Differential extra-renal expression of the mouse renin genes

Abstract

We have used RNase-protection analyses to study renin gene expression in one- and two-gene mouse strains. The RNase-protection assay is capable of discriminating between the transcripts from the different renin genes. In a two-gene strain containing Ren-1^D and Ren-2, we demonstrate transcriptional activity from Ren-1^D in kidney, submandibular gland (SMG), testes, liver, brain and heart. Ren-2 is clearly expressed in kidney, SMG and testes. Similar analyses of one gene strains (containing Ren-1^C only) show expression in kidney, SMG, testes, brain and heart. We cannot detect renin mRNA in the liver of these mice. Ren-1^C and Ren-1^D thus display quite different tissue-specificities. In order to determine whether the different tissue-specificities of the highly homologous Ren-1^C and Ren-1^D genes are due to different trans-acting factors in the different mouse strains or to different cis-acting DNA elements inherent to the genes, we introduced a Ren-1^D transgene (Ren-1^*) into a background strain containing only the Ren-1^C gene. The transgene exhibits the same tissue-specificity as the Ren-1^D gene of two-gene strains suggesting the presence of different cis-acting DNA elements in Ren-1^C and Ren-1^D.