20E诱导家蚕抗菌肽CecropinB6的上调表达  

Upregulation of CecropinB6 expression was triggered by 20E in silkworm,Bombyx mori

作　　者：王禹生 田小利[1] 肖阳[2] 张杰[1] 梁宽 黄浩贤 邓小娟[1] WANG Yu-Sheng;TIAN Xiao-Li;XIAO Yang;ZHANG Jie;LIANG Kuan;HUANG Hao-Xian;DENG Xiao-Juan(Guangdong Provincial Key Laboratory of Agro-animal Genomics and Molecular Breeding/Guangdong Provincial Sericulture and Mulberry Engineering Research Center,College of Animal Science,South China Agricultural University,Guangzhou 510642,China;The Sericultural and Agri-Food Research Institute of the Guangdong Academy of Agricultural Sciences,Guangzhou 510610,China)

机构地区：[1]华南农业大学动物科学学院/广东省农业动物功能基因组学与分子育种重点实验室/广东省蚕桑工程技术研究中心,广州510642 [2]广东省农业科学院蚕业与农产品加工研究所,广州510610

出　　处：《环境昆虫学报》2023年第5期1306-1317,共12页Journal of Environmental Entomology

基　　金：广东省自然科学基金(2019A1515011533)。

摘　　要：蜕皮激素(20-hydroxyecdysone,20E)是调控昆虫发育的重要激素,在昆虫的蜕皮和变态中起关键作用。近年来的研究表明,20E也调控昆虫抗菌肽的表达,揭示昆虫的发育和免疫之间具有重要的联系。家蚕是重要的经济昆虫,家蚕抗菌肽对蜕皮激素(20E)的应答及其调控机制仍有待研究。本文利用20E注射家蚕5龄第3天幼虫,qRT-PCR结果表明20E处理的脂肪体中抗菌肽CecropinB6基因(BmCecB6)的表达上调。通过对抗菌肽BmCecB6上游启动子的截短和双荧光素酶活性分析,结果显示BmCecB6响应20E的调控位点在启动子-448~-170区域,该区域内存在潜在的FoxO、E74A和BR-C等结合位点。本研究表明20E抑制了ILS通路水平,暗示ILS下游的转录因子FoxO被激活。进一步对BmCecB6的启动子进行FoxO结合位点的缺失突变,双荧光素酶检测结果表明20E对BmCecB6的诱导活性并没有丧失,推测BmCecB6对20E的应答不是通过转录因子FoxO结合BmCecB6启动子中的顺式调控元件直接调控的。20E激活BmCecB6表达的分子调控机制还需要进一步深入研究。20-hydroxyecdysone(20E)is an important hormone involved in insect development and it plays a key role in insect molting and metamorphosis.Recent studies have shown that 20E also regulates the expression of antimicrobial peptides(AMPs),revealing the crosstalk between insect development and immunity.Silkworm is an important economic insect.The expression of AMPs in response to 20E in silkworm and the regulatory mechanism remain to be studied.In this study,we showed by qRT-PCR that the expression of CecropinB6(BmCecB6)gene in the fat body was upregulated when 20E was injected into the hemocoel of the 3 rd day of 5 th instar silkworm larvae.Then a series of BmCecB6 truncated promoters were constructed and analyzed for their transcriptional activities by Dual-luciferase reporter assays.The results showed that the 20E responsive elements were located in the promoter region between-448 and-170 bp,which contains potential DNA binding sites for FoxO,E74A and BR-C transcription factors.Our study showed that 20E inhibited the level of the ILS pathway,suggesting that FoxO,the transcription factor downstream of the ILS pathway,was activated.The Dual-luciferase activity results showed that the mutated BmCecB6 promoter,in which the potential FoxO binding sites were deleted,was still activated by 20E.Therefore,activation of BmCecB6 by 20E was not directly due to the binding of transcription factor FoxO to the cis-regulatory sites in the BmCecB6 promoter.The molecular mechanism of BmCecB6 expression in response to 20E needs to be further studied.

关 键 词：家蚕 蜕皮激素 抗菌肽 CECROPIN 调控 

分 类 号：Q963[生物学—昆虫学] S89[农业科学—特种经济动物饲养]