Abstract: 68

LOCALIZATION OF HEPARIN INTERACTING PROTEIN (HIP) IN THE RAT TESTIS.

E. Gloria C. Regisford^{1 *}
Department of Biology, Prairie View A&M University, Prairie View, TX 77446 ¹

Heparin Interacting Protein (HIP) has been localized in a variety of reproductive tissues in both humans and the mouse. It has been suggested that HIP promotes cell-cell attachment. In the male mouse, HIP is highly expressed in the testes, epididymis and in sperm, but not in the seminal vesicles. To determine which testicular cells express HIP, testicular tissue from the c-kit mutant mouse, which is devoid of germ cells, and the c-kit wild type, was analyzed by Western blot analysis. The 24kDa protein HIP was absent in the c-kit mutant mouse, but was present in the wild type. Evidence suggests that the onset of HIP expression could be coincidental with the onset of germ cell production in the testis. A developmental study was then performed to determine the onset of HIP expression in the testes. Testicular tissue taken from rats at ages 15, 25, 35, 45 and 55 days, was analyzed by Western blot analysis and immunocytochemistry. Western blot analysis indicated that HIP is constituitively expressed in rat testes at all ages. Immunocytochemical analysis determined that HIP is expressed in cells in the basal compartment of the seminiferous tubules of very young animals. HIP was also expressed in spermatogonia, spermatocytes, spermatids and in mature sperm cells. Expression of HIP appears to be localized to sperm tails. HIP was marginally expressed in Leydig cells. The localization of HIP in these cells suggest that HIP could play a role(s) in germ cell and Sertoli cell interaction and in Leydig cell differentiation and/or function. (Supported by ASCB/fellowship)

    This abstract is being presented on Sunday, August 1 at 8:00 AM to 10:15 AM at CUB 2nd Floor Ballroom.