Genetic control of alcohol dehydrogenase isozymes in maize

By means of horizontal gel electrophoresis and the zymogram technique, genetic variants and the formation of a hybrid molecule of the enzyme alcohol dehydrogenase (ADH) have been found in Zea mays. Each inbred homozygous stock examined showed two types of ADH isozyme patterns: a fast faint zone and a slower deeply staining zone, both anode-migrating at pH 8.5. The variants found differed in that each of the ADH zones varied in its electrophoretic mobility when compared to its counterpart in the other strain. When appropriate genetic crosses were made, the resulting heterozygotes showed the parental ADH zones, and, in addition, a band of intermediate mobility was formed between the deep-staining ADH bands. However, in the fast-moving zone only the parental isozymes were represented in the heterozygote. The formation of the hybrid molecule and the apparent gene dosage effects support the hypothesis that ADH-2 in maize exists as a dimer, whereas ADH-1 may exist as a monomer.This work was supported by the U.S. Atomic Energy Commission, under contract No. AT(11-1)-1338.