title: Identification of a male-specific histocompatibility protein on preimplantation porcine embryos.
abstract: An indirect immunofluorescence assay was used to detect the presence of male-specific protein(s) on various stages of preimplantation porcine embryos. Embryos were collected at slaughter from the reproductive tracts of day-2.5, -4, -5, -6, and -8 (day 0 = first day of estrus) sows and gilts. Embryos were placed in medium containing an anti-male primary antibody, washed, and transferred to culture drops containing a fluorescein isothiocyanate (FITC)-labeled secondary antibody. Embryos were classified as either fluorescent (H-Y positive) or nonfluorescent (H-Y negative), transferred to coded drops, and karyotyped to examine sex chromosomes. A total of 91 eight-cell to blastocyst stage embryos were evaluated; of these, 46% were classified as fluorescent and 54% as nonfluorescent. Of readable metaphase spreads (65%) from these embryos, 81% (48 of 59, P less than 0.005) were correctly sexed by immunological detection of the male-specific antigen. Although 13% (2/15) of four-cell embryos evaluated were classified as fluorescent, the accuracy with which embryos at this stage were sexed by detection of H-Y antigen was not different from 50%. Fifty percent of eight-cell embryos were classified as H-Y positive with 78% of embryos correctly sexed. It was concluded that the eight-cell embryo is the earliest stage of development for which there is evidence for expression of H-Y antigen. Detection of the male-specific protein was difficult at the expanded blastocyst stage.
mesh_terms: D000818:Animals; D001755:Blastocyst / Q000166:cytology / Q000276:immunology* / Q000502:physiology; D005260:Female; D006182:H-Y Antigen / Q000032:analysis*; D007106:Immune Sera; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL / Q000276:immunology; D009028:Morula / Q000276:immunology / Q000502:physiology; D009924:Organ Culture Techniques; D012732:Sex Determination Analysis; D013552:Swine
chemical_list: D006182:H-Y Antigen; D007106:Immune Sera