abstract
The capacity of a population to adapt to selection (evolvability) depends on whether the structure of genetic variation permits the evolution of fitter trait combinations. Selection, genetic variance and genetic covariance can change under environmental stress, and males and females are not genetically independent, yet the combined effects of stress and dioecy on evolvability are not well understood. Here, we estimate selection, genetic (co)variance and evolvability in both sexes of Tribolium castaneum flour beetles under stressful and benign conditions, using a half-sib breeding design. Although stress uncovered substantial latent heritability, stress also affected genetic covariance, such that evolvability remained low under stress. Sexual selection on males and natural selection on females favoured a similar phenotype, and there was positive intersex genetic covariance. Consequently, sexual selection on males augmented adaptation in females, and intralocus sexual conflict was weak or absent. This study highlights that increased heritability does not necessarily increase evolvability, suggests that selection can deplete genetic variance for multivariate trait combinations with strong effects on fitness, and tests the recent hypothesis that sexual conflict is weaker in stressful or novel environments.
Collapse
Affiliation(s)
- L Holman
- School of BioSciences, University of Melbourne, Parkville, VIC, Australia
| | - F Jacomb
- Research School of Biology, Australian National University, Canberra, ACT, Australia
| |
Collapse
|
32
|
Zajitschek F, Connallon T. Partitioning of resources: the evolutionary genetics of sexual conflict over resource acquisition and allocation. J Evol Biol 2017; 30:826-838. [DOI: 10.1111/jeb.13051] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Revised: 01/15/2017] [Accepted: 01/27/2017] [Indexed: 01/20/2023]
Affiliation(s)
- F. Zajitschek
- Department of Biological Sciences Monash University Clayton Vic. Australia
| | - T. Connallon
- Department of Biological Sciences Monash University Clayton Vic. Australia
| |
Collapse
|
33
|
Martinossi-Allibert I, Arnqvist G, Berger D. Sex-specific selection under environmental stress in seed beetles. J Evol Biol 2016; 30:161-173. [DOI: 10.1111/jeb.12996] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Revised: 09/21/2016] [Accepted: 10/13/2016] [Indexed: 01/15/2023]
Affiliation(s)
| | - G. Arnqvist
- Department of Ecology and Genetics; Animal Ecology; Uppsala University; Uppsala Sweden
| | - D. Berger
- Department of Ecology and Genetics; Animal Ecology; Uppsala University; Uppsala Sweden
| |
Collapse
|
34
|
Berger D, Martinossi-Allibert I, Grieshop K, Lind MI, Maklakov AA, Arnqvist G. Intralocus Sexual Conflict and the Tragedy of the Commons in Seed Beetles. Am Nat 2016; 188:E98-E112. [DOI: 10.1086/687963] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
|
35
|
Connallon T, Hall MD. Genetic correlations and sex‐specific adaptation in changing environments. Evolution 2016; 70:2186-2198. [DOI: 10.1111/evo.13025] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2016] [Revised: 07/20/2016] [Accepted: 07/26/2016] [Indexed: 01/18/2023]
Affiliation(s)
- Tim Connallon
- School of Biological Sciences Monash University Clayton Victoria 3800 Australia
| | - Matthew D. Hall
- School of Biological Sciences Monash University Clayton Victoria 3800 Australia
| |
Collapse
|
36
|
Collet JM, Fuentes S, Hesketh J, Hill MS, Innocenti P, Morrow EH, Fowler K, Reuter M. Rapid evolution of the intersexual genetic correlation for fitness in Drosophila melanogaster. Evolution 2016; 70:781-95. [PMID: 27077679 PMCID: PMC5069644 DOI: 10.1111/evo.12892] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2014] [Revised: 02/16/2016] [Accepted: 02/17/2016] [Indexed: 01/05/2023]
Abstract
Sexual antagonism (SA) arises when male and female phenotypes are under opposing selection, yet genetically correlated. Until resolved, antagonism limits evolution toward optimal sex‐specific phenotypes. Despite its importance for sex‐specific adaptation and existing theory, the dynamics of SA resolution are not well understood empirically. Here, we present data from Drosophila melanogaster, compatible with a resolution of SA. We compared two independent replicates of the “LHM” population in which SA had previously been described. Both had been maintained under identical, controlled conditions, and separated for around 200 generations. Although heritabilities of male and female fitness were similar, the intersexual genetic correlation differed significantly, being negative in one replicate (indicating SA) but close to zero in the other. Using population sequencing, we show that phenotypic differences were associated with population divergence in allele frequencies at nonrandom loci across the genome. Large frequency changes were more prevalent in the population without SA and were enriched at loci mapping to genes previously shown to have sexually antagonistic relationships between expression and fitness. Our data suggest that rapid evolution toward SA resolution has occurred in one of the populations and open avenues toward studying the genetics of SA and its resolution.
