Laboratorio de Genética y Biología Molecular, IRNASUS-CONICET, Facultad de Ciencias Químicas, Universidad Católica de Córdoba, Córdoba, Argentina.
Mol Genet Genomics. 2020 May;295(3):685-693. doi: 10.1007/s00438-020-01652-2. Epub 2020 Feb 22.
Yeast microsatellite loci consist of short tandem-repeated DNA sequences of variable length. The high mutational rate at these loci generates a remarkable repertoire of alleles, useful for strain differentiation and population genetic studies. In this work, we analyze the DNA sequences of thirteen alleles from each of ten microsatellite loci described for the yeast Starmerella bacillaris. Our results show that polymorphic variants of some informative alleles are dependent on SNPs and indels rather than on length variation at their originally defined tandem-repeated motifs. The analysis was extended to 55 previously described hypervariable microsatellite loci from a total of 26 sequenced genomes of yeast species that dominate the microbiota of spontaneously fermenting grape musts (i.e., Hanseniaspora uvarum, Saccharomyces cerevisae, Saccharomyces uvarum, and Torulaspora delbrueckii) or lead to wine spoilage (Brettanomyces bruxellensis and Meyerozyma guilliermondii). We found that allelic variants for some microsatellite loci of these yeast species are also dependent on SNPs and/or indels flanking their tandem-repeated motifs. For some loci, the number of units at their tandem repeats was found to be identical among the various characterized alleles, with allelic differences being dependent exclusively on flanking polymorphisms. Our results indicate that allele sizing of microsatellite loci using PCR, although valid for strain differentiation and population genetic studies, does not necessarily score the number of units at their tandem-repeated motifs. Sequence analysis of microsatellite loci alleles could provide relevant information for evolutionary and phylogeny studies of yeast species.
酵母微卫星位点由可变长度的短串联重复 DNA 序列组成。这些位点的高突变率产生了大量的等位基因，可用于菌株分化和群体遗传研究。在这项工作中，我们分析了为 Starmerella bacillaris 酵母描述的十个微卫星位点中的每个位点的十三个等位基因的 DNA 序列。我们的结果表明，一些信息丰富的等位基因的多态性变体依赖于 SNP 和 indels，而不是其原始定义的串联重复基序的长度变化。该分析扩展到了来自主导自然发酵葡萄汁微生物群的 26 个已测序酵母物种的总共 55 个先前描述的高变微卫星位点，这些酵母物种包括（Hanseniaspora uvarum、Saccharomyces cerevisae、Saccharomyces uvarum 和 Torulaspora delbrueckii）或导致葡萄酒变质（Brettanomyces bruxellensis 和 Meyerozyma guilliermondii）。我们发现，这些酵母物种的一些微卫星位点的等位基因变体也依赖于其串联重复基序侧翼的 SNP 和/或 indels。对于一些位点，其串联重复的单位数在各种特征等位基因中是相同的，等位基因差异仅依赖于侧翼多态性。我们的结果表明，使用 PCR 对微卫星位点的等位基因进行大小分析，尽管对于菌株分化和群体遗传研究是有效的，但不一定能对其串联重复基序的单位数进行评分。微卫星位点等位基因的序列分析可为酵母物种的进化和系统发育研究提供相关信息。
