Antibody:	anti-ColI
Detection system:	Secondary antibody coupled to Alexa Fluor 488
Assay notes:	The authors did not detail the specificity of the antibody, both Col1a1 and Col1a2 have been annotated.

Structure	Level	Pattern	Image	Note
TS26: mitral valve	Present		1I , 1J
TS26: tricuspid valve	Present		1I , 1J
TS26: heart	Present	Regionally restricted	1J , 1I	Expression is in the chordae tendineae.
TS26: ventricle cardiac muscle	Weak		1I , 1K
TS26: trabeculae carneae	Weak		1L , 1I

Structure	Level	Pattern	Image	Note
TS26: arterial system	Present		3A
TS26: interatrial septum	Present		3A
TS26: mitral valve	Present		3A
TS26: tricuspid valve	Present		3A
TS26: venous system	Present		3A
TS26: heart	Present	Regionally restricted	3A	Expression is in the epicardium.
TS26: atrium cardiac muscle	Present	Regionally restricted	3A	Expression is in the extracellular matrix.
TS26: ventricle cardiac muscle	Present	Regionally restricted	3A	Expression is in the extracellular matrix.

Structure	Level	Pattern	Image	Note
TS26: ventricle cardiac muscle	Strong	Regionally restricted	3B	Expression is in localized regions of the compact layer of the ventricular myocardium.

Structure	Level	Pattern	Image	Note
TS26: mitral valve	Strong		3C
TS26: tricuspid valve	Strong		3C
TS26: ventricle cardiac muscle	Strong	Regionally restricted	3C	Expression is in localized deposits.

Structure	Level	Pattern	Image	Note
TS26: mitral valve	Strong		3D
TS26: tricuspid valve	Strong		3D
TS26: ventricle cardiac muscle	Strong		3D

Structure	Level	Pattern	Image	Note
TS26: mitral valve leaflet	Present	Regionally restricted	4A	Expression is in the core and is absent on the atrial and ventricular surface.

Structure	Level	Pattern	Image	Note
TS26: aortic valve leaflet	Weak		4B

Structure	Level	Pattern	Image	Note
TS26: mitral valve leaflet	Present		4C	There is a 3-fold increased immunoreactivity in this mutant and expression is expanded throughout the leaflet.

Structure	Level	Pattern	Image	Note
TS26: aortic valve leaflet	Strong	Punctate	4D	There is a 2.5-fold increased immunoreactivity in this mutant.

Structure	Level	Pattern	Image	Note
TS26: mitral valve leaflet	Strong		4E	There is a 4-fold increased immunoreactivity in this mutant.

Structure	Level	Pattern	Image	Note
TS26: aortic valve leaflet	Strong		4F	There is a 5-fold increased immunoreactivity in this mutant.

Structure	Level	Pattern	Image	Note
TS26: mitral valve leaflet	Strong		4G	There is a 4-fold increased immunoreactivity in this mutant.

Structure	Level	Pattern	Image	Note
TS26: aortic valve leaflet	Strong		4H	There is a 7-fold increased immunoreactivity in this mutant.

Structure	Level	Pattern	Image	Note
TS26: ventricle cardiac muscle	Weak	Regionally restricted	5A	Expression is in the extracellular matrix.

Structure	Level	Pattern	Image	Note
TS26: trabeculae carneae	Weak	Regionally restricted	5B	Expression is in the extracellular matrix.

Structure	Level	Pattern	Image	Note
TS26: ventricle cardiac muscle	Strong		5C	There is a 7-fold increased immunoreactivity in this mutant.

Structure	Level	Pattern	Image	Note
TS26: trabeculae carneae	Weak		5D	Expression in this tissue is the same as in wild-type.

Structure	Level	Pattern	Image	Note
TS26: ventricle cardiac muscle	Strong		5E	There is a 5-fold increased immunoreactivity in this mutant.

Structure	Level	Pattern	Image	Note
TS26: trabeculae carneae	Strong	Regionally restricted	5F	There is a 3-fold increased immunoreactivity in this mutant. There are focal areas with increased expression.

Structure	Level	Pattern	Image	Note
TS26: ventricle cardiac muscle	Strong		5G	There is a 8-fold increased immunoreactivity in this mutant.

Structure	Level	Pattern	Image	Note
TS26: trabeculae carneae	Strong		5H	There is a 3-fold increased immunoreactivity in this mutant.