RENN, Susan C.P.; FRASER, Eleanor J.; AUBIN-HORTH, Nadia; HOFMANN, Hans A.; Harvard University, Bauer Center for Genomics Research; Harvard University, Bauer Center for Genomics Research; Harvard University, Bauer Center for Genomics Research; Harvard University, Bauer Center for Genomics Research: Fish & Chips: Genes, Environment, and the Evolution of Social Behavior

Brain gene expression patterns as the most basal of phenotypes can inform our understanding of behavioral differences within and across closely related species. Our brain-specific cDNA microarray allows the simultaneous profiling of thousands of genes in African cichlid fishes, which are famous for their complex and diverse social systems and extraordinary plasticity. By exploiting this behavioral plasticity, we can determine to what extent similar (i.e. conserved) molecular pathways underlie similar behaviors and to what extent different molecular building blocks underlie similar behaviors (i.e. convergence). Species of the genus Julidochromis exhibit a variety of sex-role phenotypes. Neural expression profiles comparing between sex and between species for the sex-role reversed J. marlieri and the closely related J. transcriptus, which exhibits conventional sex roles, enables us to remove the confounds of sex and reproductive state. A complementary intra-species comparison of neural transcription profiles for socially dominant and subordinate males of the Tanganyikan cichlid Astatotilapia burtoni yielded several hundred genes that are differentially expressed. Females of this species can be experimentally induced to exhibit male-like dominance behavior without changing sex. By comparing neural gene expression profiles of these animals we can now identify the molecular mechanisms underlying “dominance” behavior independent of sex and social status. — Supported by NIH & NATEQ.