Probe:	Pbx3a cDNA
Probe preparation:	Antisense labelled with digoxigenin RNA
Visualized with:	Alkaline phosphatase

Structure	Level	Pattern	Image	Note
TS15: forelimb bud	Present		1A
TS15: head	Present		1A

Structure	Level	Pattern	Image	Note
TS15: 1st branchial arch mandibular component	Present		1A green inset
TS15: 1st branchial arch maxillary component	Present		1A green inset
TS15: 2nd branchial arch	Present		1A green inset
TS15: fronto-nasal process	Present		1A green inset
TS15: optic vesicle	Present		1A green inset
TS15: 3rd branchial arch	Absent		1A green inset

Structure	Level	Pattern	Image	Note
TS17: 1st branchial arch maxillary component	Strong	Regionally restricted	1B	Highest expression in maxilla and branchial arch 1, especially in distal domains.
TS17: optic cup	Present	Regionally restricted	1B	Authors report marked expression in the optic vesicle.
TS17: 2nd branchial arch	Present		1B
TS17: fronto-nasal process	Present		1B

Structure	Level	Pattern	Image	Note
TS17: 3rd branchial arch	Weak

Structure	Level	Pattern	Image	Note
TS17: 1st branchial arch ectoderm	Present		1C
TS17: 1st branchial arch mesenchyme	Present		1C
TS17: 2nd branchial arch ectoderm	Present		1C
TS17: 2nd branchial arch mesenchyme	Present		1C
TS17: 3rd branchial arch mesenchyme	Weak		1C
TS17: 3rd branchial arch ectoderm	Absent		1C
TS17: pericardium	Present		1C
TS17: heart	Absent		1C

Structure	Level	Pattern	Image	Note
TS17: fronto-nasal process ectoderm	Present
TS17: fronto-nasal process mesenchyme	Present

Structure	Level	Pattern	Image	Note
TS19: 1st branchial arch	Present			Authors report expression in the frontonasal process, maxilla, and branchial arches 1 and 2 are relatively unchanged compared to that at E10.5.
TS19: 2nd branchial arch	Present			Authors report expression in the frontonasal process, maxilla, and branchial arches 1 and 2 are relatively unchanged compared to that at E10.5.
TS19: fronto-nasal process	Present			Authors report expression in the frontonasal process, maxilla, and branchial arches 1 and 2 are relatively unchanged compared to that at E10.5.
TS19: maxillary process	Present			Authors report expression in the frontonasal process, maxilla, and branchial arches 1 and 2 are relatively unchanged compared to that at E10.5.

Structure	Level	Pattern	Image	Note
TS14: septum transversum	Present		1E

Structure	Level	Pattern	Image	Note
TS15: forelimb bud	Present	Regionally restricted	2A	Expression in the proximal-anterior region of the forelimb.

Structure	Level	Pattern	Image	Note
TS15: hindlimb ridge	Absent		2B

Structure	Level	Pattern	Image	Note
TS17: forelimb bud	Present	Regionally restricted	2C	Expression in the proximal-anterior region of the forelimb.

Structure	Level	Pattern	Image	Note
TS17: hindlimb bud	Absent		2D

Structure	Level	Pattern	Image	Note
TS19: forelimb bud mesenchyme	Present	Regionally restricted	2E	Expression localized to the anterior and posterior mesenchyme of the forelimb proximal to the autopod.

Structure	Level	Pattern	Image	Note
TS19: hindlimb bud mesenchyme	Weak	Regionally restricted	2F	Very weak expression in the anterior and posterior mesenchyme of the hindlimb proximal to the autopod.

Structure	Level	Pattern	Image	Note
TS20: forelimb mesenchyme	Present	Regionally restricted	2G	Weak expression in the proximal and anterior domain of the forelimb.
TS20: forelimb interdigital region	Present		2G

Structure	Level	Pattern	Image	Note
TS20: hindlimb interdigital region	Present		2H

Structure	Level	Pattern	Image	Note
TS20: forelimb interdigital region	Present		2K

Structure	Level	Pattern	Image	Note
TS20: hindlimb interdigital region	Present		2L

Structure	Level	Pattern	Image	Note
TS20: diencephalon	Present	Regionally restricted	3A	Marked expression in the diencephalon, especially intense in the ventral thalamus; in the mesencephalon, specifically in the pretectum and superior colliculus; and in the rhombencephalon, including the cerebellum.
TS20: hindbrain	Present	Regionally restricted	3A	Marked expression in the diencephalon, especially intense in the ventral thalamus; in the mesencephalon, specifically in the pretectum and superior colliculus; and in the rhombencephalon, including the cerebellum.
TS20: midbrain	Present	Regionally restricted	3A	Marked expression in the diencephalon, especially intense in the ventral thalamus; in the mesencephalon, specifically in the pretectum and superior colliculus; and in the rhombencephalon, including the cerebellum.
TS20: thalamus	Present	Regionally restricted	3A	Marked expression in the diencephalon, especially intense in the ventral thalamus; in the mesencephalon, specifically in the pretectum and superior colliculus; and in the rhombencephalon, including the cerebellum.
TS20: cerebellum primordium	Present		3A

