Cytotoxicity and genotoxicity of tributyltin in the early embryonic chick, Gallus gallus domesticus

Tributyltin (TBT) is used in many commercial applications, including pesticides and antifouling paints, due to its biocidal properties. We examined the cytotoxicity and genotoxicity of TBT in the early chick embryo (Gallus gallus domesticus). Chick embryos (11 days) were treated with various doses of TBT to measure LD50 values for 24, 48, and 72 h exposures, which were determined to be 110, 54, and 18 & mu;g/egg, respectively. The embryos were exposed to sub-lethal doses of TBT for evaluation of cytotoxicity and genotoxicity. An increase in the incidence of micronuclei (MN) was observed but it was not statistically significant. Induction of other nuclear abnormalities (ONA) after 72 h TBT exposure was significant. A significant increase in comet assay tail DNA content was also detected in TBT-exposed embryos. Cytotoxicity was also evidenced by alteration in the polychromatic erythrocytes (PCE) to normochromatic erythrocytes (NCE) ratio and by an increase in the erythroblast population in treated organisms. The cytotoxicity and genotoxicity of TBT may have long-term complications in later stages of the life cycle.