Molecular analysis of intraerythrocytic parasite population dinamics and acquirement of biological diversity

在东方泰勒虫感染牛的过程中，携带不同MPSP基因的寄生虫种群交替出现，这可能是东方泰勒虫的免疫逃避机制之一。因此，寄生虫种群的分析是重要的，在理解发病机制和发展控制方法。在这项研究中，退化凝胶电泳方法的分析寄生虫亚群在遗传水平上已经发展。应用该方法可检测C型等位基因MPSP基因内的突变。从牛和布法罗的血液样品中，这可能是不同的泰勒虫感染，通过rRNA基因靶向PCR分析，发现混合感染4个不同的物种。表达序列标签分析表明，T.本文还对蜱、哺乳动物和泰勒虫相互作用的唾液和唾液腺进行了研究。一些蛋白质及其基因，包括水泥蛋白，蛋白酶抑制剂已被确定。这些蜱蛋白中的一些可能影响宿主的保护性反应，并帮助寄生虫侵入哺乳动物宿主。

During the course of Theileria orientalis infection in cattle, parasite population bearing different major piroplasm surface protein (MPSP) genes appear by turns, which may be one of immune evasion mechanisms of the parasite. Therefore, analysis of parasite population is important in understanding pathogenesis and developing control methods.In this study, degenerated gel electrophoresis methods for the analysis of parasite subpopulations at genetic level has been developed. By using this method, mutations within MPSP gene of C-type allele could be detected. From blood samples from cattle and buffalo, which were possibly infected with different Theileria, species was analyzed by rRNA gene-targeted PCR analysis and revealed mixed infection with 4 different species. The expressed sequence tag analysis of T. parva and EST mapping on chromosomes was carried out and 461 ESTs have been mapped.We further focused on tick saliva and salivary glands where tick, mammals and Theileria interact. Several proteins and their genes including cement proteins, proteinase inhibitors have been characterized. Probably, some of these tick proteins affect host protective responses and help parasite to invade into mammalian hosts.