Probe:	Hoxa4 probe2
Probe preparation:	Antisense RNA

Structure	Level	Pattern	Image	Note
TS21: embryo	Present		8A/B
TS21: central nervous system	Strong		8A/B
TS21: limb	Weak	Regionally restricted	8A/B

Structure	Level	Pattern	Image	Note
TS11: allantois	Absent		9B/C
TS11: embryo ectoderm	Absent		9B/C
TS11: extraembryonic component	Absent		9B/C
TS11: embryo mesoderm	Present		9B/C

Structure	Level	Pattern	Image	Note
TS16: trunk mesenchyme	Present	Regionally restricted	10A/B	Expression was detected in the lateral plate mesoderm.
TS16: neural tube	Present		10A/B

Structure	Level	Pattern	Image	Note
TS16: head	Absent		10C/D
TS16: heart	Absent		10C/D
TS16: liver	Absent		10C/D
TS16: forelimb bud	Present	Uniform	10C/D
TS16: gut	Strong	Regionally restricted	10C/D	Expression was detected in the mesodermal layer of primitive intestine and stomach primordium.

Structure	Level	Pattern	Image	Note
TS16: trunk paraxial mesenchyme	Present		10E/F

Structure	Level	Pattern	Image	Note
TS20: hindbrain	Strong	Regionally restricted	11B	Shows the anterior boundary of expression within the myelencephalon (immediately posterior to the otic vesicle).
TS20: 4th ventricle	Present	Regionally restricted	11B	Boundary extends more anteriorly in the ventral floor of the ventricle than in the roof plate.
TS20: spinal cord	Present	Graded	11B	Expression is strong in upper spinal cord and decreases posteriorly, while remaining above background levels up to the most posterior regions of the spinal cord.

Structure	Level	Pattern	Image	Note
TS20: hindbrain	Strong	Regionally restricted	11C/D	Shows the anterior boundary of expression within the myelencephalon (immediately posterior to the otic vesicle).

Structure	Level	Pattern	Image	Note
TS23: medulla oblongata	Present			The ventral boundary of expression lies in the anterior part next to the limit between the medulla and the pons. Expression was present in the grey matter and absent in the white matter.

Structure	Level	Pattern	Image	Note
TS20: dorsal root ganglion	Present	Graded	11E	Intensity of signal gradually decreases from the upper thoracic level to the most posterior ganglia.
TS20: spinal cord mantle layer	Strong		11E	Expression was detected in the ventral horns and the dorsal regions of cervical spinal cord.
TS20: spinal cord	Present	Regionally restricted	11E	Expression was detected in the cervical spinal cord, but absent in the neuroepithelial layer.

Structure	Level	Pattern	Image	Note
TS20: dorsal root ganglion	Present	Graded	11F	Intensity of signal gradually decreases from the upper thoracic level to the most posterior ganglia.
TS20: spinal cord mantle layer	Strong	Regionally restricted	11F	Expression was detected in the dorsal regions of thoracic spinal cord but was absent in the neuroepithelial layer.

Structure	Level	Pattern	Image	Note
TS20: spinal cord mantle layer	Strong	Regionally restricted	11G	Expression was detected in the dorsal regions of lumbar spinal cord but was absent in the neuroepithelial layer.
TS20: dorsal root ganglion	Present	Graded	11G	Intensity of signal gradually decreases from the upper thoracic level to the most posterior ganglia.

Structure	Level	Pattern	Image	Note
TS20: C2 vertebral cartilage condensation	Weak		12B/C	Labelling begins to weaken at the second thoracic prevertebra but remains slightly above background until the most posterior identified prevertebra.
TS20: T2 vertebral cartilage condensation	Weak		12B/C	Labelling begins to weaken at the second thoracic prevertebra but remains slightly above background until the most posterior identified prevertebra.
TS20: thoracic vertebral cartilage condensation	Weak		12B/C	Labelling begins to weaken at the second thoracic prevertebra but remains slightly above background until the most posterior identified prevertebra.
TS20: C3 vertebral cartilage condensation	Strong		12B/C
TS20: C4 vertebral cartilage condensation	Strong		12B/C
TS20: C5 vertebral cartilage condensation	Strong		12B/C
TS20: C6 vertebral cartilage condensation	Strong		12B/C
TS20: C7 vertebral cartilage condensation	Strong		12B/C
TS20: T1 vertebral cartilage condensation	Strong		12B/C
TS20: C1 vertebral cartilage condensation	Absent		12B/C

Structure	Level	Pattern	Image	Note
TS21: rib cartilage condensation	Strong		12D
TS21: limb	Weak	Regionally restricted	12D

Structure	Level	Pattern	Image	Note
TS21: rib cartilage condensation	Strong	Regionally restricted	12E	Expression was detected in the cells surrounding the cartilaginous cells; the central portion is absent.

Structure	Level	Pattern	Image	Note
TS20: embryo mesenchyme	Present	Regionally restricted	13A/B	Expression was detected between the aortic arch and the heart base.
TS20: trachea mesenchyme	Strong		13A/B

Structure	Level	Pattern	Image	Note
TS20: lung mesenchyme	Present	Regionally restricted	13C/D	Expression was stronger in the peripheral parenchyma than in the peribronchial regions.
TS20: main bronchus epithelium	Absent		13C/D

Structure	Level	Pattern	Image	Note
TS23: rib	Present	Regionally restricted	13E/F	Expression was restricted to mesodermal cells in the course of cartilage differentiation.
TS23: main bronchus epithelium	Absent		13E/F
TS23: lung mesenchyme	Present		13E/F

Structure	Level	Pattern	Image	Note
TS21: diaphragm	Strong		14A/B
TS21: gut	Present	Regionally restricted	14A/B	Expression was detected in the mesenchymal cells but was absent from the epithelium.
TS21: stomach	Present	Regionally restricted	14A/B	Expression was detected in the mesenchymal cells but was absent from the epithelium.
TS21: urinary system	Weak	Regionally restricted	14A/B	Expression was detected in the mesonephros.

Structure	Level	Pattern	Image	Note
TS20: gut	Present	Regionally restricted	14C/D	Expression was detected in the mesenchymal cells but was absent from the epithelium.
TS20: stomach	Present	Regionally restricted	14C/D	Expression was detected in the mesenchymal cells but was absent from the epithelium.

Structure	Level	Pattern	Image	Note
TS23: gut	Present	Regionally restricted	14E/F	Expression was detected in the mesenchymal cells but was absent from the epithelium. Double layer of positive cells due to muscle differentiation.

Structure	Level	Pattern	Image	Note
TS23: metanephros	Present	Uniform	14G/H
TS23: adrenal gland	Absent		14G/H
TS23: reproductive system	Absent		14G/H

Structure	Level	Pattern	Image	Note
TS15: trunk paraxial mesenchyme	Present	Regionally restricted		Expression was detected in the nephrotomes.