Probe:	3' UTR clone 21
Probe preparation:	Antisense labelled with digoxigenin RNA
Visualized with:	Alkaline phosphatase

Structure	Level	Pattern	Image	Note
TS15: central nervous system	Present		4A	There is even expression in the entire neural tube encompassing the anlagen of the brain and spinal cord.
TS15: somite	Absent		4A

Structure	Level	Pattern	Image	Note
TS17: future spinal cord	Present		4B	Expression is strongest in the more caudal, developmentally younger regions.
TS17: tail future spinal cord	Present		4B	Expression is strongest in the more caudal, developmentally younger regions.
TS17: nose	Present		4B	Expression is present in restricted areas.
TS17: branchial arch	Present	Regionally restricted	4B	Expression is present in maxillar, mandibular, and second branchial arch anlagen.
TS17: central nervous system	Present	Non-Uniform	4B
TS17: trunk myotome	Present	Regionally restricted	4B	Expression is present in subregions.
TS17: telencephalon	Present		4B	This is the region of the brain with the highest expression levels.
TS17: somite	Present	Regionally restricted	4B	Expression is seen as segmental stripes in the mature, rostral somite derivatives.

Structure	Level	Pattern	Image	Note
TS15: central nervous system	Present		4C	There is even expression in the entire neural tube encompassing the anlagen of the brain and spinal cord.
TS15: tail central nervous system	Present		4C	Expression is present in the developmentally youngest aspects of the neural anlagen near the terminal sprouting zone of the embryo.
TS15: somite	Absent		4C

Structure	Level	Pattern	Image	Note
TS17: future spinal cord	Present		4D
TS17: tail future spinal cord	Present		4D	Expression in present in the neural anlagen.
TS17: paraxial mesenchyme	Absent		4D	There is no expression in the younger somitic mesoderm caudal to the hindlimb bud (whereas there is expression in the mature, rostral somite derivatives).

Structure	Level	Pattern	Image	Note
TS17: brain	Present	Non-Uniform	4E	Expression delineates certain borders. It is slightly enhanced in the rostral mesencephalon delineating the border toward the diencephalon and in the rostral half of the diencephalon.
TS17: diencephalon	Present	Non-Uniform	4E	Expression delineates certain borders. It is slightly enhanced in the rostral mesencephalon delineating the border toward the diencephalon and in the rostral half of the diencephalon.
TS17: midbrain	Present	Non-Uniform	4E	Expression delineates certain borders. It is slightly enhanced in the rostral mesencephalon delineating the border toward the diencephalon and in the rostral half of the diencephalon.
TS17: nose	Present		4E	Expression is present in restricted areas.
TS17: branchial arch	Present		4E	Expression is present in maxillar, mandibular, and second branchial arch anlagen.
TS17: telencephalon	Present		4E	This is the region of the brain with the highest expression levels.

Structure	Level	Pattern	Image	Note
TS17: brain	Present	Non-Uniform	4F	Expression delineates certain borders. It is slightly enhanced in the rostral mesencephalon delineating the border toward the diencephalon and in the rostral half of the diencephalon.
TS17: diencephalon	Present	Non-Uniform	4F	Expression delineates certain borders. It is slightly enhanced in the rostral mesencephalon delineating the border toward the diencephalon and in the rostral half of the diencephalon.
TS17: midbrain	Present	Non-Uniform	4F	Expression delineates certain borders. It is slightly enhanced in the rostral mesencephalon delineating the border toward the diencephalon and in the rostral half of the diencephalon.
TS17: telencephalon	Present		4F	This is the region of the brain with the highest expression levels.
TS17: branchial arch	Present		4F	Expression is present in maxillar, mandibular, and second branchial arch anlagen.
TS17: nose	Present		4F	Expression is present in restricted areas.

Structure	Level	Pattern	Image	Note
TS17: hindbrain ventricular layer	Strong		4G
TS17: hindbrain marginal layer	Absent		4G

Structure	Level	Pattern	Image	Note
TS17: trunk myotome	Present	Regionally restricted	4H	Expression is centered upon the middle third of each segment. In addition the dorsalmost (epaxial) moiety is devoid of expression, the central moiety has the highest expression, and the ventral (hypaxial) moiety has just started to express.
TS17: future spinal cord	Present	Non-Uniform	4H	Expression is strongest in the more caudal, developmentally younger regions.
TS17: tail future spinal cord	Present	Non-Uniform	4H	Expression is strongest in the more caudal, developmentally younger regions.

