中文摘要：

tmRNA， tRNA 相关的碎片的联合和小 mRNA 碎裂，作为 genomic 岛(GIs ) 的集成地点被证实。用顺序排列和比较 genomics，与 tmRNA 基因联系的 68 GIs 在 Enterobacteriaceae 的 13 个类之中被识别。在他们之中， 53 GIs 在 Escherichia coli 和沙门氏菌 enterica 被发现。在这 53 GIs 之中，双人脚踏车 GIs 在八 S 被验证。enterica 和二 E。coli 染色体。在大多数 E 的 tmRNA 基因的下游的区域。coli 和 S。enterica 染色体包括官方补给的或双人脚踏车 GIs 区域和对 tmRNA 远侧的一个残余变量区域。进染色体的双人脚踏车 GIs 的集成的年表更远非显示了那 GIs tmRNA 从 tmRNA 更近比那些早被合并到染色体。tmRNA 的 integrases 联系基因的 GIs 能进一步被分成三种子类型：HP1 integrases， PhiCTX integrases，和 P4 integrases，它最占优势。GIs 是第一集成于由 P4 integrase 的染色体，随后由 PhiCTX integrase，并且最后由 HP1 integrase。因此， tmRNA 基因是为调查双人脚踏车 GIs 的遗传和进化的一个重要地点。

英文摘要：

tmRNA, a combination of a tRNA-related fragment and a small mRNA fragment, was confirmed as the integration site of genomic islands （GIs）. Using sequence alignment and comparative genomics, 68 GIs associated with tmRNA genes were identified among 13 genera of Enterobacteriaceae. Among them, 53 GIs were found in Escherichia coli and Salmonella enterica. Among these 53 GIs, tandem GIs were verified in eight S. enterica and two E. coli chromosomes. The downstream regions of the tmRNA genes in most of the E. coli and S. enterica chromosomes include one GI or tandem GIs region and a remnant variable region distal to the tmRNA. The chronology of integration of tandem GIs into the genome indicated that GIs farther from the tmRNA were incorporated into the genome earlier than those nearer from the tmRNA. The integrases of the tmRNA gene-associated GIs can be further categorized into three subtypes： HP1 integrases, PhiCTX integrases, and P4 integrases, which are the most predominant. The GIs were first integrated into the chromosome by the P4 integrase, subsequently by the PhiCTX integrase, and finally by the HP1 integrase. Thus, the tmRNA gene is an important site for investigating the genetics and evolution of tandem GIs.