RESUMO
Culturing pronuclear embryos from CD-1 mice with o,p'-DDT and p,p'-DDT was examined as a means for directly evaluating toxicant risk and for increasing the speed of screening developmental toxicants. Pronuclear (2PN) embryos from CD-1 mice were cultured 96 h in modified Earle's balanced salt solution containing 0.1% (v/v) ethanol (control) or 10-fold dilutions of 17/beta-estradiol, o,p'-DDT, or p,p'-DDT. Compared to control treatment, 96 h incubation of 2PN embryos with 0.1 gg/mL o,p'-DDT significantly reduced embryo development to blastocyst and mean cell number, and increased the percentage of cells undergoing apoptosis. The effects of o,p'-DDT on developmental parameters were dose-responsive. Embryo sexing by multiplex polymerase chain reaction indicated that both sexes were susceptible to toxicant injury with comparable reduction in development to blastocyst (27% and 24%, respectively) in the presence of o,p'-DDT. Results of this study suggest that in vitro exposure of preimplantation embryos to xenobiotics may provide a useful tool for rapidly screening developmental toxicants.