Study on Sex Identification of Bovine preimplantation Embryos by Indirect Immunofluorescent Assay

Totally 37 normal 6-7 days old bovine embryos collected from superovulated cows were used in this study.Embryos were first stained in 1:5 diluted H-Y antisera in M2 for 30 minutes and subsequently in 1:10 diluted fluorescencein isothiocynate-conjugated goat anti-mouse IgG for another 30 minutes.Both stain procedures were performed under 39℃,5%CO2,95% air in incubator.Or these embryos,57% (21/37) with fluorescence were classified as H-Y negative (male) and 43% (16/37) without fluorescence as H-Y negative (female) under inverted fluorescence microscope.There was no significant difference between our result and bovine natural sex ratio (P<0.05).Five fluorescence positive embryos and three fluorescence negative embryos were transferred to 5 recipients (one or two embryos per recipient),two healthy female calve were born by H-Y negative embryo bearing recipients arter full term in vivo development.Out result indicated that this method in sex identification are reliable.