大鼠卡氏肺孢子虫的三个基因序列分析

目的 分析我国大鼠源卡氏肺孢子虫的基因序列特征。方法：以Wistar大鼠建立肺孢子虫肺炎动物模型，收集鼠肺，抽提DNA，以PCR方法扩增卡氏肺孢子虫的5SrRNA基因、线粒体rRNA大亚基基因（mtLSU rRNA）、胸腺嘧啶核苷酸合成酶基因（TS）。纯化扩增产物，直接测序。检索基因库（GenBank），进行序列比较。结果 三个基因的PCR扩增呈阳性。感染Wistar大鼠的卡氏肺孢子虫5S rRNA基因与gb|S78185|S78185、gb|M28193|PMCRAA两个序列同源性分别为93.3%和91.7%；mtLSU rRNA基因与gb|U20173|PCU20173 、gb|U20169|PCU20169两个序列同源性分别为76.2%和55.2%；TS基因与gb|M25415|PMCTHYSY、gb|S77510|S77510两个序列同源性均为90.9%。结论 Wistar大鼠感染的卡氏肺孢子虫的三个基因与GenBank内的相应基因序列同源性较高。

THE ANALYSIS OF THREE GENE SEQUENCES OF PNEUMOCYSTIS CARINII DERIVED FROM WISTARRATS

Aim To analyse the identity of genes of Pneumocystis carinii derived from Wistar rats to those from rats in GenBank.Methods Pneumocystis carinii pneumonia (PCP) rat models were established by injection with cortisone acetate.PCP rat lungs were collected.The total DNA was extracted by phenol-chloroform method.5S rRNA gene,the large-subunit mitochondrial rRNA (mtLSU rRNA) gene andthymidylate synthase (TS)gene of P.carinii were amplified by polymerase chain reaction (PCR).The PCR products were demonstrated by 2% agarose gel electrophoresis.The PCR products were purified,then directly sequenced.The sequences were compared with those in the GenBank.Results The electrophoresis showed the three brands of the three genes respectively.Identity of 5S rRNA gene of P.carinii derived from Wistar rats to the two sequences (gb|S78185|S78185,gb|M28193|PMCRAA) in the GenBank is 93.3%,91.7% respectively.Identity of mtLSU rRNA gene of P.carinii derived from Wistar rats to the two sequences (gb|U20173|PCU20173,gb|U20169|PCU20169) in the GenBank is 76.2%,55.2% respectively.Identity of TS gene of P.carinii derived from Wistar rats to the two sequences (gb|M25415|PMCTHYSY,gb|S77510|S77510)in the GenBank is 90.9% respectively.Conclusion The three genes of P.carinii derived from Wistar rats are highly identical to those of P.carinii in the GenBank.