Alcohol dehydrogenase isozymes in the clawed frog, Xenopus laevis

Alcohol dehydrogenase (ADH; EC 1.1.1.1) activity in Xenopus laevis was highest in liver tissue, with decreasing activities in kidney, heart, and gut tissues, respectively. Essentially no activity was found among other tissues screened, including lung, ovary, eye, and testes. Also, there was no apparent sexual dimorphism of ADH activity in either liver or kidney tissue. All ADH isozymes were inhibited by 10 mM pyrazole, and no eye-specific retinol dehydrogenase activity was detected on starch gel electropherograms. Isozyme patterns from 418 offspring from 11 different crosses could be explained genetically assuming the presence of two structural genes coding for ADH production: one carrying two electrophoretically separable variants and the other showing quantitative variation in its expression. The ADH system in X. laevis should be useful for studies concerning the molecular mechanisms governing the expression of ADH activity in vertebrate development.