9511822 Hall In all male mammalian species, including man, spermatozoa that leave the testis are infertile and immobile. The acquisition of fertilizing capacity and motility by spermatozoa occurs in an organ called the epididymis and the overall process is often referred to as "sperm maturation". It is now well accepted in reproductive biology and biochemistry that spermatozoan maturation is mediated by proteins and glycoproteins called fertility antigens. These fertility antigens are secreted by the epididymis under the control of the male hormone, testosterone. Using the rat as an experimental model, Dr. Hall has identified a key fertility antigen that is secreted by the epididymis and binds to the sperm plasma membrane. This sperm plasma membrane antigen which is synthesized by the epididymis plays a key physiological role in plasma membrane changes on the surface spermatozoa that accompany the development of fertilizing capacity and motility in mammals. An initial step toward elucidating the basic causes of male infertility or developing compounds as potential male contraceptives is to understand how these fertility antigens are regulated in the mammalian epididymis. Thus, the broad, long-term objective of the present study is to provide a basic understanding of how fertility antigens are regulated. A working model for the androgen-dependent synthesis of this fertility antigen is proposed in this study. A unique feature of the model is that the synthesis of this fertility antigen may be regulated at the level of its own messenger RNA (mRNA). He further hypothesizes that the rate at which this fertility antigen is synthesized in cells of the epididymis is controlled by proteins that bind to its mRNA. If this hypothesis proves correct, it may be possible in the near future to develop a compound that can selectively block (contraceptive) or enhance (conception) the synthesis of the fertility antigen. ***
