Probe:	Armh4 probe1
Probe preparation:	Antisense labelled with digoxigenin RNA

Structure	Level	Pattern	Image	Note
TS12: primary heart field	Present		2A	Earliest detectable expression within midline first heart field cardiac crescent. Expression is cardiac restricted; no expression in rest of the embryo.
TS12: sinus venosus	Present		2A

Structure	Level	Pattern	Image	Note
TS12: primitive heart tube	Present	Widespread	2B	Expression restricted to heart, expressed within entire heart tube (including arterial and venous poles) as primiitve heart tube relocates to midline.
TS12: sinus venosus	Present		2B

Structure	Level	Pattern	Image	Note
TS12: cardiogenic plate	Present	Regionally restricted	2C	Expression in arterial mesodermal second heart field progenitors.

Structure	Level	Pattern	Image	Note
TS12: outflow tract	Present	Regionally restricted	2D	Expression in outflow tract cardiomyocyte layer.

Structure	Level	Pattern	Image	Note
TS12: common atrial chamber cardiac muscle	Present		2E
TS12: foregut diverticulum endoderm	Absent		2E

Structure	Level	Pattern	Image	Note
TS12: sinus venosus left horn	Present		2F
TS12: sinus venosus right horn	Present		2F
TS12: septum transversum	Present		2F

Structure	Level	Pattern	Image	Note
TS12: sinus venosus left horn	Present		2G
TS12: sinus venosus right horn	Present		2G

Structure	Level	Pattern	Image	Note
TS14: heart	Present	Widespread	3A
TS14: sinus venosus	Present	Widespread	3A
TS14: yolk sac	Absent		3A

Structure	Level	Pattern	Image	Note
TS14: secondary heart field	Present		3B
TS14: primitive ventricle	Present	Regionally restricted	3B	Lower levels of expression in left ventricle.

Structure	Level	Pattern	Image	Note
TS15: outflow tract	Strong		3C	Robust expression second heart field and outflow tract.
TS15: secondary heart field	Strong		3C	Robust expression second heart field and outflow tract.
TS15: heart atrium	Weak	Regionally restricted	3C	Weak expression in left ventricle and atria.
TS15: primitive ventricle	Weak	Regionally restricted	3C	Weak expression in left ventricle and atria.
TS15: forebrain-midbrain boundary region	Present		3C

Structure	Level	Pattern	Image	Note
TS15: outflow tract	Present	Regionally restricted	3D left	Expression localized to outflow tract outer myocardial layer.
TS15: foregut epithelium	Absent		3D left

Structure	Level	Pattern	Image	Note
TS15: outflow tract	Present	Regionally restricted	3D left-center	Expression localized to outflow tract outer myocardial layer.
TS15: foregut epithelium	Absent		3D left-center

Structure	Level	Pattern	Image	Note
TS15: primitive ventricle	Present	Regionally restricted	3D center-right	Expression localized to right ventricle.
TS15: common atrial chamber	Present		3D center-right
TS15: secondary heart field	Present		3D center-right
TS15: foregut epithelium	Absent		3D center-right

Structure	Level	Pattern	Image	Note
TS15: sinus venosus right horn	Present		3D right

Structure	Level	Pattern	Image	Note
TS17: mesenchyme derived from splanchnopleure	Strong	Regionally restricted	3E	Robust expression in second heart field.
TS17: primitive ventricle	Strong	Regionally restricted	3E	Robust expression in right ventricle.
TS17: forebrain-midbrain boundary region	Present		3E

Structure	Level	Pattern	Image	Note
TS17: mesenchyme derived from splanchnopleure	Strong	Regionally restricted	3F	Robust expression in second heart field.
TS17: primitive ventricle	Strong	Regionally restricted	3F	Robust expression in right ventricle.
TS17: trigeminal ganglion	Present		3F

Structure	Level	Pattern	Image	Note
TS17: mesenchyme derived from splanchnopleure	Strong	Regionally restricted	3G	Robust expression in second heart field.
TS17: primitive ventricle	Strong	Regionally restricted	3G	Robust expression in right ventricle.

