Eukaryote-to-eukaryote gene transfer events revealed by the genome sequence of the wine yeast Saccharomyces cerevisiae EC1118
Eukaryote-to-eukaryote gene transfer events revealed by the genome sequence of the wine yeast Saccharomyces cerevisiae EC1118
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DOI：
10.1073/pnas.0904673106
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发表时间：
2009-09-22
影响因子：
11.1
通讯作者：
Dequin, Sylvie
中科院分区：
文献类型：
--
作者：
Novo, Maite;Bigey, Frederic;Dequin, Sylvie
酿酒酵母用于酿酒已有数千年的历史，但人们对作用于葡萄酒酵母基因组的选择性作用力知之甚少。我们对二倍体商业葡萄酒酵母EC1118的全基因组进行了测序，结果得到了31个支架的组装，覆盖了S288c参考基因组的97%。酿酒酵母与其他酿酒酵母菌株的显著区别在于具有3个独特的大区域，其中2个是亚端粒，另一个插入在EC1118染色体内。这些区域包含34个与葡萄酒发酵关键功能有关的基因。系统发育和同源性分析表明，其中1个区域起源于与酵母属亲缘关系较近的物种，而另外2个区域起源于非酵母属。我们确定葡萄酒发酵的主要污染物贝氏酵母是这两个地区中的一个地区的供体物种。虽然已经描述了酵母菌株之间的自然杂交，但这份报告提供了基因转移可能发生在酵母和非酵母物种之间的证据。我们表明，所确定的区域是频繁的，并且在酿酒酵母分支之间存在差异分布，几乎只在葡萄酒菌株中发现，这表明通过最近的转移事件获得了这些区域。总体而言，这些数据表明，葡萄酒酵母基因组通过外源基因的贡献受到不断的重塑。我们的结果表明，这些过程有利于生态接近，并参与了葡萄酒酵母对高糖、低氮和高乙醇浓度条件的分子适应。
Saccharomyces cerevisiae has been used for millennia in winemaking, but little is known about the selective forces acting on the wine yeast genome. We sequenced the complete genome of the diploid commercial wine yeast EC1118, resulting in an assembly of 31 scaffolds covering 97% of the S288c reference genome. The wine yeast differed strikingly from the other S. cerevisiae isolates in possessing 3 unique large regions, 2 of which were subtelomeric, the other being inserted within an EC1118 chromosome. These regions encompass 34 genes involved in key wine fermentation functions. Phylogeny and synteny analyses showed that 1 of these regions originated from a species closely related to the Saccharomyces genus, whereas the 2 other regions were of non-Saccharomyces origin. We identified Zygosaccharomyces bailii, a major contaminant of wine fermentations, as the donor species for 1 of these 2 regions. Although natural hybridization between Saccharomyces strains has been described, this report provides evidence that gene transfer may occur between Saccharomyces and non-Saccharomyces species. We show that the regions identified are frequent and differentially distributed among S. cerevisiae clades, being found almost exclusively in wine strains, suggesting acquisition through recent transfer events. Overall, these data show that the wine yeast genome is subject to constant remodeling through the contribution of exogenous genes. Our results suggest that these processes are favored by ecologic proximity and are involved in the molecular adaptation of wine yeasts to conditions of high sugar, low nitrogen, and high ethanol concentrations.