Identification of protein tyrosine phosphatases expressed in murine male germ cells.

Abstract We cloned five cDNAs encoding putative protein tyrosine phosphatases (PTPs; protein-tyrosine-phosphatase phosphohydrolase, EC 3.1.3.48) from the murine testis by using degenerate primers and the polymerase chain reaction cloning technique. Two of them were identical to the mouse cytoplasmic PTP and PTP-1B. The remaining three were likely to represent the murine counterparts of human FTP δ, human FTP ϵ, and rat striatum-enriched PTP. The cells expressing these genes were determined either by in situ hybridization histochemistry or by Northern blot hybridization. Moreover, Northern blot hybridization revealed that the transcripts of FTP-1B, mouse cytoplasmic FTP and the murine homologue of human PTP δ were quantitatively and/or structurally regulated during germ cell development, suggesting their roles in spermatogenesis.