| Abstract: | Mouse oocytes at the dictyate and metaphase II stages as well as fertilized eggs have been studied by indirect immunofluorescence for the expression of H-2 histocompatibility antigens on surface membranes. Serologically specific reactivity to H-2 antibody was observed as patchy fluorescence distributed over the surface of the oocyte membrane. In contrast, one-cell zygotes exhibited variable reactivity, and early two-cell stages were negative. Absorption studies confirmed the serologic specificity of the reactivity on oocytes, which could be shown to be due to H-2 antibody. The results suggest that fertilization results in altered expression of major histocompatibility complex surface antigens, and confirms earlier studies that cleavage stage mouse embryos are not reactive with H-2 antibody. |
