Expression of the mouse Ren-1 gene in the coagulating gland: localization and regulation

The components of the renin-angiotensin system have been detected in various reproductive tissues of mammals including the testis, epididymis, ovary, and placenta. Using Northern blot and in situ hybridization analyses, we detected abundant levels of renin mRNA in the coagulating gland (anterior prostate) of mice with one (Ren-1) but not two (Ren-1/Ren-2) copies of the renin gene. In contrast to mice, the single renin gene of the rat (R. norvegicus) was silent in the coagulating gland. The results of this survey suggest that the ability of the renin gene to express in the coagulating gland was acquired during the speciation of mice and subsequently lost as a result of the duplication event at the renin locus. In the coagulating gland, we found that renin mRNA transcripts initiated at a series of upstream start sites, some of which map within a 0.5-kb transposable-like element previously identified in the promoter region of the mouse, but not the rat, renin gene. Furthermore, renin gene expression in the coagulating gland was positively regulated by testosterone. The coagulating gland thus represents a male reproductive tissue that demonstrates high-level, species-specific, and differential expression of renin mRNA.