Zerknüllt基因调控飞蝗浆膜和浆膜表皮形成的分子机制研究

有翅昆虫出现了完整的浆膜及其分泌的浆膜表皮，是卵适应陆地环境的重要结构。它们的形成受同时期起源于Hox3的同源基因Zerknüllt（zen）调控，但具体机制未知。申请人发现：直翅目农业害虫飞蝗有完整的浆膜和浆膜表皮，有1个Lmzen调控浆膜细胞多核化和几丁质合成酶表达，从而影响浆膜和浆膜表皮形成。在此基础上，围绕转录因子LmZen调控浆膜和浆膜表皮形成的分子机制，本研究拟：（1）利用荧光标记zen的转基因飞蝗和实时成像技术，阐明Lmzen时空表达与浆膜和浆膜表皮形成的关系；（2）利用分阶段胚胎dsRNA注射，分别解析Lmzen影响浆膜和浆膜表皮形成的表型和关键基因；（3）结合RNA-seq和ChIP-seq，在转录调控水平揭示LmZen调控浆膜细胞多核化基因和几丁质合成酶基因的分子机制，进而与家衣鱼比较zen调控机制的异同。研究结果将为昆虫胚胎发育和卵期害虫防治研究提供新的思路和策略。

The serosa and its secreted serosal cuticle surrounding the yolk and embryo emerged in the ancestors of winged insects, and have been playing a key role in adapting to a terrestrial environment. The differentiation of the serosa and the formation of serosal cuticle are regulated by the gene Zerknüllt (zen), which originated from Hox3 in the ancestors of winged insects. However, its molecular function remains elusive. Locusta migratoria, a hazardous agricultural pest and research model in insect metamorphosis, has a complete serosa and serosal cuticle covering the whole embryo and yolk. In our previous research, Lmzen was found to regulate the differentiation of serosa cells by controlling the multinucleation of serosal cell and regulate serosal cuticle formation through affecting expression of cuticle related genes. In this research, we focus on the detailed molecular mechanisms of how Lmzen regulates serosa differentiation and serosal cuticle formation. First, zen transgenic locust and live imaging technology will be utilized to correlate the spatiotemporal expression of Lmzen, serosa differentiation and serosal cuticle formation. Then, embryonic RNAi for Lmzen will be used to inhibit its expression at different stages to clarify its function in serosa and serosal cuticle formation and the altered expression of the serosal cell multinucleation associated genes such as Lmfzr and serosal cuticle chitin synthases associated genes such as LmCHS1. Later, RNA-seq and ChIP-seq will be used to screen and identify the downstream genes of transcription factor LmZen and clarify its regulatory mechanism on target gene Lmfzr and LmCHS1 directly or indirectly in transcription molecular level. Finally, the zen regulatory mechanism will be investigated by comparative studies in Thermobia domestica to confirm whether it is conserved in insects with incomplete serosal and serosal cuticle outside the embryo. The findings in this project will provide novels ideas and strategies for insect embryonic development and pest control targeting the egg stage.