This gene encodes a testis-specific, differentiation antigen, acrosomal vesicle protein 1, that arises within the acrosomal vesicle during spermatogenesis, and is associated with the acrosomal membranes and matrix of mature sperm. The acrosomal vesicle protein 1 may be involved in sperm-zona binding or penetration. Alternatively spliced transcript variants have been described. [provided by RefSeq, Nov 2010].