Sex‐specific associations between life‐history traits and a novel reproductive polymorphism in the Pacific field cricket

Abstract

Associations between heritable polymorphisms and life‐history traits, such as development time or reproductive investment, may play an underappreciated role in maintaining polymorphic systems. This is because selection acting on a particular morph could be bolstered or disrupted by correlated changes in life history or vice versa. In a Hawaiian population of the Pacific field cricket (Teleogryllus oceanicus), a novel mutation (flatwing) on the X‐chromosome is responsible for a heritable polymorphism in male wing structure. We used laboratory cricket colonies fixed for male wing morph to investigate whether males and females bearing the flatwing or normal‐wing (wild‐type) allele differed in their life‐history traits. We found that flatwing males developed faster and had heavier testes than normal‐wings, whereas flatwing homozygous females developed slower and had lighter reproductive tissues than normal‐wing homozygous females. Our results advance our understanding of the evolution of polymorphisms by demonstrating that the genetic change responsible for a reproductive polymorphism can also have consequences for fundamental life‐history traits in both males and females.

Intralocus sexual conflict can maintain alternative reproductive tactics

“…The copyright holder for this preprint this version posted November 27, 2021. ; https://doi.org/10. 1101/2021 Sexual conflict maintains ARTs size greater than or equal to a threshold value became alpha males, and those below the threshold became beta males. Females, which did not express these ARTs, had a fecundity value proportional to their body size.…”

“…The copyright holder for this preprint this version posted November 27, 2021. ; https://doi.org/10. 1101/2021 Sexual conflict maintains ARTs Clark 2014), and promote speciation (Bonduriansky 2011), the potential for intralocus sexual conflict to maintain alternative reproductive tactics is comparatively understudied. There is nevertheless reason to think that intralocus sexual conflict could be a potent force that maintains variation in nature.…”

“…The copyright holder for this preprint this version posted November 27, 2021. ; https://doi.org/10. 1101/2021 Sexual conflict maintains ARTs we also varied the degree to which males and females could evolve independently by varying the number of genetic loci with sex-dependent expression. We used these models to test our hypothesis that intralocus sexual conflict may influence ART frequency over time, and that this process might be altered by different selection regimes and/or the breakdown of intersexual genetic correlations through sex-specific gene expression.…”

Variable dosage compensation is associated with female consequences of an X-linked, male-beneficial mutation

“…One might therefore expect flatwing to have little if any effect on female gene expression or associated phenotypes; however, this does not appear to be the case. Recent reports indicate that the flatwing mutation has pleiotropic or otherwise linked consequences for female gene expression [23], and for female life-history traits (reduced reproductive investment, increased rate of mating failure, increased somatic mass index, growth rate) [24][25][26]. While there is therefore evidence that flatwing has sexually antagonistic fitness effects in at least some contexts, such as reproductive investment, we can confidently infer only that it is under strong sex-biased selection, providing considerable fitness benefits to males via sex-limited phenotypic effects on wing morphology (Zuk et al [22] found < 1% of flatwing males harboured lethal endoparasitic larvae, versus > 30% of normal-wing males).…”

A neglected conceptual problem regarding phenotypic plasticity's role in adaptive evolution: The importance of genetic covariance and social drive

“… 2019b ; Richardson et al. 2021 ). In populations where flatwing has spread rapidly under selection, a variety of reproductive, behavioral, and physiological traits show plastic responses to the altered, largely silent, social environment.…”