Benítez T, Martínez P, Codón A C
Departamento de Genética, Facultad de Biología, Universidad de Sevilla, España.
Microbiologia. 1996 Sep;12(3):371-84.
Saccharomyces cerevisiae industrial yeast strains are highly heterogeneous. These industrial strains, including bakers', wine, brewing and distillers', have been compared with respect to their DNA content, number and size of chromosomes, homologies between their genes and those of laboratory strains, and restriction fragment lengths of their mitDNA. A high variability, and the presence of multigenic families, were observed in some industrial yeast groups. The occurrence or the lack of chromosomal polymorphism, as well as the presence of multiple copies of some genes, could be related to a selective process occurring under specific industrial conditions. This polymorphism is generated by reorganization events, that take place mainly during meiosis and are mediated by repetitive Y' and Ty elements. These elements give rise to ectopic and asymmetric recombination and to gene conversion. The polymorphism displayed by the mitDNA could also result from specific industrial conditions. However, in enological strains the selective process is masked by the mutagenic effect that ethanol exerts on this DNA.
酿酒酵母工业酵母菌株具有高度的异质性。这些工业菌株，包括面包酵母、葡萄酒酵母、啤酒酵母和蒸馏酒酵母，已在DNA含量、染色体数量和大小、其基因与实验室菌株基因之间的同源性以及其线粒体DNA的限制性片段长度方面进行了比较。在一些工业酵母群体中观察到高度变异性以及多基因家族的存在。染色体多态性的出现或缺失，以及某些基因的多拷贝存在，可能与特定工业条件下发生的选择过程有关。这种多态性是由重组事件产生的，这些事件主要发生在减数分裂期间，并由重复的Y'和Ty元件介导。这些元件导致异位和不对称重组以及基因转换。线粒体DNA显示的多态性也可能是由特定工业条件导致的。然而，在酿酒酵母菌株中，选择过程被乙醇对该DNA施加的诱变作用所掩盖。
