Probe:	Smad2 cDNA1
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	1B	Expression was detected in the respiratory duct system of the lung.
TS21: spinal cord	Strong	Regionally restricted	1B	Expression was detected in the presumptive motor neurons.
TS21: dorsal root ganglion	Present		1B
TS21: heart	Weak		1B

Structure	Level	Pattern	Image	Note
TS23: lung	Strong	Regionally restricted	1D	Expression was detected in the respiratory duct system of the lung.
TS23: comma-shaped body	Present		1D
TS23: esophagus epithelium	Present		1D
TS23: stomach epithelium	Present		1D
TS23: gut epithelium	Present	Regionally restricted	1D	Expression was detected in small gut and colon epithelium.
TS23: diencephalon	Strong		1D
TS23: thalamus	Strong		1D
TS23: cerebral cortex	Present		1D
TS23: hindbrain	Present	Regionally restricted	1D	Expression was detected in the ventral part of the hindbrain.
TS23: spinal cord	Present	Regionally restricted	1D	Expression was detected in the ventral part of the spinal cord.
TS23: cardiac muscle tissue	Present		1D

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

Structure	Level	Pattern	Image	Note
TS23: comma-shaped body	Present		2G/H

Structure	Level	Pattern	Image	Note
TS23: stomach epithelium	Present		2L/M

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

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

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

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

Structure	Level	Pattern	Image	Note
TS25: dorsal root ganglion	Present		6G/H

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

Structure	Level	Pattern	Image	Note
TS25: olfactory epithelium	Present		6P/Q

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

Structure	Level	Pattern	Image	Note
TS15: cardiac muscle tissue	Present
TS15: endocardial lining	Present
TS15: future forebrain	Present
TS15: future hindbrain	Present
TS15: future spinal cord	Present
TS15: otocyst	Present
TS15: dorsal aorta	Weak	Regionally restricted		Weak expression was detected in the endothelial cells of the dorsal aorta.

Structure	Level	Pattern	Image	Note
TS17: forebrain	Present	Ubiquitous
TS17: hindbrain	Present	Ubiquitous
TS17: future spinal cord	Present

Structure	Level	Pattern	Image	Note
TS19: neural tube marginal layer	Strong	Regionally restricted		Expression was detected in the marginal layer of the spinal cord next to the ventral roots.

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 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: nephric duct	Present
TS21: paramesonephric duct	Present
TS21: trigeminal ganglion	Present
TS21: mesonephros	Present	Regionally restricted		Expression was detected in mesonephric mesenchyme.
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: 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

Structure	Level	Pattern	Image	Note
TS25: vibrissa	Present	Regionally restricted		Expression was detected in all epithelial-derived structures and in the condensed mesenchyme.
TS25: adenohypophysis	Present
TS25: cerebral cortex	Present	Regionally restricted		Expression was detected in the outer cell layer of the cortex.
TS25: brain	Strong	Regionally restricted		Expression was observed around the ventricles.
TS25: cranial ganglion	Strong
TS25: cardiac muscle tissue	Weak