促旋酶(gyrase) B亚单位基因gyrB在鉴别细菌近缘种中的应用

Application of gyrB in the identification of closely related bacteria—— A review

摘要:

单拷贝的gyrB是普遍存在于细菌中编码促旋酶B亚单位的基因，该基因进化速率快，每100万年的平均碱基替换率为0.7%~0.8%。研究证明，该区段基因能对假单胞菌、芽孢杆菌、弧菌、肠杆菌、分枝杆菌、气单胞菌、乳酸菌等不同属或科内的近缘种进行区分鉴定，还可通过设计种特异性引物进行定量PCR或者限制性片段分析，同时也能结合变性梯度凝胶电泳技术（DGGE）追踪微生物的动态。gyrB基因弥补了非蛋白编码基因16S rDNA或者基因间隔序列(ITS)DNA无法区分近缘种的缺陷，给近缘种的鉴别或者其群体指纹图谱的分析带来了新的希望，为当前国内外用于近缘种研究的热点，是细菌系统发育分析上非常值得重视的新靶标。

关键词:促旋酶;gyrB;近缘种;系统发育

Abstract:

The single-copied gyrB gene, encoding the subunit B of gyrase and distributing universally in all bacteria, has the average substitution rate of 0.7%~0.8% per million years. It’s proved that this region could be used to discriminate and identify the closely related species of different bacteria such as Pseudomonoas, Bacillus, Vibrio, Enterobacteriaceae, Mycobacteria, Aeromonas, Lactic acid bacteria et.al. It also can be used of quantitative or restriction fragment analysis of bacteria with the aid of species-specific primers or combined with DGGE(denaturing gradient gel electrophoresis). It really brings new promise for the identifying closest isolates or fingerprinting population due to overcoming the shortage of undistinguishing them acutely with the non-protein-encoding genes such as 16S rDNA or ITS(internal transcribed spacer) DNA. It’s an important new molecular marker for researches of closely related species and becoming an attractive topic in current microbial research world.

Key words:gyrase; gyrB; closely related species; phylogenetics