Probe:	Id2 cDNA5
Probe preparation:	Antisense labelled with S35 RNA

Structure	Level	Pattern	Image	Note
TS20: genital tubercle	Present		1A
TS20: olfactory epithelium	Present		1A
TS20: remnant of Rathke's pouch	Present		1A
TS20: trigeminal ganglion	Present		1A
TS20: vertebral cartilage condensation	Present		1A
TS20: mandibular process mesenchyme	Present		1A	Expression in the mesenchyme includes regions of the tooth primordia.
TS20: maxillary process mesenchyme	Present		1A	Expression in the mesenchyme includes regions of the tooth primordia.
TS20: metanephros	Strong		1A	Strong expression was detected in the mesenchyme and the epithelium.
TS20: mesenchyme of metanephros	Strong		1A
TS20: blood vessel	Present		1A	Expression was in large blood vessels.
TS20: inner ear	Present	Regionally restricted	1A	Expression was in the otic vesicle.
TS20: intestine	Strong		1A	Id2 expression was much higher in these tissues than Id1.
TS20: liver	Strong		1A	Id2 expression was much higher in these tissues than Id1.
TS20: lung epithelium	Strong		1A	Id2 expression was much higher in these tissues than Id1.
TS20: heart atrium	Present		1A	In the heart, expression was more extensive in the atrium.

Structure	Level	Pattern	Image	Note
TS20: adenohypophysis	Strong
TS20: brain	Strong
TS20: genital tubercle	Strong
TS20: heart	Strong
TS20: liver	Strong
TS20: lung epithelium	Strong
TS20: mesenchyme of metanephros	Strong
TS20: mesenchyme of urogenital sinus	Strong
TS20: neurohypophysis pars nervosa	Strong
TS20: olfactory epithelium	Strong
TS20: trigeminal ganglion	Strong
TS20: vertebral cartilage condensation	Strong
TS20: tongue	Weak
TS20: intestine	Strong	Regionally restricted		Expression was in mucosa and external layer.
TS20: metanephros	Strong	Regionally restricted		Expression was in epithelium and mesenchyme.
TS20: mandibular process mesenchyme	Strong	Regionally restricted		Expression in the mesenchyme includes regions of the tooth primordia.
TS20: maxillary process mesenchyme	Strong	Regionally restricted		Expression in the mesenchyme includes regions of the tooth primordia.
TS20: gland	Strong	Regionally restricted		Strong expression was detected in the submaxillary gland.
TS20: inner ear epithelium	Present

Structure	Level	Pattern	Image	Note
TS20: spinal cord mantle layer	Present	Graded	2A	Expression was detected throughout the ventricular zone and the mantle in a dorso-ventral gradient.
TS20: spinal cord ventricular layer	Present	Graded	2A	Expression was detected throughout the ventricular zone and the mantle in a dorso-ventral gradient.
TS20: spinal cord roof plate	Strong		2A
TS20: hindbrain ventricular layer	Present	Regionally restricted	2A	Ventricular zone inter-rhombomeric expression boundary was at r1/r2.
TS20: diencephalon	Present	Regionally restricted	2A	Expression was strongest in the subcommissural part of prosomere 1. Expression in prosomere 4 extends from the eminentia thalami into the supraoptic paraventricular area.
TS20: diencephalon mantle layer	Weak	Regionally restricted	2A	Mantle regions show weak expression, including parts of prosomere 1, and p3 (ventral thalamus).
TS20: mammillary area	Present		2A
TS20: telencephalon	Strong	Regionally restricted	2A	Intense labeling was detected in the archicortex at the site of the tela chorioidea attachment. Part of the adjoining hippocampal primordia is negative. Prosomere 6 labeling was found in the olfactory bulb and septal primordia.
TS20: neocortex	Strong	Graded	2A	A strong rostro-caudal gradient was detected along the neocortex.
TS20: cortical preplate	Present		2A	Expression is preferentially found in the mantle zone, or preplate, compared to the ventricular zone.
TS20: neurohypophysis infundibulum	Present		2A

