Meeting Abstract

S1-1.3  Thursday, Jan. 3  The Functional Evolution of Steroid Hormone Receptors: Insights from Reptiles KOHNO, Satomi*; KATSU, Yoshinao; IGUCHI, Taisen; GUILLETTE, Louis J Jr; University of Florida; National Institute of Basic Biology; National Institute of Basic Biology; University of Florida kohno@zoo.ufl.edu

Steroid hormones are essential for the normal function of most organ systems in vertebrates. Reproductive activity in females and males, such as the differentiation, growth and maintenance of the reproductive system, requires signaling by sex steroids. Although extensively studied in mammals, and a few fish and bird species, the evolution and molecular mechanisms associated with the nuclear steroid hormone receptors are poorly understood in amphibians and reptiles. Given our interest in environmental signaling of sex determination as well as a major interest in environmental contaminants that can mimic steroid hormone signaling, we have established an approach to study the molecular function (ligand binding and gene transcription) of steroid receptors from an array of reptiles. This approach involves cloning and sequencing of the receptors, phylogenetic analysis and in vitro reporter gene assay using natural and exogenous ligands. Further, we have developed an approach to obtaining mRNA for cloning and sequencing of steroid receptor in reptiles and other non-mammalian species using blood cells as a source of genetic material.