Abstract: 59

EXPRESSION PATTERN OF PRION PROTEIN MESSENGER RNA IN MOUSE AND RAT TESTES.

Masahiko Fujisawa¹ , Sang-yoon Nam¹ , Kiyoshi Kano¹ , Masamichi Kurohmaru¹ , Yoshihiro Hayashi¹
Department of Veterinary Anatomy, Graduate School of Agricultural and Life Sciences, University of Tokyo. ¹

Although the function of the cellular prion protein (PrPc) has been controversial, it still remains to be uncertain. PrPc is a protein anchored to the cell surface by glycosylphosphatidylinositol, indicating the possible role in cell signalling or adhesion. It has been also suggested that PrPc expression may aid cellular resistance to oxidative stress by influencing the activity of copper/zinc superoxide dismutase. Since oxidative stress gives strict damage to testis, PrPc may be in relation to spermatogenesis. In this study, the cDNA clone of PrP (756bp) was isolated from the testes of 8-wk-old C57BL/6J mice by RT-PCR. The nucleic acid sequence analysis confirmed the clone cDNA is completely identical to mouse brain cDNA . To determine the expression pattern of the PrP mRNA in the mouse and rat testes (8wk), Northern blot and in situ hybridization analyses using digoxigenin-labeled riboprobes were performed. By Northern blot analysis, the PrP mRNA in the testes of mice (8wk) was detected as a single transcript of 2.1-2.2 kb. In situ hybridization analysis revealed that in mice testes PrP mRNA was predominantly expressed in spermatogonia and early spermatocytes throughout all stages, whereas in rats testes it was expressed in spermatocytes and round spermatids, and that PrP mRNA could not be detected in testicular somatic cells, such as Sertoli cells and myoid cells in both. The finding is different from previous study. RT-PCR analysis demonstrated that the PrP mRNA was also expressed before puberty (1,2,3,4 and 6wk) in both mouse and rat testes. In conclusion,our findings indicate the possibility that PrPc may be involved in spermatogenesis.

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