Probe:	Id1 cDNA1
Probe preparation:	Antisense labelled with S35 RNA

Structure	Level	Pattern	Image	Note
TS20: adenohypophysis	Present		1B
TS20: genital tubercle	Present		1B
TS20: heart	Present		1B
TS20: olfactory epithelium	Present		1B
TS20: trigeminal ganglion	Present		1B
TS20: vertebral cartilage condensation	Present		1B
TS20: mandibular process mesenchyme	Present		1B	Expression in the mesenchyme includes regions of the tooth primordia.
TS20: maxillary process mesenchyme	Present		1B	Expression in the mesenchyme includes regions of the tooth primordia.
TS20: metanephros	Present	Regionally restricted	1B	Expression was primarily detected in the epithelium.
TS20: blood vessel	Present		1B	Expression was in large blood vessels.
TS20: inner ear	Present	Regionally restricted	1B	Expression was in the otic vesicle.
TS20: intestine	Weak		1B
TS20: liver	Weak		1B
TS20: lung epithelium	Weak		1B
TS20: heart ventricle	Absent		1B

Structure	Level	Pattern	Image	Note
TS20: adenohypophysis	Strong
TS20: brain	Strong
TS20: epithelium of urogenital sinus	Strong
TS20: genital tubercle	Strong
TS20: heart	Strong
TS20: mandibular process mesenchyme	Strong
TS20: maxillary process mesenchyme	Strong
TS20: neurohypophysis pars nervosa	Strong
TS20: olfactory epithelium	Strong
TS20: trigeminal ganglion	Strong
TS20: vertebral cartilage condensation	Strong
TS20: metanephros	Strong	Regionally restricted		Expression was detected in kidney epithelium.
TS20: tongue	Present
TS20: oral region epithelium	Present	Regionally restricted		Expression was in dental lamina.
TS20: inner ear	Present	Regionally restricted		Expression was in auditory vesicle.
TS20: intestine	Weak
TS20: liver	Weak
TS20: lung	Weak	Regionally restricted		Expression was weak in lung interstitial cells.

Structure	Level	Pattern	Image	Note
TS20: hindbrain ventricular layer	Present		2D
TS20: midbrain ventricular layer	Present	Regionally restricted	2D	In the alar plate of the midbrain, expression was detected principally in the ventricular zone.
TS20: choroid plexus	Strong	Regionally restricted	2D	Strong expression was detected in the choroid plexus in the forebrain.
TS20: neurohypophysis infundibulum	Strong	Regionally restricted	2D	Strong expression was detected in the infundibular floor region.
TS20: ganglionic eminence	Present	Regionally restricted	2D	Expression was detected in the ventricular zone.
TS20: telencephalon	Present	Regionally restricted	2D	Expression was detected in the ventricular zone of the septum.
TS20: diencephalon	Present	Regionally restricted	2D	Expression was detected in the ventricular zone of the eminentia thalami.

Structure	Level	Pattern	Image	Note
TS20: hindbrain ventricular layer	Present		2E
TS20: midbrain ventricular layer	Present	Regionally restricted	2E	In the alar plate of the midbrain, expression was detected principally in the ventricular zone.
TS20: choroid plexus	Strong	Regionally restricted	2E	Strong expression was detected in the choroid plexus in the forebrain.
TS20: neurohypophysis infundibulum	Strong	Regionally restricted	2E	Strong expression was detected in the infundibular floor region.
TS20: ganglionic eminence	Present	Regionally restricted	2E	Expression was detected in the ventricular zone.
TS20: telencephalon	Present	Regionally restricted	2E	Expression was detected in the ventricular zone of the septum.
TS20: diencephalon	Present	Regionally restricted	2E	Expression was detected in the ventricular zone of the eminentia thalami.

Structure	Level	Pattern	Image	Note
TS20: hindbrain ventricular layer	Present		2F
TS20: midbrain ventricular layer	Present	Regionally restricted	2F	In the alar plate of the midbrain, expression was detected principally in the ventricular zone.
TS20: choroid plexus	Strong	Regionally restricted	2F	Strong expression was detected in the choroid plexus in the forebrain.
TS20: neurohypophysis infundibulum	Strong	Regionally restricted	2F	Strong expression was detected in the infundibular floor region.
TS20: ganglionic eminence	Present	Regionally restricted	2F	Expression was detected in the ventricular zone.
TS20: telencephalon	Present	Regionally restricted	2F	Expression was detected in the ventricular zone of the septum.
TS20: diencephalon	Present	Regionally restricted	2F	Expression was detected in the ventricular zone of the eminentia thalami.

Structure	Level	Pattern	Image	Note
TS22: brain	Present	Regionally restricted	3B	Periventricular expression was seen widely throughout the brain, except in the telencephalon.
TS22: telencephalon	Present	Regionally restricted	3B	Only the choroid plexus and its attachment taeniae were labeled in the telencephalon.
TS22: choroid plexus	Present	Regionally restricted	3B	Expression was detected in the choroid plexus in the telencephalon.
TS22: hindbrain ventricular layer	Present		3B
TS22: midbrain ventricular layer	Present		3B

Structure	Level	Pattern	Image	Note
TS22: forebrain ventricular layer	Present	Regionally restricted		In the secondary prosencephalon, the ventricular zone in the region of the alar/basal boundary is positive.

Structure	Level	Pattern	Image	Note
TS24: choroid plexus	Present
TS24: brain	Present	Regionally restricted		Some periventricular areas showed expression.
TS24: subcommissural organ	Present	Regionally restricted		Expression was detected in the subcommisural organs at the dorsal midline of prosomere 1.