Meeting Abstract

111.1  Saturday, Jan. 7  Understanding the mate choice brain in two related poecillid fish with divergent mating systems LYNCH, Kathleen S.*; RAMSEY, Mary E; CUMMINGS, Molly E; University of Texas at Austin

Female mate choice is a social behavior that exhibits considerable intra- and inter-specific variation. Identifying and understanding genes underlying female mate preference provides insight into the evolution of preference behavior. Here, we compare mate preference behavior in two related poeciliid fishes with contrasting behavioral phenotypes and relate these behaviors to gene profiles in the brain. We examine three previously identified mate preference candidate genes: neuroserpin (NS), neuroligin-3 (NLG-3), and N-12 methyl-D-aspartate receptor (NMDA-R). Results reveal that one poeciliid fish, the Northern swordtail (Xiphophorus nigrensis), exhibits robust mate preference as compared to Western mosquitofish (Gambusia affinis), which utilizes a coercive mating system. Female swordtails display no significant difference in association time between male- and female-exposure trials whereas female mosquitofish spend significantly less time associating with males relative to females. Furthermore, the preference strength for large males is significantly lower in female mosquitofish relative to swordtails. Whole brain gene expression patterns reveal that NS and NLG-3 are positively associated with mate preference behavior in female swordtails. In mosquitofish females, the expression of these genes is lowered when females express biases towards males, yet are elevated in association with total motor activity patterns under asocial conditions, suggesting that the presence of males in mosquitofish species may inhibit expression of these genes. Both gene expression and female behavioral responses to males displays opposing patterns between these species, indicating that these genes may potentially act as a substrate for the evolution of mate preference behavior.