Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4051 Basel, Switzerland.
INSERM UMR 1121, Université de Strasbourg, Faculté de Chirurgie Dentaire, 8 rue Sainte Elisabeth, 67 000 Strasbourg, France.
Science. 2017 Mar 31;355(6332). doi: 10.1126/science.aal2913.
The cranial neural crest cells are multipotent cells that provide head skeletogenic mesenchyme and are crucial for craniofacial patterning. We analyzed the chromatin landscapes of mouse cranial neural crest subpopulations in vivo. Early postmigratory subpopulations contributing to distinct mouse craniofacial structures displayed similar chromatin accessibility patterns yet differed transcriptionally. Accessible promoters and enhancers of differentially silenced genes carried H3K27me3/H3K4me2 bivalent chromatin marks embedded in large -dependent Polycomb domains, indicating transcriptional poising. These postmigratory bivalent chromatin regions were already present in premigratory progenitors. At Polycomb domains, H3K27me3 antagonized H3K4me2 deposition, which was restricted to accessible sites. Thus, bivalent Polycomb domains provide a chromatin template for the regulation of cranial neural crest cell positional identity in vivo, contributing insights into the epigenetic regulation of face morphogenesis.
颅神经嵴细胞是多能细胞，可为头骨骼形成中胚层提供细胞，并对头面部形态发生起关键作用。我们分析了体内小鼠颅神经嵴亚群的染色质景观。对不同的小鼠颅面部结构有贡献的早期迁移后亚群表现出相似的染色质可及性模式，但转录上存在差异。差异沉默基因的可及启动子和增强子携带 H3K27me3/H3K4me2 双价染色质标记，嵌入在大依赖 Polycomb 结构域中，表明转录启动。这些迁移后的双价染色质区域在迁移前祖细胞中已经存在。在 Polycomb 结构域中，H3K27me3 拮抗 H3K4me2 的沉积，后者仅限于可及位点。因此，双价 Polycomb 结构域为颅神经嵴细胞在体内的位置身份的调控提供了染色质模板，为面部形态发生的表观遗传调控提供了见解。
