Drosophila neural development undergoes extensive chromatin remodeling and precise epigenetic regulation. However, the roles of chromatin remodeling in establishment and maintenance of cell identity during cell fate transition remain enigmatic. Here, we compared the changes in gene expression, as well as the dynamics of nucleosome positioning and key histone modifications between the four major neural cell types during Drosophila neural development. We find that the neural progenitors can be separated from the terminally differentiated cells based on their gene expression profiles, whereas nucleosome distribution in the flanking regions of transcription start sites fails to identify the relationships between the progenitors and the differentiated cells. H3K27me3 signal in promoters and enhancers can not only distinguish the progenitors from the differentiated cells but also identify the differentiation path of the neural stem cells (NSCs) to the intermediate progenitor cells to the glial cells. In contrast, H3K9ac signal fails to identify the differentiation path, although it activates distinct sets of genes with neuron-specific and glia-related functions during the differentiation of the NSCs into neurons and glia, respectively. Together, our study provides novel insights into the crucial roles of chromatin remodeling in determining cell type during Drosophila neural development.

中文翻译：

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顺式调控元件中的H3K27me3信号揭示了果蝇神经胶质发育过程中祖细胞的分化潜能。

果蝇的神经发育经历了广泛的染色质重塑和精确的表观遗传调控。然而，染色质重塑在细胞命运转变过程中建立和维持细胞特性中的作用仍然是个谜。在这里，我们比较了果蝇神经发育过程中四种主要神经细胞类型之间基因表达的变化，以及核小体定位和关键组蛋白修饰的动力学。我们发现神经祖细胞可以根据其基因表达谱与终末分化细胞分离，而转录起始位点侧翼区域中的核小体分布无法识别祖细胞与分化细胞之间的关系。启动子和增强子中的H3K27me3信号不仅可以将祖细胞与分化细胞区分开，而且还可以识别神经干细胞（NSC）到中间祖细胞到神经胶质细胞的分化途径。相反，尽管H3K9ac信号在NSCs分别分化为神经元和神经胶质细胞时激活具有神经元特异性和神经胶质细胞相关功能的基因的不同集合，但它无法识别分化路径。总之，我们的研究为果蝇神经发育过程中染色质重塑在确定细胞类型中的关键作用提供了新颖的见解。尽管它在NSC分别分化为神经元和神经胶质细胞时激活具有神经元特异性和神经胶质细胞相关功能的基因的不同集合。总之，我们的研究为果蝇神经发育过程中染色质重塑在确定细胞类型中的关键作用提供了新颖的见解。尽管它在NSC分别分化为神经元和神经胶质细胞时激活具有神经元特异性和神经胶质细胞相关功能的基因的不同集合。总之，我们的研究为果蝇神经发育过程中染色质重塑在确定细胞类型中的关键作用提供了新颖的见解。