后生动物肠道拥有复杂的共栖、共生微生物群落。但宿主响应和调控这些微生物的动态变化以维持内稳态的机制很大程度上仍未知。果蝇由于肠道微生物较少，已经成为解读肠道与其微生物之间复杂相互作用的研究模型。我们利用RNAi技术结合从冈田绕眼果蝇（A.o）中筛选出与肠道微生物组负荷相关CCP 结构域基因（CCP），并在核酸及蛋白水平验证；结合转录组测序探索出：CCP-Arrestin-ERK/JNK 信号通路级联-Duox，影响 ROS 活性进而使宿主肠道微生物组负荷改变。本项目拟通过在A.o体内和体外敲低、敲除、过表达、挽救等实验佐证该通路；并研究其与CCP介导的 IMD-P38、Gaq-PLCβ-Ca2+ 及 Nox-ROS三条传导途径的免疫应答的互相关系；通路中各个元件的表达情况验证其体内系统性。本研究最终有望初步揭示CCP-Duox表达的微调机制及其如何参与调控A.o肠道共生菌与宿主之间的作用。

The metazoan gut harbors complex communities of commensal and symbiotic bacterial microbes. The mechanism that host developed to respond to and manage such dynamic changes to maintain homeostasis remain largely unknown. Flies have been modeled for studying the complex interaction between intestines and their microbes duing to they have less intestinal symbiotic species than mammalian. We first screened the Amiota okadai’s (A.o) genes related from the CCP-containing genes by RNAi technique, and verified the function at both mRNA and protein level. Combined with RNA-seq results, we revealed the CCP-Arrestin-ERK/JNK signaling cascade-Duox pathway, which affects the activity of ROS and changes gut microbiome load. Therefore, the knockdown and over-expression of the A.o in vivo and in vitro and the rescue of experiments will be executed in this project to further support this cascade. Then by studying the cross-correlation among CCP-mediated IMD and P38 pathway and CCP-mediated immune response of the Gaq-phospholipase Cβ-Ca2+ pathway and CCP-mediated Nox-ROS-mediated immune response. And the expression of each element in CCP was also observed to systematically verify the pathway in vivo. Finally, Our study will preliminary elucidate CCP-Duox expression of the fine-tuning mechanism, and how to regulate the interaction between A.o intestinal symbiotic bacteria and the host.