Reagent	Source		Catalogue #		Application
Chemicals and kits
DMEM‐High Glucose with Pyruvate And l‐Glutamine	Corning		MT 10‐013‐CV		Cell culture
0.05% Trypsin EDTA	Corning		MT 25‐052‐Cl		Cell culture
10,000 U Penicillin‐Streptomycin	Corning		MT 30‐002‐CI		Cell culture
FBS, USDA, Regular, Heat Inactivated	Corning		MT 35‐011‐CV		Cell culture
α‐MEM	Stem Cell Technologies		36450		Cell culture
Advanced DMEM/F‐12	Gibco		12634010		Intestinal organoid culture
GlutaMAX™ Supplement	Gibco		35050061		Intestinal organoid culture
lscove's Modified Dulbecco’s Medium (IMDM) with l‐Glutamine	Gibco		MT 10‐016‐CV		Bone marrow colony‐forming assay
MethoCult™ GF M3434	Gibco		03434		Bone marrow colony‐forming assay
KnockOut DMEM	Gibco		10829018		mESC cell culture
Complete Protease Inhibitors—Cocktail, Tablets	Roche		04693132001		Preparation of protein extracts
Laemmli sample buffer	BioRad		1610737		Sample preparation for immunoblotting
Quick Start™ Bradford 1× dye reagent	BioRad		500‐0204		Measurement of protein concentrations
4–20% gradient precast gels	BioRad		4561094		PAGE
PVDF membranes	BioRad		1620177		Immunoblotting
Western Lightning Plus‐ECL	PerkinElmer		NEL104001EA		Enhanced chemiluminescence for immunoblotting
Hoechst 33342	Invitrogen		H3570		DNA staining
4‐Hydroxytamoxifen	Millipore Sigma Aldrich		H7904‐5MG		Induction of Ssrp1 deletion (in vitro)
Tamoxifen	Millipore Sigma Aldrich		T5648‐1G		Induction of Ssrp1 deletion (in vivo)
Caspase‐3 substrate (Ac‐DEVD‐AMC)	Enzo Life Sciences		ALX‐260‐031‐M001		Apoptosis assay
Click‐iT™ EdU Alexa Fluor™ 488/594 imaging kit	Thermo Fischer Scientific		C10337		Measurement of DNA replication
Click‐iT™ EU Alexa Fluor™ 488/594 imaging kit	Thermo Fischer Scientific		C10632		Measurement i=of general transcription
Alizarine Red S	Millipore Sigma Aldrich		A5533‐25G		Staining of differentiated osteocytes
Oil Red O	Millipore Sigma Aldrich		O0625‐25G		Staining of differentiated adipocytes
Methylene blue	Millipore Sigma Aldrich		M4159		Measuring cell viability
Resazurin sodium salt	Millipore Sigma Aldrich		R7017‐1G		Measuring the viability of intestinal organoids
Collagenase A	Millipore Sigma Aldrich		10103578001		Isolation of fibroblasts and mesenchymal stem cells
Dexamethasone	Millipore Sigma Aldrich		D4902		Differentiation of mASCs
Isobutylmethylxanthine (IBMX)	Millipore Sigma Aldrich		I5879‐100MG		Differentiation of mASCs
Insulin	Gibco		12585014		Differentiation of mASCs
β‐glycerophosphate	Millipore Sigma Aldrich		50020‐100G		Differentiation of mASCs
L‐ascorbic acid	Millipore Sigma Aldrich		A92902‐25G		Differentiation of mASC
Gentamycin	Gibco		15710064		Culturing of intestinal organoids
Murine recombinant EGF	PeproTech		315‐09		Culturing of intestinal organoids
Murine recombinant Noggin	PeproTech		250‐38		Culturing of intestinal organoids
Human recombinant R‐Spondin‐1	PeproTech		120‐38		Culturing of intestinal organoids
Matrigel	BD Biosciences		356237		Culturing of intestinal organoids
Valproic acid sodium salt	Millipore Sigma Aldrich		P4543‐10G		Culturing of intestinal organoids
GSK3 inhibitor CHIR99021	Reprocell		04‐0004		Culturing of intestinal organoids
Nextera kit	Illumina		FC‐121‐1030		ATAC‐seq
NEBNext High‐Fidelity 2X PCR Master Mix	New England Biolabs		M0541		ATAC‐seq
MinElute PCR Purification kit	Qiagen		28004		ATAC‐seq
mRNA HyperPrep kit	KAPA BIOSYSTEMS		KK8580		RNA‐seq
Antibodies
SSRP1 mouse monoclonal 10D1	BioLegend		609702		Immunoblotting: 1:3,000 Immunohistochemistry: 1:200
SPT16 monoclonal mouse 8D2	BioLegend		607002		Immunoblotting: 1:1,000
beta‐actin mouse monoclonal (HRP conjugated)	Millipore Sigma Aldrich		A3854		Immunoblotting 1:20,000
Mouse Lgr5/GPR49 Antibody	R&D Systems		MAB8240‐SP		Immunohistochemistry: 1:200
Cleaved caspase 3	Thermo Fisher Scientific		700182		Immunohistochemistry: 1:200
m‐IgGκ BP‐HRP	Santa Cruz Biotechnology		sc‐516102		Immunoblotting: 1:4,000
Secondary anti‐mouse Alexa Fluor® (488 and 594)	Life Technologies		A‐11062 and 11001		Immunohistochemistry: 1:500