Old Lesley A, Russell Roy R B
Oral Biology, School of Dental Sciences, Newcastle University, Newcastle upon Tyne, UK.
FEMS Microbiol Lett. 2008 Oct;287(2):199-204. doi: 10.1111/j.1574-6968.2008.01312.x. Epub 2008 Aug 27.
Insertion sequence (IS) elements are widely distributed selfmobilizing genetic elements that can affect genetic changes by integrating into the chromosome, mediating genetic rearrangements and facilitating horizontal gene transfer. Three members of the IS3 family have been identified in Streptococcus mutans: IS199 was discovered by its transposition while ISSmu1 and ISSmu2 were predicted from the genome sequence of S. mutans UA159. Sixty-eight strains of S. mutans were screened by PCR for carriage of the IS elements IS199, ISSmu1 and ISSmu2. Twenty-seven (30%) of the strains were positive for IS199, 33 (49%) were positive for ISSmu1 and 51 (75%) carried ISSmu2. All three IS were found in 11 strains, two were found in various combinations in 31, one was found in 16, while only 10 strains had none of the three IS for which we screened. ISSmu1 was demonstrated to be capable of transposition at a low frequency but no transposition of ISSmu2 was observed.
插入序列（IS）元件是广泛分布的可自我移动的遗传元件，可通过整合到染色体中、介导基因重排和促进水平基因转移来影响基因变化。变形链球菌中已鉴定出IS3家族的三个成员：IS199是通过其转座作用发现的，而ISSmul和ISSm u2是根据变形链球菌UA159的基因组序列预测的。通过PCR对68株变形链球菌进行筛选，以检测IS元件IS199、ISSmul和ISSm u2的携带情况。27株（30%）菌株IS199呈阳性，33株（49%）ISSmul呈阳性，51株（75%）携带ISSm u2。在11株菌株中发现了所有三种IS，31株以各种组合形式发现了两种，16株发现了一种，而只有10株没有我们筛选的这三种IS中的任何一种。已证明ISSmul能够以低频率转座，但未观察到ISSm u2的转座现象。
