Meeting Abstract

S5-1.5  Friday, Jan. 4  Consider the Timing, Consider the Source � Lessons from the Comparative Responses of Teleosts. RIPLEY, Jennifer L.; FORAN, Christy M.*; West Virginia University; West Virginia University cmforan@mail.wvu.edu

Early exposure to steroid hormones can have profound consequences on development and the resulting adult phenotype. We aim to describe three factors that can contribute to the impact of early hormone transfer and exposure. First, the consequences of steroid exposure in teleost fishes are known to be influenced by the timing of exposure. Using a model species, Japanese medaka, we have been able to report different physiological responses to steroids depending on whether concentrations are altered during parental gametogenesis or sexual differentiation. The potential transfer of parental hormones is a second variable that will mediate the effects of steroids in developing fish. Our research on Syngnathid pipefishes is evidence that species, even if closely related, can profoundly differ in the utilization of egg-derived nutrients. Finally, unbound circulating steroids have the potential to be lost through the gills or body surface in teleosts. Therefore we expect a relationship between body size and circulating steroids which may impact species� �sensitivity� to steroid hormone actions. These three factors, specifically the timing of exposure, source and utilization of nutrients, and comparative sensitivity, should also relate to the potential for developmental disruption by steroid-like environmental contaminants. We hope this review will provide some insight into the observed diversity and known consequences of teleost species sensitivity to steroid hormones.