Meeting Abstract

P3.193  Monday, Jan. 6 15:30  Regional Expression of Foxp2 in response to testosterone in the brain of Hyla cinerea SINKIEWICZ, DM*; WILCZYNSKI, W; Georgia State University; Georgia State University dsinkiewicz1@gsu.edu

Vocalization is a conspicuous form of communication that is observed across most of the vertebrate taxa. Foxp2 is a gene that is implicated in the learning of vocalizations in humans and songbirds. There is little known about the role this gene plays in the production of unlearned vocalizations, however, it is present in the brains of such animals. In the green tree frog (Hyla cinerea), unlearned vocalizations are produced only during the breeding season. The breeding season coincides with an increase in gonadal hormonal levels. In this experiment we addressed how changes in testosterone effect Foxp2 expression in the brain of adult male green tree frogs. Animals were gonadectomized and implanted with either a testosterone or empty silastic implant. Fourteen days following surgery brains were collected and trisected into forebrain, midbrain, and hindbrain. RNA was extracted from the samples using Trizol (Invitrogen) and measured for Foxp2 transcription levels using quantitative PCR. There was an observed effect of brain region on Foxp2 expression (p <0.001) with highest expression in the midbrain. Within this there is significantly greater Foxp2 expression in the midbrain than in the hindbrain regardless of treatment (p<0.01). However, we only observed a significant difference in forebrain expression in the sham animals (p=0.02), but not in testosterone implanted animals (P=0.12). Examination of the data suggests this loss of significance is due to an increase in Foxp2 expression in the forebrain of T implanted animals. This suggests that increased T levels result in increased expression of Foxp2 in the forebrain of the green tree frog.