Evaluating endocrine endpoints relative to reproductive success in Japanese quail exposed to estrogenic chemicals [poster]

Abstract

The standard US EPA guidelines for avian reproductive testing may not be sufficiently sensitive to detect effects of sublethal and chronic exposure to endocrine disrupting toxins. There is a need to evaluate endocrine endpoints as potential markers for contaminant effects, and to determine their effectiveness and sensitivity when applied to wildlife. To this end, a three generational test was conducted using the Japanese quail (Coturnix japonica) and a proven estrogenic PCB. Birds were exposed during embryonic development via maternal deposition and/or direct egg injection at day 4. Standard measures of reproductive success and productivity used in toxicological studies, as well as multiple measures of physiological and behavioral responses used in endocrine studies were collected. Long term effects on growth and apparent development were similar between treated and control offspring. Fertility of treated eggs decreased from 75%+ 4.4 (x + se) for P1, to 59% + 12.5 for F1 and 54% + 14.2 for F2. All paired control birds mated to produce viable eggs, whereas 27 % of the F1 and 41 % of the F2 treated pairs failed to produce at least 1 viable egg. Although some decreases in productivity can be related to direct toxic exposure, the response from one generation to the next was not linear with treatment, indicating a potential effect from behavioral or other endocrine alterations.