(a) Field of the Invention
The invention relates to the use of acrosomal sperm protein in immunocontraception of male and female subjects and uses thereof as a marker for fertility. 
(b) Description of Prior Art
Fertilization is a highly orchestrated process that culminates in the activation of an oocyte by a spermatozoon.  Although testicular spermatozoa are fully differentiated cells, they cannot efficiently encounter the oocyte's investments.  In order to acquire this property, spermatozoa must undergo post-testicular modifications within the epididymis.  During this transit, the male gamete is subjected to major surface modifications such as changes in the lipids composition, acquisition of new epididymal proteins as well as post-translational modifications of sperm proteins.  Taken together, these modifications are prerequisites for the spermatozoon to acquire its fertilizing ability.  These processes are regulated by the epididymal luminal microenvironment which is influenced by both epididymal and testicular protein synthesis and secretion. 
Using the hamster as a model, we have previously described a 26 kDa protein, the P26h, which shows immunocontraceptive properties when used to actively immunize male hamsters (Berube, B., Sullivan, R., 1994, Biol.  Reprod.,  51: 1255-1263).  This protein is localized on the sperm acrosome and is acquired during the epididymal transit.  P26h plays a role in egg sperm interactions as shown by the ability of P26h antibodies to inhibit sperm-zona pellucida binding in vivo and in vitro (Berube, B., Sullivan, R., 1994, Biol.  Reprod.,  51: 1255-1263). 
It would be highly desirable to be provided with to the use of an acrosomal sperm protein in immunocontraception of male and female subjects. 
It would be highly desirable to be provided with to the use of an acrosomal sperm protein as a marker for fertility.