Clark B A
Biochem Genet. 1983 Apr;21(3-4):375-90. doi: 10.1007/BF00499146.
A gene-dosage effect is characteristic of eukaryotic structural genes and is therefore useful in gene mapping. However, attributing quantitative variations in enzyme activity to a gene-dosage effect or other putative regulatory loci can be suspect when the locus in question may be inducible by variations in culture conditions. The problem of controlling for allele-specific variations in activity and regulation can be circumvented in Drosophila melanogaster by the use of synthetic duplications and deficiencies in conjunction with enzyme polymorphism. A method for constructing segmental aneupliods heterozygous for electrophoretic variants of octanol dehydrogenase (Odh) is presented which permitted variations in allozyme phenotype and enzyme activity--which show a strict dosage dependency--to be produced simultaneously. The structural gene region for Odh was identified using T(Y;A) stocks and the deficiency M(3)S31 was used to assign the locus to polytene band region 86D1-4. With this method a segmental aneuploid survey of Drosophila for purposes of gene localization can be accomplished in one generation with appropriate stocks.
基因剂量效应是真核生物结构基因的特征，因此在基因定位中很有用。然而，当所讨论的基因座可能受培养条件变化诱导时，将酶活性的定量变化归因于基因剂量效应或其他假定的调控基因座可能会有问题。通过使用合成重复和缺失结合酶多态性，在黑腹果蝇中可以规避控制等位基因特异性活性和调控变化的问题。本文介绍了一种构建八醇脱氢酶（Odh）电泳变体杂合的节段性非整倍体的方法，该方法允许同时产生等位酶表型和酶活性的变化——这些变化显示出严格的剂量依赖性。使用T(Y;A)品系鉴定了Odh的结构基因区域，并使用缺失M(3)S31将该基因座定位到多线带区域86D1-4。通过这种方法，利用合适的品系，一代内就能完成果蝇用于基因定位的节段性非整倍体研究。
