Probe:	Sp4 probe2
Probe preparation:	Antisense labelled with S35 RNA
Visualized with:	Autoradiography

Structure	Level	Pattern	Image	Note
TS14: embryo	Weak	Widespread	4A
TS14: tail bud	Strong	Regionally restricted	4A	Highest expression in region surrounding posterior neuropore.

Structure	Level	Pattern	Image	Note
TS16: future hindbrain	Strong	Regionally restricted	4B	Strong expression in primitive neroepithelial layer surrounding the 4th ventricle.
TS16: neural tube	Present	Regionally restricted	4B	Expression in more rostral aspects of primitive neural tube.
TS16: head mesenchyme	Weak	Regionally restricted	4B	Weaker expression in cephalic mesenchymal tissue adjacent to the brain and neural tube.
TS16: optic cup	Present		4B	Expression in optic vesicle.
TS16: oral region	Present	Regionally restricted	4B	Expression in developing mandible.

Structure	Level	Pattern	Image	Note
TS16: future hindbrain	Present	Regionally restricted	4C	Expression localized to primitive neuroepitheliual layer surrounding the 4th ventricle.
TS16: head mesenchyme	Weak	Regionally restricted	4C	Low level of expression in much of the primitive mesenchymal tissue in the head region, including the branchial arches.
TS16: branchial arch	Weak		4C
TS16: otocyst	Present		4C
TS16: neural tube	Present		4C

Structure	Level	Pattern	Image	Note
TS20: brain	Strong		5A
TS20: nasopharynx epithelium	Strong		5A	High levels of expression in mucosal epithelium lining the nasopharynx.
TS20: head mesenchyme	Weak	Diffuse	5A	Weak, diffuse expression throughout facial mesenchymal tissue surrounding the nasopharyngeal cavity.

Structure	Level	Pattern	Image	Note
TS20: head mesenchyme	Weak	Regionally restricted	5B	Weak, diffuse expression in facial mesenchyme.
TS20: nasopharynx epithelium	Strong		5B	Higher level of expression in mucosal epithelium lining the nasopharynx and vomeronasal organ.
TS20: vomeronasal organ epithelium	Strong		5B	Higher level of expression in mucosal epithelium lining the nasopharynx and vomeronasal organ.

Structure	Level	Pattern	Image	Note
TS20: brain	Strong	Uniform	5D	Uniformly high level of expression in developing brain.
TS20: eye	Strong		5D	Relatively high levels of expression in developing eye.

Structure	Level	Pattern	Image	Note
TS20: brain	Present		5E

Structure	Level	Pattern	Image	Note
TS20: cranial nerve	Strong
TS20: retina	Strong
TS20: spinal ganglion	Strong
TS20: trigeminal ganglion	Strong
TS20: bronchus epithelium	Present
TS20: hypothalamus	Present
TS20: intestine epithelium	Present
TS20: liver	Present
TS20: metanephros	Present
TS20: remnant of Rathke's pouch	Present
TS20: head mesenchyme	Weak	Regionally restricted		Weak expression throughout most mesenchymal tissue in the head and neck region, limbs, and abdominal cavity.
TS20: limb mesenchyme	Weak	Regionally restricted		Weak expression throughout most mesenchymal tissue in the head and neck region, limbs, and abdominal cavity.
TS20: trunk mesenchyme	Weak	Regionally restricted		Weak expression throughout most mesenchymal tissue in the head and neck region, limbs, and abdominal cavity.
TS20: cardiac muscle tissue	Weak

Structure	Level	Pattern	Image	Note
TS21: liver	Strong		6A
TS21: stomach	Weak	Regionally restricted	6A	Weaker expression in stomach mucosa and stomach wall.
TS21: testis	Moderate		6A
TS21: body wall mesenchyme	Weak		6A	Low level of expression in mesenchymal tissue in the abdominal wall.

Structure	Level	Pattern	Image	Note
TS21: testis	Present	Regionally restricted	6B	Expression localized to developing seminiferous tubules.

Structure	Level	Pattern	Image	Note
TS21: ovary	Strong
TS21: lung epithelium	Weak	Regionally restricted		Weak expression in bronchiolar epithelium.
TS21: intestine	Weak
TS21: embryo mesenchyme	Weak			Authors report weak expression in most mesenchymal tissues.

Structure	Level	Pattern	Image	Note
TS22: tooth epithelium	Strong	Regionally restricted	6C/D	Strong expression in odontogenic epithelial layers of the developing tooth.

Structure	Level	Pattern	Image	Note
TS22: dorsal root ganglion	Present		6E

Structure	Level	Pattern	Image	Note
TS22: central nervous system	Strong
TS22: embryo mesenchyme	Weak			Decreased expression in mesenchymal tissues and most of mucosal epithelial cells.
TS22: intestine epithelium	Weak			Decreased expression in mesenchymal tissues and most of mucosal epithelial cells.
TS22: gonad	Trace
TS22: liver	Trace
TS22: lung	Trace
TS22: thymus primordium	Trace

Structure	Level	Pattern	Image	Note
TS24: spinal cord	Present		6F
TS24: axial skeleton	Absent		6F	No expression in the adjacent vertebral column.

Structure	Level	Pattern	Image	Note
TS24: brain	Present
TS24: dorsal root ganglion	Present
TS24: sympathetic ganglion	Present