Structure	Level	Pattern	Image	Note
TS17: trunk myotome	Present	Regionally restricted	4I	Expression is centered upon the middle third of each segment; it does not cover the whole width of the myotomes.

Structure	Level	Pattern	Image	Note
TS17: trunk myotome	Present	Regionally restricted	4J	Expression is present in the central moiety first, then in the ventral (hypaxial) moiety. The dorsalmost (epaxial) moiety is devoid of expression.
TS17: neural tube	Present	Regionally restricted	4J	Expression is present in the differentiating neural tube but not in its dorsalmost region and ventrolateral horns.
TS17: nephric duct	Absent		4J	There is no signal the thoracic hindlimb level (although is detected at the rostral hindlimb level).

Structure	Level	Pattern	Image	Note
TS17: neural tube	Present	Regionally restricted	4K	Expression is present in the differentiating neural tube but not in its dorsalmost region and ventrolateral horns.
TS17: nephric duct	Weak	Regionally restricted	4K	Signal is detected at the rostral hindlimb level (but not at thoracic or caudal hindlimb levels).

Structure	Level	Pattern	Image	Note
TS17: neural tube	Present	Regionally restricted	4L	Expression is present in the differentiating neural tube but not in its dorsalmost region and ventrolateral horns.
TS17: nephric duct	Absent		4L	There is no signal the caudal hindlimb level (although is detected at the rostral hindlimb level).

Structure	Level	Pattern	Image	Note
TS15: nephric duct	Absent

Structure	Level	Pattern	Image	Note
TS19: brain	Weak		5A
TS19: future spinal cord	Present		5A	Expression is clearly detectable only in the lumbar to tail regions.
TS19: tail future spinal cord	Present		5A	Expression is clearly detectable only in the lumbar to tail regions.
TS19: trunk myotome	Present		5A
TS19: limb mesenchyme	Present	Regionally restricted	5A	Expression is present in the precartilaginous skeletal anlagen of the limbs.
TS19: head	Present		5A	Expression is present in a distinct craniofacial region.
TS19: telencephalon	Present		5A
TS19: somite	Present		5A	Expression is upregulated all along the rostrocaudal trunk axis.

Structure	Level	Pattern	Image	Note
TS19: hindbrain	Present	Regionally restricted	5B	Expression is strongest in the hindbrain, excluding the floor plate.
TS19: hindbrain floor plate	Absent		5B

Structure	Level	Pattern	Image	Note
TS19: neural tube ventricular layer	Present	Non-Uniform	5C	In the dorsal spinal cord there is weak uniform expression in the ventricular region. In the ventral spinal cord expression is enhanced near the sulcus limitans and dorsally to the floor plate.
TS19: spinal ganglion	Weak	Non-Uniform	5C	Weak expression is associated with the surfaces.
TS19: trunk myotome	Present		5C

Structure	Level	Pattern	Image	Note
TS19: neural tube ventricular layer	Weak		5D	Expression is strongest in the ventricular layer of the ventral trunk neural tube.
TS19: trunk myotome	Present		5D , 5E

Structure	Level	Pattern	Image	Note
TS19: neural tube ventricular layer	Present		5F
TS19: trunk myotome	Present	Non-Uniform	5F	Expression is strongest in the central moiety and weaker in the ventral (hypaxial) moiety.

Structure	Level	Pattern	Image	Note
TS19: tail future spinal cord	Present		5G
TS19: trunk myotome	Present	Non-Uniform	5G	Expression is strongest in the central moiety and weaker in the elongated ventral (hypaxial) moiety and in the small dorsalmost (epaxial) moiety.
TS19: spinal ganglion	Weak	Non-Uniform	5G	Weak expression is associated with the surfaces.

Structure	Level	Pattern	Image	Note
TS19: tail future spinal cord	Present		5H
TS19: trunk myotome	Present		5H
TS19: limb mesenchyme	Present	Regionally restricted	5H	Expression is present in the precartilaginous skeletal anlagen of the limbs.
TS19: spinal ganglion	Weak	Non-Uniform	5H	Weak expression is associated with the surfaces.

Structure	Level	Pattern	Image	Note
TS19: limb mesenchyme	Present	Regionally restricted	5I	Expression is present in the precartilaginous skeletal anlagen of the limbs.

Structure	Level	Pattern	Image	Note
TS19: nose	Present		5J	Expression is present in restricted areas.
TS19: head	Present		5J	Expression is present in a distinct craniofacial region, such as the caudal pharyngeal region, ventrally to the primary head vein at the level of the inner ear. It does not appear to be present in muscle anlagen or chondrogenic areas.