空间环境对家蚕胚胎发育的影响及变异机理的研究

The silkworm, Bombyx mori, is a lepidopteran model insect with economic importance. The silkworm is originated from China and has been cultivated for thousands of years as the contributor of sericulture. During the long-term domestication, the silkworm has acquired many unique characteristics such as short life cycle, high fecundity, moderate sizes which are suitable for rearing in a limited area such as space environment. The applicant participated in the project of SJ-10 recoverable satellite which carried silkworm embryos as one of 19 scientific experiments..Silkworm embryos were recovered from space successfully and part of silkworm embryos has been reared in the applicant’s laboratory. Preliminary experiments have been done to investigate influence of space environment on silkworm embryonic and post-embryonic development. .The current project is aiming to further investigation of the effect of space environment on silkworm embryonic development and subsequent mechanisms of mutagenesis. Using the embryos carried by SJ-10 satellite, we plan to investigate difference of embryos between space environment and ground control groups at genomic, transcriptional and translational levels. Furthermore, using the genetic manipulation technologies such as transposon-based transgenesis and the CRISPR/Cas9 system, we will perform functional analysis on selected key genes to exploit their functions in silkworm embryonic and post-embryonic development. These studies will not only contribute to modern sericulture, but also exploit how space environment affects silkworm embryonic development and provides fundamental knowledge and experimental approaches for future space life science.

项目申请人全程参加了实践十号返回式科学实验卫星项目，并利用实践十号返回式科学实验卫星开展了家蚕胚胎样品的搭载和回收工作。本项目拟利用前期实践十号返回式卫星搭载的家蚕胚胎样品，开展空间环境对家蚕胚胎发育的影响及变异机理的研究。家蚕是起源于我国的重要经济昆虫，经过长期的驯化，生活周期短、繁殖能力强、大小适中，能够在非常有限的空间内完成生命活动的全部过程，有利于开展空间环境下的各项科学实验。本项目拟在前期工作的基础上，对返回后续代饲养的家蚕进行各项生理指标的检测，同时对回收的胚胎样品开展进一步基因组、转录组、蛋白组等各方面的调查，挖掘太空环境和地面对照之间的差异表达基因，并利用转基因和基因组编辑等遗传操作技术对部分重要基因开展功能研究，以阐明空间环境影响家蚕胚胎发育的分子机制，为推进空间生命科学研究提供理论基础和实验保障。

在本基金资助下，我们成功开展了实践十号搭载以及地面模拟环境处理的家蚕胚胎发育进程和基因表达研究。研究结果相对完整地阐明了家蚕胚胎在空间环境下的基因变化规律，筛选和鉴定出一批在空间环境下影响家蚕胚胎发育的重要基因，并通过基因编辑等遗传操作手段获得了多个重要基因的敲除品系，开展了基因功能研究，揭示了易受空间环境影响的基因在家蚕胚胎发育中的重要作用，圆满完成了预期研究目标。主要成果有：1.揭示了hox基因及其辅因子Pb，Scr，Hh，exd，tsh等在家蚕口器和附肢发育中的重要作用；2.发现了苦味受体基因GR66在家蚕食物选择中起到的决定性作用，解答了“家蚕为什么爱吃桑叶”这样一个长久以来未知的科学问题，也为昆虫食性以及植物与昆虫的相互作用研究提供了新的视角; 3. 揭示了家蚕Bmznf-2在雄性性别决定过程中发挥了不可或缺的作用; 4. 揭示了 ITPR通路在昆虫水分稳态和发育中起到重要的调节作用。以上研究成果为培育适合空间环境饲养的家蚕新品种、以及未来利用家蚕进一步开展空间生命科学研究提供理论支撑和合适的实验素材。相关研究成果在PLoS Biology， Insect Biochemistry and Molecular Biology，Frontiers in Physiology，Insect Science等期刊上发表SCI论文5篇。