Résumé
The two renin genes of the mouse (
Ren1 and
Ren2) are expressed at different levels in the submaxillary gland (SMG). In contrast to mice, there is no detectable renin gene expression in the rat SMG. To determine the molecular basis for these different levels of renin expression, we have compared the 5'-flanking regions of the rat and mouse genes. The sequence of mouse, but not rat, genes reveals the presence in
Ren1 and
Ren2 of a large insertion, probably a new class of transposable elements. A second, apparently unrelated shorter insertion is present only in
Ren2. Otherwise, the mouse and rat 5'-flanking sequences are well conserved and resemble the corresponding region of the human
Ren gene, indicating that the insertions occurred after the separation of the rat and mouse species but before the duplication of the mouse
Ren gene. We suggest that these structural differences may have a role in the differential expression of the
Ren genes in mice and other animals.