Collapse
Affiliation(s)
- Julie M Collet
- Research Department of Genetics, Evolution and Environment, University College London, London, United Kingdom.,Current Address: School of Biological Sciences, University of Queensland, St. Lucia, QLD, Australia
| | - Sara Fuentes
- Research Department of Genetics, Evolution and Environment, University College London, London, United Kingdom
| | - Jack Hesketh
- Research Department of Genetics, Evolution and Environment, University College London, London, United Kingdom
| | - Mark S Hill
- Research Department of Genetics, Evolution and Environment, University College London, London, United Kingdom
| | - Paolo Innocenti
- Department of Animal Ecology, Uppsala University, Uppsala, Sweden
| | - Edward H Morrow
- Department of Animal Ecology, Uppsala University, Uppsala, Sweden.,Current Address: School of Life Sciences, University of Sussex, Brighton, United Kingdom
| | - Kevin Fowler
- Research Department of Genetics, Evolution and Environment, University College London, London, United Kingdom
| | - Max Reuter
- Research Department of Genetics, Evolution and Environment, University College London, London, United Kingdom.
| |
Collapse
|
37
|
Calsbeek R, Duryea MC, Goedert D, Bergeron P, Cox RM. Intralocus sexual conflict, adaptive sex allocation, and the heritability of fitness. J Evol Biol 2015; 28:1975-85. [PMID: 26310599 DOI: 10.1111/jeb.12713] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2014] [Revised: 06/25/2015] [Accepted: 07/29/2015] [Indexed: 11/27/2022]
Abstract
Intralocus sexual conflict arises when selection favours alternative fitness optima in males and females. Unresolved conflict can create negative between-sex genetic correlations for fitness, such that high-fitness parents produce high-fitness progeny of their same sex, but low-fitness progeny of the opposite sex. This cost of sexual conflict could be mitigated if high-fitness parents bias sex allocation to produce more offspring of their same sex. Previous studies of the brown anole lizard (Anolis sagrei) show that viability selection on body size is sexually antagonistic, favouring large males and smaller females. However, sexual conflict over body size may be partially mitigated by adaptive sex allocation: large males sire more sons than daughters, whereas small males sire more daughters than sons. We explored the evolutionary implications of these phenomena by assessing the additive genetic (co)variance of fitness within and between sexes in a wild population. We measured two components of fitness: viability of adults over the breeding season, and the number of their progeny that survived to sexual maturity, which includes components of parental reproductive success and offspring viability (RS(V) ). Viability of parents was not correlated with adult viability of their sons or daughters. RS(V) was positively correlated between sires and their offspring, but not between dams and their offspring. Neither component of fitness was significantly heritable, and neither exhibited negative between-sex genetic correlations that would indicate unresolved sexual conflict. Rather, our results are more consistent with predictions regarding adaptive sex allocation in that, as the number of sons produced by a sire increased, the adult viability of his male progeny increased.
Collapse
Affiliation(s)
- R Calsbeek
- Department of Biological Sciences, Dartmouth College, Hanover, NH, USA
| | - M C Duryea
- Department of Biological Sciences, Dartmouth College, Hanover, NH, USA
| | - D Goedert
- Department of Biological Sciences, Dartmouth College, Hanover, NH, USA.,CAPES Foundation, Ministry of Education of Brazil, Brasília, DF, Brazil
| | - P Bergeron
- Department of Biological Sciences, Dartmouth College, Hanover, NH, USA
| | - R M Cox
- Department of Biological Sciences, Dartmouth College, Hanover, NH, USA
| |
Collapse
|
38
|
Connallon T. The geography of sex-specific selection, local adaptation, and sexual dimorphism. Evolution 2015; 69:2333-44. [DOI: 10.1111/evo.12737] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2015] [Accepted: 07/15/2015] [Indexed: 12/24/2022]
Affiliation(s)
- Tim Connallon
- School of Biological Sciences; Monash University; Clayton Victoria Australia
| |
Collapse
|
39
|
Power DJ, Holman L. Assessing the alignment of sexual and natural selection using radiomutagenized seed beetles. J Evol Biol 2015; 28:1039-48. [DOI: 10.1111/jeb.12625] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2014] [Revised: 03/16/2015] [Accepted: 03/18/2015] [Indexed: 12/01/2022]
Affiliation(s)
- D. J. Power
- Division of Evolution, Ecology & Genetics; Research School of Biology; Australian National University; Canberra ACT Australia
| | - L. Holman
- Division of Evolution, Ecology & Genetics; Research School of Biology; Australian National University; Canberra ACT Australia
| |
Collapse
|
40
|
The effect of parasites on sex differences in selection. Heredity (Edinb) 2015; 114:367-72. [PMID: 25649503 DOI: 10.1038/hdy.2014.110] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2014] [Revised: 10/26/2014] [Accepted: 10/27/2014] [Indexed: 11/08/2022] Open
Abstract
The life history strategies of males and females are often divergent, creating the potential for sex differences in selection. Deleterious mutations may be subject to stronger selection in males, owing to sexual selection, which can improve the mean fitness of females and reduce mutation load in sexual populations. However, sex differences in selection might also maintain sexually antagonistic genetic variation, creating a sexual conflict load. The overall impact of separate sexes on fitness is unclear, but the net effect is likely to be positive when there is a large sex difference in selection against deleterious mutations. Parasites can also have sex-specific effects on fitness, and there is evidence that parasites can intensify the fitness consequences of deleterious mutations. Using lines that accumulated mutations for over 60 generations, we studied the effect of the pathogenic bacterium Pseudomonas aeruginosa on sex differences in selection in the fruit fly Drosophila melanogaster. Pseudomonas infection increased the sex difference in selection, but may also have weakened the intersexual correlation for fitness. Our results suggest that parasites may increase the benefits of sexual selection.
