白念珠菌菌丝相和酵母相ERG11基因部分序列差异性的探讨

The DNA Sequence Difference of ERG11 Gene Between the Yeast-form and the Hyphal-form of Candida albicans

目的研究白念珠菌菌丝相和酵母相细胞ERG11基因碱基序列上的差异,探讨两相细胞之间的差异性。方法分别抽提从同一HIV阳性患者体内分离到的7株对氟康唑敏感程度不同的白念珠菌菌丝相和酵母相的DNA,此系白念珠菌经染色体水平及DNA水平证实来源于同一亲本。根据ERG11编码序列设计一对引物,对ERG11的近3'端的310bp的碱基序列进行PCR扩增,引物序列为:上游引物5'-GGGAAAGTTTCTAAAGGGG-3';下游引物5'-TATGTTAATCCAACTAAGTAA-3'。经PCR产物直接测序比较两相细胞ERG11基因碱基序列上的差异。结果1株氟康唑剂量依赖性敏感和2株氟康唑耐药白念珠菌的菌丝相与酵母相细胞间均出现ERG11基因1547位点、1587位点和1617位点的不一致。结论白念珠菌的菌丝相和酵母相ERG11基因的部分序列存在差异。

Objective To explore the difference of gene sequence between the yeast- and the hyphal-form of Candida albicans. Methods The genomic DNA of both the yeast-form and the hyphal-form of seven isolates were extracted. The isolates were obtained from the same patient infected with HIV, but their sensitivities to fluconazole were different. These isolates were derived from the same C.albican strain as identified by chromosomal analysis and DNA subtype analysis. DNA fragments (310 bp) of ERG11 were amplified by PCR and the difference of DNA sequence between the two forms of each isolates was compared by DNA sequencing. Results Three isolates were found to have sequence difference between the yeast- and the hyphal-form of C. albicans at the position of 1 547 bp, 1 587 bp and 1 617 bp. Conclusion The sequence difference of ERG11 gene exists between the yeast- and the hyphal-form of C. albicans.