Grant: Discovery Grants Program - Individual

Most species mate multiply, generating opportunities for postcopulatory male-male competition and male-female interactions. These interactions affect not only individual reproductive success but also survival. But what are the mechanisms behind them, what is the genetic basis, and how do males and females interact?  There are four goals for this work.  First, to determine the genetics of conspecific sperm precedence and characterize the role of male - female interactions in successful fertilization. Second, to understand how reproduction affects survival by surveying phenotypic variation among males and females in postmating mortality rates.  Third, to use a high throughput gene expression approach to identify differentially expressed transcripts that associate with phenotypic differences within and between species. And fourth, to use nucleotide sequence information from identified genes combined with the availability of 12 species of Drosophila genomes completed or being sequenced to test for functional constraints and adaptive divergence at candidate genes. My research shall contribute to the understanding of mechanisms influencing fertilization success, and how reproduction affects female health. It is known that there is a genetic basis to these reproductive differences, but the quantitative trait loci (QTL) approach generally used provides no identification of genes. I will use a combination of classical genetics approaches and genomics to identify differences in gene expression that underpin within and between species phenotypic differences. Candidate genes will be used to test for the occurrence of adaptive molecular changes within and between species that indicate functional diversification. The genes identified in this project will serve both as candidates for examining differential gene expression in other insects, and for comparative genomic searches of sequence similarities suggestive of conserved function and adaptive changes linked to evolutionary transitions. The study of model organisms such as Drosophila helps elucidate biological processes that are common to other organisms.