Probe:	Smad1 cDNA3
Probe preparation:	Antisense labelled with S35 RNA
Assay notes:	Sections were post-fixed in 4% paraformaldehyde for 20 min.

Structure	Level	Pattern	Image	Note
TS21: lung	Present	Regionally restricted	1A	Expression was detected in the respiratory duct system of the lung.
TS21: spinal cord	Strong	Regionally restricted	1A	Expression was detected in the presumptive motor neurons.
TS21: dorsal root ganglion	Present		1A
TS21: heart	Weak		1A

Structure	Level	Pattern	Image	Note
TS23: lung	Strong	Regionally restricted	1C	Expression was detected in the respiratory duct system of the lung.
TS23: comma-shaped body	Present		1C
TS23: esophagus epithelium	Present		1C
TS23: hindbrain	Present		1C
TS23: stomach epithelium	Present		1C
TS23: gut epithelium	Present	Regionally restricted	1C	Expression was detected in small gut and colon epithelium.
TS23: cerebral cortex ventricular layer	Strong		1C
TS23: diencephalon	Strong		1C
TS23: cerebral cortex	Strong	Regionally restricted	1C	Expression was detected in the outer cell layer of the developing cortex.
TS23: spinal cord	Present	Widespread	1C

Structure	Level	Pattern	Image	Note
TS21: lung	Present	Regionally restricted	2A/B	Expression was detected in the respiratory duct system of the lung.

Structure	Level	Pattern	Image	Note
TS23: comma-shaped body	Present		2E/F

Structure	Level	Pattern	Image	Note
TS23: stomach epithelium	Present		2I/K

Structure	Level	Pattern	Image	Note
TS23: gut epithelium	Present	Regionally restricted	2N/O	Expression was detected in small gut epithelium.

Structure	Level	Pattern	Image	Note
TS25: tooth	Present	Regionally restricted	4A/B	Expression was detected in odontoblasts and ameloblasts.
TS25: stellate reticulum	Present		4A/B

Structure	Cell Type	Level	Pattern	Image	Note
TS25: Sertoli cell	Sertoli cell	Present		5A

Structure	Level	Pattern	Image	Note
TS25: thalamus	Present	Regionally restricted	6A/B	Expression was detected in some nuclear regions of the thalamus.

Structure	Level	Pattern	Image	Note
TS25: dorsal root ganglion	Present		6E/F

Structure	Level	Pattern	Image	Note
TS23: retina nuclear layer	Present	Regionally restricted	6I/K	Expression was detected in the inner cell layer.

Structure	Level	Pattern	Image	Note
TS25: olfactory epithelium	Present		6N/O

Structure	Level	Pattern	Image	Note
TS17: yolk sac	Present	Regionally restricted	7C , 7A/B	Expression was detected at sites of vasculogenesis in the yolk sac.

Structure	Level	Pattern	Image	Note
TS15: future forebrain	Present
TS15: future hindbrain	Present
TS15: otocyst	Present
TS15: heart	Absent

Structure	Level	Pattern	Image	Note
TS17: forebrain	Present	Ubiquitous
TS17: hindbrain	Present	Ubiquitous
TS17: future spinal cord	Present
TS17: blood vessel	Present	Regionally restricted		Expression was high on capillary endothelium.

Structure	Level	Pattern	Image	Note
TS20: oral epithelium	Present	Regionally restricted		Expression was detected in the invading epithelial bud (developing tooth).
TS20: head mesenchyme	Present	Regionally restricted		Expression was detected in the head mesenchyme underlying the epithelial bud.

Structure	Level	Pattern	Image	Note
TS21: comma-shaped body	Present
TS21: cranial ganglion	Present
TS21: forebrain	Present
TS21: hindbrain	Present
TS21: trigeminal ganglion	Present
TS21: vibrissa	Present	Regionally restricted		Expression was detected in all epithelial-derived structures and in the condensed mesenchyme.
TS21: gland	Present	Regionally restricted		Expression was detected in the adrenal gland. Levels were extremely high in the cortex.
TS21: retina	Present	Regionally restricted		Expression was detected in the inner cell layer.

Structure	Level	Pattern	Image	Note
TS23: ureteral mesenchyme	Strong
TS23: urothelium of ureter	Strong
TS23: enamel organ	Present	Regionally restricted		Expression was detected in the inner and outer enamel layer.
TS23: dental papilla	Present	Regionally restricted		Expression was detected in the condensed mesenchyme of the dental papilla.
TS23: adenohypophysis	Present
TS23: olfactory epithelium	Present
TS23: blood vessel	Present	Regionally restricted		Expression was high on capillary endothelium.

Structure	Level	Pattern	Image	Note
TS25: mesonephros	Present	Regionally restricted		Expression was detected in mesonephric mesenchyme.
TS25: adenohypophysis	Present
TS25: paramesonephric duct	Present
TS25: reproductive system	Present	Regionally restricted		Expression was detected in the Wolffian duct.
TS25: vibrissa	Present	Regionally restricted		Expression was detected in all epithelial-derived structures and in the condensed mesenchyme.
TS25: cerebral cortex	Present	Regionally restricted		Expression was detected in the outer cell layer.

Structure	Level	Pattern	Image	Note
TS28: placenta	Present	Regionally restricted		Expression was detected in the sinus system in the maternal part of the placenta at E10.5 and E15.5.