Meade J H, Riley M I, Manney T R
J Bacteriol. 1977 Mar;129(3):1428-34. doi: 10.1128/jb.129.3.1428-1434.1977.
An examination of gene expression in diploids may not always be sufficient for determination of the dominant or recessive character of an allele. In Saccharomyces cerevisiae resistance to cryptopleurine has been attributed to a single recessive nuclear gene, cryl, located on chromosome III. We found, contrary to expectations, that resistance to cryptopleurine is not expressed in diploids that are monosomic for chromosome III. Examination of strains of different ploidy on gradient plates shows that the presence of the sensitive allele in a cell does not affect the level of resistance, but rather the level of resistance is directly related to the ratio of resistant alleles to the number of chromosome sets.
对二倍体中基因表达的检测可能并不总是足以确定等位基因的显性或隐性特征。在酿酒酵母中,对隐品碱的抗性归因于位于III号染色体上的一个隐性核基因cryl。与预期相反,我们发现,对于III号染色体单体型的二倍体,对隐品碱的抗性并未表达。在梯度平板上对不同倍性的菌株进行检测表明,细胞中敏感等位基因的存在并不影响抗性水平,相反,抗性水平与抗性等位基因与染色体组数量的比例直接相关。