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

Structure	Level	Pattern	Image	Note
TS23: head	Present	Regionally restricted	1F
TS23: palatal rugae	Strong		1F	Abundant expression in retina and palatal rugae.
TS23: retina	Strong		1F	Abundant expression in retina and palatal rugae.
TS23: hair follicle	Present		1F
TS23: molar	Present		1F
TS23: eyelid	Absent		1F	Expression levels too low to assess at this scale.

Structure	Level	Pattern	Image	Note
TS23: upper jaw molar mesenchyme	Present	Regionally restricted	2JJ	Expression restricted narrow band of mesenchyme surrounding molars at outer edge of Ptch1 and Gli1 expression, at a distance from Shh-expressing cells. Strong expression in narrow band of peripheral mesenchyme, including dental follicle, encompassing developing molars. Faint expression detected throughout remaining mesenchymal components.
TS23: dental sac	Strong		2JJ
TS23: upper jaw molar epithelium	Weak		2JJ	Faint expression detected throughout remaining pithelial components.

Structure	Level	Pattern	Image	Note
TS23: lower jaw molar mesenchyme	Present	Regionally restricted	2KK	Expression restricted narrow band of mesenchyme surrounding molars at outer edge of Ptch1 and Gli1 expression, at a distance from Shh-expressing cells. Strong expression in narrow band of peripheral mesenchyme, including dental follicle, encompassing developing molars. Faint expression detected throughout remaining mesenchymal components.
TS23: dental sac	Strong		2KK
TS23: lower jaw molar epithelium	Weak		2KK	Faint expression detected throughout remaining pithelial components.

Structure	Level	Pattern	Image	Note
TS23: hair follicle dermal papilla	Present	Regionally restricted	2LL	Expression in condensing mesenchyme surrounding epithelial compartment of hair follicle. Weak expression in peripheral cells of dermal condensate and inner portions of hair peg.
TS23: dermis	Strong	Regionally restricted	2LL	Strongest expression in narrow region of noncondensing dermal mesenchyme surrounding dermal condensate and hair peg.

Structure	Level	Pattern	Image	Note
TS23: palatal shelf mesenchyme	Strong	Graded	2MM	Graded and robust pattern of expression, strongest in palatal mesenchyme adjacent to Shh-expressing rugae. Strong expression in palatal mesenchyme adjacent to palatal oral epithelium of palatal rugae in large region overlapping with and extending behond that of Gli1 and Ptch1 expression. Mesenchymal expression is graded, with strongest expression closest to oral epithelium.

Structure	Level	Pattern	Image	Note
TS23: eyelid	Trace	Regionally restricted	2NN	Faint expression in mesenchyme of eyelid tip.

Structure	Level	Pattern	Image	Note
TS23: neural retina	Present	Regionally restricted	2OO	Expression throughout neural retina, slightly stronger in neuroblast layer.

Structure	Level	Pattern	Image	Note
TS23: retina ganglion cell layer	Present	Graded	2PP	Expression extended across both neuroblastic layer and differentiated cell layer in graded manner. Expression strongest in neuroblastic layer.
TS23: retina nuclear layer	Present	Graded	2PP	Expression extended across both neuroblastic layer and differentiated cell layer in graded manner. Expression strongest in neuroblastic layer.
TS23: perioptic mesenchyme	Present	Regionally restricted	2PP	Narrow band of expression in scleral condensation of extraocular mesenchyme, marking boundary with retina pigmented epithelium.