Ghatak Atreyi, Majumdar Anasuya, Ghosh Ranajit K
Molecular Biology Laboratory, Indian Institute of Chemical Biology, 4, Raja SC Mullick Road, Jadavpur, Kolkata 700 032, India.
J Biosci. 2005 Dec;30(5):619-25. doi: 10.1007/BF02703562.
We have cloned, sequenced and analysed all the five classes of the intergenic (16S-23S rRNA) spacer region (ISR) associated with the eight rrn operons (rrna-rrnh) of Vibrio cholerae serogroup O1 El Tor strains isolated before, during and after the O 139 outbreak. ISR classes 'a' and 'g' were found to be invariant, ISR-B (ISRb and ISRe) exhibited very little variation, whereas ISR-C (ISRc, ISRd, and ISRf) and ISRh showed the maximum variation. Phylogenetic analysis conducted with all three ISR classes (ISR-B, ISR-C and ISRh) showed that the pre-O 139 serogroup and post-O 139 serogroup O1 El Tor strains arose out of two independent clones, which was congruent with the observation made by earlier workers suggesting that analyses of ISR-C and ISR-h, instead of all five ISR classes, could be successfully used to study phylogeny in this organism.
我们已经克隆、测序并分析了与霍乱弧菌O1群El Tor菌株的8个rrn操纵子（rrna-rrnh）相关的基因间（16S-23S rRNA）间隔区（ISR）的所有五类。发现在O139疫情之前、期间和之后分离的霍乱弧菌O1群El Tor菌株中，ISR类别“a”和“g”是不变的，ISR-B（ISRb和ISRe）表现出很小的变异，而ISR-C（ISRc、ISRd和ISRf）和ISRh表现出最大的变异。对所有三类ISR（ISR-B、ISR-C和ISRh）进行的系统发育分析表明，O139疫情前血清群和O139疫情后血清群的O1 El Tor菌株源自两个独立的克隆，这与早期研究人员的观察结果一致，即表明可以成功地使用ISR-C和ISR-h的分析，而不是所有五类ISR，来研究该生物体的系统发育。
