Gorman J A, Gorman J W, Koltin Y
Department of Gene Expression Sciences, Smithkline Beecham, King of Prussia, PA 19406.
Curr Genet. 1992 Mar;21(3):203-6. doi: 10.1007/BF00336842.
The galactose analogue 2-deoxy-galactose (2DG) has been widely used to select for mutations in the gene encoding the galactose pathway enzyme galactokinase (GalK). We have tested the effect of 2DG on Candida albicans to see if it could be used to obtain GalK- mutants in this diploid asexual yeast. 2DG was shown to be toxic to wild-type cells. Enzyme assays demonstrated that 2DG can induce GalK as efficiently as galactose. Examination of the initial rate of galactose uptake indicated that the galactose transport system is constitutive. 2DG-resistant mutants were isolated from mutagenized cultures and shown to have very low levels of GalK activity. The potential genetic applications of this system of direct mutant selection are discussed.
半乳糖类似物2-脱氧半乳糖（2DG）已被广泛用于筛选编码半乳糖途径酶半乳糖激酶（GalK）的基因突变。我们测试了2DG对白色念珠菌的作用，以确定它是否可用于在这种二倍体无性酵母中获得GalK-突变体。结果表明2DG对野生型细胞有毒性。酶活性测定表明，2DG诱导GalK的效率与半乳糖相同。对半乳糖摄取初始速率的检测表明，半乳糖转运系统是组成型的。从诱变培养物中分离出2DG抗性突变体，结果显示其GalK活性水平非常低。本文还讨论了这种直接突变体筛选系统的潜在遗传学应用。