Structure	Level	Pattern	Image	Note
TS20: spinal cord mantle layer	Present	Graded	2B	Expression was detected throughout the ventricular zone and the mantle in a dorso-ventral gradient.
TS20: spinal cord ventricular layer	Present	Graded	2B	Expression was detected throughout the ventricular zone and the mantle in a dorso-ventral gradient.
TS20: spinal cord roof plate	Strong		2B
TS20: spinal cord	Present	Regionally restricted	2B	Two longitudinal columns of expressing cells that may flank the alar/basal boundary were also observed.
TS20: hindbrain mantle layer	Present	Regionally restricted	2B	The mantle expression boundary was detected at about r4/r5.
TS20: diencephalon mantle layer	Weak	Regionally restricted	2B	Weak expression was detected in the mantle region of prosomeres 1, 2, and 3.
TS20: diencephalon	Present	Regionally restricted	2B	Expression in prosomere 4 extends from the eminentia thalami into the supraoptic paraventricular area.
TS20: telencephalon	Strong	Regionally restricted	2B	Intense labeling was detected in the archicortex at the site of the tela chorioidea attachment. Part of the adjoining hippocampal primordia is negative.
TS20: neocortex	Strong	Graded	2B	A strong rostro-caudal gradient was detected along the neocortex.

Structure	Level	Pattern	Image	Note
TS20: spinal cord mantle layer	Present	Graded	2C	Expression was detected throughout the ventricular zone and the mantle in a dorso-ventral gradient.
TS20: spinal cord ventricular layer	Present	Graded	2C	Expression was detected throughout the ventricular zone and the mantle in a dorso-ventral gradient.
TS20: spinal cord roof plate	Strong		2C
TS20: hindbrain ventricular layer	Present	Regionally restricted	2C	A more lateral section showed ventricular zone expression extending to r1 and the cerebellar area.
TS20: hindbrain mantle layer	Present	Regionally restricted	2C	Mantle expression terminated at r1/r2.
TS20: 4th ventricle choroid plexus	Strong	Regionally restricted	2C	Expression was strong in the tela chorioidea of the rhombencephalon.
TS20: cerebellum primordium	Present	Regionally restricted	2C	Expression was detected in the isthmocerebellar plate, with expression in the isthmic area and rhombic lip, but less or no expression in the interposed region.
TS20: rhombic lip	Present	Regionally restricted	2C	Expression was detected in the isthmocerebellar plate, with expression in the isthmic area and rhombic lip, but less or no expression in the interposed region.
TS20: midbrain	Present	Regionally restricted	2C	Expression was detected in the entire alar midbrain and the tectum. There was less expression in the midbrain basal plate, except for a cluster of cells in the region of the primordium of the substantia nigra.
TS20: midbrain roof plate	Present		2C
TS20: telencephalon	Strong	Regionally restricted	2C	Intense labeling was detected in the archicortex at the site of the tela chorioidea attachment.
TS20: neocortex	Strong	Graded	2C	A strong rostro-caudal gradient was detected along the neocortex.

Structure	Level	Pattern	Image	Note
TS22: hindbrain	Present	Regionally restricted	3A	Expression was largely limited to an alar domain extending across r8-r2. A subpial crescent of labeled cells was also noted.
TS22: cerebellum	Present	Diffuse	3A	Laterally, cerebellar expression was diffuse and found in the primordia of the cerebellar nuclei and Purkinje cells.
TS22: midbrain-hindbrain junction	Present	Regionally restricted	3A	Expression was detected in alar territory corresponding to the position of the parabigeminal and parabrachial nuclei.
TS22: lateral ganglionic eminence	Absent		3A
TS22: medial ganglionic eminence	Absent		3A
TS22: neocortex	Present	Regionally restricted	3A	Expression was detected in the rostral-caudal and latero-medial maturational gradients. Expression was in the mantle zone, with little or no expression in the proliferative zone.
TS22: main olfactory bulb	Strong		3A

