GENETICS OF ALDEHYDE DEHYDROGENASE ISOZYMES IN THE MOUSE: EVIDENCE FOR MULTIPLE LOCI AND LOCALIZATION OF Ahd-2 ON CHROMOSOME 19

Glenn P. Timms ¹ and Roger S. Holmes ¹

¹ School of Science, Griffith University, Nathan 4111, Australia

Electrophoretic and activity variation of the cytoplasmic isozyme of aldehyde dehydrogenase (designated AHD-B₄) was observed among inbred strains and Harwell linkage-testing stocks of Mus musculus. The phenotypes are inherited in a normal Mendelian fashion, with two alleles showing co-dominant expression at a single locus (Ahd-2). The locus was shown to segregate independently of Ahd-1 (encoding the mitochondrial AHD-A₂ isozymes on chromosome 4; Holmes 1978). Linkage data of Ahd-2 with ep (pale ears), ru (ruby eyes) and bm (brachymorphic) suggest that it is localized near the centromeric end of chromosome 19. Electrophoretic evidence for a third AHD isozyme (designated AHD-Cy), which is predominantly localized in the liver microsomal fraction, is also presented.