IDENTIFICATION AND CHARACTERIZATION OF THE DEVELOPMENTALLY-REGULATED PATTERN OF EXPRESSION IN THE TESTIS OF A MOUSE GENE EXHIBITING SIMILARITY TO THE FAMILY OF PHOSPHODIESTERASES

A cDNA for a rat brain phosphodiesterase (PDE) was used to screen a mo use testis library to identify the murine PDEs which are expressed in this tissue. A clone of 981 bp, p4-6, was isolated and shown to exhibi t limited identity at the amino acid level to the rat brain PDE (20%). The putative protein encoded by clone p4-6 also contains multiple pot ential modification sites, for phosphorylation, myristylation, and gly cosylation, many of which are located at positions similar to those fo und for rat brain PDE. The gene identified by p4-6 yields 3 transcript s, an abundant 1.9 kb transcript, and less abundant transcripts of 3.8 and 6.7 kb. Of the nine tissues examined in this study, the expressio n of the corresponding gene was limited to the adult mouse testis. Fur thermore, the expression in the testis was most abundant in the germ c ell lineage, although low levels were detected in somatic cells of the testis as well. Analysis of RNA from testes at different stages of de velopment suggested that the p4-6 gene is most abundantly expressed in germ cells that have completed the meiotic divisions.