Department of Bioengineering, College of Biological Science and Biotechnology, Fuzhou University, Fuzhou, Fujian, China.
Microb Biotechnol. 2014 Jul;7(4):307-14. doi: 10.1111/1751-7915.12121. Epub 2014 Apr 30.
We evaluated whether epigenetic changes contributed to improve ethanol tolerance in mutant populations of Saccharomyces cerevisiae (S. cerevisiae). Two ethanol-tolerant variants of S. cerevisiae were used to evaluate the genetic stability in the process of stress-free passage cultures. We found that acquired ethanol tolerance was lost and transcription level of some genes (HSP104, PRO1, TPS1, and SOD1) closely related to ethanol tolerance decreased significantly after the 10th passage in ethanol-free medium. Tri-methylation of lysine 4 on histone H3 (H3K4) enhanced at the promoter of HSP104, PRO1, TPS1 and SOD1 in ethanol-tolerant variants of S. cerevisiae was also diminished after tenth passage in stress-free cultures. The ethanol tolerance was reacquired when exogenous SOD1 transferred in some tolerance-lost strains. This showed that H3K4 methylation is involved in phenotypic variation with regard to ethanol tolerance with respect to classic breeding methods used in yeast.
我们评估了表观遗传变化是否有助于提高酿酒酵母（Saccharomyces cerevisiae）突变群体的乙醇耐受性。使用两种乙醇耐受型酿酒酵母变体来评估无应激传代培养过程中的遗传稳定性。我们发现，在无乙醇培养基中进行第 10 次传代后，获得的乙醇耐受性丧失，并且一些与乙醇耐受性密切相关的基因（HSP104、PRO1、TPS1 和 SOD1）的转录水平显著下降。在酿酒酵母乙醇耐受变体中，H3 组蛋白赖氨酸 4 的三甲基化（H3K4）在 HSP104、PRO1、TPS1 和 SOD1 的启动子上增强，在无应激培养的第 10 次传代后也减弱。当外源 SOD1 转入一些耐受丧失的菌株中时，乙醇耐受性得以恢复。这表明 H3K4 甲基化参与了与经典酵母育种方法相比，关于乙醇耐受性的表型变异。
