PM11 Wildlife Ecotoxicology
Exhibit Hall
8:00 AM - Monday
(PM204) Assessment Of An Embryo Dose Range Finding Protocol In Japanese Quail: Sensitivity To Estradiol.
Lavoie, E1, Quinn, Jr., M1, McKernan, M1, Abdelnabi, M1, Touart, L2, Ottinger, M1, 1 University of Maryland, Colege Park, MD, USA2 Environmental Protection Agency, Washington, DC, USA
ABSTRACT- An embryo dose range finding protocol was developed to address dose range needs for the avian two generation test. This study evaluated sensitivity of endpoints for the protocol in Japanese quail exposed to estradiol in ovo. Eggs were injected with vehicle control (sesame oil) or 0.5, 50 or 500 
g/egg of estradiol (E2) in sesame oil at either embryonic day (ED) 4 or 11. Quail were sampled at day 1; a subset of control, 50 and 500 g/egg groups were sampled at maturity. Tissues and data were collected to evaluate neuroendocrine, behavioral and immune endpoints. Embryonic mortality did not differ between treatments. In hatchlings, bursa weight decreased in 50 and 500 g/egg exposed females. Adult males exposed to 50 or 500 g/egg at ED4 had increased relative left testis weight 2 fold over control; 50 g/egg males had significantly increased serum androgens, and reduced time to mount a female compared to controls. Adult female quail exposed to 50 and 500 g/egg at ED11 had persistent right oviducts and several birds became egg bound. Ovary mass decreased in 50 g/egg (ED4) exposed birds. Exposure to 500 g/egg at ED11 increased serum androgens by three fold in females. There was no calcified egg production by 17 weeks for females exposed to E2 at ED4 or 11; control females began laying eggs by 12 weeks. These results demonstrate the use of an avian egg injection protocol to evaluate sensitivity to selected endocrine disruptors. The wide dose range proves important for determining exposure levels that will provide useful data in an avian two generation test. A combination of both biochemical and behavior endpoints will be most useful for the dose range finding protocol. The remaining challenge is to convert egg injection doses in the range finding protocol tocorresponding dietary concentrations to be used in the definitive two generation test. Funded by Battelle Labs in support of a U.S. EPA contract.
Key words: Japanese quail, endocrine disruption, estradiol, avian