Antibody:	anti-Cx43
Detection system:	Secondary antibody coupled to rhodamine
Assay notes:	Data was summarized in Table 2 (including date not shown).

Structure	Level	Pattern	Image	Note
TS21: heart atrium	Present		6I
TS21: visceral pericardium	Present		6I

Structure	Level	Pattern	Image	Note
TS15: primitive ventricle cardiac muscle	Present	Regionally restricted	7A/B	Expressed in ventricular outermost myocytes. No expression in the trabecular network.

Structure	Level	Pattern	Image	Note
TS17: primitive ventricle cardiac muscle	Present		8C	Expressed in the myocytes of the trabecular network of both ventricles and the compact ventricular free wall. Weak expression in interventricular septum.

Structure	Level	Pattern	Image	Note
TS22: interventricular septum	Present	Regionally restricted	10F	Only expressed in the inner myocytes, intrinsic to the interventricular septum. Neither detected in the myocytes of the primitive His bundle nor in those of the anterior regions of the primitive bundle branches.
TS22: ventricle cardiac muscle	Present	Regionally restricted	10F	Only expressed in the inner myocytes, intrinsic to the interventricular septum. Neither detected in the myocytes of the primitive His bundle nor in those of the anterior regions of the primitive bundle branches.

Structure	Level	Pattern	Image	Note
TS13: heart	Absent
TS13: vascular system	Absent

Structure	Level	Pattern	Image	Note
TS15: atrioventricular canal	Absent
TS15: heart atrium	Absent

Structure	Level	Pattern	Image	Note
TS17: atrioventricular canal	Absent
TS17: heart atrium	Absent
TS17: outflow tract	Absent

Structure	Level	Pattern	Image	Note
TS19: atrioventricular canal	Absent
TS19: heart atrium	Absent
TS19: outflow tract	Absent
TS19: heart left ventricle	Present
TS19: heart right ventricle	Present
TS19: interventricular septum	Weak

Structure	Level	Pattern	Image	Note
TS20: atrioventricular canal	Absent
TS20: outflow tract	Absent
TS20: heart atrium	Weak
TS20: heart left ventricle	Strong
TS20: heart right ventricle	Present
TS20: interventricular septum	Present

Structure	Level	Pattern	Image	Note
TS21: atrioventricular canal	Absent
TS21: impulse conducting system	Absent
TS21: outflow tract	Absent
TS21: heart left ventricle	Strong
TS21: heart right ventricle	Strong
TS21: interventricular septum	Present

Structure	Level	Pattern	Image	Note
TS22: atrioventricular bundle	Absent
TS22: atrioventricular canal	Absent
TS22: outflow tract	Absent
TS22: heart atrium	Present
TS22: heart left ventricle	Strong
TS22: heart right ventricle	Strong

Structure	Level	Pattern	Image	Note
TS28: ventricle cardiac muscle	Present	Regionally restricted		Only expressed in the inner myocytes, intrinsic to the interventricular septum. Neither detected in the myocytes of the primitive His bundle nor in those of the anterior regions of the primitive bundle branches.