Expression of alcohol dehydrogenase during pearl danio development.

The ontogeny of alcohol dehydrogenase (ADH) was examined in the pearl danio (Brachydanio albolineatus) by the utilization of vertical slab acrylamide gel electrophoresis. The restriction of ADH activity to liver tissue in B. albolineatus is consistent with observations reported for other species of brachydanio. At 118 hours posthatching, a time when larval fishes were found to undergo functional maturation of the liver, the ADH homopolymer appeared. The enzyme was observed to increase in activity concurrently with decreasing yolk reserves. It is suggested that the state of liver cell differentiation and/or the physiological function of liver tissue provides the stimulation required to activate the Adh locus in Brachydanio.