Probe:	Sax-1 cDNA2
Probe preparation:	Antisense labelled with digoxigenin RNA

Structure	Level	Pattern	Image	Note
TS9: embryo	Absent

Structure	Level	Pattern	Image	Note
TS10: embryo ectoderm	Present	Regionally restricted	2A	The expression signal is delimited anteriorly by the end of the primitive streak, while posteriorly it fades out before reaching the caudal limit. It is strongest just lateral to the streak, waning more lateral and in the midline.
TS10: embryo endoderm	Absent		2A
TS10: embryo mesoderm	Absent		2A

Structure	Level	Pattern	Image	Note
TS10: embryo ectoderm	Present	Regionally restricted	2E	Expression is restricted to a broad pairwise stripe in the ectoderm aligning to the primitive streak.

Structure	Level	Pattern	Image	Note
TS11: primitive streak	Present	Regionally restricted	2B	Expression is present in the ectoderm of the primitive streak.
TS11: neural fold	Present	Regionally restricted	2B	Expression is present in the neural groove anterior to the node.

Structure	Level	Pattern	Image	Note
TS11: primitive streak	Present	Regionally restricted	2F	Expression is present in the ectoderm of the primitive streak.
TS11: embryo ectoderm	Present	Regionally restricted	2F	Expression is present in the neural groove anterior to the node.
TS11: neural fold	Present	Regionally restricted	2F	Expression is present in the neural groove anterior to the node.

Structure	Level	Pattern	Image	Note
TS12: neural ectoderm	Present	Regionally restricted	2C	The anterior end of expression ends at the level of the last-formed somite.

Structure	Level	Pattern	Image	Note
TS12: neural ectoderm	Present	Non-Uniform	2G	The strongest signal is in the open neural groove; the neural folds are generally weakly labeled. Cells in the ventral midline show less intense staining.
TS12: embryo mesenchyme	Absent		2G
TS12: surface ectoderm	Absent		2G

Structure	Level	Pattern	Image	Note
TS14: neural tube	Present	Regionally restricted		Expression is present in the recently formed neuroectoderm.
TS14: future spinal cord neural fold	Absent			There is no expression in fusing neural folds.
TS14: surface ectoderm	Absent

Structure	Level	Pattern	Image	Note
TS17: tail mesenchyme	Present	Regionally restricted	2D	Expression is present in the dorsal part of the tail bud.
TS17: tail neural tube	Present		2D

Structure	Level	Pattern	Image	Note
TS17: tail neural tube	Present	Regionally restricted	2H	Expression fades out anteriorly at the level of the most recently formed somite.

Structure	Level	Pattern	Image	Note
TS12: neural fold	Present			Expression levels in the mutant are only slightly reduced compared to those seen in wild type.
TS12: primitive streak	Present			Expression levels in the mutant are only slightly reduced compared to those seen in wild type.

Structure	Level	Pattern	Image	Note
TS13: primitive streak	Present	Regionally restricted	3A	The anterior end of expression ends at the level of the last-formed somite.
TS13: neural fold	Present		3A	Expression is present in the neural groove.

Structure	Level	Pattern	Image	Note
TS13: neural fold	Present		3B	Expression levels in the mutant are strongly reduced compared to those seen in wild type.
TS13: primitive streak	Present		3B	Expression levels in the mutant are strongly reduced compared to those seen in wild type.

Structure	Level	Pattern	Image	Note
TS15: tail neural tube	Strong	Regionally restricted	3C	Expression is present in the posterior neuropore. The anterior end of expression ends at the level of the last-formed somite.

Structure	Level	Pattern	Image	Note
TS15: tail neural tube	Absent		3D

Structure	Level	Pattern	Image	Note
TS11: embryo ectoderm	Present	Regionally restricted	4B	Expression spreads out laterally and extends anterior to the node, into the neural groove. In the primitive streak, expression is only present in the ectoderm cells.
TS11: primitive streak	Present	Regionally restricted	4B	Expression spreads out laterally and extends anterior to the node, into the neural groove. In the primitive streak, expression is only present in the ectoderm cells.
TS11: future spinal cord neural fold	Present		4B	Expression is present in the neural groove.
TS11: allantois	Absent		4B

Structure	Level	Pattern	Image	Note
TS11: embryo ectoderm	Present	Regionally restricted	4E	Expression spreads out laterally and extends anterior to the node, into the neural groove. In the primitive streak, expression is only present in the ectoderm cells.
TS11: primitive streak	Present	Regionally restricted	4E	Expression spreads out laterally and extends anterior to the node, into the neural groove. In the primitive streak, expression is only present in the ectoderm cells.
TS11: future spinal cord neural fold	Present		4E	Expression is present in the neural groove.
TS11: allantois	Absent		4E

Structure	Level	Pattern	Image	Note
TS11: embryo ectoderm	Present	Regionally restricted	4H	In the primitive streak, expression is only present in the columnar ectodermal cells, while there is no expression in the flat cells.
TS11: embryo endoderm	Absent		4H
TS11: embryo mesoderm	Absent		4H

Structure	Level	Pattern	Image	Note
TS15: future spinal cord	Present			Expression is as in wild type.

