MOORE, Brandon C; BRAUN, Edward L; BERMUDEZ, Dieldrich; KOHNO, Satomi; IGUCHI, Taisen ; GUILLETTE, Louis J; University of Florida; University of Florida; University of Florida; National Institute of Basic Biology, Japan ; University of Florida; University of Florida; ; : An investigation of a leptin-like molecule in the American alligator (Alligator mississipiensis)

A growing body of research has implicated the protein hormone leptin in the modulation of vertebrate reproduction. While the results of mammalian studies, both physiological and molecular, has been extensive, leptin research in non-mammalian vertebrates has been less robust. Researchers have presented tissue immunoreactivity, seasonal cyclicity and life-stage related changes in hormone expression, and physiological responsiveness to exogenous leptin treatments in some fish, reptiles, and birds. However, the use of molecular techniques to investigate leptin in these species has been limited to a few avian species. Furthermore, some controversy exists regarding the validity of the proposed genetic sequences. Therefore, we have investigated the possible presence of a leptin-like molecule in another archosaur species, the American alligator (Alligator mississipiensis), using western blotting, radioimmunoassay, and the polymerase chain reaction. We will present initial results addressing tissue specific expression patterns in hatchling, juvenile, and adult animals, adult seasonal cyclicity of plasma leptin immunoreactivity, and sexual dimorphism of hormone and receptor expression.