利用26S rDNAD1/D2区序列和微卫星标记分析各种工业酿酒酵母的种内遗传差异

选取30株传统发酵工业中不同来源的酿酒酵母菌株和实验室常用酿酒酵母菌株,利用大亚基(26S)rDNA D1/D2区序列和微卫星标记分析酿酒酵母种内菌株间的遗传多样性和系统发育关系,以揭示酿酒酵母在长期的各种工业发酵环境下发生的遗传变异。结果表明:30株酿酒酵母的26S rDNA D1/D2区序列(591bp)比较保守,与测序菌株S288C相比序列相似度在99.8%–100%,说明种内菌株间存在一定的多态性,但序列差异并不十分明显,其变异情况表现在个别碱基的差异(大多由转换突变引起);通过扩增11个微卫星位点,每个菌株均有其独特的基因型,即30种基因型,共得到188个等位基因,观测杂合度平均值和期望杂合度平均值分别为0.576、0.886,多态信息含量平均值高达0.858,说明酿酒酵母种内菌株间具有较高的遗传多样性,而聚类分析表明30株酿酒酵母可以得到很好地区分,但是没有呈现与其工业来源相关的聚类。

Genetic analysis of industrial yeast (Saccharomyces cerevisiae) based on sequencing of 26S rRNA gene D1/D2 domain and microsatellite markers

Thirty Saccharomyces cerevisiae strains were obtained from different industrial applications in traditional brewing industry and laboratories or public collections. The genetic variation and phylogenetic relationship among these strains were studied using sequencing of the large-subunit (26S) rRNA gene D1/D2 domain and microsatellite markers. The sequences of 26S rRNA gene D1/D2 domain (591bp) were highly conserved in the tested strains and the sequence similarities of thirty strains with S. cerevisiae S288C are from 99.8% to 100%. A total of 30 multilocus genotypes and 188 alleles were observed by microsatellite markers among thirty strains. The mean observed heterozygosity and the mean expected heterozygosity were 0.576 and 0.886, respectively, and the average polymorphic information content (PIC) was 0.858. These results showed that the abundant polymorphism exists among the tested isolates. The clustering analysis showed that all strains can be differentiated but the correlation between clustering relationships and industrial sources or applications of the strains was not observed.