Abstract
Single blastomeres were isolated from 2-cell mouse embryos and analysed for their sex by using partially deleted Y-chromosome as a marker. Sex identification of 83% of the embryos was achieved with conventionally Giemsa-stained chromosome preparations. The other half-embryos were cultured individually or recombined with another half-embryo of the same sex, and were transferred to pseudopregnant recipient females. Six percent of the half and 18% of the recombined embryos developed into live fetuses. The sex of these fetuses was identical with that determined prior to embryo transfer. Sex analysis in this way was accurate and early enough to allow utilization of sex-known embryos for development and sex differentiation studies at the cleavage stage.
