Met和Kr-h1基因在褐飞虱变态发育中的功能分析  

Function of Methoprene-tolerant and Krüppel-homolog 1 genes in metamorphosis in the brown planthopper,Nilaparvata lugens( Hemiptera:Delphacidae)

作　　者：姚云[1] 王博[1] 蒋建茹[1] 林欣大[1] 

机构地区：[1]中国计量学院生命科学学院,杭州310018

出　　处：《昆虫学报》2015年第11期1151-1159,共9页Acta Entomologica Sinica

基　　金：国家自然科学基金项目(31471771);浙江省自然科学基金项目(LY14C140002)

摘　　要：【目的】保幼激素受体Methoprene-tolerant(Met)控制保幼激素信号传导途径中重要下游转录因子Krüppelhomolog 1(Kr-h1)的表达,调控昆虫的变态发育。本研究旨在探究褐飞虱Nilaparvata lugens Met基因与Kr-h1在褐飞虱变态发育中的功能。【方法】利用PCR技术扩增Nl Met基因的ORF序列。通过RNA干扰技术分别或同时沉默褐飞虱若虫的Nl Met和Nl Kr-h1基因,进一步研究其功能。【结果】克隆得到Nl Met,其开放阅读框包含1 185 bp,编码395个氨基酸,包括b HLH,PAS-A,PAS-B和PAC 4个结构域;其中PAS-B和PAC保守性较高,而b HLH和PAS-A保守性相对较低。采用RNA干扰技术沉默Nl Met和Nl Kr-h1基因后发现,单独对4龄若虫Nl Kr-h1基因干扰后,若虫阶段及初羽化雌虫和雄虫死亡率均显著上升(P<0.05);对5龄若虫Nl Kr-h1基因干扰后只有若虫死亡率上升(P<0.05),单独对Nl Met基因干扰后死亡率没有显著变化(P>0.05);二者共同沉默后的死亡率同单独对Nl Kr-h1沉默时类似。此外,我们还发现单独对4龄若虫Nl Kr-h1干扰后在雌虫中出现了生殖器畸形,虽然Nl Met干扰并未出现生殖器发育畸形现象,但二者共同干扰后,在若虫、初羽化雌雄成虫中畸形比例均显著增加(P<0.05)。【结论】Nl Met与下游转录因子Nl Kr-h1对褐飞虱变态发育起到重要作用,影响若虫到成虫的变态和外生殖器的发育。本研究有助于揭示Nl Met和Nl Kr-h1在昆虫变态发育中的重要作用。[Aim ] The receptor of juvenile hormone（ JH）,methoprene-tolerant（ Met）,activates Krüppel-homolog 1（ Kr-h1）,a key transcription factor in JH signaling pathway. Met plays a crucial role in insect metamorphosis. The aim of this study is to explore the functions of Nl Met and Nl Kr-h1 in metamorphosis in the brown planthopper,Nilaparvata lugens. [Methods ] An opening reading frame（ ORF） of Nl Met was cloned from N. lugens by PCR. The mRNA expression levels of Nl Met and/or Nl Krh1 were down-regulated by RNAi, and the effects of RNAi on metamorphosis and external genital morphology were observed. [Results]The open reading frame of Nl Met is 1 185 bp in length,encoding 395 amino acids. The Nl Met protein contains four domains,i. e.,b HLH,PAS-A,PAS-B and PAC. PAS-B and PAC are highly conserved,whereas the other two show relative lower similarities. By disruption of Nl Met and Nl Krh-1 expression singly or both in the same time by RNAi in N. lugens,we found that downregulating Nl Kr-h1 in the 4th instar nymphs significantly increased the mortality of nymphs and the newly emerged male and female adults（ P〈0. 05）. After interference of Nl Kr-h1 in the 5th instar nymphs,only the mortality of nymphs significantly increased（ P〈0. 05）,while after interference of Nl Met in the 5th instar nymphs,the mortality of nymphs had no significant change（ P〉0. 05）. After interference of both genes,the change tendency of mortality was similar to that after interference of Nl Kr-h1. Furthermore,we found that Nl Kr-h1 RNAi caused abnormity in female external genitalia. Although we found no visible abnormity of the external genitalia after inference with Nl Met,the abnormity rate of the external genitalia increased significantly when both genes were silenced. [Conclusion]Nl Met cooperates with the downstream transcription factor and has an important role in both metamorphosis and external genitalia development of N. lugens. Our study helps to understand the function of the Nl Met and Nl Kr-h1 genes in metamo

关 键 词：褐飞虱 变态 保幼激素受体基因 保幼激素信号途径 RNA干扰 

分 类 号：Q966[生物学—昆虫学]