Probe:	Ptch1 probe
Probe preparation:	Antisense labelled with digoxigenin RNA

Structure	Level	Pattern	Image	Note
TS23: head	Present	Regionally restricted	1D
TS23: eyelid	Strong		1D	Robust expression across all tissues examined.
TS23: hair follicle	Strong		1D	Robust expression across all tissues examined.
TS23: molar	Strong		1D	Robust expression across all tissues examined.
TS23: palatal rugae	Strong		1D	Robust expression across all tissues examined.
TS23: retina	Strong		1D	Robust expression across all tissues examined.

Structure	Level	Pattern	Image	Note
TS23: upper jaw molar	Present	Widespread	2V	Expression throughout epithelial and mesenchymal structures.
TS23: dental sac	Strong		2V	Strongest expression in condensing ectomesenchyme, including dental papilla and follicle.
TS23: upper jaw molar dental papilla	Strong		2V	Strongest expression in condensing ectomesenchyme, including dental papilla and follicle.
TS23: stellate reticulum	Present		2V	Robust expression in internal and external dental epithelium, intermediate stratum, and distal stellate reticulum.
TS23: stratum intermedium	Present		2V	Robust expression in internal and external dental epithelium, intermediate stratum, and distal stellate reticulum.
TS23: upper jaw molar epithelium	Present		2V	Robust expression in internal and external dental epithelium, intermediate stratum, and distal stellate reticulum.

Structure	Level	Pattern	Image	Note
TS23: lower jaw molar	Present	Widespread	2W	Expression throughout epithelial and mesenchymal structures.
TS23: dental sac	Strong		2W	Strongest expression in condensing ectomesenchyme, including dental papilla and follicle, and stellate reticulum and pedicle.
TS23: lower jaw molar dental papilla	Strong		2W	Strongest expression in condensing ectomesenchyme, including dental papilla and follicle, and stellate reticulum and pedicle.
TS23: lower jaw molar epithelium	Strong		2W	Robust expression in internal and external dental epithelium, intermediate stratum, and distal stellate reticulum.
TS23: stellate reticulum	Strong		2W	Robust expression in internal and external dental epithelium, intermediate stratum, and distal stellate reticulum.
TS23: stratum intermedium	Strong		2W	Robust expression in internal and external dental epithelium, intermediate stratum, and distal stellate reticulum.

Structure	Level	Pattern	Image	Note
TS23: hair follicle	Present	Widespread	2X	Expression throughout epithelial and mesenchymal components of hair follicle.
TS23: hair epidermal placode	Strong	Regionally restricted	2X	Strongest expression in distal half of epithelial-derived hair peg, both in basal layer epidermal cells, comprising outer layer cells of hair peg, and cells of interior.
TS23: hair follicle dermal papilla	Present	Regionally restricted	2X	Expression uniformly through dermal condensate.
TS23: hair	Weak	Regionally restricted	2X	Weak expression in most proximal aspect of hair peg.
TS23: dermis	Weak	Regionally restricted	2X	Weak expression in surrounding noncondensed dermal mesenchyme directly adjacent to hair peg and dermal condensate.

Structure	Level	Pattern	Image	Note
TS23: palatal shelf	Present	Widespread	2Y	Expression throughout epithelial and mesenchymal structures.
TS23: palatal shelf epithelium	Strong	Regionally restricted	2Y	Strong expression in thickened palatal oral epithelium in region overlapping with but extending beyond that of Shh expression.
TS23: palatal shelf mesenchyme	Strong	Graded	2Y	Robust expression extending into palatal mesenchyme immediately adjacent to palatal oral epithelium in a gradient fashion.

Structure	Level	Pattern	Image	Note
TS23: eyelid	Present	Widespread	2Z	Expression throughout epithelial and mesenchymal structures.
TS23: eyelid epithelium	Strong	Regionally restricted	2Z	Stronger expression in epithelium. Strong expression within basal layer eyelid epithelium in similar range of basal as Ptch2 expression.
TS23: lower eyelid epithelium	Present	Regionally restricted	2Z	Following fusion, expression in basal layer of eyelid epithelium originating from both upper and lower lid primordia.
TS23: upper eyelid epithelium	Present	Regionally restricted	2Z	Following fusion, expression in basal layer of eyelid epithelium originating from both upper and lower lid primordia.
TS23: eyelid mesenchyme	Weak	Regionally restricted	2Z	Weaker expression extends into adjacent mesenchyme of eyelid tip.

Structure	Level	Pattern	Image	Note
TS23: neural retina	Present	Regionally restricted	2AA	Expression throughout both retinal layers, with slightly stronger expression in neuroblast layer.
TS23: eye anterior segment	Present	Regionally restricted	2AA	Weak expression in stroma of iris.

Structure	Level	Pattern	Image	Note
TS23: retina	Present	Widespread	2BB	Expression throughout epithelial and mesenchymal structures.
TS23: retina nuclear layer	Present	Regionally restricted	2BB	Expression overlapping with that of Gli1 in neuroblast layer of neural retina
TS23: retina ganglion cell layer	Present		2BB	Expression extended into differentiated cell layer.
TS23: perioptic mesenchyme	Present	Regionally restricted	2BB	Narrow band of expression in scleral condensation of extraocular mesenchyme, marking boundary with retina pigmented epithelium.