Probe:	Id1 cDNA
Probe preparation:	Antisense labelled with S35 RNA
Visualized with:	Autoradiography

Structure	Level	Pattern	Image	Note
TS7: ectoderm	Present	Regionally restricted	1_E5.5 left	Expressed in the proximal side of the embryonic ectoderm juxtaposed to the extraembryonic ectoderm.
TS7: extraembryonic visceral endoderm	Present		1_E5.5 left
TS7: extraembryonic ectoderm	Absent		1_E5.5 left

Structure	Level	Pattern	Image	Note
TS9: embryo ectoderm	Present		1_E6.5 upper left	Same as that observed at E5.5.
TS9: extraembryonic visceral endoderm	Present		1_E6.5 upper left	Same as that observed at E5.5.
TS9: extraembryonic ectoderm	Absent		1_E6.5 upper left

Structure	Level	Pattern	Image	Note
TS11: allantois	Present		2A/B
TS11: chorion	Present		2A/B
TS11: yolk sac endoderm	Present	Regionally restricted	2A/B	Expressed in the cell layer in the visceral yolk sac which is derived from the proximal endoderm.
TS11: embryo ectoderm	Present	Regionally restricted	2A/B	Expressed in the proximal portion.
TS11: embryo endoderm	Present	Regionally restricted	2A/B	Expressed in the proximal portion.
TS11: embryo mesoderm	Present	Regionally restricted	2A/B	Expressed in the proximal portion.

Structure	Level	Pattern	Image	Note
TS19: neural tube roof plate	Strong		3A/E
TS19: neural tube ventricular layer	Present	Regionally restricted	3A/E	Weaker expression throughout the rest of the ventricular zone except in the dorsal one-third.
TS19: neural tube floor plate	Absent		3A/E

Structure	Level	Pattern	Image	Note
TS19: midbrain	Present		3B/F
TS19: diencephalon	Present		3B/F	Expression is much weaker and more restricted.
TS19: telencephalon	Present	Regionally restricted	3B/F	Expressed in the medial side of the telencephalic vesicles, located laterally to the third ventricle.

Structure	Level	Pattern	Image	Note
TS19: hindbrain	Present		3C/G

Structure	Level	Pattern	Image	Note
TS19: myelencephalon	Present		3D/H

Structure	Level	Pattern	Image	Note
TS20: diencephalon	Present		4A/B
TS20: midbrain	Present		4A/B
TS20: telencephalon	Present	Regionally restricted	4A/B	Expressed in the medial side of the telencephalic vesicles, located laterally to the third ventricle.

Structure	Level	Pattern	Image	Note
TS22: midbrain ventricular layer	Present		4F/G

Structure	Level	Pattern	Image	Note
TS22: telencephalon ventricular layer	Present		4K/L
TS22: choroid plexus	Present		4K/L

Structure	Level	Pattern	Image	Note
TS24: brain ventricular layer	Present		4P/Q

Structure	Level	Pattern	Image	Note
TS19: otocyst epithelium	Present		6E/F
TS19: otocyst	Present		6E/F	Expressed in both the epithelium of the otic vesicle and its surrounding mesenchyme.

Structure	Level	Pattern	Image	Note
TS22: neural retinal epithelium	Present		7A/B
TS22: pigmented retinal epithelium	Absent		7A/B
TS22: lens	Present	Scattered	7A/B

Structure	Level	Pattern	Image	Note
TS19: nasal pit epithelium	Present	Non-Uniform	7F/G
TS19: nasal process	Present	Regionally restricted	7F/G	Expressed in the area surrounding the nasal placode.

Structure	Level	Pattern	Image	Note
TS22: olfactory epithelium	Present	Regionally restricted	7K/L	Expressed in the presumptive olfactory neuronal progenitors located next to the mesenchyme.
TS22: nasal mesenchyme	Present	Regionally restricted	7K/L	Expressed in the supporting cell layer, which is located adjacent to the lumen of the nasal cavity.

Structure	Level	Pattern	Image	Note
TS6: embryo	Absent
TS6: extraembryonic component	Absent

Structure	Level	Pattern	Image	Note
TS13: neural fold	Present

Structure	Level	Pattern	Image	Note
TS15: neural tube	Present
TS15: optic vesicle	Present

Structure	Level	Pattern	Image	Note
TS17: optic cup inner layer	Present
TS17: trigeminal ganglion	Present
TS17: lens vesicle	Present	Scattered
TS17: optic cup outer layer	Absent
TS17: olfactory placode	Present			Expression is not uniform throughout the placodal epithelium.
TS17: nasal process	Present	Regionally restricted		Expressed in the area surrounding the nasal placode.

Structure	Level	Pattern	Image	Note
TS19: Rathke's pouch	Present
TS19: infundibular recess of 3rd ventricle	Present

Structure	Level	Pattern	Image	Note
TS20: neural retinal epithelium	Present
TS20: lens vesicle	Present	Scattered
TS20: pigmented retinal epithelium	Absent

Structure	Level	Pattern	Image	Note
TS24: neural retina	Present
TS24: lens	Present	Scattered
TS24: pigmented retinal epithelium	Absent

Structure	Level	Pattern	Image	Note
TS28: decidua	Present	Regionally restricted		Expressed in the fibroblastic stromal cells prior to their decidulation.