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Research Agenda
I am interested in the study of sexual selection and sexual conflict, especially at the genomic and molecular levels. Recently described genomic and molecular evolutionary patterns associated with reproductive processes have become the center of much attention. Male-biased patterns of gene expression, for example, are a hypothesized evolutionary response to sexual selection (Singh and Kulathinal, 2005). Furthermore, many gonad-associated protein-coding genes have undergone positive selection and demonstrate a faster rate of evolution compared to genes expressed elsewhere in the soma (reviewed in Swanson and Vacquier, 2002).
Currently we are using commercial oligonucleotide microarrays to elucidate sex- and gonad-biased patterns of gene expression in Danio rerio. In addition we are performing molecular evolutionary analyses (including tests for positive selection) of ovary- and testis- biased genes whose orthologs have been sequenced in multiple Danio species.
Other work involves a similar approach in the family Syngnathidae (pipefishes and seahorses). Using cDNA microarrays designed for Syngnathus scovelli (the Gulf pipefish), we again are looking at sex- and gonad-biased gene expression. Syngnathus scovelli is sex-role-reversed, so if sexual selection does play a substantial role in sex-specific expression patterns, we expect a genomic shift towards female-biased expression. Furthermore, if sexual selection and/or intersexual conflict influence the evolution of reproductive genes, we can make a priori predictions about lineage-specific patterns of molecular evolution (e.g. positive selection) based on mating system variation. The two sister genera Syngnathus and Hippocampus (seahorses) provide an ideal group for this type of study because they include species with monogamous, polyandrous, and polygynandrous genetic mating systems. |
