Antibody:	anti-DPEAAE
Detection system:	Secondary antibody coupled to fluorescein
Assay notes:	Fixative was 2% or 4% paraformaldehyde.

Structure	Level	Pattern	Image	Note
TS15: endocardial lining	Present		4C
TS15: atrioventricular canal	Present	Regionally restricted	4C	Expression is in the extracellular matrix of mesenchymal cells in the endocardial cushions of the atrioventricular canal.
TS15: cardiac muscle tissue	Trace		4C	Little or no staining.

Structure	Level	Pattern	Image	Note
TS15: outflow tract	Present

Structure	Level	Pattern	Image	Note
TS17: heart	Strong	Regionally restricted	5C	Expression is in the extracellular matrix of the densely packed cells subjacent in the endocardium and is absent in the extracellular matrix of the core region.

Structure	Level	Pattern	Image	Note
TS20: atrioventricular endocardial cushion	Present	Regionally restricted	6D , 6C	Staining is at spaces between cells in the densely packed cell region with lower levels in the extracellular matrix of mesenchymal cells in the cushion core. Higher levels in the superior cushion at areas surrounding loosely packed cells near endocardium.

Structure	Level	Pattern	Image	Note
TS22: heart valve	Present	Regionally restricted	7E , 7D	Expression is little or none in regions of loosely packed mesenchymal cells adjacent to the densely packed cells and is mostly absent in the highly compacted cell region of the atrioventricular valve leaflets. Staining is mostly at the elongated portion.