Sexual conflict and reproductive isolation in flies

Sexual conflict is predicted to generate more rapid reproductive isolation between larger populations. While there is some empirical support for this, the data are inconsistent and, additionally, there has been criticism of some of the evidence. Here we reanalyse two experimental-evolution datasets using an isolation index widely applied in the speciation literature. We find evidence for reproductive isolation through sexual conflict in Sepsis cynipsea , but not in Drosophila melanogaster , and this occurred to a greater degree in larger populations, which is consistent with previous findings.

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Faculty Opinions recommendation of Assessing putative interlocus sexual conflict in Drosophila melanogaster using experimental evolution.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1158249.618377 ◽

2009 ◽

Author(s):

David Houle

Keyword(s):

Drosophila Melanogaster ◽

Sexual Conflict ◽

Experimental Evolution

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Assessing putative interlocus sexual conflict in Drosophila melanogaster using experimental evolution

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2005.3182 ◽

2005 ◽

Vol 272 (1576) ◽

pp. 2029-2035 ◽

Cited By ~ 67

Author(s):

Andrew D Stewart ◽

Edward H Morrow ◽

William R Rice

Keyword(s):

Drosophila Melanogaster ◽

Sexual Conflict ◽

Experimental Evolution ◽

Large Body ◽

Direct Costs ◽

Empirical Prediction ◽

Indirect Benefits ◽

Almost All ◽

Sexually Antagonistic Coevolution

The theoretical foundation of sexually antagonistic coevolution is that females suffer a net fitness cost through their interactions with males. The empirical prediction is that direct costs to female lifetime fecundity will exceed indirect benefits despite a possible increase in the genetic quality of offspring. Although direct costs of males have been repeatedly shown, to date no study has comprehensively tested whether females are compensated for this direct harm through indirect benefits. Here we use experimental evolution to show that a mutation giving Drosophila melanogaster females nearly complete resistance to the direct costs of male courtship and remating, but which also excluded almost all indirect benefits, is strongly favoured by selection. We estimated the selection coefficient favouring the resistance allele to be +20%. These results demonstrate that any indirect benefits that females accrued were not sufficient to counter-balance the direct costs of males, and reinforce a large body of past studies by verifying interlocus sexual conflict in this model system.

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Manipulation of feeding regime alters sexual dimorphism for lifespan and reduces sexual conflict in Drosophila melanogaster

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2017.0391 ◽

2017 ◽

Vol 284 (1854) ◽

pp. 20170391 ◽

Cited By ~ 10

Author(s):

Elizabeth M. L. Duxbury ◽

Wayne G. Rostant ◽

Tracey Chapman

Keyword(s):

Drosophila Melanogaster ◽

Life History ◽

Sexual Dimorphism ◽

Sexual Conflict ◽

Experimental Evolution ◽

Fruit Fly ◽

Developmental Time ◽

Feeding Regime ◽

Focal Female ◽

Feeding Regimes

Sexual dimorphism for lifespan (SDL) is widespread, but poorly understood. A leading hypothesis, which we test here, is that strong SDL can reduce sexual conflict by allowing each sex to maximize its sex-specific fitness. We used replicated experimental evolution lines of the fruit fly, Drosophila melanogaster , which had been maintained for over 360 generations on either unpredictable ‘Random’ or predictable ‘Regular’ feeding regimes. This evolutionary manipulation of feeding regime led to robust, enhanced SDL in Random over control, Regular lines. Enhanced SDL was associated with a significant increase in the fitness of focal males, tested with wild-type (WT) females. This was due to sex-specific changes to male life history, manifested as increased early reproductive output and reduced survival. In contrast, focal female fitness, tested with WT males, did not differ across regimes. Hence increased SDL was associated with a reduction in sexual conflict, which increased male fitness and maintained fitness in females. Differences in SDL were not associated with developmental time or developmental survival. Overall, the results showed that the expression of enhanced SDL, resulting from experimental evolution of feeding regimes, was associated with male-specific changes in life history, leading to increased fitness and reduced sexual conflict.

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Cuticular hydrocarbon divergence in Drosophila melanogaster populations evolving under differential operational sex ratios

10.1101/351718 ◽

2018 ◽

Author(s):

Rochishnu Dutta ◽

Tejinder Singh Chechi ◽

Ankit Yadav ◽

Nagaraj Guru Prasad

Keyword(s):

