Lack of xenoestrogen-induced vitellogenin in male olive ridley sea turtles (Lepidochelys olivacea) from the Pacific coast of Costa Rica

Abstract

Olive ridley sea turtles (Lepidochelys olivacea) distribute widely throughout Eastern Pacific (EP) waters. During reproduction these animals aggregate near coastal waters where they may be exposed to industrial or agrochemical environmental pollutants that may disrupt the endocrine system of these reptiles. One group of compounds of concern is the persistent organic pollutants (POPs), some of which have been detected in Costa Rican waters. Some of these POPs, such as polychlorinated biphenyls and DDT and its metabolites, exhibit estrogenic activity in reptiles. It is unknown whether olive ridleys are exposed to endocrine disruptive doses of these POPs throughout their life in EP waters. Consequently, this study was conducted to determine whether there is evidence of exposure of male olive ridleys to estrogenic compounds. During the study a total of 35 males were hand-captured while mating off the coast of Ostional, Costa Rica, a major nesting beach for this species. The captured turtles were brought aboard a small boat, and blood samples taken with a hypodermic syringe. Turtles were carefully released in the water after the blood samples were taken. In the laboratory, blood collected from these males was analyzed by Western blot using an antibody developed against red-eared slider turtle vitellogenin. Vitellogenin is a female-specific protein that is induced by estrogen during gonadal recrudescence. Estrogenic compounds have been shown to induce this protein in reptilian species. Results of this study indicate the lack of evidence of vitellogenin in the blood of olive ridley males as shown by Western blot analysis. This study demonstrates the feasibility of using the slider’s vitellogenin antibody to detect the presence of the protein in the olive ridley sea turtle, L. olivacea. Rev. Biol. Trop. 56 (Suppl. 4): 49-57. Epub 2009 June 30.