Enhancer activation by FGF signalling during otic induction

We report that FGF exposure of sensory progenitors (pPPR) leads to rapid deposition of active chromatin marks H3K27ac near hundreds of FGF-responsive, otic-epibranchial progenitor (OEP) genes, while H3K27ac is depleted in the vicinity of non-otic genes. Genomic regions that gain H3K27ac act as cis-regulatory elements controlling OEP gene expression in time and space and define a unique transcription factor signature likely to control their activity. Thus, during ear induction FGF signalling modifies the chromatin landscape to promote enhancer activation and chromatin accessibility. Examination of 2 different histone modifications in Cnt and FGF2 treated posterior pre-placodal (pPPR) explants.

本研究报道：对感觉前体细胞（posterior pre-placodal region, pPPR）施加成纤维细胞生长因子（Fibroblast Growth Factor, FGF）处理后，会在数百个FGF响应性听-鳃弓前体（otic-epibranchial progenitor, OEP）基因附近快速沉积组蛋白H3第27位赖氨酸乙酰化（H3K27ac）标记，而在非听源性基因的邻近区域则出现H3K27ac的缺失。获得H3K27ac修饰的基因组区域可作为顺式调控元件，在时间与空间维度上调控OEP基因的表达，并定义了一组可能调控其活性的独特转录因子特征。因此，在耳诱导过程中，FGF信号通路通过重塑染色质组构，促进增强子激活与染色质开放。本研究检测了对照组（Cnt）与成纤维细胞生长因子2（FGF2）处理的后置原基板（pPPR）外植体中的两种不同组蛋白修饰。