Structure	Level	Pattern	Image	Note
TS21: diencephalon	Present	Regionally restricted	3B	Marked expression in the diencephalon, especially intense in the ventral thalamus; in the mesencephalon, specifically in the pretectum and superior colliculus; and in the rhombencephalon, including the cerebellum.
TS21: hindbrain	Present	Regionally restricted	3B	Marked expression in the diencephalon, especially intense in the ventral thalamus; in the mesencephalon, specifically in the pretectum and superior colliculus; and in the rhombencephalon, including the cerebellum.
TS21: midbrain	Present	Regionally restricted	3B	Marked expression in the diencephalon, especially intense in the ventral thalamus; in the mesencephalon, specifically in the pretectum and superior colliculus; and in the rhombencephalon, including the cerebellum.
TS21: thalamus	Present	Regionally restricted	3B	Marked expression in the diencephalon, especially intense in the ventral thalamus; in the mesencephalon, specifically in the pretectum and superior colliculus; and in the rhombencephalon, including the cerebellum.
TS21: cerebellum	Present		3B

Structure	Level	Pattern	Image	Note
TS21: olfactory lobe	Present	Regionally restricted	3C	Expression localized to the epithelium of the olfactory bulb.

Structure	Level	Pattern	Image	Note
TS21: cranial ganglion	Strong			Authors report intense expression in the cranial ganglia.

Structure	Level	Pattern	Image	Note
TS21: peripheral nervous system	Present	Regionally restricted	3D	Marked expression in the peripheral nervous system, particularly in the spinal ganglia.
TS21: spinal ganglion	Present		3D

Structure	Level	Pattern	Image	Note
TS20: rib pre-cartilage condensation	Strong	Regionally restricted	3E	High expression in proliferating chondrocytes of the developing ribs.

Structure	Level	Pattern	Image	Note
TS21: rib cartilage condensation	Strong	Regionally restricted	3F	High expression in proliferating chondrocytes of the developing ribs.

Structure	Level	Pattern	Image	Note
TS22: rib cartilage condensation	Absent		3G	No expression in rib hypertrophic chondrocytes.
TS22: axial skeleton thoracic region	Present	Regionally restricted	3G	Expression restricted to mesenchyme surrounding the ribs.

Structure	Level	Pattern	Image	Note
TS22: skeleton	Present	Regionally restricted	3H	High expression in developing articulations, especially in joint tendons, ligaments, and in the domains of capsules.
TS22: limb cartilage condensation	Absent		3H	No expression in perichondrium of limb endochondral bones.

Structure	Level	Pattern	Image	Note
TS20: respiratory tract	Strong	Regionally restricted	3J	Strong expression in the respiratory tract, especially in the mesenchyme condensing around the main bronchi.
TS20: main bronchus mesenchyme	Strong		3J

Structure	Level	Pattern	Image	Note
TS20: respiratory system	Present	Regionally restricted	3K	Expression in the mesenchyme surrounding the pseudostratified epithelium of airways.
TS20: respiratory system epithelium	Present	Regionally restricted	3K	Expression on the apical side of epithelial cells lining the airways.

Structure	Level	Pattern	Image	Note
TS22: respiratory system epithelium	Present	Regionally restricted	3L	Expression on the apical side of epithelial cells lining the airways.

Structure	Level	Pattern	Image	Note
TS23: lung epithelium	Present

Structure	Level	Pattern	Image	Note
TS24: lung	Absent

Structure	Level	Pattern	Image	Note
TS23: enteric nervous system	Strong	Regionally restricted	4A	High expression in the brain, specifically in the olfactory lobe of the telencephalon; in the mesencephalon, particularly in the pretectum; and in the rhombencephalon.
TS23: midbrain	Strong	Regionally restricted	4A	High expression in the brain, specifically in the olfactory lobe of the telencephalon; in the mesencephalon, particularly in the pretectum; and in the rhombencephalon.
TS23: telencephalon	Strong	Regionally restricted	4A	High expression in the brain, specifically in the olfactory lobe of the telencephalon; in the mesencephalon, particularly in the pretectum; and in the rhombencephalon.
TS23: olfactory lobe	Strong		4A
TS23: pretectum	Strong		4A

