DNA高级结构对家蚕胚胎发育的表观遗传调控

核酸上鸟嘌呤（G）或胞嘧啶（C）连续重复出现，可分别形成G4或i-motif非双螺旋高级结构。DNA高级结构参与基因转录调控属新的表观遗传调控机制。保证胚胎发育整齐出蚕一致是蚕业生产一个重要问题。我们前期发现，家蚕基因组中大量存在G4和i-motif，且转录因子BmPOUM2上的高级结构及其结合蛋白参与了胚胎发育。本项目将围绕DNA高级结构调控家蚕胚胎发育开展5个方面研究：（1）BmPOUM2参与调控家蚕胚胎发育的分子机理；（2）DNA高级结构结合蛋白BmLARK和BmILF参与调控家蚕胚胎发育的分子机理；（3）家蚕胚胎发育过程全基因组DNA高级结构鉴定分析；（4）DNA高级结构对家蚕胚胎发育表观遗传调控机理分析；（5）针对DNA高级结构调控家蚕胚胎发育的小分子化合物筛选。研究结果有助于揭示DNA高级结构对基因表观遗传的调控机制，并为解决生产中胚胎发育整齐，孵化一致提供理论指导和技术支持。

When multiple guanines (G) or cytosines (C) are present repeatedly and tandemly in DNA (or RNA) molecules, G-quadruplex (G4) or i-motif secondary structures can be formed. DNA secondary structures are found to be involved in the regulation of gene transcription, which is a new epigenetic regulatory mechanism. It is a critical issue in silkworm production that the uniform embryonic development and egg hatching are ensured. We have found that there are lots of secondary structures, such as G4 and i-motif, in the silkworm genome and the secondary structures in the promoter of transcription factor BmPOUM2 gene and their binding proteins are involved in the embryonic development of the silkworm. In this project, we will investigate the epigenetic regulation of embryonic development by secondary DNA structures in the silkworm by conducting the following five contents: (1) Molecular mechanism of transcription factor BmPOUM2 involving in the regulation of embryonic development. (2) Molecular mechanism of G4 and i-motif binding proteins BmLARK and BmILF involving in the regulation of embryonic development. (3) Identification and analysis of the secondary structures in the genomic DNA during the embryonic development. (4) Epigenetic regulatory mechanism of DNA secondary structures in the embryonic development. (5) Screening and analysis of small molecular compounds targeting DNA secondary that regulate embryonic development. The results of study should be helpful to reveal the epigenetic molecular mechanism of gene transcription by DNA secondary structures. It will also provide theoretical guidance and technical support for ensuring the uniform embryonic development and egg hatching in silkworm production.