Validation of an egg-injection method for testing in ovo toxicity of PBDE-99 in a small songbird model species, the zebra finches (Taeniopygia guttata)

Egg injection was validated for studies of in ovo exposure to xenobiotics in the zebra finch (Taeniopygia guttata). Puncturing eggs and injecting DMSO had no effect on embryo development or hatching success, but DMSO negatively affected post-hatching growth in males. In ovo injection was used to test the long-term, inter-generational effects of embryonic exposure to the polybrominated diphenyl ether PBDE-99. Eggs were dosed at 10, 100 and 1000 ng/egg and chicks, their offspring and grand-offspring were followed (three generations). In ovo PBDE exposure did not affect hatching success, chick growth, thyroid hormone levels or hematology (measured at 30 and 90 days of age). However, there were effects of PBDE treatment on adult phenotype of in ovo exposed bird: reduced clutch size, longer laying intervals. Second generation chicks of PBDE-exposed parents had decreased growth, but there were no longer-term effects on adult reproductive phenotype of second-generation offspring, or growth of their (third-generation) offspring.