Abstract
The low plasma alkaline phosphatase (ALP) activity of the IS strain of rats was genetically analized by using the cross matings with the BN strain. In the F1hybrids, the ALP activities were intermediate but largely biased to the low activity. In the (F1×BN) back-cross progeny, the distributions of plasma ALP activities were apparently bimodal in both sexes.Al p-2locus with two alleles ofAlp-2handAlp-2lis tentatively proposed.Alp-2locus did not link to the rat linkage group (LG) I, II, IV, V, and LGs containingAmy-1and Cs-1. In the (F1×IS) back-cross progeny, the plasma ALP activities were not different from that of the F1hybrids and the distribution was not bimodal.Alp-2lmay be dominant overAlp-2h. One third of the back-cross progeny showed vertebral anomalies and the difference of plasma ALP activities was not detected between the rats with and whithout vertebral anomalies.