Structure	Level	Pattern	Image	Note
TS22: cerebellum ventricular layer	Present	Regionally restricted		Expression was detected in the ventricular zone only in the midline area.
TS22: midbrain ventricular layer	Present	Regionally restricted		Midbrain expression was mainly in the ventricular zone of caudal tectal plate.
TS22: midbrain	Present	Regionally restricted		Expression was found in the basal plate in the region of the developing substantia nigra.
TS22: epithalamus	Weak	Scattered
TS22: diencephalon	Present	Non-Uniform		Weak expression was in the ventral parts of prosomeres 1 and 2. Expression was detected in the eminentia thalami.
TS22: mammillary area	Present
TS22: neurohypophysis infundibulum	Present
TS22: forebrain	Present	Regionally restricted		Expression in prosomere 5 was detected.

Structure	Level	Pattern	Image	Note
TS24: cerebellum	Present	Patchy	3C	Irregular patches of expression in groups of cells that were likely to be immature Purkinje cells. Some sections show gaps of expression while others (particularly anterior or median areas) may not.
TS24: cerebellum external granule cell layer	Absent		3C
TS24: deep cerebellar nucleus	Absent		3C
TS24: pretectum	Present	Regionally restricted	3C	Expression was detected in prosomere 1 in the dorsomedial periventricular areas of the pretectum.
TS24: epithalamus	Present		3C
TS24: dorsal thalamus	Weak		3C
TS24: diencephalon	Present	Regionally restricted	3C	The diencephalon showed expression in prosomeres 1 and 2, but prosomere 3 was negative.
TS24: telencephalon	Strong	Regionally restricted	3C	Much of prosomere 4 was negative. However, there was some expression in the archicortex up to the apex of the intraventricular convex curve. In prosomere 5, the neocortical and paleocortical plates, subplate and intermediate zones showed strong expression, while the ventricular zone does not.
TS24: cortical plate	Strong	Regionally restricted	3C	The rostral expression boundary stopped abruptly in the region of the anterior olfactory nucleus.
TS24: cortical subplate	Strong	Regionally restricted	3C	The rostral expression boundary stopped abruptly in the region of the anterior olfactory nucleus.
TS24: cerebral cortex intermediate zone	Strong	Regionally restricted	3C	Expression was continuous with the olfactory bulb.
TS24: cerebral cortex ventricular layer	Absent		3C
TS24: main olfactory bulb	Strong	Regionally restricted	3C	Expression was found in the anlage of the glomerular layer, the deep olfactory bulb layers, and the anterior olfactory nucleus.

Structure	Level	Pattern	Image	Note
TS24: medulla oblongata	Present	Regionally restricted	3D	Expression was detected in the corpus pontobulbare.
TS24: pons	Present		3D
TS24: telencephalon	Strong	Regionally restricted	3D	In prosomere 5, the neocortical and paleocortical plates, subplate and intermediate zones showed strong expression, while the ventricular zone does not.
TS24: cortical plate	Strong	Regionally restricted	3D	The rostral expression boundary stopped abruptly in the region of the anterior olfactory nucleus.
TS24: cortical subplate	Strong	Regionally restricted	3D	The rostral expression boundary stopped abruptly in the region of the anterior olfactory nucleus.
TS24: cerebral cortex ventricular layer	Absent		3D
TS24: cerebral cortex intermediate zone	Strong	Regionally restricted	3D	Expression was continuous with the olfactory bulb.
TS24: main olfactory bulb	Strong	Regionally restricted	3D	Expression was found in the anlage of the glomerular layer, the deep olfactory bulb layers, and the anterior olfactory nucleus.
TS24: telencephalon septum	Present	Regionally restricted	3D	Expression was detected in the medial and lateral septal nuclei.

Structure	Level	Pattern	Image	Note
TS24: superior colliculus	Weak	Regionally restricted		Weak expression was detected in the superficial stratum of the superior colliculus.
TS24: midbrain	Weak	Regionally restricted		A faint patch of label was detected in the basal plate that appears to correspond with the substantia nigra.
TS24: inferior colliculus	Absent