Cytological and Immunological Investigations of Sperm-Egg Interactions in Selected Decapods (Crustacea) and Limulus polyphemus L. (Merostomata)

The initial events of sperm-egg interaction have been examined in several crustaceans. These have large non-motile spermatozoa and sperm-egg attachment is polyspermic. Sperm-egg attachment in vitro is largely species specific among the organisms examined. Antisperm sera produced in rabbits agglutinates the crustacean spermatozoa. Interspecific agglutinations do occur. Appropriate absorption experiments demonstrate more than one sperm surface antigen. Spermatozoa pretreated with univalent, non-agglutinating antibody fail to attach to eggs of the species. This indicates that one or more sperm surface antigens are involved in sperm-egg attachment. Antigens are distributed over the entire sperm surface as shown by the morphology of agglutination and by immunofluorescence. Two or more soluble antigens can be extracted from crustacean spermatozoa, depending upon species. Some of these antigens give interspecific reactions, others are species specific.