cDNA cloning of androgen-repressed mRNA in rat seminal vesicles: partial characterization of a cDNA clone, pSvr-1.

When the in vitro translation products of mRNAs from castrated animals (48 h) were compared with those from androgen-treated animals (48 h) to survey the molecular mechanism of androgen-responsive gene expressions in the rat seminal vesicles, some peptide bands which were repressed in response to androgen were observed. From these findings, we constructed a partial cDNA library of poly(A+)RNAs which had been isolated from the seminal vesicles of castrated rats (48 h) and modestly enriched with respect to the concentration of androgen-repressed mRNAs by sucrose density gradient centrifugation, and screened by differential colony hybridization. One cDNA clone, pSvr-1, whose mRNA is markedly induced within 24 h after castration of the animal in the seminal vesicles as well as in the ventral prostate, was isolated. pSvr-1 hybridized to a mRNA of 1,700 nucleotides in length. Partial sequence analysis showed that this clone had highly homologous but not identical sequences to those reported for rat sulfated glycoprotein-2. This cDNA clone may provide a useful probe for the study of the negative regulation mechanism of gene expression by androgens.