Collapse
|
41
|
Duffy E, Joag R, Radwan J, Wedell N, Hosken DJ. Inbreeding alters intersexual fitness correlations in Drosophila simulans. Ecol Evol 2014; 4:3330-8. [PMID: 25535550 PMCID: PMC4228608 DOI: 10.1002/ece3.1153] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2014] [Revised: 05/20/2014] [Accepted: 06/02/2014] [Indexed: 12/18/2022] Open
Abstract
Intralocus sexual conflict results from sexually antagonistic selection on traits shared by the sexes. This can displace males and females from their respective fitness optima, and negative intersexual correlations (r mf) for fitness are the unequivocal indicator of this evolutionary conflict. It has recently been suggested that intersexual fitness correlations can vary depending on the segregating genetic variation present in a population, and one way to alter genetic variation and test this idea is via inbreeding. Here, we test whether intersexual correlations for fitness vary with inbreeding in Drosophila simulans isolines reared under homogenous conditions. We measured male and female fitness at different times following the establishment of isofemale lines and found that the sign of the association between the two measures varied with time after initial inbreeding. Our results are consistent with suggestions that the type of genetic variation segregating within a population can determine the extent of intralocus sexual conflict and also support the idea that sexually antagonistic alleles segregate for longer in populations than alleles with sexually concordant effects.
Collapse
Affiliation(s)
- Eoin Duffy
- Institute of Environmental Science, Jagiellonian University Gronostawa 7, Krakow, Poland
| | - Richa Joag
- Institute of Environmental Science, Jagiellonian University Gronostawa 7, Krakow, Poland
| | - Jacek Radwan
- Institute of Environmental Science, Jagiellonian University Gronostawa 7, Krakow, Poland
| | - Nina Wedell
- Centre for Ecology & Conservation, University of Exeter Tremough, Penryn, TR10 9FE, U.K
| | - David J Hosken
- Centre for Ecology & Conservation, University of Exeter Tremough, Penryn, TR10 9FE, U.K
| |
Collapse
|
42
|
Connallon T, Clark AG. Balancing selection in species with separate sexes: insights from Fisher's geometric model. Genetics 2014; 197:991-1006. [PMID: 24812306 PMCID: PMC4096376 DOI: 10.1534/genetics.114.165605] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2013] [Accepted: 05/06/2014] [Indexed: 01/08/2023] Open
Abstract
How common is balancing selection, and what fraction of phenotypic variance is attributable to balanced polymorphisms? Despite decades of research, answers to these questions remain elusive. Moreover, there is no clear theoretical prediction about the frequency with which balancing selection is expected to arise within a population. Here, we use an extension of Fisher's geometric model of adaptation to predict the probability of balancing selection in a population with separate sexes, wherein polymorphism is potentially maintained by two forms of balancing selection: (1) heterozygote advantage, where heterozygous individuals at a locus have higher fitness than homozygous individuals, and (2) sexually antagonistic selection (a.k.a. intralocus sexual conflict), where the fitness of each sex is maximized by different genotypes at a locus. We show that balancing selection is common under biologically plausible conditions and that sex differences in selection or sex-by-genotype effects of mutations can each increase opportunities for balancing selection. Although heterozygote advantage and sexual antagonism represent alternative mechanisms for maintaining polymorphism, they mutually exist along a balancing selection continuum that depends on population and sex-specific parameters of selection and mutation. Sexual antagonism is the dominant mode of balancing selection across most of this continuum.
Collapse
Affiliation(s)
- Tim Connallon
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York 14853
| | - Andrew G Clark
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York 14853
| |
Collapse
|