靶向鞘脂质代谢途径关键酶的miRNAs对褐飞虱生殖的调控机制

Sphingolipid metabolic pathway is one of the key signaling pathways in living organisms, which involves inseveral cellular functions such as growth and apoptosis. Our previous studies found that sphingolipid metabolic pathway have crucial influence on the reproduction of insects, and many microRNAs targeting the key enzymes in the sphingolipid metabolic pathway also have essential regulatory roles in reproductive process (especially the ovarian development). In this project, we will take the destructive agricultural insect pest, the brown planthopper, Nilaparvata lugens, as a working model, focusing on identification and selection of the miRNAs that can regulate the key enzymes for sphingolipid metabolic pathway, including Serine palmitoyltransferase, (SPT), Ceramidase (CDase), Ceramide synthase (CerS), sphingomyelin synthase (SMS), Ceramide-1-P kinase (CerK), sphingolipid phosphatase (SPP) and Sphingosine kinase (SPK). Through elucidatingthespatial-temporal distribution,cellular characteristics and physiological and ecological characterizations of miRNAs, we want tofind out their regulations duringthe vitellogenesis progress. Finally, a regulating network for the reproduction of the hemimetabolic insect integrating the miRNAs targeting the key enzymes in the sphingolipid metabolic pathway will be established.

鞘脂类代谢途径是生物体重要的信号转导途径之一，对细胞的生长和凋亡有重要调控作用。本课题组的前期研究发现鞘脂类代谢途径对昆虫的生殖和种群发展有重要的影响，而众多微小RNA(microRNA, miRNA)也以鞘脂类代谢的关键酶为靶标，对昆虫的生殖(特别是卵巢发育)产生影响。本项目以重大农业害虫褐飞虱Nilaparvata lugens为研究对象，通过筛选以褐飞虱鞘脂类代谢关键限速酶：丝氨酸棕榈酰转移酶(SPT)、神经酰胺酶(CDase)、神经酰胺合酶（CerS）、鞘磷脂合酶(SMS)、神经酰胺-1-磷酸激酶(CerK)、鞘氨醇-1-磷酸磷酸酶(SPPase)和鞘氨醇激酶(SPK)为靶标的miRNA，研究其时空动态分布、细胞学特征和生理生态学特征与生殖的关系，揭示其调控卵黄生成的一系列步骤，明确昆虫繁殖的鞘脂质信号的miRNA调控途径。

鞘脂类是真核细胞膜必不可少的、普遍存在的、具有生物活性的脂质成分，也是增殖、凋亡等生物过程的第二信使。筛选克隆出重大农业害虫褐飞虱繁殖的鞘脂质信号关键基因中性神经酰胺酶，研究关键代谢酶在褐飞虱的时空表达特征、系统发育关系、生化特征及其生理功能。分析三种水稻植食性昆虫的鞘脂质组成及其代谢酶基因，阐明了昆虫体内鞘脂类物质的种类、数量并构建昆虫鞘脂类化合物的定量系统。通过小RNA高通量测序鉴定褐飞虱不同生殖发育时期差异表达的miRNAs，明确褐飞虱雌虫生殖发育相关的miRNA，阐明miRNAs在褐飞虱生殖发育中的功能及其作用机制。从鞘脂质代谢途径辅以miRNA的角度揭示褐飞虱卵黄生成的信号调控机制，关注褐飞虱生殖发育学研究，为褐飞虱新型绿色防控策略奠定理论基础。