Probe:	Mf1 cDNA1
Probe preparation:	Antisense labelled with S35 RNA
Visualized with:	Autoradiography

Structure	Level	Pattern	Image	Note
TS13: somite	Strong		1A/B
TS13: pericardio-peritoneal canal mesothelium	Strong	Regionally restricted	1A/B	Strong expression in dorsal portion of mesenchyme around pericardial-peritoneal canal.
TS13: mesenchyme	Weak	Regionally restricted	1A/B	Weak but significant expression in rest of mesenchymal tissues.
TS13: endocardial tube	Weak		1A/B	Weak but significant expression in endocardium (endothelial lining) of heart tube.

Structure	Level	Pattern	Image	Note
TS15: heart	Trace		1C/D	Very little expression above background was detected.

Structure	Level	Pattern	Image	Note
TS17: aortic sac	Present	Regionally restricted		Expression in dorsal portion of aortic sac.

Structure	Level	Pattern	Image	Note
TS18: somite	Strong		2A/B
TS18: mediastinum	Strong	Regionally restricted	2A/B	Strong expression in mesenchyme surrounding anterior cardinal vein, bronchi and foreut.
TS18: septum primum	Weak		2A/B	Expression above background in septum primum.
TS18: heart atrium	Strong	Regionally restricted	2A/B	Expression in inner layer of atrial wall.

Structure	Level	Pattern	Image	Note
TS18: somite	Strong		2C/D
TS18: mediastinum	Strong	Regionally restricted	2C/D	Strong expression in mesenchyme surrounding anterior cardinal vein, bronchi and foregut.
TS18: umbilical vein	Present		2C/D
TS18: heart atrium	Present	Regionally restricted	2C/D	Cardiac tissue expression predominantly in dorsal component of septum primum and inner layer of atrial wall.
TS18: septum primum	Present	Regionally restricted	2C/D	Cardiac tissue expression predominantly in dorsal component of septum primum and inner layer of atrial wall.
TS18: primitive ventricle	Weak	Regionally restricted	2C/D	To a lesser extent, expression in trabeculated wall of ventricle.

Structure	Level	Pattern	Image	Note
TS18: mediastinum	Strong	Regionally restricted	3A , 4A	Strong expression in mesenchyme surrounding laryngeo-tracheal groove.
TS18: septum primum	Present		3A , 4A

Structure	Level	Pattern	Image	Note
TS18: mediastinum	Strong	Regionally restricted	4B , 3B	Strong expression in mesenchyme surrounding laryngeo-tracheal groove.
TS18: septum primum	Present		3B , 4B
TS18: heart atrium	Weak		3B , 4B	Authors report weak but significant expression in inner layer of atrial wall

Structure	Level	Pattern	Image	Note
TS18: mediastinum	Strong	Regionally restricted	4C , 3C	Strong expression in mesenchyme surrounding laryngeo-tracheal groove.
TS18: septum primum	Present		4C , 3C

Structure	Level	Pattern	Image	Note
TS18: mediastinum	Strong	Regionally restricted	4D , 3D	Strong expression in mesenchyme surrounding laryngeo-tracheal groove.

Structure	Level	Pattern	Image	Note
TS18: mediastinum	Strong	Regionally restricted	3E , 4E	Strong expression in mesenchyme surrounding laryngeo-tracheal groove.
TS18: heart mesenchyme	Weak	Regionally restricted	4E , 3E	Authors report weak but significant expression in dense layer of mesenchymal tissue which is continuous with mesenchyme surrounding laryngo-tracheo groove, thus likely representing the spina vestibulli.

Structure	Level	Pattern	Image	Note
TS18: mediastinum	Strong	Regionally restricted	3F , 4F	Strong expression in mesenchyme surrounding laryngeo-tracheal groove.

Structure	Level	Pattern	Image	Note
TS21: bronchus mesenchyme	Present		5A/B
TS21: rib pre-cartilage condensation	Present		5A/B
TS21: thoracic body wall	Present	Regionally restricted	5A/B	Expression in inner cell layer of thoracic body wall.
TS21: interatrial septum	Present	Regionally restricted	5A/B	Expression in ventral component of atrial septum.
TS21: septum primum	Present	Regionally restricted	5A/B	Expression in ventral part of septum primum, which is continuous with the atrioventricular cusion and forms the atrial septum.
TS21: atrioventricular endocardial cushion	Present		5A/B
TS21: mitral valve	Present		5A/B
TS21: right atrium venous valve	Present		5A/B
TS21: tricuspid valve	Present		5A/B
TS21: interventricular septum	Absent		5A/B
TS21: trabecular myocardium	Present	Regionally restricted	5A/B	Expression in trabeculated region of ventricular wall.

Structure	Level	Pattern	Image	Note
TS21: endocardial lining	Strong	Regionally restricted	5C/D	Strongest expression in endocardium covering septa and valves, including atrial septum, mitral valve, tricuspid valve and venous valve.
TS21: heart mesenchyme	Present		5C/D	Expression decreases in mesenchymal cells that have migrated into cushion tissue, valve leaflets and intraventicular septum.

Structure	Level	Pattern	Image	Note
TS21: aortic valve	Present		6A/B
TS21: heart ventricle	Present	Regionally restricted	6A/B	Expression in in tissue between right and left ventricles.

Structure	Level	Pattern	Image	Note
TS21: pulmonary valve	Present		6C/D

Structure	Level	Pattern	Image	Note
TS23: heart	Weak		7A/B	Decreased expression in heart at E15 compared to that at E13.
TS23: interatrial septum	Present		7A/B
TS23: mitral valve	Present		7A/B
TS23: tricuspid valve	Present		7A/B
TS23: trabecular myocardium	Present	Regionally restricted	7A/B	Expression in trabeculated regions of ventricles.

Structure	Level	Pattern	Image	Note
TS23: interatrial septum	Present		7C/D
TS23: mitral valve	Present		7C/D
TS23: right atrium venous valve	Present		7C/D
TS23: tricuspid valve	Present		7C/D

Structure	Level	Pattern	Image	Note
TS23: aortic valve	Present		7G/H

Structure	Level	Pattern	Image	Note
TS23: pulmonary valve	Present		7I/J