Mammalian spermatozoa are not motile when they leave the testis. They
have to undergo a complex maturation process to be able to fertilize i
n vivo. The maturation changes of mammalian sperm membrane have been e
xtensively studied using lectins and antibodies. Some of these antigen
s have been purified and cloned. The interaction of secreted proteins
with sperm membranes and acquisition of sperm motility as essential st
eps for spermatozoa to be fertile are well documented. The role of the
se epididymal maturation proteins in infertility and the possibility o
f using these antigens for immunocontraception are discussed in this r
eview.