Probe:	Err1 cDNA1
Probe preparation:	Antisense labelled with S35 RNA

Structure	Level	Pattern	Image	Note
TS13: primitive ventricle	Present		1B
TS13: trophectoderm	Present		1B
TS13: yolk sac mesenchyme	Present		1B
TS13: neural fold	Weak	Regionally restricted	1B	Expression was detected within the neural groove cells.

Structure	Level	Pattern	Image	Note
TS17: common atrial chamber cardiac muscle	Present		2A
TS17: primitive ventricle	Present	Regionally restricted	2A	Expression was detected in the trabeculations of the common ventricular chamber and in the interventricular septum.
TS17: primitive ventricle cardiac muscle	Present	Regionally restricted	2A	Expression was detected in the muscular part (non-trabeculated) of the interventricular septum.
TS17: dorsal mesocardium	Present		2A
TS17: endocardial cushion	Absent		2A	The endocardial cushion associated with the wall of the atrio-ventricular canal is not labelled.

Structure	Level	Pattern	Image	Note
TS21: limb musculature	Present	Regionally restricted	2B	Expression was detected in the premuscular mass.
TS21: epidermis	Present	Regionally restricted	2B	Expression was detected in limb epidermis.

Structure	Level	Pattern	Image	Note
TS25: forelimb epidermis	Present		2C
TS25: forelimb musculature	Present		2C

Structure	Level	Pattern	Image	Note
TS21: heart atrium	Present			At E13.5, labelling displays the same basic characteristics as observed at E10.5.
TS21: heart ventricle	Present			At E13.5, labelling displays the same basic characteristics as observed at E10.5.

Structure	Level	Pattern	Image	Note
TS23: heart atrium	Present	Regionally restricted		Expression was detected in the atrial wall.
TS23: ventricle cardiac muscle	Present	Regionally restricted		Expression was detected in the trabecules and in the wall of the myocardial ventricles.

Structure	Level	Pattern	Image	Note
TS25: heart atrium	Present	Regionally restricted		Expression was detected in the wall of the atrium.
TS25: ventricle cardiac muscle	Present	Regionally restricted		Expression was detected in the trabecules and in the wall of the myocardial ventricles.

Structure	Level	Pattern	Image	Note
TS17: dorsal root ganglion	Present		3A
TS17: future spinal cord	Present		3A
TS17: heart	Present		3A
TS17: brain	Present		3A	Expression was detected at a high level in the cephalic neuroepithelium.
TS17: central nervous system	Present	Graded	3A	All along the anteroposterior axis, expression was noted in a dorso-ventral gradient in the neural tube.

Structure	Level	Pattern	Image	Note
TS17: neural tube	Present	Regionally restricted	3B	Expression was detected in differentiating cells of the intermediate zone in the ventral and peripheral parts of the neural tube and weakly in the ventricular zone.
TS17: dorsal root ganglion	Present		3B

Structure	Level	Pattern	Image	Note
TS21: cerebral cortex	Present		3C

Structure	Level	Pattern	Image	Note
TS21: hypothalamus	Present		3D
TS21: thalamus	Present		3D
TS21: midbrain	Present	Regionally restricted	3D	Labelling is much more in the intermediate zone of the midbrain than in the mantle.

Structure	Level	Pattern	Image	Note
TS21: midbrain	Present	Regionally restricted		Expression was periventricular in the mesencephalon.
TS21: adenohypophysis	Present
TS21: cerebral cortex	Present	Regionally restricted		Expression was detected in the neopallial cortex.
TS21: cerebellum	Present	Regionally restricted		Expression was detected in the cerebellar peduncle.
TS21: pons	Present	Regionally restricted		Expression was detected in the basal region of the pons.
TS21: medulla oblongata basal plate	Present	Regionally restricted		Expression was detected in the medullary raphe.
TS21: esophagus	Present	Regionally restricted		Expression was detected in the entrance of the esophagus.
TS21: stomach	Present	Regionally restricted		Expression was detected in the mucosal lining of the stomach.
TS21: liver	Weak
TS21: lung	Weak
TS21: urinary system	Present	Regionally restricted		Expression was detected in the definitive and vesical region of the urogenital system.
TS21: gonad	Absent

Structure	Level	Pattern	Image	Note
TS21: corpus striatum	Present	Regionally restricted	3F	Expression was detected in median and lateral corpus striatum. The caudate nucleus and putamen were also labelled.

Structure	Level	Pattern	Image	Note
TS21: trigeminal ganglion	Present		3G
TS21: vestibulo-cochlear ganglion	Present		3G

Structure	Level	Pattern	Image	Note
TS21: cerebral cortex intermediate zone	Present		3H

Structure	Level	Pattern	Image	Note
TS23: cerebellum	Present	Regionally restricted	3I	Expression was detected in the rostral extension of the primitive cerebellum.

Structure	Level	Pattern	Image	Note
TS23: cerebral cortex	Weak		3J	Expression was detected in the periventricular region of the cerebral trunk but its level decreases dramatically at this stage.

