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. Overall design: Examination of 2 different histone modifications in Cnt and FGF2 treated posterior pre-placodal (pPPR) explants.