Adaptation of Saccharomyces cerevisiae to saline stress through laboratory evolution.

Most laboratory evolution studies that characterize evolutionary adaptation genomically focus on genetically simple traits that can be altered by one or few mutations. Such traits are important, but they are few compared with complex, polygenic traits influenced by many genes. We know much less about complex traits, and about the changes that occur in the genome and in gene expression during their evolutionary adaptation. Salt stress tolerance is such a trait. It is especially attractive for evolutionary studies, because the physiological response to salt stress is well-characterized on the molecular and transcriptome level. This provides a unique opportunity to compare evolutionary adaptation and physiological adaptation to salt stress. The yeast Saccharomyces cerevisiae is a good model system to study salt stress tolerance, because it contains several highly conserved pathways that mediate the salt stress response. We evolved three replicate lines of yeast under continuous salt (NaCl)...

多数从基因组层面解析进化适应机制的实验室进化研究，均聚焦于可通过单个或少数突变即可改变的遗传简单性状。这类性状固然重要，但相较于受多基因调控的复杂多基因性状而言，此类简单性状仍属少数。目前学界对复杂性状，以及其进化适应过程中基因组与基因表达层面发生的变化，所知仍十分有限。盐胁迫耐受性（salt stress tolerance）正是这类复杂性状之一。该性状尤其适合开展进化研究，因为学界对盐胁迫的生理响应在分子与转录组层面的机制已有充分解析，这为对比盐胁迫下的进化适应与生理适应机制提供了独特契机。酿酒酵母（Saccharomyces cerevisiae）是研究盐胁迫耐受性的理想模式系统，因其拥有多条介导盐胁迫响应的高度保守通路。本研究通过持续施加氯化钠（NaCl）盐胁迫，培育了三组酵母重复进化株系……