CTCF counter-regulates cardiomyocyte development and maturation programs in the embryonic heart [RNA-seq]

Analysis of chromatin architecture suggests that the 3D structure of the genome plays a major role in regulating gene expression, orchestrating the compartmentalization of chromatin and facilitating specific enhancer-promoter interactions. However, the mechanisms that control this structuring of the genome are not fully understood. We have addressed this issue by analyzing the role of CTCF, a major architectural factor in chromatin structure, in the embryonic heart. Loss of CTCF triggered an overall downregulation of the cardiac developmental program, suggesting that CTCF facilitates enhancer-promoter interactions in the developing heart. Detailed analysis of the IrxA gene cluster showed that CTCF loss leads to disruption of the heart-specific regulatory domain that surrounds Irx4, resulting in changes in expression of IrxA cluster genes and neighboring genes. In contrast to the critical role proposed for CTCF in organizing large-scale chromatin domains, our results show that CTCF preferentially mediates local regulatory interactions. Overall design: RNAseq of mouse embryonic E10.5 hearts in three conditions: 1) control (labeled as WT), 2) heterozygous (labeled as HET) and 3) homozygous (labeled as KO). Three replicates were performed for each condition, each consisting of a pool of 6 hearts. Tissue was mechanically disaggregated and RNA extracted with trizol and purified through columns.

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Gomez-Velazquez M, Badia-Careaga C, Lechuga-Vieco AV, Nieto-Arellano R, Tena JJ, Rollan I, Alvarez A, Torroja C, Caceres EF, Roy AR, Galjart N, Delgado-Olguin P, Sanchez-Cabo F, Enriquez JA, Gomez-Skarmeta JL, Manzanares M