Induction of polyspermy in sea urchin eggs by antibodies raised against a hamster sperm protein

Polyclonal antibodies raised against a hamster sperm protein (P26h) induce polyspermic fertilizations in the green sea urchin without affecting the fertilizing ability of the spermatozoa nor the elevation of the fertilization membrane. While the adsorption of the antibodies on sperm decreased the polyspermic effect, preincubation of unfertilized eggs with the anti-P26h did not cause polyspermy. These results suggest that common epitopes are involved in fertilization processes in phylogenetically distant species.