GSE120237
Genome-wide chromatin accessibility profile of zebrafish cardiomyocytes throughout heart development
By using transgenic zebrafish lines Tg(nxk2.5:GFP) (Witzel et al. 2012) and Tg(myl7:EGFP) (D'Amico et al. 2007), we have characterized  chromatin accessibility of FACS-isolated CM (GFP+) from developing zebrafish heart at 24, 48 and 72 hpf, corresponding to heart tube formation, chamber formation and differentiation and heart maturation, respectively. GFP- cells were used as a control. We have identified cardiac regulatory networks playing a crucial role in heart morphogenesis. To validate their importance in heart development, we employed zebrafish mutants of cardiac transciption factors Gata5, Hand2 and Tbx5a, the disruption of which were previously linked to impaired migration of the cardiac primordia to the embryonic midline, reduced number  of  myocardial  precursors and failure of heart looping, respectively (Reiter et al. 1999; Yelon et al. 2000; Garrity et al. 2002). ATAC-seq was performed from homozygous gata5tm236a/tm236a, tbx5am21/ m21, hand2s6/s6 mutant 72 hpf embryos in Tg(myl7:EGFP) genetic background. Homozygous mutant embryos for analyses were selected on the basis of their phenotypes of cardia bifida (gata5tm236a/tm236a, hand2s6/s6) or heart-string (tbx5am21/ m21) . Overall design: Examination of chromatin accessibility maps of cardiomycytes at 3 stages of heart development