Linkage and polymorphism of a gene controlling lactate dehydrogenase in the rat.

The amount of lactate dehydrogenase subunit A in rat serum is under the control of the lactate dehydrogenase regulatory gene Ldr-1, and it is determined by two alleles, Ldr-1a (high) and Ldr-1b (low). Sex and LDH-A level segregate independently, so the Ldr-1 gene is autosomal. The genes for albino, red eye, hemoglobin, and Ldr-1 are linked (linkage group I), and their order is Ldr-1-Hbb-r-c. Our data put Ldr-1 45 cM from Hbb, and Hbb is 7 cM from c. Data in the literature separate r and c by 0.3 cM.