格特隐球菌核基因、交配型位点和线粒体基因的多位点序列分型及重组分析

Multilocus Sequence Typing & Recombination Analyses of Nucleus Genes,Mating Type Locus & Mitochondria Genes of Cryptococcus gattii

研究格特隐球菌VGI和VGII基因型菌株间线粒体基因重组与核基因、交配型位点重组间的关系。采用分子鉴定区分受试格特隐球菌的血清型、基因型和交配型;选取包含核基因和线粒体基因10个位点的多位点序列分型(MLST)进行基因型和系统发育分析;采用同质性检验评价基因系谱间的一致性。多位点的序列和系统发育分析结合同质性检验表明,受试位点中,仅ATP6位点发现VGI和VGII菌株间基因的杂交和重组,该基因系谱与其余位点的基因系谱呈现不一致性。结果显示,受试的部分VGI菌株中的ATP6位点含有VGII菌株的基因序列,表明VGI和VGII菌株间线粒体基因的重组;没有发现核基因及交配型位点中两者间的重组,提示VGI和VGII菌株间线粒体基因的重组现象与交配行为无关。

Relationship among recombination of mitochondria genes, nucleus genes and mating type locus among Cryptococcus gattii VGI and VGII genotypic strains was studied. Molecular methods were adopted to identify and dis-tinguish serotype, genotype and mating types of the tested C. gattii, ten loci were selected from nucleus and mitochon-dria genes for multilocus sequence typing （ MLST） and phylogenetic analysis. Homogeneity test was conducted for the evaluation of the congruence among various gene genealogies. The multilocus sequences and phylogenetic analyses, combined with homogeneity test, indicated that among the tested loci, only at ATP6 locus VGI and VGII inter-strain genes hybridation and recombination was found, and the genealogy of the gene was incongruent with genealogies of oth-er genes. The results indicate that partial tested VGI strains in this study were found to have gene sequence from VGII strains at ATP6 locus, indicating it was an inter-strain recombination of VGI and VGII mitochondria genes;no recom-bination between both loci of nucleus genes and mating type was found, prompting that the inter-strain mitochondria recombination phenomenon among VGI and VGII strains was irrelevant with mating type.