Restriction fragment length polymorphisms for the renin gene in Dahl rats

Genomic DNAs from inbred Dahl salt-hypertension sensitive (S) and inbred Dahl salt-hypertension resistant (R) rats were examined for restriction fragment length polymorphisms (RFLPs) using a rat renin cDNA probe. Eight of the 28 restriction enzymes used yielded polymorphic fragments between S and R strains. This suggests a major structural difference in or near the renin gene of Dahl rats. Some, but not all, of the polymorphisms are compatible with an insertion/deletion mutation of about 1.1 kb in size. The ratio of renin gene copy numbers for S to R was found to be 1, showing that the RFLPs are not likely to be due to gene duplication.