Structure	Level	Pattern	Image	Note
TS18: forebrain	Present		6A
TS18: hindbrain	Present		6A
TS18: midbrain	Present		6A
TS18: tail	Present		6A
TS18: telencephalon	Present		6A
TS18: future spinal cord	Present	Regionally restricted	6A	Expression is present in two bilateral, longitudinal stripes that extend caudally to the hindlimb bud.

Structure	Level	Pattern	Image	Note
TS18: neural tube lateral wall	Present	Regionally restricted	6B	Expression is present in the ventrolateral part of the neural tube, medially and dorsally adjacent to the ventral horns.

Structure	Level	Pattern	Image	Note
TS18: neural tube lateral wall	Present	Regionally restricted	6C	In the thorax, expression is as in wild type, present in two, bilateral stripes. There are pairwise stripes seen earlier and a second pair, located just ventral to the sulcus limitans.

Structure	Level	Pattern	Image	Note
TS18: neural tube lateral wall	Present	Regionally restricted	6D	The two, bilateral stripes of expression seen in wild type have fused ventrally in the lumbar area of the mutant.

Structure	Level	Pattern	Image	Note
TS18: neural tube lateral wall	Absent		6E	Unlike in wild type, there is no expression at this level of the neural tube.

Structure	Level	Pattern	Image	Note
TS15: future hindbrain	Present	Single cells		Expression is present in a few cells.

Structure	Level	Pattern	Image	Note
TS16: neural tube	Present	Regionally restricted		Expression is present to the level of the hindlimbs.
TS16: future midbrain	Present	Regionally restricted		Expression is present in the anterior mesencephalon/future tegmentum.

Structure	Level	Pattern	Image	Note
TS17: rhombomere 1 lateral wall	Strong	Regionally restricted	7B	There is strong expression in the basal plate.
TS17: rhombomere 1 floor plate	Absent		7B
TS17: rhombomere	Present	Regionally restricted	7B	Expression is present in rhombomeres caudal to R1; it is expressed in longitudinal stripes resembling the spinal cord signals.

Structure	Level	Pattern	Image	Note
TS16: future midbrain	Present	Regionally restricted		Expression is present in the pretectum.

Structure	Level	Pattern	Image	Note
TS17: neural tube	Present	Regionally restricted		Expression is present in continuous, pairwise stripes located in the ventricular zone adjacent to the ventral horns.

Structure	Level	Pattern	Image	Note
TS17: rhombomere	Present	Regionally restricted	7E	Expression is present in rhombomeres caudal to R1; it is expressed in longitudinal stripes resembling the spinal cord signals.

Structure	Level	Pattern	Image	Note
TS18: rhombomere 1 lateral wall	Strong	Regionally restricted	7H	There is strong expression in the basal plate.
TS18: rhombomere	Present	Regionally restricted	7H	Expression is present in rhombomeres caudal to R1; it is expressed in longitudinal stripes resembling the spinal cord signals.

Structure	Level	Pattern	Image	Note
TS19: midbrain	Strong	Regionally restricted	8A	Expression is mainly around the pretectum; labeling is in the axon tracts of the posterior commissure and the cells of the anterior pretectum. From the basal plate, two stripes of expression extend through the cranial two thirds of the midbrain.
TS19: diencephalon	Present	Regionally restricted	8A	Expression is present along the zona limitans intrathalamica, a thin layer of cells between the dorsal and ventral thalamus.

Structure	Level	Pattern	Image	Note
TS19: midbrain	Strong	Regionally restricted	8C	Expression is mainly around the pretectum; labeling is in the axon tracts of the posterior commissure, single, dispersed cells in the anterior pretectum, and a cluster of cels in the basal plate of the posterior pretectum.
TS19: diencephalon	Present	Regionally restricted	8C	Expression is present along the zona limitans intrathalamica, a thin layer of cells between the dorsal and ventral thalamus.