Cell type-specific epigenomic analysis in the developing heart

The molecular mechanisms governing heart development provide an important framework to understand congenital heart disease. The embryonic vertebrate heart tube develops an atrioventricular canal that divides the atrial and ventricular chambers, forms atrioventricular conduction tissue and organizes valve development. To better understand the molecular mechanism underlying atrioventricular canal versus chamber myocardium expression, a double-reporter transgenic mouse line was generated in which the expression of EGFP (green fluorescent protein) and Katushka (red fluorescent protein) are selectively expressed in the atrioventricular canal and in the chamber myocardium, respectively. We assessed the genome-wide H3K27ac pattern in isolated embryonic AV canal and in chamber cardiomyocytes, respectively. Overall design: EGFP and Katushka-positive cells were purified by FACS and fixed. ChIP was performed with the truemicro ChIP (Diagenode) according to the manufacturer's protocol using the H3K27ac antibody (abcam ab4729). Chipped DNA were subjected to library preparation using the 5500 Series SOLiD™ Systems ample preparation kit (Applied Biosystems) according to manufactures recommendations and sequenced using the 5500 wildfire system (SOLiD).