乙肝病毒特异性核酶的构建及体外切割活性的初步研究

目的对我国伯氏考克斯体（Ｃｂ）分离株的２３ＳｒＲＮＡ基因插入片段（２３ＳＩＶＳ）作核酸序列分析。方法用聚合酶链反应（ＰＣＲ）扩增７株Ｃｂ中国分离株和２株外国参考株的２３ＳＩＶＳ，用双脱氧核苷酸法对扩增产物进行测序。结果重庆，四川，内蒙分离株以及Ｈｅｎｚｅｒｌｉｎｇ和Ｇｒｉｔａ等６株的ＩＶＳ序列均相同，ＹＳ－８，ＹＳ－９和ＹＨ－１１等云南分离株的ＩＶＳ与前６株的比较仅少一个７个碱基的重复序列。结论Ｃｂ２３ＳＩＶＳ为高度保守基因片段，与高度异质性的钩端螺旋体的同源性基因片段不同；云南株和其它６株的ＩＶＳ差别与Ｃｂ分离株的地理分布的不同有关，云南分离株可能为一亚种

Analysis of the intervening sequences in 23S rRNA genes of the Chinese Coxiella burnetii isolates

Objective To study the nucleic acids sequence of the intervening sequences(IVS) carried by 23S rRNA genes of Coxiella burnetii (Cb). Methods The IVSs from seven Chinese isolates and two foreign reference strains were amplified by polymerase chain reaction (PCR) and the amplimers were directly sequenced by dideoxynucleotide methods. Results The IVSs of the isolated from different locations and sources in this study, except three isolates from Yunnan province, were identical. The IVSs of three Yunnan isolates from human and sheep were identical and they were devoid of one 7 base repeat unit which existed in the other 6 isolates. Conclusions Our results demonstrated that the IVS of Cb is a highly conservative element in the chromosome and it is different from its homologous elements existing in the chromosome of Spirochete which are highly divergent among strains. The difference of Cb IVSs is related to the geographic distribution of the organisms and the Yunnan strains probably belong to a subspecies of Cb.