格特隐球菌IGS5b基因亚型和a交配型菌株的鉴定

Identification of sub-genotype IGS5b and mating type a Cryptococcus gattii

目的鉴定1株格特隐球菌VGⅢ基因型中的少见基因亚型IGS5b及a交配型菌株。方法采用PCR指纹法、基因内间隔区(IGS)和磷脂酶基因(PLB1)测序分析鉴定基因型。采用PCR特异扩增法和交配试验鉴定交配型。采用GEF1基因序列分析同步鉴定基因型和交配型。结果结合PCR指纹法和序列分析,鉴定受试株RV63979为VGⅢ基因型中的少见基因亚型。针对交配型位点内STE12和STE20基因的特异性引物均扩增阴性。交配试验证实为a交配型。GEF1位点测序准确鉴定其基因型和交配型。结论本文通过多种鉴定手段结合IGS序列分析,鉴定1株VGⅢ基因型中的少见基因亚型IGS5b,证实VGⅢ基因型中至少存在IGS5a和IGS5b2种基因亚型。交配型分析表明该菌为VGⅢ基因型中少见的a交配型。

Objective To characterize an isolate belonging to rare sub-genotype IGS5b within VGⅢ genotype and mating type a.Methods Genotype was characterized by PCR fingerprinting,intergenic spacer （IGS） sequencing,and phospholipase （PLB1） gene sequencing. PCR with specific primers and mating assay were performed to analyze the mating type. Sequencing GEF1 gene was conducted for simultaneous identification of genotype and mating type.Results The strain RV63979 was characterized as a rare sub-genotype within VGⅢ genotype consists of at least two sub-genotypes, namely IGSSa and IGS5b. Mating type analysis shows MATa, a rare mating type within VGⅢ genotype.