A polymorphic variant of the lactate dehydrogenase B subunit in the rat.

A new electrophoretic variant of the lactate dehydrogenase B subunit was found in the erythrocytes of the COP strain of the rat. The location of the band after the electrophoresis suggested a product of the structural gene for the B subunit. Two alleles that regulated the high amount (Ldh-2a) or the low amount (Ldh-2b) of the B subunit were found and segregated in Mendelian fashion. The activity was regulated by the closely linked (less than 1 cM) regulatory gene Ldr-1.