Drosophila Melanogaster ◽

Reproductive Isolation ◽

Cuticular Hydrocarbons ◽

Sexual Conflict ◽

Cuticular Hydrocarbon ◽

Mate Recognition ◽

Mate Preference ◽

Sexually Dimorphic ◽

Cuticular Hydrocarbon Profile ◽

Buridan’S Ass

AbstractThe ability of interlocus sexual conflict to facilitate reproductive isolation is widely anticipated. However, very few experimental evolutionary studies have convincingly demonstrated the evolution of reproductive isolation due to sexual conflict. Recently a study on replicate populations of Drosophila melanogaster under differential sexual conflict found that divergent mate preference evolved among replicate populations under high sexual conflict regime. The precopulatory isolating mechanism underlying such divergent mate preference could be sexual signals such as cuticular hydrocarbons since they evolve rapidly and are involved in D. melanogaster mate recognition. Using D. melanogaster replicates used in the previous study, we investigate whether cuticular hydrocarbon divergence bears signatures of sexually antagonistic coevolution that led to reproductive isolation among replicates of high sexual conflict regime. We found that D. melanogaster cuticular hydrocarbon profiles are sexually dimorphic. Although replicate populations under high sexual conflict displayed assortative mating, we found no significant differences in the cuticular hydrocarbon profile between the high and low sexual conflict regimes. Instead we find cuticular hydrocarbon divergence patterns to be suggestive of the Buridan’s Ass regime which is one of the six possible mechanisms to resolve sexual conflict. Sexual selection that co-vary between populations under high and low sexual conflict regimes may also have contributed to the evolution of cuticular hydrocarbons. This study indicates that population differentiation as a result of cuticular hydrocarbon divergence cannot be credited to sexual conflict despite high sexual conflict regime evolving divergent cuticular hydrocarbon profiles.

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Sexual selection affects the evolution of contact pheromones in Drosophila melanogaster populations isolated by differential sexual conflict

10.21203/rs.2.13749/v1 ◽

2019 ◽

Author(s):

Rochishnu Dutta ◽

Tejinder Singh Chechi ◽

N. G. Prasad

Keyword(s):

Drosophila Melanogaster ◽

Sexual Selection ◽

Reproductive Isolation ◽

Sexual Conflict ◽

Population Differentiation ◽

Lipid Profiles ◽

Mate Preference ◽

Cuticular Lipid ◽

Antagonistic Coevolution ◽

Sexually Antagonistic Coevolution

Abstract Background: The ability of sexual conflict to facilitate reproductive isolation is widely anticipated. However, very few experimental evolutionary studies have convincingly demonstrated the evolution of reproductive isolation due to sexual conflict. Recently a study on the replicates of Drosophila melanogaster populations under differential sexual conflict found that divergent mate preference evolved among replicates under high sexual conflict regime. The precopulatory isolating mechanism underlying such divergent mate preference could be sexual signals such as cuticular lipids since they evolve rapidly and are involved in D. melanogaster mate recognition. Using Drosophila melanogaster replicates used in the previous study, we investigate whether cuticular lipid divergence bears signatures of sexually antagonistic coevolution that led to reproductive isolation among replicates of high sexual conflict regime. Results: We found that their cuticular lipid profiles are sexually dimorphic. Although replicates with male biased sex ratio evolved isolation in reproductive traits due to high sexual conflict, the patterns of cuticular lipid divergence in high and low sexual conflict regimes suggest that sexual selection is the dominant selection pressure rather than sexual conflict affecting the cuticular lipid profile. We also find cuticular lipid divergence patterns to be suggestive of the Buridan’s Ass regime which is one of the six possible mechanism to resolve sexual conflict. Conclusions: Although reproductive isolation due to sexual conflict is anticipated, evolution of a sexually selected trait under sexual conflict may not lead to population differentiation in expected lines. This is because speciation due to sexually antagonistic coevolution is only one of the several outcomes of sexual conflict. This study indicates that population differentiation as a result of cuticular lipid divergence cannot be credited to sexual conflict despite high sexual conflict regime evolving divergent cuticular lipid profiles.

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No evidence that experimental manipulation of sexual conflict drives premating reproductive isolation in Drosophila melanogaster

Journal of Evolutionary Biology ◽

10.1111/j.1420-9101.2006.01107.x ◽

2006 ◽

Vol 19 (4) ◽

pp. 1033-1039 ◽

Cited By ~ 29

Author(s):

S. WIGBY ◽

T. CHAPMAN

Keyword(s):

Drosophila Melanogaster ◽

Reproductive Isolation ◽

Sexual Conflict ◽

Experimental Manipulation

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Reproductive Isolation through Experimental Manipulation of Sexually Antagonistic Coevolution in Drosophila melanogaster

10.1101/079657 ◽

2016 ◽

Author(s):

Syed Zeeshan Ali ◽

Martik Chatterjee ◽

Manas Arun Samant ◽

Nagaraj Guru Prasad

Keyword(s):

Drosophila Melanogaster ◽

Reproductive Isolation ◽

Sexual Conflict ◽

Evolutionary Model ◽

Experimental Manipulation ◽

Allopatric Populations ◽

Antagonistic Coevolution ◽

Before And After ◽

Postmating Prezygotic Isolation ◽

Sexually Antagonistic Coevolution

AbstractPromiscuity can drive the evolution of sexual conflict before and after mating occurs. Post-mating, the male ejaculate can selfishly manipulate female physiology leading to a chemical arms race between the sexes. Theory suggests that drift and sexually antagonistic coevolution can cause allopatric populations to evolve different chemical interactions between the sexes, thereby leading to postmating reproductive barriers and speciation. There is, however, little empirical evidence supporting this form of speciation. We tested this theory by creating an experimental evolutionary model of Drosophila melanogaster populations undergoing different levels of interlocus sexual conflict. We found that allopatric populations under elevated sexual conflict show assortative mating indicating premating reproductive isolation. Further, these allopatric populations also show reduced copulation duration and sperm defense ability when mating happens between individuals between individuals across populations compared to that within the same population, indicating postmating prezygotic isolation. Sexual conflict can cause reproductive isolation in allopatric populations through the coevolution of chemical (postmating prezygotic) as well as behavioural (premating) interaction between the sexes. Thus, to our knowledge, we provide the first comprehensive evidence of postmating (as well as premating) reproductive isolation due to sexual conflict.

