吕氏泰勒虫和尤氏泰勒虫内转录间隔区基因序列的测定与系统进化分析

Sequencing and phylogenetic analysis of ITS genes of Theileria luwenshuni and T. uilenbergi isolated in China

自试验感染吕氏泰勒虫（渭源株）和尤氏泰勒虫（隆德株）绵羊的血液中纯化虫体，提取虫体基因组DNA，通过PCR扩增内转录间隔区（ITS1-5．8S-ITS2 rRNA）基因，然后进行测序，构建了系统发生树并与GenBank中各种动物梨形虫的ITS1-5．8S-ITS2 rRNA基因序列进行比较。结果显示，这两种泰勒虫的ITS1-5．8S-ITS2 rRNA基因大小为817-842bp，同源性高达96．8％，分布在同一大枝上。通过比较ITS基因的同源性，尤其是ITS2基因的变异性，可以区别这两种泰勒虫与其他梨形虫。

Theileria luwenshuni Weiyuan isolate and T. uilenbergi Longde isolate in China were purified from the blood of sheep inoculated experimentally with T. luwenshuni or T. uilenbergi,and their genomic DNAs were extracted. Then, the first internal transcribed spacer （ITS-1）, 5.8S gene and the second internal transcribed spacer （ITS-2） of the two Theileria species were amplified by PCR, sequenced, and compared with those of other spec length of the ITS-1-5.8S gene and bp and their homology was 96.8% es of piroplasms available in GenBankTM. The results showed that the ITS-2 gene of the two Theileria species varied between 817 bp and 842 The two Chinese isolates were in the same branch and could be differentiated with other piroplasms or between them by comparing the homology of ITS sequences,in particular the variation in ITS-2 sequences.