PNNL

Abstract

An important question in ecotoxicology is whether other classes of endocrine disruptors besides potent xenoestrogens alter fertility in sexually maturing fish. In this study, we exposed sexually maturing male trout to BDE-47 (a polybrominated diphenyl ether) and female trout to trenbolone (an anabolic steroid widely used in animal husbandry as a growth promoter). The male trout were orally exposed for 17 days to 55 µg/Kg/day BDE-47 and female trout continuously exposed for 60-77 days to a measured trenbolone water concentration of 35 ng/L. After the exposure, eggs and semen were collected and in-vitro fertilization trials performed using gametes from unexposed male and female donors. All fertility trials used a sperm:egg ratio of 300,000:1. All treatments were evaluated at two-three developmental time-points representing first cleavage, embryonic keel, and eyed stages, respectively. The results indicated that BDE-47 exposure did not alter fertility as embryonic survival was similar between control and exposed groups. Trenbolone exposure also did not alter embryo survival. However, in the embryos fertilized with eggs from trenbolone exposed females, a noticeable delay in developmental progress was observed. On day 19 when eye development should be largely established, the majority of the embryos either lacked or displayed minimal eye development, in contrast to control embryos. This finding suggests steroidal androgen exposure in maturing females can impact subsequent viability of F1 offspring. .