REAGENT or RESOURCE	SOURCE	IDENTIFIER
Antibodies
Rabbit anti-α-smooth muscle actin	Abcam	Cat #ab5694; RRID: AB_2223021
Mouse anti-Desmin, Clone D33	Dako	Cat #M0760; RRID: AB_2335684
Rabbit anti-Fibronectin	Millipore	Cat #AB2047; RRID: AB_2278547
Goat anti-CD31	R&D Systems	Cat #AF3628; RRID: AB_2161028
Mouse anti-MAP2	Sigma	Cat #M2320; RRID: AB_609904
Rabbit anti-Triadin	Dr. Isabelle Marty	N/A
Mouse anti-MyoD	BD Pharmingen	Cat #554130; RRID: AB_395255
Rabbit anti-BrdU	Abcam	Cat #ab152095
Mouse anti-Integrin α5, clone SNAKA51	Millipore	Cat #MABT201
Rat anti-Integrin β1, clone 9EG7	BD Pharmingen	Cat #550531; RRID: AB_393729
Goat anti-Tensin	Abcam	Cat #ab52008; RRID: AB_883131
Donkey Anti-Mouse IgG (H+L) Highly Cross-Adsorbed Secondary Antibody, Alexa Fluor 488	Thermo Fisher Scientific	Cat #A21202; RRID: AB_141607
Goat Anti-Mouse IgG (H+L) Highly Cross-Adsorbed Secondary Antibody, Alexa Fluor 555	Thermo Fisher Scientific	Cat #A21424; RRID: AB_141780
Donkey Anti-Rabbit IgG (H+L) Highly Cross-Adsorbed Secondary Antibody, Alexa Fluor 488	Thermo Fisher Scientific	Cat #A21206; RRID: AB_2535792
Goat Anti-Rabbit IgG (H+L) Highly Cross-Adsorbed Secondary Antibody, Alexa Fluor 555	Thermo Fisher Scientific	Cat #A21429; RRID: AB_2535850
Donkey anti-Rabbit IgG (H+L) Highly Cross-Adsorbed Secondary Antibody, Alexa Fluor 568	Thermo Fisher Scientific	Cat #A10042; RRID: AB_2534017
Donkey Anti-Goat IgG (H+L) Highly Cross-Adsorbed Secondary Antibody, Alexa Fluor 555	Thermo Fisher Scientific	Cat #A21432; RRID: AB_2535853
Donkey Anti-Goat IgG (H+L) Highly Cross-Adsorbed Secondary Antibody, Alexa Fluor 647	Thermo Fisher Scientific	Cat #A21447; RRID: AB_2535864
Donkey anti-Rat IgG (H+L) Highly Cross-Adsorbed Secondary Antibody, Alexa Fluor 488	Thermo Fisher Scientific	Cat #A21208; RRID: AB_2535794
Chemicals, Peptides, and Recombinant Proteins
Collagenase type I	Sigma-Aldrich	Cat #C0130
Dispase	Roche	Cat #04942078001
Iscove’s Modified Dulbecco’s Medium (IMDM) with GlutaMAX	Invitrogen	Cat #31980022
Fetal bovine serum (FBS)	Eurobio	Cat #CVFSVF00-01
Penicillin/streptomycin (Penstrep)	Thermo Fisher Scientific	Cat #15140122
Horse serum	Thermo Fisher Scientific	Cat #26050088
Chicken embryo extract	This paper	N/a
Matrigel	Corning	Cat #354230, lot 6305006
Recombinant Rat Agrin	R&D systems	Cat #550-AG-100
Lipofectamine RNAiMAX transfection reagent	Invitrogen	Cat #L3000015
Lipofectamine 3000 transfection reagent	Invitrogen	Cat #13778150
Opti-MEM I Reduced Serum Medium	GIBCO	Cat #31985070
Goat serum	Sigma-Aldrich	Cat #G9023
Bovine serum albumin (BSA)	Sigma-Aldrich	Cat #A7906
Saponin	Sigma-Aldrich	Cat #47036
Fluoromount-G	Invitrogen	Cat #00-4958-02
Mitomycin C	Sigma-Aldrich	Cat #M7949
Fibronectin	Sigma-Aldrich	Cat #F1141
Laminin	Sigma-Aldrich	Cat #L2020
Collagen	Ibidi	Cat #50201
Cilengitide	Sigma-Aldrich	Cat #SMG 1594
ML141 (Cdc42 inhibitor)	Sigma-Aldrich	Cat #SML0407
Rac1 inhibitor	Merck Millipore	Cat #553502
Y-27632 (ROCK inhibitor)	Merck Millipore	Cat #688001
FAK inhibitor	Sigma-Aldrich	Cat #PZ0117
Src inhibitor,PPi	Merck Millipore	Cat #539571
Nonidet P-40	Euromedex	Cat #9016-45-9
