Probe:	Hox-1.4 probe2
Probe preparation:	Antisense labelled with S35 RNA
Visualized with:	Autoradiography

Structure	Level	Pattern	Image	Note
TS20: central nervous system	Present	Regionally restricted	1A/B	Transcripts showed a marked anterior-to-posterior fall in abundance over the anterior region of the spinal cord. This fall in abundance was anterior to prevertebra 1 in dorsal parts of the spinal cord but posterior to prevertebra 5 in ventral parts.
TS20: spinal cord	Present	Regionally restricted	1A/B	Transcripts showed a marked anterior-to-posterior fall in abundance over the anterior region of the spinal cord. This fall in abundance was anterior to prevertebra 1 in dorsal parts of the spinal cord but posterior to prevertebra 5 in ventral parts.

Structure	Level	Pattern	Image	Note
TS20: central nervous system	Present	Regionally restricted	2A
TS20: medulla oblongata	Present	Regionally restricted	2A	The anterior boundary was found in the mid-myelencephalon. The Hox1.4 boundary was located slightly posterior to the Hox2.6 (Fig. 2B) and Hox 5.1 (Fig. 2C) boundaries.

Structure	Level	Pattern	Image	Note
TS20: C1 vertebral cartilage condensation	Absent		3A
TS20: C2 vertebral cartilage condensation	Weak		3A
TS20: C3 vertebral cartilage condensation	Strong		3A
TS20: vertebral cartilage condensation	Present	Graded	3A	A gradual and progressive decline in the abundance of transcripts was noted posterior to prevertebra 7.
TS20: lumbar vertebral cartilage condensation	Present		3A	Level of labeling remained above background even within the lumbar region.
TS20: lung	Present	Regionally restricted	3A	Transcripts were found in the mesodermal derivatives but not the lining endothelium of the lung.

Structure	Level	Pattern	Image	Note
TS20: axial skeleton	Present		4A

Structure	Level	Pattern	Image	Note
TS20: thymus primordium	Present		5A/B
TS20: thyroid gland	Present		5A/B
TS20: trachea	Present	Regionally restricted	5A/B	Expression in the mesodermal derivatives (not lining endothelium) of the trachea.

Structure	Level	Pattern	Image	Note
TS20: stomach	Present	Regionally restricted	6A/B	Transcripts were abundant in the mesodermal derivatives.
TS20: liver	Absent		6A/B
TS20: mesonephros	Present		6A/B
TS20: metanephros	Present		6A/B
TS20: testis	Absent		6A/B
TS20: stomach epithelium	Absent		6A/B	No expression in the lining endothelium of the stomach.

Structure	Level	Pattern	Image	Note
TS20: gut	Present	Regionally restricted		Expression in posterior regions of the intestine.

Structure	Level	Pattern	Image	Note
TS13: lateral plate mesoderm	Present	Regionally restricted	7A/B	Transcripts were confined to more posterior parts, lateral plate mesoderm, somtatic mesoderm, and neurectoderm.
TS13: neural ectoderm	Present	Regionally restricted	7A/B	Transcripts were confined to more posterior parts, lateral plate mesoderm, somtatic mesoderm, and neurectoderm.
TS13: trunk paraxial mesenchyme	Present	Regionally restricted	7A/B	Transcripts were confined to more posterior parts, lateral plate mesoderm, somtatic mesoderm, and neurectoderm.

Structure	Level	Pattern	Image	Note
TS15: future spinal cord	Present		8A/B	Expression in lateral plate mesoderm, somatic mesoderm, and neurectoderm.
TS15: trunk mesenchyme	Present		8A/B	Expression in lateral plate mesoderm, somatic mesoderm, and neurectoderm.
TS15: trunk paraxial mesenchyme	Present		8A/B	Expression in lateral plate mesoderm, somatic mesoderm, and neurectoderm.