【摘要】 目的:利用数据库和临床分离的志贺菌菌株分析志贺菌中成簇的规律间隔短回文重复序列(CRISPR)的特点,探讨CRISPR-Q1的特性及CRISPR间的关联性。方法:根据志贺菌基因组数据库利用引物序列和PCR扩增获得志贺菌的CRISPR序列信息,采用多序列比对等方法获得每个菌株中CRISPR的分布、间隔序列数及序列特点;利用BLAST分析CRISPR-Q1中重复序列和间隔序列,检测重复序列和间隔序列在菌株中的分布特点以及CRISPR-Q1在菌株中的位置及特征;分析数据库和实验室中志贺菌CRISPR-Q1中间隔序列数与CRISPR1或CRISPR2的关系。结果:在数据库107株志贺菌中,106株志贺菌含有CRISPR1或CRISPR2,8株志贺菌的CRISPR1或CRISPR2含有多个间隔序列;106株志贺菌含有CRISPR-Q1,其中有13株志贺菌的CRISPR-Q1中有多个间隔序列。在实验室12株志贺菌中,有6株含有CRISPR1或CRISPR2,12株均含有CRISPR-Q1;CRISPR-Q1间隔序列中的一部分(约35bp)在同一个菌株的染色体基因组上分布广泛,重复序列同样如此,CRISPR-Q1中还存在基因外重复序列(REP)元素。数据库志贺菌中的CRISPR-Q1间隔序列数与CRISPR1和CRISPR2有关联(χ~2=61.6,P<0.01),实验室志贺菌中的CRISPR-Q1间隔序列数与CRISPR1和CRISPR2有关联(P=0.015)。结论:CRISPR-Q1在志贺菌中广泛分布,其序列中存在REP元素;志贺菌的CRISPR1和CRISPR2与CRISPR-Q1有关联。更多还原

【Abstract】 Objective:To analyze the characteristics of clustered regularly interspaced short palindromic repeats(CRISPR)in Shigella from the database and clinic,and to explore the characteristics of CRISPR-Q1 and the correlations among CRISPRs.Methods:According to the genome database of Shigella,the primer sequences and PCR amplication were used to obtain the CRISPR sequences of Shigella,and the multiple sequence alignment was used to analyze the CRISPR distribution,the number and features of spacer;BLAST was used to analyze the repeats and spacers in CRISPR-Q1;the distribution characteristics of the repeats and spacers in Shigella and the location and features of CRISPR-Q1 in the strain were detected;the relationships between the spacer number of CRISPR-Q1 and CRISPR1/CRISPR2 in the database and laboratory were analyzed.Results:Among 107 Shigellastrains in the database,106 Shigella strains contained CRISPR1 or CRISPR2,8 Shigella strains contained severial spacers;106 Shigellastrains contained CRISPR-Q1,and 13 Shigellastrains contained severial spacers.A total of 6 among12 Shigellastrains in the laboratory contained CRISPR1 or CRISPR2,all of the 12 strains contained CRISPR-Q1.A portion of the CRISPR-Q1 spacer(about 35 bp)widely distributed in the genome of the same strain of chromosome,as was the repeat sequence;CRISPR-Q1 contained the repetitive extragenic palindromic elements(REP).The spacer number of CRISPR-Q1 was related to the CRISPR1 or CRISPR2 of Shigellain the database(χ~2=61.60,P<0.01)and in the laboratory(P=0.015).Conclusion:CRISPR-Q1 widely distributes in Shigella and the REP elements can be found in CRISPR-Q1.There are correlations between CRISPR1 or CRISPR2 and CRISPR-Q1 in Shigella.更多还原