Sodium deoxycholate	Sigma-Aldrich	Cat #30970
Urea	Sigma-Aldrich	Cat #U1250
Glutaraldehyde	Electron Microscopy Sciences	Cat #16216
Formamide	Sigma-Aldrich	Cat #47671
Poly(ethylene glycol) (PEG)	Sigma-Aldrich	Cat #P2139
Phalloidin 488 Alexa Fluor	Life Technologies	Cat #A12379; RRID: AB_2315147
Phalloidin 555 Alexa Fluor	Life Technologies	Cat #A34055
4’,6-diamidino-2-phenylindole dihydrochloride (DAPI)	Sigma-Aldrich	Cat #32670
Critical Commercial Assays
RNeasy micro kit	Qiagen	Cat #50974004
High capacity RNA-to-cDNA kit	Applied Biosystems	Cat #4387406
Experimental Models: Organisms/Strains
Mouse: C57BL/6	Charles River	Strain code: 027
Mouse: Pax7-nGFP	(Sambasivan et al., 2009)	RRID: MGI:5308730
Oligonucleotides
siRNA non-targeting sequence: Scrambled UUCUCCGAACGU GUCACGUTT, ACGUGACACGUUCGGAGAATT	Genecust	N/A
siRNA targeting sequence: mouse α5 Integrin (Itga5) #1 CCUCAGG AAUGAAUCAGAAtt	Ambion	cat # 4390771 s68428
siRNA targeting sequence: mouse α5 Integrin (Itga5) #2 GGGAGUC GUAUUUAUAUUCtt	Ambion	cat #AM16708 155908
siRNA targeting sequence: mouse Fibronectin (Fn1) #1 CCUACAAC AUCAUAGUGGAtt	Ambion	cat # 4390771 s66183
siRNA targeting sequence: mouse Fibronectin (Fn1) #2 CCGUUUU CAUCCAACAAGAtt	Ambion	cat # 4390771 s66182
α5-integrin: Forward primer; 5’-AAAGGACCCACAGAATGACCC-3’	This paper	N/A
α5-integrin: Reverse primer; 5’-CCAAAATCTGAGCGGCAAGG-3’	This paper	N/A
Fibronectin: Forward primer; 5’-TGACTGGCCTTACCAGAGGG-3’	This paper	N/A
Fibronectin: Reverse primer; 5’-CATCTGTAGGCTGGTTCAGGC-3’	This paper	N/A
Hypoxanthine Phosphoribosyltransferase 1: Forward primer; 5’-GTTAAGCAGTACAGCCCCAAA-3’	This paper	N/A
Hypoxanthine Phosphoribosyltransferase 1: Reverse primer; 5’-AGGGCATATCCAACAACAAACTT-3’	This paper	N/A
Recombinant DNA
GFP-fibronectin	N/A	Addgene plasmid: Cat #56600
ChR2-GFP	(Zhang et al., 2007)	Addgene plasmid: Cat #20939
GCaMP6f	(Chen et al., 2013)	Addgene plasmid: Cat #40755
Software and Algorithms
GraphPad Prism	GraphPad software	Version 5; RRID:SCR_002798
StepOne Software	Thermo Fisher Scientific	Version 2.3; RRID:SCR_014281
Metamorph	Molecular Devices	RRID: SCR_002368
ZEN software 2012	Carl Zeiss MicroImaging	RRID:SCR_013672
ZEN software 2.1 (black)	Carl Zeiss MicroImaging	RRID:SCR_013672
FlowJo	FlowJo software	Version 10; RRID:SCR_008520
Fiji	https://fiji.sc	RRID: SCR_002285
Adobe Ilustrator CS5	Adobe Systems	N/A
Other
Fluorodishes	World Precision Instruments (WPI)	Cat #FD35-100
μ-Slide 8 Well ibiTreat: #1.5 polymer coverslip, tissue culture treated, sterilized	Ibidi	Cat #80826
37°C/5% CO2 incubator	Okolab	N/A
20x 0.3 NA PL Fluo dry objective	Leica Microsystems	N/A
Nikon Ti microscope	Nikon	N/A
CoolSNAP HQ2 camera	Roper Scientific	N/A
XY-motorized stage	Nikon	N/A
Zeiss LSM 710	Carl Zeiss MicroImaging	N/A
Zeiss LSM 880	Carl Zeiss MicroImaging	N/A
63x 1.4 NA Plan-Apochromat objective	Carl Zeiss MicroImaging	N/A
Zeiss Cell Observer Spinning Disk system	Carl Zeiss MicroImaging	N/A
Z-piezo	Prior	N/A
Spinning Disk CSU-X1M 5000	Yokogawa	N/A
37°C/5% CO2 incubator	Pekon	N/A
EM-CCD camera Evolve 512	Photometrics	N/A
Polystyrene beads	Phosphorex	Cat #1020KB