疟疾是严重危害人类健康的三大传染病之一，恶性疟原虫是导致人类疟疾感染毒力最强、致死率最高的疟原虫虫种。疟原虫病原相关基因表达多变，而目前人们对其基因表达调控机制的认识还很匮乏。疟原虫缺乏内源性microRNA这一广泛存在于真核生物中的调节性小非编码RNA，提示有其它类型ncRNA发挥关键调控作用。本课题前期工作系统地分析和鉴定了红内期恶性疟原虫长度在50-500nt之间的ncRNA(is-ncRNA)，共获得1,198条新is-ncRNA。本研究将利用piggyBac转座子系统筛选is-ncRNA敲除虫株，进一步研究特定is-ncRNA的功能。通过比较敲除虫株和正常虫株在转录组和蛋白质组方面的差异鉴定is-ncRNA的靶基因，明确is-ncRNA对红内期恶性疟原虫基因表达的调控作用。该研究将加深人们对疟原虫基因表达调控机制的了解，为抗疟药靶点和疟疾疫苗的研发提供新思路。

Malaria remains one of three most severe human infectious diseases worldwide, and the unicellular eukaryote, Plasmodium falciparum (P. falciparum), is the etiological agent of the most virulent and lethal form of malaria in human. The expression of the pathogeny related genes is variable. However, little is known about the gene expression regulation mechanisms of the parasite. Existing studies suggest that microRNAs, which are small regulatory ncRNAs that have been identified and characterized as vital components in most eukaryotic organisms, have not yet been discovered in P. falciparum by traditional cloning and sequencing methods. During the preliminary work in our lab, ncRNAs ranging from 50-50 nt in lenth, referred as intermediate-size ncRNA (is-ncRNA), of the intraerythrocytic P. falciparum had been identified and analyzed systematically. A total of 1,198 novel is-ncRNA candidates were obtained. In this study, P. falciparum strains with is-ncRNA(s) knocked out will be selected using the piggyBac transposon system and the function of particular is-ncRNAs will be studied. Target genes of the is-ncRNAs will be identified by comparing the differences between the is-ncRNA knocked out and normal P. falciparum strains in both the transcriptomics and proteomics. Functionalizing the is-ncRNA space will elucidate the regulatory roles of the is-ncRNAs in development of the intraerythrocytic P. falciparum. This study will undoubtedly help better understanding of the gene expression regulation mechanisms of the parasite and will lead to important insight about development of the antimalarial drugs and malaria vaccines.