Adh Genotypes Research Articles

Biochemical differences between alcohol dehydrogenases of Drosophila melanogaster.

This paper describes substrate specificities, developmental changes in activity, pH profiles, and heat stabilities of isozymes produced by four Adh genotypes in D. melanogaster. No differences are found in the substrate specificities of isozymes from the different genotypes but studies of the other three properties reveal significant differences between the isozymes. Thus relatively low activities are found among extracts of AdhF Adhn2 larvae and among extracts of AdhF AdhF adults aged 44 days. Also AdhF AdhS and AdhS AdhS extracts have relatively high activities at pH 6-5, and AdhF Adhn2 extracts have relatively low activities at pH values above 10-0. Finally, extracts of AdhF AdhF and AdhF AdhS are more stable at 40 degrees C than are those of AdhS AdhS and AdhF Adhn2.

Selection at the alcohol dehydrogenase locus in Drosophila melanogaster imposed by environmental ethanol.

SUMMARYThis paper describes selective differences imposed by environmental ethanol on six genotypes at the alcohol dehydrogenase (Adh) locus in Drosophila melanogaster. Probit analyses were used to relate differences between the percentage survival of adults of different Adh genotypes to ethanol concentration. Regression analyses were used to relate differences between the pre-adult developmental times of different Adh genotypes to ethanol concentration. The directions of differences between some of the genotypes were found to differ in these two components of fitness. The differences in developmental time are linearly related to the differences in the in vitro alcohol dehydrogenase activity expressed by these genotypes. Percentage survival differences amongst adults are not linearly related to these differences in enzymic activity. The development of AdhF AdhF pre-adults is retarded the least on ethanol impregnated media but AdhFAdhS adults are most likely to survive on such media.

Isozyme variability in species of the genus Drosophila. VI. Frequency-property-environment relationships of allelic alcohol dehydrogenases in D. melanogaster.

Adult Drosophila melanogaster from naturally occurring populations in the Eastern United States were examined by gel electrophoresis for their alcohol dehydrogenase (ADH) phenotype. The ADH enzymes were partially purified and characterized. Frequencies of the controlling alleles, Adh4 and Adh6, were discovered to vary in a clinal pattern. Adh6 reaches a maximum frequency of about 0.90 in the South and minimum of about 0.50 in the North. Partially purified enzymes from the three Adh genotypes varied according to specific activity, substrate specificity, and heat stability. A differential influence of pH was indicated. There was little variation in Km values for ethanol and DPN+ among the enzymes.