针对粘孢子虫病害频发、难防治、危害大损失重现状，从鲤鱼集约化养殖危害严重的吉陶单极虫病出发，在前期报道和我们组学研究表明蛋白酶在粘孢子虫组织入侵和营养代谢中重要性大的基础上，以14个预测的吉陶单极虫可分泌蛋白酶为研究对象，实时定量PCR筛选在营养体和孢子中高表达或表达差异大的可分泌蛋白酶，酶学性质研究分析高活性的可分泌蛋白酶，通过免疫印迹、免疫组化和免疫荧光共聚焦锁定在虫体表面或虫体外有分布的关键分泌蛋白酶；采用iTRAQ-TAILS定量N端蛋白组学方法鉴定关键分泌蛋白酶作用鱼寄主的寄主靶蛋白，通过酶解靶蛋白产物的质谱分析揭示分泌蛋白酶降解寄主靶蛋白机制；生物信息学预测靶蛋白功能， RNA干扰寄主靶蛋白结合转录组和蛋白组分析，在细胞水平上解析寄主靶蛋白所涉及的功能，阐明吉陶单极虫分泌蛋白酶作用鱼寄主的分子机制，为深入寄生虫与宿主互作研究、确证药靶及新药开发奠定基础，促进水产健康养殖。

In view of the situations for Myxosporean, such as frequent occurrence of diseases, difficult to control, great harm and heavy losses, this project will focus on Thelohanellus kitauei, one kind of Myxosporean which do great harm to intensive culture of carp. Based on previous study especially our genomics study, protease was shown to play a key role in tissue invasion and nutrition metabolism of Myxosporean. The predicted 14 secretory proteases of T. kitauei genome will be investigated, and the key secretory proteases, which are high-expression or high differential expression in the plasmodia and spore, will be screened by RT qPCR. High-activity secretory proteases will be screened by activity analysis. The distribution of these key secretory proteases in the T. kitauei or the infected tissues of carps will be investigated by Western blotting, immunohistochemistry and confocal immunofluorescence microscopy analysis. Host target proteins of secretory proteases will be determined by iTRAQ-TAILS. The degradation mechanism of host target proteins by secretory protease will be revealed by mass spectrometry of protease-digested productions. The function of host target proteins will be predicted by bioinformatics. The functions of host target proteins on cellular levels will be disclosed by RNA interferes and the transcriptional and proteomic analysis. The molecular mechanism of interaction between T. kitauei secretory protease and fish host will be elucidated. These research results will provide the basis for the in-depth study of host-parasite relationships, drug target validation and the new drug development against T. kitauei, which will promote healthy development in aquaculture.