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Sexual conflict drives micro- and macroevolution of sexual dimorphism in immunity

BMC Biology ◽

10.1186/s12915-021-01049-6 ◽

2021 ◽

Vol 19 (1) ◽

Author(s):

Basabi Bagchi ◽

Quentin Corbel ◽

Imroze Khan ◽

Ellen Payne ◽

Devshuvam Banerji ◽

...

Keyword(s):

Sex Differences ◽

Sexual Dimorphism ◽

Mating System ◽

Sexual Conflict ◽

Experimental Evolution ◽

Parasitic Infections ◽

Pathogen Dynamics ◽

Trade Offs ◽

Host Pathogen ◽

Seed Beetles

Abstract Background Sexual dimorphism in immunity is believed to reflect sex differences in reproductive strategies and trade-offs between competing life history demands. Sexual selection can have major effects on mating rates and sex-specific costs of mating and may thereby influence sex differences in immunity as well as associated host–pathogen dynamics. Yet, experimental evidence linking the mating system to evolved sexual dimorphism in immunity are scarce and the direct effects of mating rate on immunity are not well established. Here, we use transcriptomic analyses, experimental evolution and phylogenetic comparative methods to study the association between the mating system and sexual dimorphism in immunity in seed beetles, where mating causes internal injuries in females. Results We demonstrate that female phenoloxidase (PO) activity, involved in wound healing and defence against parasitic infections, is elevated relative to males. This difference is accompanied by concomitant sex differences in the expression of genes in the prophenoloxidase activating cascade. We document substantial phenotypic plasticity in female PO activity in response to mating and show that experimental evolution under enforced monogamy (resulting in low remating rates and reduced sexual conflict relative to natural polygamy) rapidly decreases female (but not male) PO activity. Moreover, monogamous females had evolved increased tolerance to bacterial infection unrelated to mating, implying that female responses to costly mating may trade off with other aspects of immune defence, an hypothesis which broadly accords with the documented sex differences in gene expression. Finally, female (but not male) PO activity shows correlated evolution with the perceived harmfulness of male genitalia across 12 species of seed beetles, suggesting that sexual conflict has a significant influence on sexual dimorphisms in immunity in this group of insects. Conclusions Our study provides insights into the links between sexual conflict and sexual dimorphism in immunity and suggests that selection pressures moulded by mating interactions can lead to a sex-specific mosaic of immune responses with important implications for host–pathogen dynamics in sexually reproducing organisms.

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Combining metabolomics and experimental evolution reveals key mechanisms underlying longevity differences in laboratory evolved Drosophila melanogaster populations

10.1101/2021.10.16.464668 ◽

2021 ◽

Author(s):

Mark Phillips ◽

Kenneth R. Arnold ◽

Zer Vue ◽

Heather Beasley ◽

Edgar Garza Lopez ◽

...

Keyword(s):

Drosophila Melanogaster ◽

Carbohydrate Metabolism ◽

Experimental Evolution ◽

Statistical Power ◽

Accelerated Aging ◽

Experimental System ◽

Tca Cycle ◽

Dna And Rna ◽

Metabolomic Data ◽

Genetic Mechanisms

Experimental evolution with Drosophila melanogaster has been used extensively for decades to study aging and longevity. In recent years, the addition of DNA and RNA sequencing to this framework has allowed researchers to leverage the statistical power inherent to experimental evolution study the genetic basis of longevity itself. Here we incorporated metabolomic data into to this framework to generate even deeper insights into the physiological and genetic mechanisms underlying longevity differences in three groups of experimentally evolved D. melanogaster populations with different aging and longevity patterns. Our metabolomic analysis found that aging alters mitochondrial metabolism through increased consumption of NAD+ and increased usage of the TCA cycle. Combining our genomic and metabolomic data produced a list of biologically relevant candidate genes. Among these candidates, we found significant enrichment for genes and pathways associated with neurological development and function, and carbohydrate metabolism. While we do not explicitly find enrichment for aging canonical genes, neurological dysregulation and carbohydrate metabolism are both known to be associated with accelerated aging and reduced longevity. Taken together, our results in total provide very plausible genetic mechanisms for what might be driving longevity differences in this experimental system. More broadly, our findings demonstrate the value of combining multiple types of omic data with experimental evolution when attempting to dissect mechanisms underlying complex and highly polygenic traits like aging.

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