Development of new defense systems in mosquito for West, Nile virus infection in Japan

本研究的目的是通过阐明JNK的生物学功能来建立控制蚊虫生长的方法，并在此基础上开发一种新的杀虫剂。2003年和2004年的研究阐明了以下几点：1.在蚊子培养细胞中，通过暴露JNK抑制剂(SP600125)对白纹伊蚊一龄幼虫的生长抑制作用，证实了JNK具有抗细胞凋亡的功能。2.通过向蚊子细胞中加入脂多糖(LPS)观察到JNK的激活，并发现了一个新的基因，该基因编码抗菌肽，3.对siRNA的转染方法进行了考察，以评价JNK的功能。尽管向三龄幼虫注射针对JNK的siRNA会导致蚊子生长减慢，但不可能适用于大量幼虫的显微注射方法。在此基础上，对siRNA的制备方法进行了改进，建立了siRNA的转染法。在含有真菌来源的强效几丁质酶抑制剂的培养液中培育出一龄幼虫，两种培养液对其生长均有抑制作用。编码抑制物的基因目前正在鉴定中。在这项研究中，我们澄清了JNK在蚊子中扮演着重要的角色。此外，有效的几丁质酶抑制剂对蚊子的生长也有抑制作用。

The purpose of this research is establishment the method of controlling mosquito's growth by clarifying biological functions of JNK, and development of a new insecticide based on this fundamental research.The following were clarified from the research in 2003 and 2004.1.It was succeeded in the obstruction of growth by exposing a JNK inhibitor (SP600125) to first instar larvae of Aedes albopictus In mosquito cultured cell, JNK was confirmed to have a function of anti-apoptosis.2.JNK was observed the activation by adding Lipopolysaccharide(LPS) to mosquito cells, and a novel gene, which should code anti-bacterial peptide, was discovered from the cells.3.The transfection method of siRNA was examined for evaluating the function of JNK. Although inicroinjection siRNA against JNK to third instar larvae lead to decrease growth of mosquito, it was impossible to handle microinjection method to a lot of larvas. Then, we tried to improve the method of siRNA using reagents for transfection. However, we could not obtain superior to the microinjection method.4.First instar larvae was bred in the culture medium containing potent insect chitinase inhibitors of fungal origin, and the growth was obstructed by two kinds of culture medium. The gene that codes the inhibitors is now under identification.In this research, we clarified that JNK plays important roles in mosquito. Moreover, potent inhibitors of chitinase are useful for inhibition growth of mosquito.