Probe:	Foxp1 cDNA2
Probe preparation:	Antisense labelled with digoxigenin RNA
Visualized with:	Alkaline phosphatase

Structure	Level	Pattern	Image	Note
TS17: 1st branchial arch	Present	Regionally restricted	1B	Expression was excluded from the oral and anterior regions.

Structure	Level	Pattern	Image	Note
TS19: branchial arch mesenchyme	Present	Regionally restricted	1F	Expressed in the first pharyngeal arches, restricted to the dorsal-lateral (aboral) domain. Complementary to the expression of Lhx6 and Lhx8.
TS19: 1st branchial arch maxillary component	Present	Regionally restricted	1F	Expressed in both the epithelium and the mesenchyme.
TS19: branchial arch epithelium	Present	Regionally restricted	1F	Expressed in the first pharyngeal arches.

Structure	Level	Pattern	Image	Note
TS19: branchial arch mesenchyme	Present	Regionally restricted	1J	Expressed in the first pharyngeal arches, restricted to the dorsal-lateral (aboral) domain. Complementary to the expression of Lhx6 and Lhx8.
TS19: 1st branchial arch maxillary component	Present	Regionally restricted	1J	Expressed in both the epithelium and the mesenchyme.
TS19: branchial arch epithelium	Present	Regionally restricted	1J	Expressed in the first pharyngeal arches.
TS19: mandibular process mesenchyme	Present	Regionally restricted	1J	Mostly concentrated in and around the tongue.

Structure	Level	Pattern	Image	Note
TS19: mandibular process mesenchyme	Present	Regionally restricted	1N	Mostly concentrated in and around the tongue.
TS19: 1st branchial arch maxillary component	Present		1N	Expressed in both the epithelium and the mesenchyme.

Structure	Level	Pattern	Image	Note
TS20: face mesenchyme	Present	Regionally restricted	2A	Not expressed in the mesenchyme of the ventral (oral) domain of the palatal shelf.

Structure	Level	Pattern	Image	Note
TS20: face mesenchyme	Strong	Regionally restricted	2F	Expressed in the mesenchymal condensations in the lateral first pharyngeal arches.

Structure	Level	Pattern	Image	Note
TS20: face mesenchyme	Strong	Regionally restricted	2K	Expressed in the posterior first pharyngeal arches, where the maxillary arch and the mandibular arch joined.

Structure	Level	Pattern	Image	Note
TS21: tooth mesenchyme	Absent		4A

Structure	Level	Pattern	Image	Note
TS21: chondrocranium bone	Present	Regionally restricted	4G	Expressed in the mesenchymal mass of the developing zygomatic bone.
TS21: cranial muscle	Present	Regionally restricted	4G	Expressed in the masseter.
TS21: connective tissue	Present	Regionally restricted	4G	Expressed in the tendons.
TS21: face mesenchyme	Present	Regionally restricted	4G	Expressed in the tendons.
TS21: palatal shelf mesenchyme	Ambiguous	Regionally restricted	4G	Not expressed in ventral (oral) domain of the palatal shelf.
TS21: tooth mesenchyme	Absent		4G

Structure	Level	Pattern	Image	Note
TS21: cranial muscle	Present		4M
TS21: face mesenchyme	Present	Regionally restricted	4M	Expressed in the muscles and the surrounding connective tissues.

Structure	Level	Pattern	Image	Note
TS21: face mesenchyme	Strong	Regionally restricted	4S	Expressed in the lateral mesenchyme of the first pharyngeal arches.

Structure	Level	Pattern	Image	Note
TS21: face mesenchyme	Weak	Regionally restricted	4X	Minimal expression in the medial mesenchyme.

Structure	Level	Pattern	Image	Note
TS21: tooth mesenchyme	Absent		4c
TS21: face mesenchyme	Weak	Regionally restricted	4c	Minimal expression in the medial mesenchyme.

Structure	Level	Pattern	Image	Note
TS21: face mesenchyme	Weak	Regionally restricted	4h	Minimal expression in the medial mesenchyme.

Structure	Level	Pattern	Image	Note
TS22: facial muscle	Present		6A
TS22: chondrocranium bone	Present	Regionally restricted	6A	Down-regulated expression in zygomatic arch compared with the earlier stages.
TS22: connective tissue	Present	Regionally restricted	6A	Expressed in the tendons surrounding the muscles.
TS22: face mesenchyme	Present	Regionally restricted	6A	Expressed in the tendons surrounding the muscles.

Structure	Level	Pattern	Image	Note
TS22: facial muscle	Present		6F
TS22: chondrocranium bone	Present	Regionally restricted	6F	Down-regulated expression in zygomatic arch compared with the earlier stages.
TS22: connective tissue	Present	Regionally restricted	6F	Expressed in the tendons surrounding the muscles.
TS22: face mesenchyme	Present	Regionally restricted	6F	Expressed in the tendons surrounding the muscles.

Structure	Level	Pattern	Image	Note
TS22: facial muscle	Present		6K
TS22: connective tissue	Present	Regionally restricted	6K	Expressed in the tendons surrounding the muscles.
TS22: face mesenchyme	Present	Regionally restricted	6K	Expressed in the tendons surrounding the muscles.

Structure	Level	Pattern	Image	Note
TS22: facial muscle	Present		6P
TS22: connective tissue	Present	Regionally restricted	6P	Expressed in the tendons surrounding the muscles.
TS22: face mesenchyme	Present	Regionally restricted	6P	Expressed in the tendons surrounding the muscles.
TS22: temporal bone petrous part	Present	Regionally restricted	6P	Expressed in the developing temporo-mandibular joint.

Structure	Level	Pattern	Image	Note
TS23: facial muscle	Weak		7B
TS23: connective tissue	Weak	Regionally restricted	7B	Expressed in the tendons.
TS23: jaw mesenchyme	Weak	Regionally restricted	7B	Expressed in the tendons.
TS23: tooth mesenchyme	Absent		7B

Structure	Level	Pattern	Image	Note
TS23: jaw mesenchyme	Weak		7E

Structure	Level	Pattern	Image	Note
TS23: temporo-mandibular joint primordium	Weak	Regionally restricted	7H	Expressed in the articular disc.
TS23: facial muscle	Weak		7H
TS23: connective tissue	Weak	Regionally restricted	7H	Expressed in the tendons.
TS23: jaw mesenchyme	Weak	Regionally restricted	7H	Expressed in the tendons.

Structure	Level	Pattern	Image	Note
TS24: face mesenchyme	Absent