Gene activation of alcohol dehydrogenase in danio hybrids.

The regulation of alleles encoding the enzyme alcohol dehydrogenase (ADH) was investigated in F1Brachydanio hybrids (zebra danio female x spotted danio male) by acrylamide gel electrophoresis. Both parental species showed a single, cathodal band of species-specific ADH. During development at 26 degrees C, hybrid fry showed a preferential activation of the maternally derived Adh allele. It is suggested that the low activity of the paternally derived allele may result from an incompatibility between maternal regulatory factors and the paternal regulative element controlling gene expression.