[The heterozygous effect of X-ray or ENU-induced null-mutant Adh alleles on alcohol tolerance of Drosophila melanogaster].
To study the mechanisms of partial dominance, 12 intragenic alcohol dehydrogenase null mutations (Adhn) in Drosophila melanogaster were used as a model system. These known sequenced mutations, either single base substitutions or small intragenic deletions (9-16 bp) were analyzed for peptide production, dimer formation and enzymatic activity of the heterodimer. Multiple mechanisms leading to partial enzyme expression in heterozygotes and a wide range of dominance varying from almost complete recessive to a high degree of dominance were found. An expression of partial dominance for alcohol tolerance was observed for all 12 Adhn under the high stress of 10% ethanol. The genetic background on which the null mutations are expressed is a major determinant for alcohol tolerance of the heterozygous adult flies. The mutations induced by X-ray had higher average dominance than that of ENU-induced mutations, and the mutations that formed nonfunctional heterodimers had the highest dominance.
Tong
G L
GL
Institute of Life Science and Technology, Shanghai Jiaotong University, China.
Lin
Z X
ZX
Jiang
J C
JC
D000426:Alcohol Dehydrogenase / Q000235:genetics*; D000818:Animals; D004331:Drosophila melanogaster / Q000187:drug effects* / Q000235:genetics; D000431:Ethanol / Q000494:pharmacology*; D005038:Ethylnitrosourea / Q000633:toxicity*; D006579:Heterozygote; D009154:Mutation; D014965:X-Rays
D000431:Ethanol; D000426:Alcohol Dehydrogenase; D005038:Ethylnitrosourea