Regulated expression of the Ren-2 gene in transgenic mice derived from parental strains carrying only the Ren-1 gene.
The Ren-2 gene encoding the mouse submaxillary gland (SMG) renin was microinjected into the pronuclei of fertilized eggs from mice carrying only the Ren-1 gene. In addition to the whole transcription unit, the injected DNA contained 2.5 and 3 kb of upstream and downstream flanking sequences, respectively. Three independent transgenic mice lines were obtained; two of them had integrated one copy of the Ren-2 gene, the last one had integrated five and eleven copies at two independent sites. Independently of the number of Ren-2 copies integrated, the pattern of Ren-2 gene expression in all the transgenic mice was identical to that observed in wild-type animals in which Ren-1 and Ren-2 are closely linked on chromosome 1. In particular, the exogenous Ren-2 gene was only transcribed in the kidney and in the SMG. In the kidney, Ren-1 and Ren-2 mRNAs were present at a comparable level, whereas in the SMG Ren-2 mRNA was at least 100-fold more abundant than Ren-1 mRNA. Moreover, Ren-2 expression in the SMG was positively regulated by androgens. Only one difference between transgenic mice and wild-type mice carrying the Ren-2 gene has been observed: the basal level of Ren-2 transcription in the SMG of transgenic females was lower than in two-gene strain females. Androgen treatment of transgenic females induced SMG renin mRNA to a level identical to that of transgenic males. This suggests that the basal level of SMG renin mRNA is dependent upon cis-acting elements which are not present in the microinjected fragment.
Tronik
D
D
Dreyfus
M
M
Babinet
C
C
Rougeon
F
F
D000818:Animals; D003001:Cloning, Molecular; D003433:Crosses, Genetic; D005260:Female; D005786:Gene Expression Regulation; D005796:Genes; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D008845:Microinjections; D012333:RNA, Messenger / Q000235:genetics / Q000302:isolation & purification; D012083:Renin / Q000235:genetics*; D013363:Submandibular Gland / Q000201:enzymology
D012333:RNA, Messenger; D012083:Renin