GENOME ANALYSIS OF THEILERIA PARASITES

本课题对泰勒氏菌的基因组进行了分析，获得了800个泰勒氏菌的部分序列作为表达序列标签(EST)。其中一些基因定位在微小毛滴虫的染色体上。构建了一个细菌人工染色体文库，每个文库包含50-200kb的细小毛滴虫染色体片段，文库由3600个克隆组成，理论上覆盖了细小毛滴虫全基因组。鉴定了含有寄生虫生长必需基因(S)的BAC克隆，其中包括子孢子表面蛋白，这将有助于分析这些基因组两侧的基因组结构。该种的每条染色体大小和总基因组大小与细小毛滴虫几乎相同。对帕氏锥虫和瑟氏锥虫染色体上几个同源基因的比较图谱分析表明，部分基因间的共性不保守，这表明这两种泰勒虫的基因组结构存在差异。虽然还需要进一步研究才能确定泰勒虫的整个染色体结构，但本项目的结果通过建立BAC文库，获得EST，并进行两个基因组的比较，为了解泰勒虫的基因组结构提供了基础信息。

This project was carried out to analyze genomes of Theileria parasites Eight hundred cDNA clones of Theileria parva was partially sequences to use as expressed sequence tags (ESTs). Some of them were mapped on chromosomes of T.parva. A bacterial artificial chromosome (BAC) library, each of which clones contained 50-200 kilobase pairs of T.parva chromosome fragments, was constructed.The library consisted of 3600 clones that theoretically covered entire T.parva genome. BAC clones that contained gene(s) essential for parasite growth including sporozoite surface protein were identified, which will be useful to analyze genome structures flanking these genes.4 chromosomes of T.sergenti were identified. Size of each chromosome and total genome size of this species was almost same as those of T.parva. Comparative mapping analysis of several homologous genes on T.parva and T.sergenti chromosomes revealed that syntenies among some of the genes are not conserved, which indicated difference of genome structures between these two Theileria species.Although further studies are required to determine whole chromosome structure of T.parva, the results of this project provide a basal information about genome structures of Theileria parasite by establishing BAC library, obtaining ESTs, and comparing two theilerial genomes.