肠炎沙门氏菌2种rDNA 16s～23s基因间隔区序列分析

Cloning and Sequence Analysis of Two Types of rDNA 16 s￣23 s Intergenic Spacer from Salmonella enteritidis

采用凝胶分离ＰＣＲ产物的方法，对肠炎沙门氏菌中２种ｒＤＮＡ１６ｓ～２３ｓ基因间隔区进行克隆和序列分析．肠炎沙门氏菌小ｒＤＮＡ１６ｓ～２３ｓ基因间隔区，全长３５４个碱基对，包含１个谷氨酸ｔＲＮＡ基因．大ｒＤＮＡ１６ｓ～２３ｓ基因间隔区，全长５１８个碱基对，其中包含异亮氨酸和丙氨酸２个ｔＲＮＡ基因．它们分别与大肠杆菌的２个ｒＲＮＡ操纵子ｒｎＥ和ｒｒｎＨ有较高的序列相似性．肠炎沙门氏菌大ｒＤＮＡ１６ｓ～２３ｓ基因间隔区比大肠杆菌ｒＤＮＡ对应的区域长７１个碱基对，这一插入片段很可能是沙门氏菌属ｒＤＮＡ的一个特征序列．

Two types of rDNA 16s￣23s intergenic spacer from S enteritidis were cloned and sequenced by using agarose gel separation of PCR products. The small rDNA spacer, containing a Glu tRNA gene, is 354 b in length; while the large rDNA spacer is 518 b long due to the existings of Ile and Ala tRNA genes within it. By computer analysis, the two rDNA spacers were found to be closely related to E.coli rRNA operon rrn E and rrn H, respectively. Moreover, a 71 b insert, which is most probably a characteristic of genus Salmonella , was discovered in the high divergent region of the large rDNA spacer of S. enteritidis.