Structure	Level	Pattern	Image	Note
TS17: mesenchyme derived from splanchnopleure	Strong	Regionally restricted	3H	Expression in second heart field extends from branchial arches all the way down along the outflow tract and arterial chamber wall to the septum transversum.
TS17: common atrial chamber	Present		3H
TS17: outflow tract	Present		3H
TS17: septum transversum	Present		3H

Structure	Level	Pattern	Image	Note
TS17: outflow tract cardiac muscle	Present		3I
TS17: common atrial chamber right part cardiac muscle	Present		3I
TS17: mesenchyme derived from splanchnopleure	Present	Regionally restricted	3I	Expression extends into branchial arch/second heart field region.

Structure	Level	Pattern	Image	Note
TS18: mesenchyme derived from splanchnopleure	Present	Regionally restricted	3K	Expression throughout proximal pharyngeal arch/second heart field region and second heart field.
TS18: outflow tract	Present		3K
TS18: primitive ventricle cardiac muscle	Strong	Regionally restricted	3K	Predominant expression in right ventricular cardiomyocytes.
TS18: outflow tract endocardial cushion	Absent		3K

Structure	Level	Pattern	Image	Note
TS20: heart right ventricle	Present		3L
TS20: outflow tract cardiac muscle	Present		3L
TS20: right atrium	Present		3L
TS20: endocardial cushion	Absent		3L

Structure	Level	Pattern	Image	Note
TS21: outflow tract cardiac muscle	Present		3M
TS21: right ventricle cardiac muscle	Present		3M
TS21: outflow tract endocardial cushion	Absent		3M	No expression in conal and truncal endocardial cushions.

Structure	Level	Pattern	Image	Note
TS20: dorsal root ganglion	Present		4A

Structure	Level	Pattern	Image	Note
TS20: dorsal root ganglion	Present		4B

Structure	Level	Pattern	Image	Note
TS21: dorsal root ganglion	Present		4C

Structure	Level	Pattern	Image	Note
TS21: dorsal root ganglion	Present		4D
TS21: spinal cord	Present	Regionally restricted	4D	Punctate expression within ventral regions of neural tube.

Structure	Level	Pattern	Image	Note
TS20: maxillary process	Present		4E	Expression within maxillary prominences above primordial mouse.
TS20: nasal process	Present		4E	Expression on either side of nasal septum.

Structure	Level	Pattern	Image	Note
TS20: trigeminal ganglion	Present		4F
TS20: telencephalon	Present	Regionally restricted	4F	Expression in telencephalon walls. Expression in medial sulcus.
TS20: hindbrain marginal layer	Present	Regionally restricted	4F	Expression in marginal layer around 4th ventricle.

Structure	Level	Pattern	Image	Note
TS14: heart	Present	Widespread	5A
TS14: secondary heart field	Present	Widespread	5A

Structure	Level	Pattern	Image	Note
TS14: heart	Present		5B
TS14: secondary heart field	Present		5B

Structure	Level	Pattern	Image	Note
TS14: heart	Present		5C
TS14: secondary heart field	Present		5C

Structure	Level	Pattern	Image	Note
TS14: heart	Present		5D	Expression in second heart field and heart appears unaltered compared with littermate controls.
TS14: secondary heart field	Present		5D	Expression in second heart field and heart appears unaltered compared with littermate controls.

Structure	Level	Pattern	Image	Note
TS15: primitive ventricle	Weak	Regionally restricted	5E	Authors report expression similarly diminished in both age-matched wild type and Pax3-/- left ventricles.

Structure	Level	Pattern	Image	Note
TS15: primitive ventricle	Weak	Regionally restricted	5F	Authors report expression similarly diminished in both age-matched wild type and Pax3-/- left ventricles.
TS15: outflow tract	Present		5F	Expression unperturbed in outflow tract and second heart field.
TS15: secondary heart field	Present		5F	Expression unperturbed in outflow tract and second heart field.