Immune response by insect eggs to parasitism

虽然昆虫幼虫和成虫对寄生虫表现出免疫反应是众所周知的，但昆虫卵只是最近才被证明可以通过免疫反应成功地科普寄生虫。结果表明，赤眼蜂寄生烟草天蛾卵后，一些免疫相关基因的转录被迅速诱导，而另一些则先被抑制后被诱导。约36%的寄生M.发现Sexta卵在寄生后存活。其他实验室先前的研究表明，昆虫幼虫或成虫的免疫挑战可能会积极影响对后来挑战的免疫反应。关于这种免疫启动效应的机制知之甚少。也不知道昆虫卵的免疫反应是否会受到这种引发的影响。本项目旨在阐明（1）是否可以用M. sexta雌性影响其卵对寄生虫的免疫反应。进一步的研究将解决鸡蛋的免疫挑战是否会导致对随后挑战的免疫反应的启动效应的问题。我们将探讨以下问题：（2）幼M. sexta eggs，T. evanescens影响对卵进一步寄生（过寄生）的免疫应答;在卵寄生中存活下来的Sexta幼虫对Cotesia congregata的幼虫寄生表现出其他免疫反应，而不是在胚胎发育过程中没有受到卵寄生蜂挑战的幼虫。通过定量真实的时间RT-PCR测定免疫相关基因的转录水平来研究免疫应答。

While insect larvae and adults are well known to show immune responses to parasitism, insect eggs have only recently been demonstrated to successfully cope with parasitoids by immune reactions. We showed that parasitization of Manduca sexta eggs by the parasitoid Trichogramma evanescens induces quickly transcription of some immune relevant genes, while others are first suppressed and induced later. About 36% of parasitized M. sexta eggs were found to survive parasitism. Previous studies by other labs showed that immune challenging of insect larvae or adults may positively affect immune responses to later challenges. Little is known about the mechanisms of such immune priming” effects. Neither is known whether immune responses of insect eggs can be affected by such priming . This project aims to elucidate (1) whether an immune challenge of M. sexta females affects immune responses of their eggs to parasitism. Further studies will address the question whether an immune challenge of eggs can result in priming effects on immune responses to later challenges. We will investigate the questions (2) whether parasitization of young M. sexta eggs by T. evanescens affects immune responses to further egg parasitism (superparasitism), and (3) whether M. sexta larvae that survived egg parasitism show other immune reactions to larval parasitization by Cotesia congregata than larvae that have not been challenged by egg parasitoids during their embryonic development. Immune responses will be studied by determination of transcription levels of immune relevant genes by quantitative real time RT-PCR.