Assessing the Association Between Sex-Linkage and Sexual Dimorphism: A Novel Quantitative Genetic Approach.

University Of California-Riverside, Riverside CA

Investigators

Abstract

Males and females within species often differ dramatically in size and shape, a phenomenon known as sexual dimorphism. This project asks how such dimorphisms can arise despite the substantively identical genomes of males and females. It tests the hypothesis that sexually dimorphic traits are particularly influenced by genes on the sex chromosomes (sex-linked genes), using water striders as a model system. A novel experimental breeding design will enable the investigators to measure the influence of sex-linked genes on a suite of traits ranging from sexually monomorphic, through sexually dimorphic to sex-limited (found only in males). A major advance of this research is quantifying aspects of genetic variance that have been conflated in all previous investigations of sex-linked effects. The results will reveal the genetic mechanisms that allow response to sexually-divergent selection and, more generally, will increase our understanding of the functionality of sex-chromosomes. In addition, this research will contribute new statistical algorithms for genetic analyses and these will be incorporated into a software package for dissemination. The project also provides research opportunities for many graduate and undergraduate students, contributes pedagogical materials for outreach and non-specialist courses, and supports a specialized research infrastructure that draws national and international collaborators.