Abstract
To obtain identical twins with predicted sex, an efficient and reliable method for manipulation and analysis of bovine embryos has been developed using in vitro produced embryos and PCR. Expanded blastocysts graded as excellent were bisected into halves following biopsy to remove approximately 10% of trophoectoderm. Viability and cell number of these biopsied demi-embryos at 48 h in culture were compared with demi-embryos which have been only bisected. No significant difference was seen in survival rates between the biopsied demi-embryos (80.7%) and demi-embryos (87.0%). The mean cell number of the biopsied demi-embryos (70.00 ± 18.84) was slightly lower than that in the demi-embryos (77.50 ± 20.82). The sex of small sample and one biopsied demi-embryo was determined by PCR. The sex of 48 (96.0%) of the biopsied demi-embryos survived was consistent with the sample-side with 27 males and 21 females. These findings indicate that the sex of biopsied demi-embryos can be determined with a high accuracy, and their in vitro viability is comparable to that of demi-embryos.
