FERTILIZATION DEFECTS IN SPERM FROM MICE LACKING FERTILIN-BETA

Fertilin, a member of the ADAM family, is found on the plasma membrane of mammalian sperm. Sperm from mice tacking fertilin beta were shown to be deficient in sperm-egg membrane adhesion, sperm-egg fusion, migr ation from the uterus into the oviduct, and binding to the egg zona pe llucida. Egg activation was unaffected. The results are consistent wit h a direct role of fertilin in sperm-egg plasma membrane interaction. Fertilin could also have a direct role in sperm-zona binding or oviduc t migration; alternatively, the effects on these functions could resul t from the absence of fertilin activity during spermatogenesis.