Probe:	Ptch2 probe
Probe preparation:	Antisense labelled with digoxigenin RNA

Structure	Level	Pattern	Image	Note
TS23: head	Present	Regionally restricted	1E
TS23: molar	Strong		1E	Expression levels similar to that of Shh.
TS23: eyelid	Present		1E	Expression levels similar to that of Shh.
TS23: hair follicle	Present		1E	Expression levels similar to that of Shh.
TS23: palatal rugae	Ambiguous		1E	Expression levels too low to assess at this scale.
TS23: retina	Ambiguous		1E	Expression levels too low to assess at this scale.

Structure	Level	Pattern	Image	Note
TS23: upper jaw molar epithelium	Present	Regionally restricted	2CC	Expression throughout internal and external dental epithelium. Strongest expression within internal dental epithelium, extending behond range of Shh expression, particularly on buccal side. Weak expression within external dental epithelium.
TS23: stellate reticulum	Weak		2CC	Weak expression in intermediate stratum and stellate reticulum.
TS23: stratum intermedium	Weak		2CC	Weak expression in intermediate stratum and stellate reticulum.
TS23: dental sac	Weak		2CC	Weak expression within condensing ectomesenchyme of dental papilla and follicle.
TS23: upper jaw molar dental papilla	Weak		2CC	Weak expression within condensing ectomesenchyme of dental papilla and follicle.

Structure	Level	Pattern	Image	Note
TS23: lower jaw molar epithelium	Present	Regionally restricted	2DD	Expression throughout internal and external dental epithelium. Strongest expression within internal dental epithelium, extending behond range of Shh expression, particularly on buccal side. Weak expression within external dental epithelium.
TS23: stellate reticulum	Weak		2DD	Weak expression in intermediate stratum and stellate reticulum.
TS23: stratum intermedium	Weak		2DD	Weak expression in intermediate stratum and stellate reticulum.
TS23: dental sac	Weak		2DD	Weak expression within condensing ectomesenchyme of dental papilla and follicle.
TS23: upper jaw molar dental papilla	Weak		2DD	Weak expression within condensing ectomesenchyme of dental papilla and follicle.

Structure	Level	Pattern	Image	Note
TS23: hair epidermal placode	Present		2EE	Expression in distal epithelium of hair peg, overlapping with that of Shh but extending beyond Shh-expressing region, up outer walls of hair peg.

Structure	Level	Pattern	Image	Note
TS23: palatal shelf epithelium	Absent		2FF	Expression not detected in palatal oral epithelium.

Structure	Level	Pattern	Image	Note
TS23: eyelid epithelium	Present	Regionally restricted	2GG	Following fusion, expression in basal layer of eyelid epitehlium originating from both upper and lower lid primordia. Expression restricted to basal layer eyelid epithelium, but with broader expression teritory that overlaps and extends beyond region of Shh expression.

Structure	Level	Pattern	Image	Note
TS23: eye	Ambiguous		2HH	Authors state that expression is too close to background levels to make a definitive assessment.

Structure	Level	Pattern	Image	Note
TS23: retina	Absent		2II	Expression not detected.