PW01 Wildlife Toxicology
Exhibit Hall
8:00 AM - Wednesday, 12 November 2003
(PW033) Vitellogenin as a biomarker of xenoestrogens in populations of Chelonia mydas in Baja California, Mexico.
Sifuentes, I. 1, Vázquez, C.1, Gardner, S.C.1, 1 Centro de Investigaciones Biológicas del Noroeste (CIBNOR), La Paz, BCS, Mexico
ABSTRACT- The seven remaining sea turtle species are considered either threatened or endangered. Currently sea turtles have to face over fishing, incidental catch and they are also harmed by the increasing loads of nonbiodegradable waste and pollutants to oceans. A number of chemicals released into the environment, including pesticides and industrial chemicals, have the potential to interfere with physiological and developmental processes by disrupting endocrine pathways. Among the best known of this chemicals are those that mimics the action of the steroid hormone 17
-estradiol. This compounds are known as environmental estrogens or xenoestrogens. The impact of this common pollutants on the reproductive success of wildlife may be considerable specially in endangered species such as the green turtle, Chelonia mydas. In this research we design an assay for detect xenoestrogens based on the induction of vitellogenin (VTG). Vitellogenin is a complex protein that is produce in response of estrogen stimulation in oviparous vertebrates, it is normally found in adult females and absent in males and juveniles. However juveniles and males can produce VTG in response to xenoestrogens. To induce the production of VTG, two captive male turtles (Chelonia mydas) were injected with 17-estradiol (1mg/kg) every three days during two weeks. Plasma samples were taken before and after the induction. The protein was visualized by native PAGE (polyacrylamide gel electrophoresis) and identified as a 550 kDa protein approximately. Green turtle vitellogenin was purified from a treated male plasma by filtration gel and ion exchange chromatography. Polyclonal antibodies were generated in rabbits with the purify VTG. The resulting antiserum was used to develop an enzyme-linked immunosorbent assay (ELISA) for measurement of plasma vitellogenin of wild turtles. Plasma samples were collected from three different sites of the Peninsula of Baja California in order to detect the presence of environmental estrogens in green turtles wild populations.
Key words: biomarker, vitellogenin, xenoestrogens, Chelonia mydas