Meeting Abstract

P1.119  Thursday, Jan. 3  Brain Region Activity during Female Mate Choice in Swordtails (Xiphophorus nigrensis) WONG, R. Y.*; CUMMINGS, M. E.; University of Texas at Austin; University of Texas at Austin ryan.wong@mail.utexas.edu

Where in the brain is female mate choice behavior regulated? Although a fundamental behavior in sexual selection, not much is known about the proximate mechanisms underlying female mate choice behavior. Using an integrative approach, we utilize the knowledge of female preference in the swordtail system and non-radioactive in situ hybridization with an immediate early gene (IEG) probe to identify brain nuclei involved with female choice. As IEGs are one of the first genes up-regulated upon neural stimulation, several studies have measured IEG (e.g. egr-1) activity to identify brain nuclei that were stimulated by a behavior or external stimulus. In this study we compared egr-1 expression levels across various brain nuclei from females exposed to mate choice conditions relative to those exposed to female only and non-stimuli controls. We placed females in a dichotomous choice design for 30 min., immediately sacrificed and froze the brains on dry ice. Brains were cryosectioned at 16 microns and processed for digoxigenin-labeled egr-1 in situ hybridization. Through optical density measurements, we identified differentially regulated egr-1 expression of some brain nuclei during treatment; thus suggesting having functional significance during mate choice. This study provides a better understanding of the neural basis of sexual selection not only in a focal species but possibly across taxa as well.