Probe:	Osr2 probe3
Probe preparation:	Antisense labelled with digoxigenin RNA

Structure	Level	Pattern	Image	Note
TS15: mesonephros	Present		2A	Expression first detected at E9.25 specifically in mesonephros.

Structure	Level	Pattern	Image	Note
TS16: 1st branchial arch mesenchyme	Strong		2C
TS16: forelimb bud	Strong		2C
TS16: mesonephros	Strong		2C

Structure	Level	Pattern	Image	Note
TS16: 1st branchial arch mandibular component mesenchyme	Present	Regionally restricted	2D	Restricted expression in rostro-lateral mesenchyme of proximal mandibular processes.

Structure	Level	Pattern	Image	Note
TS16: forelimb bud	Present	Regionally restricted	2E	Expression in dorsal, but not ventral, limb tissues. Authors report expression follows a dorsal to ventral sequence in the forelimb.
TS16: mesonephros	Present	Regionally restricted	2E	Expression in discrete mesonephric vesicles.

Structure	Level	Pattern	Image	Note
TS16: forelimb bud mesenchyme	Present	Regionally restricted	2F	Expression restricted to sharply demarcated central mesenchymal domain underlying dorsal limb ectoderm.

Structure	Level	Pattern	Image	Note
TS16: forelimb bud mesenchyme	Present	Regionally restricted	2G	Expression increased in dorsal forelimb mesenchyme. Expression in ventral forelimb region in mesenchyme underlying limb ectoderm.

Structure	Level	Pattern	Image	Note
TS17: forelimb bud mesenchyme	Present	Regionally restricted	2H	Expression in dorsal and ventral forelimb mesenchyme.
TS17: hindlimb bud mesenchyme	Present	Regionally restricted	2H	Expression in hindlimb buds in the dorsal mesenchyme.

Structure	Level	Pattern	Image	Note
TS17: 1st branchial arch mandibular component	Present	Regionally restricted	2I	Distinct expression patterns in maxillary and mandibular processes.
TS17: 1st branchial arch maxillary component	Present	Regionally restricted	2I	Distinct expression patterns in maxillary and mandibular processes.
TS17: 2nd branchial arch	Present		2I
TS17: forelimb bud	Present		2I
TS17: hindlimb bud	Present		2I
TS17: somite	Absent		2I

Structure	Level	Pattern	Image	Note
TS17: 1st branchial arch maxillary component	Present	Regionally restricted	2K	Expression in two stripes of cells at oral side of maxillary processes corresponding to where bilateral palatal processes initiate (secondary palate primordia).
TS17: 1st branchial arch mandibular component	Present		2K
TS17: 2nd branchial arch	Present		2K

Structure	Level	Pattern	Image	Note
TS18: 1st branchial arch mandibular component mesenchyme	Present	Regionally restricted	2M	Expression domain in mandibular mesenchyme extends into maxillary mesenchyme.
TS18: 1st branchial arch maxillary component mesenchyme	Present	Regionally restricted	2M	Expression domain in mandibular mesenchyme extends into maxillary mesenchyme.
TS18: hindlimb bud	Present	Regionally restricted	2M	Expression in ventral side of hindlimb. Authors report expression follows a dorsal to ventral sequence in the hindlimb.
TS18: eye	Present	Regionally restricted	2M	Authors report expression in regions surrounding the developing eye.

Structure	Level	Pattern	Image	Note
TS19: maxillary process	Present	Regionally restricted	2N	Expression in distal maxillary processes.
TS19: medial-nasal process	Present		2N

Structure	Level	Pattern	Image	Note
TS19: eye	Present	Regionally restricted	2P	Authors report expression in regions surrounding developing eye, with stronger expression in posterior and ventral regions
TS19: 2nd branchial pouch	Present		2P	Expression in pharyngeal pouches between second and third branchial arches.
TS19: 3rd branchial pouch	Present		2P	Expression in pharyngeal pouches posteror to third branchial arch.
TS19: mandibular process	Strong	Regionally restricted	2P	Strong expression persists in specific regions of maxillary and mandibular processes.
TS19: maxillary process	Strong	Regionally restricted	2P	Strong expression persists in specific regions of maxillary and mandibular processes.
TS19: forelimb bud	Strong	Regionally restricted	2P	Strong expression persists in specific regions of forelimbs and hindlimbs.
TS19: hindlimb bud	Strong	Regionally restricted	2P	Strong expression persists in specific regions of forelimbs and hindlimbs.