PCR-AMPLIFIED VITRONECTIN MESSENGER-RNA LOCALIZES IN-SITU TO SPERMATOCYTES AND ROUND SPERMATIDS IN THE HUMAN TESTIS

Vitronectin is an adhesion protein present within the acrosomal cap re gion of human spermatozoa and is liberated during the acrosome reactio n. The purpose of this study was to determine if vitronectin mRNA was synthesized in the male genital tract using the reverse transcriptase in-situ polymerase chain reaction (PCR) technique. Twelve genital trac t tissues, which included six testes, one showing Sertoli cells only a nd one from a 3 year old boy, as well as sections from the prostate, s eminal vesicles, and epididymis, were analysed for vitronectin transcr ipts. PCR-amplified vitronectin cDNA was detected in the seminiferous tubules of the four adult testes that showed normal spermatogenesis an d localized to the spermatocytes and round spermatids. PCR-amplified v itronectin cDNA was not detected in the tissues of the prostate, epidi dymis, and seminal vesicles from the men whose testes did contain the message, nor in the testes with Sertoli cells only or that of the prep ubertal boy. It is concluded that, in the male genital tract, vitronec tin is transcribed exclusively in the germ cells at the spermatocyte a nd round spermatid stages. This demonstrates that the translated prote in present in the spermatozoon is being produced in situ. Further stud y is needed to determine the role of this protein in the dynamics of s perm-oocyte interaction.