Confocal laser fluorescence scanning microscopy of the oolemma distribution of monoclonal antibodies against mouse and human egg surface membrane.

Monoclonal antibodies were raised against zona-free mouse oocytes by intrasplenic immunizations. Antibodies, which detected antigen epitopes in unfertilized but not in fertilized mouse eggs (fertilization-specific antibodies) and which in addition recognized epitopes in unfertilized human oocytes (mouse-human cross-reacting antibodies) were used to visualize the distribution of their corresponding antigens by confocal laser fluoresence scanning microscopy (CLFSM). We found that among 26 antibodies tested, two ones showed a patch pattern. Since a patchy distribution of cell membrane molecules indicates the presence of integral proteins with ability to transduce signals to the cytoplasm, we suggest that the method here applied will select for those oolemma molecules that could be involved in the fusion of sperm cells.