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 intras plenic immunizations. Antibodies, which detected antigen epitopes in unfert ilized but not in fertilized mouse eggs (fertilization-specific antibodies) and which in addition recognized epitopes in unfertilized human oocytes (m ouse-human cross-reacting antibodies) were used to visualize the distributi on of their corresponding antigens by confocal laser fluoresence scanning m icroscopy (CLFSM). We found that among 26 antibodies tested, two ones showe d a patch pattern. Since a patchy distribution of cell membrane molecules i ndicates the presence of integral proteins with ability to transduce signal s 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 cell s.