Structure	Level	Pattern	Image	Note
TS24: hindbrain	Strong	Regionally restricted	4B	High expression in the brain, specifically in the olfactory lobe of the telencephalon; in the mesencephalon, particularly in the tectum; and in the rhombencephalon.
TS24: midbrain	Strong	Regionally restricted	4B	High expression in the brain, specifically in the olfactory lobe of the telencephalon; in the mesencephalon, particularly in the tectum; and in the rhombencephalon.
TS24: telencephalon	Strong	Regionally restricted	4B	High expression in the brain, specifically in the olfactory lobe of the telencephalon; in the mesencephalon, particularly in the tectum; and in the rhombencephalon.
TS24: olfactory lobe	Strong		4B
TS24: tectum	Strong		4B

Structure	Level	Pattern	Image	Note
TS24: olfactory epithelium	Present		4B orange inset

Structure	Level	Pattern	Image	Note
TS23: neural retina	Present		4C

Structure	Level	Pattern	Image	Note
TS24: neural retina	Present		4D

Structure	Level	Pattern	Image	Note
TS24: submandibular gland epithelium	Present		4E

Structure	Level	Pattern	Image	Note
TS23: enteric nervous system	Present	Regionally restricted	4F	Expression detectable in the ganglia of the myenteric nerve plexus.

Structure	Level	Pattern	Image	Note
TS24: myenteric nerve plexus	Weak	Regionally restricted	4G	Very low levels of expression in the ganglia of the myenteric nerve plexus.

Structure	Level	Pattern	Image	Note
TS23: enteric nervous system	Present	Regionally restricted	4H	Expression detectable in the ganglia of the myenteric nerve plexus.

Structure	Level	Pattern	Image	Note
TS24: adrenal cortex	Present		4I
TS24: adrenal medulla	Absent		4I

Structure	Level	Pattern	Image	Note
TS17: gut mesenchyme	Present

Structure	Level	Pattern	Image	Note
TS21: gut mesenchyme	Strong		5A
TS21: gut epithelium	Absent		5A

Structure	Level	Pattern	Image	Note
TS22: spleen primordium	Weak	Regionally restricted	5B	Weak expression in mesenchymal cells of the spleen anlage on the side of the stomach.
TS22: liver	Absent		5B
TS22: stomach	Absent		5B

Structure	Level	Pattern	Image	Note
TS22: liver	Absent		5C
TS22: stomach epithelium	Absent		5C

Structure	Level	Pattern	Image	Note
TS22: enteric nervous system	Present	Regionally restricted	5C1	Expression detected in the myenteic nerve plexus (Auerbach's plexus) of the stomach. No expression in the submucosal nerve plexus.

Structure	Level	Pattern	Image	Note
TS22: pancreas epithelium	Strong	Regionally restricted	5F	Strong expression localized in the epithelium of the acini of the pancreas, and in potential duct cells surrounding the lumina.

Structure	Level	Pattern	Image	Note
TS23: pancreas	Weak	Regionally restricted		Weak expression in pancreatic epithelial cells.

Structure	Level	Pattern	Image	Note
TS24: pancreas	Absent			No expression in pancreatic epithelial cells.

Structure	Level	Pattern	Image	Note
TS21: gland	Present	Regionally restricted	6A	Authors report expession in the adrenal gland in the cortex, but not the medulla or capsule.

Structure	Level	Pattern	Image	Note
TS21: renal cortex	Present	Regionally restricted	6B	Expression localized to cluster of cells within the kidney cortex.
TS21: cap mesenchyme	Strong		6B	Particularly intense expression in mesenchymal cells condensing to form nephron precursors.
TS21: ureter	Absent		6B	No expression in the epithelium of the adjacent ureteric bud.

Structure	Level	Pattern	Image	Note
TS22: adrenal cortex	Present		6C
TS22: adrenal medulla	Absent		6C
TS22: adrenal gland	Present	Regionally restricted	6C	No expression in the adrenal capsule.
TS22: metanephros	Present	Regionally restricted	6C	Expression in clusters of cells throughout the kidney, morphologically resembling nephron precursors.
TS22: mesenchyme of metanephros	Strong	Regionally restricted	6C	Marked expression in mesenchymal cells surrounding the ureter.
TS22: ureter	Absent		6C	No expression in the ureter epithelium.

Structure	Level	Pattern	Image	Note
TS23: adrenal cortex	Present
TS23: adrenal medulla	Absent
TS23: adrenal gland	Present	Regionally restricted		No expression in the adrenal capsule.

Structure	Level	Pattern	Image	Note
TS24: metanephros	Trace			Barely detectable expression in the kidney.

Structure	Level	Pattern	Image	Note
TS22: ovary	Weak		6D , 6D1	Weak expression throughout the ovary.

Structure	Level	Pattern	Image	Note
TS22: testis	Trace		6F	Little to no expresssion detected in the testis.