Peris David, Belloch Carmela, Lopandić Ksenija, Álvarez-Pérez José Manuel, Querol Amparo, Barrio Eladio
Institute Cavanilles of Biodiversity and Evolutionary Biology, University of Valencia, Spain.
Yeast. 2012 Feb;29(2):81-91. doi: 10.1002/yea.2891. Epub 2012 Jan 6.
New double- and triple-hybrid Saccharomyces yeasts were characterized using PCR-restriction fragment length polymorphism of 35 nuclear genes, located on different chromosome arms, and the sequencing of one nuclear and one mitochondrial gene. Most of these new hybrids were originally isolated from fermentations; however, two of them correspond to clinical and dietary supplement isolates. This is the first time that the presence of double-hybrid S. cerevisiae×S. kudriavzevii in non-fermentative substrates has been reported and investigated. Phylogenetic analysis of the MET6 nuclear gene confirmed the double or triple parental origin of the new hybrids. Restriction analysis of gene regions in these hybrids revealed a high diversity of genome types. From these molecular characterizations, a reduction of the S. kudriavzevii fraction of the hybrid genomes is observed in most hybrids. Mitochondrial inheritance in hybrids was deduced from the analysis of mitochondrial COX2 gene sequences, which showed that most hybrids received the mitochondrial genome from the S. kudriavzevii parent. However, two strains inherited a S. cerevisiae COX2, being the first report of S. cerevisiae×S. kudriavzevii hybrids with S. cerevisiae mitochondrial genomes. These two strains are those showing a higher S. kudriavzevii nuclear genome reduction, especially in the wine hybrid AMH. This may be due to the release of selective pressures acting on the other hybrids to maintain kudriavzevii mitochondria-interacting genes.
利用位于不同染色体臂上的35个核基因的PCR限制性片段长度多态性以及一个核基因和一个线粒体基因的测序，对新型双杂交和三杂交酿酒酵母进行了表征。这些新型杂交酵母大多最初是从发酵过程中分离出来的；然而，其中有两个对应于临床和膳食补充剂分离株。这是首次报道并研究非发酵底物中双杂交酿酒酵母×库德里亚夫齐酵母的存在。MET6核基因的系统发育分析证实了新型杂交酵母的双亲或三亲起源。对这些杂交酵母基因区域的限制性分析揭示了基因组类型的高度多样性。从这些分子表征中可以观察到，大多数杂交酵母的杂交基因组中库德里亚夫齐酵母部分有所减少。通过对线粒体COX2基因序列的分析推断出杂交酵母中的线粒体遗传情况，结果表明大多数杂交酵母从库德里亚夫齐酵母亲本那里获得了线粒体基因组。然而，有两个菌株继承了酿酒酵母的COX2，这是具有酿酒酵母线粒体基因组的酿酒酵母×库德里亚夫齐酵母杂交酵母的首次报道。这两个菌株就是那些库德里亚夫齐酵母核基因组减少程度较高的菌株，尤其是葡萄酒杂交酵母AMH。这可能是由于作用于其他杂交酵母以维持与库德里亚夫齐酵母线粒体相互作用基因的选择压力的释放。
