PARENT SESSION
PS1 - Wildlife Toxicology
Sunday, 17 November 2002
8:00 AM to 6:30 PM
Exhibit Hall
(P041) Estrogen induction of vitellogenin in the tiger salamander, Ambystoma tigrinum: A potential species for field studies of endocrine disruption.
Selcer, Kyle*,1, Allyson, Day1, Nespoli, Lisa1, 1 Duquesne University, Pittsburgh, PA, USA
ABSTRACT- A number of chemicals released into the environment mimic the action of the steroid hormone estrogen. These environmental estrogens pose potential health risks to humans and wildlife by disrupting physiological and developmental processes. Our laboratory has been designing in vivo bioassays for environmental estrogens based on induction of the egg yolk precursor protein vitellogenin. We have previously developed tests using the African clawed frog (Xenopus laevis) as a model organism. However, there is a need for model organisms than can be employed in field studies of endocrine disruption; which means that tests are needed that are based on native species. We have previously developed vitellogenin induction assays for the northern leopard frog (Rana pipiens) and the red eared slider turtle (Trachemys scripta). In the present study, we provide information on vitellogenin induction by estrogens in the tiger salamander, Ambystoma tigrinum. Attributes that make A. tigrinum a good model organism for field studies of endocrine disruption are: its widespread distribution, the large amount of collateral information on its biology, and the fact that larvae, and some adults (neotenic) are fully aquatic. Using gel electrophoresis and Western blotting of serum and hepatic cytosol, we found that male tiger salamanders exposed to various estrogens by injection produce vitellogenin in a dose- and time- dependent manner. A specific vitellogenin antibody is now in development for this species. Assays developed for vitellogenesis in A. tigrinum could be used to screen chemicals for estrogenic properties, to test waters for the presence of estrogenic agents or to assess exposure of wild populations to environmental estrogens.
Key words: endocrine disruption, vitellogenin, estrogen, salamander