Structure	Level	Pattern	Image	Note
TS23: accessory nerve	Present
TS23: adenohypophysis	Present
TS23: anal canal	Present
TS23: choroid plexus	Present
TS23: cochlear ganglion	Present
TS23: glossopharyngeal ganglion	Present
TS23: gut	Present
TS23: larynx aditus	Present
TS23: mammary gland primordium	Present
TS23: oral cavity	Present
TS23: spinal cord	Present
TS23: thyroid gland	Present
TS23: trigeminal ganglion	Present
TS23: lung	Ambiguous			Relative to E13.5, the thymic rudiment and lung are less labelled.
TS23: thymus primordium	Ambiguous			Relative to E13.5, the thymic rudiment and lung are less labelled.
TS23: esophagus epithelium	Weak

Structure	Level	Pattern	Image	Note
TS25: spinal cord	Present		3K	All the spinal cord is labelled, but the axons which emerge from the spinal cord were not labelled.
TS25: cerebellum	Present	Regionally restricted	3K	Expression was detected in the cerebellar peduncle.
TS25: pons	Present		3K

Structure	Level	Pattern	Image	Note
TS23: olfactory epithelium	Present		4A
TS23: vomeronasal organ	Present		4A
TS23: cerebral cortex	Present	Regionally restricted	4A	Expression was detected in the neopallial cortex.

Structure	Level	Pattern	Image	Note
TS25: epidermis	Present	Regionally restricted	4D	Expression was detected in differentiating cells of the suprabasal layer immediately above the basal cell layer and not in the proliferating cells of the Malpighian layer.

Structure	Level	Pattern	Image	Note
TS25: vagus ganglion	Present

Structure	Level	Pattern	Image	Note
TS21: vomeronasal organ	Present	Regionally restricted	5A	Expression was detected in the pharyngeal wall of the vomeronasal organ.

Structure	Level	Pattern	Image	Note
TS21: thymus primordium	Present		5B	Expression was detected in the lobes of the thymic rudiment.

Structure	Level	Pattern	Image	Note
TS23: intestine epithelium	Present		5C

Structure	Level	Pattern	Image	Note
TS23: urogenital sinus	Present	Regionally restricted	5E	Expression was detected in the internal epithelium of the urogenital sinus.

Structure	Level	Pattern	Image	Note
TS21: mammary gland primordium epithelium	Present		6A

Structure	Level	Pattern	Image	Note
TS21: corpus striatum	Strong	Regionally restricted		Strong expression was noted in the lateral and median corpus striatum. Moderate expression was noted in the caudate/putamen.
TS21: cerebral cortex	Strong	Regionally restricted		Expression was detected in the roof of the neopallial cortex.
TS21: accessory nerve	Moderate
TS21: choroid plexus	Moderate
TS21: telencephalon dura mater	Moderate	Regionally restricted		Expression was detected in the falx cerebri.
TS21: telencephalon	Strong	Regionally restricted		Expression was detected in the wall of the telencephalon.
TS21: alar columns	Strong
TS21: cochlear ganglion	Strong
TS21: crus commune	Strong
TS21: external auditory meatus	Strong
TS21: glossopharyngeal ganglion	Strong
TS21: hypothalamus	Strong
TS21: medulla oblongata alar plate	Strong
TS21: medulla oblongata mantle layer	Strong
TS21: olfactory epithelium	Strong
TS21: semicircular canal	Strong
TS21: superior cervical ganglion	Strong
TS21: thalamus	Strong
TS21: trigeminal ganglion	Strong
TS21: vagus ganglion	Strong
TS21: vestibular ganglion	Strong
TS21: metencephalon	Strong	Regionally restricted		Expression was detected in the rhombic lip.
TS21: pons	Strong	Regionally restricted		Expression was detected in the tegmentum of pons
TS21: medulla oblongata	Moderate	Regionally restricted		Expression was detected in the medullary raphe.
TS21: spinal cord	Strong	Regionally restricted		Expression was detected in the fundamental layer (motor neurons) of the spinal cord.

Structure	Level	Pattern	Image	Note
TS23: cerebral cortex	Moderate	Regionally restricted		Expression was detected in the roof of the neopallial cortex.
TS23: choroid plexus	Weak
TS23: medulla oblongata mantle layer	Weak
TS23: vagus ganglion	Weak
TS23: telencephalon	Weak	Regionally restricted		Expression was detected in the wall of the telencephalon.
TS23: pons	Weak	Regionally restricted		Expression was detected in the tegmentum of pons.
TS23: medulla oblongata	Weak	Regionally restricted		Expression was detected in the medullary raphe.
TS23: alar columns	Moderate
TS23: cochlear ganglion	Moderate
TS23: glossopharyngeal ganglion	Moderate
TS23: olfactory epithelium	Moderate
TS23: trigeminal ganglion	Moderate
TS23: vestibular ganglion	Moderate
TS23: spinal cord	Moderate	Regionally restricted		Expression was detected in the fundamental layer (motor neurons) of the spinal cord.

Structure	Level	Pattern	Image	Note
TS25: telencephalon	Weak	Regionally restricted		Expression was detected in the wall of the telencephalon.
TS25: pons	Weak	Regionally restricted		Expression was detected in the tegmentum of pons.
TS25: alar columns	Moderate
TS25: spinal cord	Moderate	Regionally restricted		Expression was detected in the fundamental layer (motor neurons) of the spinal cord.
TS25: trigeminal ganglion	Weak
TS25: vagus ganglion	Weak