Yang De-qin, Liu Tian-jia, Qi Qing-guo, Zhuang Heng, Li Song
Key Laboratory of Oral Biomedical Engineering of Ministry of Education, Sichuan University, Chengdu 610041, China.
Hua Xi Kou Qiang Yi Xue Za Zhi. 2007 Feb;25(1):1-4.
To study the genetic diversity and the gene expression of membrane-bound proton-translocating ATPase (F-ATPase) subunit gene uncG derived from Streptococcus mutans (S. mutans) clinical isolates.
38 S. mutans strains derived from caries-active and caries-free individuals including 18 strains displaying high acid tolerance and 20 strains displaying low acid tolerance. Gene uncG was amplified with specific primers from S. mutans genomic DNA, then the PCR product was analyzed by RFLP and sequenced. The relative expression quantity of uncG gene against the housekeeping gene recA was determined by using RT-PCR method. A gel documentation system and QUANTITY ONES software were used to analyze the data results.
It was testified that four genotypes A, B, C and D of PCR-RFLP were revealed when respectively digested with Alu I and Bsr I, but the distributions of the four genotype strains showed no difference (P > 0.05). The differences of uncG gene transcript quantities derived from different genotype or different aciduranc strains had no significance (P > 0.05).
This study indicated that uncG gene of F-ATPase obviously displayed genetic diversity and existed polymorphism at mRNA expression level, while the Alu I-RFLP genotypes and the expression levels would not be responsive to different acid tolerance of S. mutans strains.
研究变形链球菌临床分离株中膜结合质子转运ATP酶（F-ATP酶）亚基基因uncG的遗传多样性及基因表达情况。
选取38株来自患龋和无龋个体的变形链球菌菌株，其中18株表现出高耐酸性，20株表现出低耐酸性。用特异性引物从变形链球菌基因组DNA中扩增uncG基因，然后对PCR产物进行RFLP分析和测序。采用RT-PCR法测定uncG基因相对于看家基因recA的相对表达量。使用凝胶成像系统和QUANTITY ONES软件分析数据结果。
经Alu I和Bsr I分别酶切后，证实PCR-RFLP存在A、B、C和D四种基因型，但四种基因型菌株的分布无差异（P>0.05）。不同基因型或不同耐酸性菌株的uncG基因转录量差异无统计学意义（P>0.05）。
本研究表明，F-ATP酶的uncG基因明显表现出遗传多样性，在mRNA表达水平存在多态性，而Alu I-RFLP基因型和表达水平对变形链球菌菌株的不同耐酸性无反应。
