Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA, USA.
J Bacteriol. 2011 Jul;193(13):3286-92. doi: 10.1128/JB.01167-10. Epub 2011 May 6.
Swarming colonies of independent Proteus mirabilis isolates recognize each other as foreign and do not merge together, whereas apposing swarms of clonal isolates merge with each other. Swarms of mutants with deletions in the ids gene cluster do not merge with their parent. Thus, ids genes are involved in the ability of P. mirabilis to distinguish self from nonself. Here we have characterized expression of the ids genes. We show that idsABCDEF genes are transcribed as an operon, and we define the promoter region upstream of idsA by deletion analysis. Expression of the ids operon increased in late logarithmic and early stationary phases and appeared to be bistable. Approaching swarms of nonself populations led to increased ids expression and increased the abundance of ids-expressing cells in the bimodal population. This information on ids gene expression provides a foundation for further understanding the molecular details of self-nonself discrimination in P. mirabilis.
成群的独立奇异变形杆菌分离株相互识别为外来菌，不会融合在一起，而克隆分离株的对生群体则会融合在一起。缺失 ids 基因簇的突变体群体不会与亲本融合。因此，ids 基因参与了奇异变形杆菌区分自身和非自身的能力。在这里，我们对 ids 基因的表达进行了特征描述。我们表明，idsABCDEF 基因作为一个操纵子转录，并且我们通过缺失分析定义了 idsA 上游的启动子区域。ids 操纵子的表达在对数后期和早期静止期增加，并且似乎是双稳态的。接近非自身群体的群体导致 ids 表达增加，并增加了双峰群体中表达 ids 的细胞的丰度。关于 ids 基因表达的这一信息为进一步了解奇异变形杆菌中自我-非自我识别的分子细节提供了基础。
