PP60(C-SRC) EXPRESSION IN RAT SPERMATOGENESIS

A fractionation of the membrane extract of rat testes revealed the existence of pp60(c-src) kinase activity. The expression of pp60(c-src) was examined in the developing rat testes. The immunecomplex kinase assay using a monoclonal antibody specific to pp60(c-src)(mAb327) showed that the expression of pp60(c-src) kinase activity increased during the development of rat testes and declined in the adult. The increase in pp60(c-src) kinase activity observed during the development of rat testes was accompanied with an increase in the amount of pp60(c-src) protein. The peak period in the increase of pp60(c-src) kinase activity well coincided with the timing, when the spermatogenesis by meiosis just began. The immunohistochemical staining of pp60(c-src) in rat testes demonstrated that pp60(c-src) is most abundantly expressed in the spermatids which are the spermatogenic cells in the post-meiotic phase of the spermatogenesis. These findings strongly suggest that pp60(c-src) is a developmentally regulated gene product which is involved in rat spermatogenesis. (C) 1995 Academic Press, Inc.