Use of the non-electrophoretic method to detect testis specific protein gene for sexing in preimplantation bovine embryos

Testis-specific protein (TSPY) is a Y-specific gene, with up to 200 copy numbers in bulls. In order to make bovine embryo sexing under farm condition more feasible, the possibility of using a non-electrophoretic method to detect the TSPY gene for sexing bovine early embryos was examined. Primers were designed to amplify a portion of the TSPY gene and a common gene as an internal control primer. PCR optimization was carried out using a DNA template from bovine whole blood. Furthermore, embryo samples were diagnosed by this method and the sexing results were contrasted with those of the Loop-Mediated Isothermal Amplification (LAMP) method. The results showed that TSPY was as reliable a sexing method as LAMP. Forty-three morula and blastocyst embryos collected from superovulated donor dairy cattle were sexed by this method, and twenty-one embryos judged to be female embryos were transferred non-surgically to recipients 6 to 8 days after natural estrus. Out of 21 recipients, 9 were pregnant (42.86%) and all delivered female calves. The results showed that the sex predicted by this protocol was 100% accurate. In conclusion, the TSPY gene was a good male specific marker and indicated that a non-electrophoretic method was feasible and accurate to detect the TSPY gene for sexing preimplantation bovine embryos.