[特邀报告]Development and Evolution of Drosophila Chromatin Landscape in a 3D genome context

Development and Evolution of Drosophila Chromatin Landscape in a 3D genome context
特邀报告

报告开始:5月14日 15:00:00 (Asia/Shanghai)

报告时间:20min

所在会议:[S4] 分会场四 [S4-2] 系统生物学、群体遗传学与分子进化

摘要
Chromatin states of genes and transposable elements (TEs) dictated by combinations of various histone modifications comprise key information for understanding the mechanisms of genome organization and regulation. However, little is known about the principles of their dynamic changes during development and evolution in a three-dimensional genome context. To address this, we study Drosophila pseudoobscura, a Drosophila model species that diverged from D. melanogaster about 25 million years ago. We collected 71 epigenomic datasets targeting 11 histone modification marks and 4 Hi-C datasets, and projected 15 chromatin states across four different developmental stages and two adult tissues. We estimate that before zygotic genome activation, 41% of the genome has already been deposited with histone modifications, while 20% of the rest genome switches from a ‘null’ state to an active/inactive chromatin state after the zygotic genome activation. Over two thirds of the genomic region exhibit at least one transition between different chromatin states during development. And such transitions on cis-regulatory regions are associated with tissue- or stage-specific formation of chromatin loops or topologically associated domain borders (TABs), as well as specific activation of gene expression. We further demonstrate that while evolutionarily young TEs are preferentially targeted by silencing histone modifications, old TEs are more frequently domesticated as TABs or specific enhancers that further contribute to the genome organization or local gene regulation. Interestingly, this trend is reversed on the newly evolved X chromosome in D. pseudoobscura, due to the acquisition of dosage compensation mechanism. Overall we characterize the developmental and evolutionary dynamics of Drosophila epigenomic states, and highlight the roles of certain TEs of different evolutionary ages in genome organization and regulation.
报告人
周琦
教授 浙江大学

周琦博士,浙江大学生命科学研究院长聘正教授,研究方向是动物性染色体演化历史、动物性别决定机制研究等。实验室开展演化与发育方面的各项交叉研究,运用前沿的新技术测序和生物信息的方法,进一步发展非模式物种中的基因组编辑技术,以期望可以在鸟瞰全基因组进化格局的同时,对特定基因和复杂性状进行功能刻画。周琦团队至今发表通讯作者论文22篇,Science, Nature, Nature Communications, Nature Ecology and Evolution, PNAS等杂志, 总论文引用次数超过5400次。获得国家自然科学基金优秀青年基金项目,牛顿高级访问学者项目和面上项目。