长爪沙鼠和新西兰白兔源肺孢子虫ITS1-5.8S rDNA-ITS2序列的测定与分析

目的测定长爪沙鼠及新西兰白兔源肺孢子虫的ITS1-5.8S rDNA-ITS2序列,并与大鼠源肺孢子虫的相应序列进行比较分析。方法用地塞米松免疫抑制法诱导长爪沙鼠和新西兰白兔感染肺孢子虫;制作肺印片进行瑞-姬氏复合染色,通过镜检初步了解感染情况;提取肺孢子虫总DNA,设计合成引物进行PCR扩增;纯化扩增产物后克隆测序;与登录Gen-Bank的大鼠源肺孢子虫相关序列进行比较分析。结果长爪沙鼠源肺孢子虫的ITS1、5.8S rDNA和ITS2基因序列长分别为158、157和172bp,新西兰白兔源肺孢子虫的相应序列分别为129、158和178bp。结论本实验测得的长爪沙鼠及新西兰白兔源肺孢子虫的ITS1-5.8S rDNA-ITS2序列以往未曾报道,此结果为肺孢子虫的遗传学研究提供了新的资料。

Sequencing and analysis of the ITS1-5.8S rDNA-ITS2 sequence of Pneumocystis pneumoniae isolated from Meriones unguiculatus and New Zealand white rabbits

To detect the ITS1-5.8S rDNA-ITS2 sequence of Pneumocystis pneumoniae from Mefriones unguiculatus and New Zealand white rabbits and to compare with the corresponding sequence from rats.These animals rendered immunodepressant by subcutaneous injection of dexamethasone were suffered from P.pneumoniae and the severity of infection was observed by the microscopical examinations of the lung impression smears stained with Wright-Giemsa's modified staining.The DNAs of P.pneumocystis were extracted from the bronchalveolar fluid(SALF) and lung tissues of the infected animals.ITS1-5.8S rDNA and ITS2 of P.pneumocystis were amplifed by PCR.The PCR products were purified,cloned and sequenced.The sequences were analyzed and aligned and compared with some related sequences in GenBank.It was demonstrated that the lengths of ITS1-5.8S rRNA and ITS2 gene sequences of P.pneumocystis from M.unguiculatus were 158,157 and 172 bp,while those from New Zealand white rabbis were 129,158 and 178 bp respectivlely.This results of observations have not been reported previously and thus provide new data for the phylogenetic studies of P.pneumocystis.