Probe:	Osr1 probe
Probe preparation:	Antisense labelled with digoxigenin RNA
Visualized with:	Alkaline phosphatase

Structure	Level	Pattern	Image	Note
TS13: intermediate mesenchyme	Present	Regionally restricted	2A	Expression is in a U-shaped domain on either side of the neural plate, extending from the prospective anterior spinal cord to the tail end of the embryo.

Structure	Level	Pattern	Image	Note
TS13: intermediate mesenchyme	Present	Regionally restricted	2B

Structure	Level	Pattern	Image	Note
TS15: trunk mesenchyme	Present	Regionally restricted	2C	Expression is in a U-shaped domain. The expression has shifted to the caudal half of the embryonic trunk and diffuse expression is found in the anterior embryonic trunk.

Structure	Level	Pattern	Image	Note
TS15: trunk mesenchyme	Present	Regionally restricted	2D

Structure	Level	Pattern	Image	Note
TS17: 1st branchial arch	Present		2E
TS17: 2nd branchial arch	Present		2E
TS17: forelimb bud	Present		2E
TS17: hindlimb bud	Present		2E
TS17: trunk mesenchyme	Present	Regionally restricted	2E	Expression is caudal to the branchial arches and caudal to the forelimb.

Structure	Level	Pattern	Image	Note
TS17: 2nd branchial arch mesenchyme	Present		2F
TS17: 2nd branchial groove ectoderm	Present		2F
TS17: 2nd branchial membrane ectoderm	Present		2F
TS17: 2nd branchial membrane endoderm	Present		2F
TS17: forebrain	Present		2F

Structure	Level	Pattern	Image	Note
TS17: forelimb bud mesenchyme	Present	Regionally restricted	2G	Expression is in the mesenchyme undelying the ectoderm.

Structure	Level	Pattern	Image	Note
TS17: forelimb bud mesenchyme	Present	Regionally restricted	2H	Expression is in the mesenchyme underlying the ectoderm.

Structure	Level	Pattern	Image	Note
TS19: 1st branchial arch	Present		2J , 2I
TS19: 2nd branchial arch	Present		2J , 2I
TS19: 3rd branchial arch	Present		2J , 2I
TS19: forelimb bud	Present		2I , 2K
TS19: hindlimb bud	Present		2I

Structure	Level	Pattern	Image	Note
TS19: trunk mesenchyme	Present	Regionally restricted	2L	Expression is in the ventral lateral mesenchyme that is underlying the ectoderm.

Structure	Level	Pattern	Image	Note
TS20: arm	Present		2M
TS20: forelimb interdigital region	Present		2M
TS20: hindlimb interdigital region	Present		2M
TS20: leg	Present		2M
TS20: nasal cavity	Present		2M
TS20: oral region	Present		2M
TS20: trunk mesenchyme	Weak	Regionally restricted	2M	The expression is ventral.

Structure	Level	Pattern	Image	Note
TS20: arm	Present		2N
TS20: forelimb interdigital region	Present		2N

Structure	Level	Pattern	Image	Note
TS20: hindlimb interdigital region	Present		2O
TS20: leg	Present		2O