Characterization of Fibronectin on Human Spermatozoa

Abstract

Ejaculated human spermatozoa had fibronectin polypeptides on their surface. Immunofluorescence studies revealed fibronectin as a belt-like fluorescent band on the post-acrosomal area of sperm heads, whereas none was found in sperm tails. The location of the fluorescent band corresponded to the equatorial segment of the spermatozoon. Fibronectin polypetides were heterogeneous with MW of 35,000-210,000, as revealed by immunoblotting and by immunoprecipitation of detergent extracts from surface-radioiodinated spermatozoa.