Meeting Abstract

P2.42  Wednesday, Jan. 5  Comparative Gene Expression in Sex-Role Phenotypes LANGDON, Quinn*; SCHUMER, Molly; WOOD, Kelsey; RENN, Suzy C. P.; Reed College; Reed College; Reed College; Reed College langdonq@reed.edu

For many animals, the expression of sex-typical behavior can be plastic depending on the social environment. We use the African Julidochromis cichlid fish as a model to determine the underlying physiological and molecular mechanisms that account for differences and plasticity in expression of sex-typical behaviors. Sex-roles in most monogamous cichlids consist of territory defense by the larger male and parental care by the smaller female. Behavioral studies show that the species J. transcriptus follows these sex-role conventions. However, the sister species, J. marlieri , exhibits a reversal of these sex-roles. J. marlieri females are dominant to their mates and are clearly the aggressive sex. To examine the molecular changes that accompany this heritable, yet plastic phenotype, we have used microarray techniques to determine relative gene expression within and between sexes and species. We have contrasted indirect (intraspecific analysis) and direct comparison (interspecific analysis) using the microarray approach. We show that indirect meta-analysis comparison does identify a large number of highly regulated genes however the approach does not reveal relative expression levels between species. These genes identified by indirect comparison are also identified by direct comparisons, which in addition to revealing relative expression between species offers greater statistical power. Due to the close phylogenetic relationship of these species, cross species heterologous gene expression analysis is not dramatically compromised by sequence divergence. The direct comparison between species identifies gene modules for gonadal sex, phenotype, and species independent of each other.