Probe:	Shh probe
Probe preparation:	Antisense labelled with digoxigenin RNA

Structure	Level	Pattern	Image	Note
TS23: head	Present	Regionally restricted	1B
TS23: molar	Strong		1B	Expression most readily detected in molars.
TS23: eyelid	Present		1B
TS23: hair follicle	Present		1B
TS23: palatal rugae	Present		1B
TS23: retina	Weak		1B	Low level of expression disproportionate to relatively large size.

Structure	Level	Pattern	Image	Note
TS23: upper jaw molar epithelium	Present	Regionally restricted	2H	Expression generally restricted to epithelial structures. Expression more extensive on lingual side. Strongest expression in internal dental epithelium and intermediate stratum.
TS23: stratum intermedium	Strong		2H
TS23: stellate reticulum	Present		2H	Expression also extends into varying portions of stellate reticulum.

Structure	Level	Pattern	Image	Note
TS23: lower jaw molar epithelium	Present	Regionally restricted	2I	Expression generally restricted to epithelial structures. Expression more extensive on lingual side. Strongest expression in internal dental epithelium and intermediate stratum.
TS23: stratum intermedium	Strong		2I
TS23: stellate reticulum	Present		2I	Expression also extends into varying portions of stellate reticulum.

Structure	Level	Pattern	Image	Note
TS23: hair epidermal placode	Present	Regionally restricted	2J	Expression generally restricted to distal end of epithlelial downgrowth, within concave basal border cells contacting dermal condensate.

Structure	Level	Pattern	Image	Note
TS23: palatal rugae epithelium	Present		2K	Expression generally restricted to small, thickened regions of palatal oral epithelium known as rugae.

Structure	Level	Pattern	Image	Note
TS23: lower eyelid epithelium	Present	Regionally restricted	2L	Following fusion, expression in basal layer of eyelid epithelium originating from both upper and lower lid primordia. Expression restricted to small patch of basal layer eyelid epithelium on corneal side.
TS23: upper eyelid epithelium	Present	Regionally restricted	2L	Following fusion, expression in basal layer of eyelid epithelium originating from both upper and lower lid primordia. Expression restricted to small patch of basal layer eyelid epithelium on corneal side.

Structure	Level	Pattern	Image	Note
TS23: neural retina	Present	Regionally restricted	2M	Expression restricted to differentiated cell layer, consistent with its expression by retinal ganglion cells.
TS23: eye anterior segment	Absent		2M	No expression in stroma of iris.

Structure	Level	Pattern	Image	Note
TS23: retina ganglion cell layer	Weak		2N	Expression segregated to differentiated cell layer where retinal ganglion cells are located.