REAGENT or RESOURCE	SOURCE	IDENTIFIER
Antibodies
H3K27ac	Abcam	Cat# ab4729; RRID: AB_2118291
H3K27ac	Cell Signaling Technology	Cat# 8173S; RRID: AB_10949503
NKX2-5	R&D	Cat# AF2444; RRID: AB_ 355269
Rabbit Control IgG antibody	ABclonal	Cat# AC005; RRID: AB_ 2771930
Cardiac Troponin I	Abcam	Cat# ab56357; RRID: AB_ 880622
WGA	Invitrogen	Cat# w32464; RRID: AB_ 2924839
PH3	Cell Signaling Technology	Cat# 9701S; RRID: AB_ 2924838
Bacterial and virus strains
Bl21 (DE3)	TransGen Biotech	Cat# CD601
Trans5α Chemically Competent Cell	TransGen Biotech	Cat# CD201
Chemicals, peptides, and recombinant proteins
Formaldehyde Solution	SIGMA	Cat# F8775-500ML
Glycine	AMRESCO	Cat# 0167-1KG
Phosphate Buffered Daline (PBS)	Hyclone	Cat# SH30256.01
HBSS, no Calcium, no Magnesium, no Phenol Red	Gibco	Cat# 14175103
Sodium butyrate	SIGMA	Cat# 303410-100G
Ampicillin Na	AMRESCO	Cat# VT0236
IPTG	INALCO	Cat# 1758-1400
HEPES free acid	AMRESCO	Cat# 0511-1KG
Potassium hydroxide (KOH)	XiLong SCIENTIFIC	Cat# 1310-58-3
Sodium chloride (NaCl)	SIGMA	Cat# S7653
Glycerol	SIGMA	Cat# 49767-100ML
CA-630	SIGMA	Cat# 56741
Triton X-100	SIGMA	Cat# T8787-50ML
EDTA-free Protease Inhibitor Cocktail	Roche	Cat# 04693132001
Phenyl Methane Sulfonyl Fluoride (PMSF)	AMRESCO	Cat# 0754-5G
Poly(ethyleneimine) solution (PEI)	SIGMA	Cat# P3143-100ML
Ni-NTA Agarose	QIAGEN	Cat# 30210
Imidazole	SIGMA	Cat# 792527-100G
EDTA DISODIUM SALT DIHYDRATE	AMRESCO	Cat# 0105-1KG
Dithiothreitol (DTT)	INALCO	Cat# 1758-9030
TRIS	AMRESCO	Cat# 0497-5KG
TAPS	SIGMA	Cat# T-5130
Magnesium chloride solution (MgCl2)	SIGMA	Cat# 68475-100ML
N,N-Dimethylformamide (DMF)	SIGMA	Cat# D4551-250ML
SODIUM DODECYL SULFATE (SDS)	AMRESCO	Cat# 0227-1KG
Spermidine	SIGMA	Cat# S2501-1G
BioMag Plus Concanavalin A	Bangs Laboratories	Cat# BP531
Potassium chloride (KCl)	XiLong SCIENTIFIC	Cat# 7447-40-7
Calcium chloride dihydrate (CaCl2)	XiLong SCIENTIFIC	Cat# 10035-04-8
Manganese (II) chloride tetrahydrate (MnCl2)	XiLong SCIENTIFIC	Cat# 13446-34-9
Digitonin	SIGMA	Cat# D141-500MG
Bovine Serum Albumin	SIGMA	Cat# A1933-100G
Proteinase K	AMRESCO	Cat# 0706-100MG
KAPA HiFi HotStart ReadyMix	BIOSYSTEMS	Cat# KM2602
AMPure XP	BECKMAN COULTER	Cat# A63881
MboI	NEB	Cat# R0147M
T4 DNA ligase	NEB	Cat# M0202S
T7 RNA polymerase	Roche	Cat# 10881767001
DIG RNA labeling mix	Roche	Cat# 11277073910
TRIzol	Thermo Fisher	Cat# 15596018
Critical commercial assays
cDNA synthesis kit	Vazyme	Cat# R223-01
AceQ Universal SYBR qPCR Master Mix	Vazyme	Cat# R511-02
TIANquick Mini Purification Kit	TIANGEN	Cat# DP203-02
Deposited data
Raw and analyzed data	This paper	Database: GSE133760
Single cell RNA-seq for E7.25-E9.25 heart cells	Xiong et al.57	Database: GSE108963
RNA-seq data for E8.25 hearts	ENA	Database: ERR332388
RNA-seq data for E9.5 hearts	Papoutsi et al.58	Database: GSE104670
RNA-seq data for E12.5 hearts	Rahmanian et al.59	Database: GSE82471
RNA-seq data for E16.5 hearts	Rahmanian et al.59	Database: GSE78317
H3K27ac ChIP-seq data for E12.5 hearts	The ENCODE Project Consortium	Database: GSE82449
H3K27ac RNA-seq data for E16.5 hearts	The ENCODE Project Consortium	Database: GSE82973
NKX2-5 ChIP-seq data for E9.5 hearts	Wang et al.60	Database: GSE129335
NKX2-5 ChIP-seq data for E11.5 hearts	Dupays et al.50	Database: GSE44576
E8.25 Hi-C	figshare	Database: https://doi.org/10.6084/m9.figshare.22300177
Oligonucleotides
See Table S1 for primer sequence used in this study	N/A	N/A
Software and algorithms
Bowtie2	Langmead et al.61	http://bowtie-bio.sourceforge.net/bowtie2/index.shtml; RRID:SCR_016368
Samtools	Li et al.62	http://www.htslib.org/; RRID:SCR_002105
BEDTools	Quinlan et al.63	http://bedtools.readthedocs.io/en/latest/; RRID:SCR_006646
deepTools	Ramírez et al.64	https://deeptools.readthedocs.io/en/develop/; RRID:SCR_016366
MACS2	Zhang et al.65	https://github.com/taoliu/MACS; RRID:SCR_013291
Picard	N/A	http://broadinstitute.github.io/picard/; RRID:SCR_006525