飞蝗变态前后脂肪体细胞功能发生转变的分子机制研究

昆虫脂肪体相当于脊椎动物的肝脏和脂肪组织，在昆虫的变态过程，脂肪体经历了从主要执行能量储存与代谢到大量合成蛋白质的功能转变，但是其分子调控机制仍不明确。飞蝗属于不完全变态昆虫，保幼激素具有在幼虫中拮抗蜕皮激素调控昆虫的变态和在成虫中促进生殖的双重功能，我们发现飞蝗幼虫脂肪体在保幼激素类似物的诱导下不能合成大量的卵黄原蛋白，而成虫脂肪体在保幼激素类似物的诱导下则具备合成大量卵黄原蛋白的能力。本项目通过对雌性飞蝗若虫和成虫的脂肪体进行转录组测序和KEGG信号通路分析，比较若虫脂肪体和成虫脂肪体中的差异表达基因，挑选出在成虫高表达的与细胞器合成相关的基因作为候选基因，利用RNA干扰技术结合表型观察，鉴定候选基因中调控细胞器合成且促进卵黄发生的关键基因；利用定量PCR、免疫组织化学、荧光素酶检测和染色质免疫沉淀等技术，建立激素与关键基因的调控关系，进一步完善保幼激素调控飞蝗卵黄发生的分子机制。

Insect fat body is equivalent to the liver and adipose tissue of vertebrates. During the metamorphosis of insects, fat body has undergone the functional transformation from mainly performing energy storage and metabolism to synthesizing a large number of proteins, but its molecular regulation mechanism is still unclear. Locusta migratoria belongs to incomplete metamorphosis insects. Juvenile hormone has dual functions of antagonizing ecdysone in larvae, regulating insect metamorphosis and promoting reproduction in adults. We found that larval fat body can‘t synthesize a lot of vitellogenin under the induction of juvenile hormone analogues, while adult fat body can synthesize a lot of vitellogenin under the induction of juvenile hormone analogues. In this project, transcriptome sequencing and KEGG signal transduction analysis of fat body in nymph and adult females of the locusts migratory, comparing the differentially expressed genes in nymph and adult fat bodies, and the genes associated with organelle synthesis were selected as candidate genes. The RNA interference technique combined with phenotypic observation was used to identify the candidate genes that regulate organelle synthesis and promote their synthesis. By using quantitative PCR, immunohistochemistry, luciferase detection and chromatin immunoprecipitation techniques, we established the regulatory relationship between JH and key genes, and further improved the molecular mechanism of juvenile hormone regulating the vitellogenesis of Locusta migratoria.