Probe:	Tbx18 probe
Probe preparation:	Antisense labelled with digoxigenin RNA
Visualized with:	Alkaline phosphatase

Structure	Level	Pattern	Image	Note
TS12: trunk unsegmented mesenchyme	Present	Regionally restricted	2A	Expression is in two stripes representing the anterior half of two newly forming somites.
TS12: head paraxial mesenchyme	Present	Regionally restricted	2A

Structure	Level	Pattern	Image	Note
TS13: head paraxial mesenchyme	Present		2B
TS13: trunk unsegmented mesenchyme	Present	Regionally restricted	2B	The expression s found in two stripes representing the anterior half of two newly forming somites.
TS13: somite	Present	Regionally restricted	2B	Expression is in the anterior half that will become the sclerotomal compartment.
TS13: splanchnopleure	Present	Regionally restricted	2B	Expression is in two wings caudo-lateral to the heart tube.
TS13: heart	Strong	Regionally restricted	2B	Expression is in the epicardium.

Structure	Level	Pattern	Image	Note
TS13: trunk unsegmented mesenchyme	Present	Regionally restricted	2C	The expression s found in two stripes representing the anterior half of two newly forming somites.
TS13: somite	Present	Regionally restricted	2C	Expression is in the anterior half that will become the sclerotomal compartment.
TS13: splanchnopleure	Present	Regionally restricted	2C	Expression is in two wings caudo-lateral to the heart tube.
TS13: heart	Strong	Regionally restricted	2C	Expression is in the epicardium.
TS13: head paraxial mesenchyme	Present		2C

Structure	Level	Pattern	Image	Note
TS13: septum transversum	Present		2D
TS13: heart	Strong	Regionally restricted	2D	Expression is in the epicardium.
TS13: trunk unsegmented mesenchyme	Present	Regionally restricted	2D	Expression is in the anterior half of the two newly forming somites.
TS13: head paraxial mesenchyme	Present		2D
TS13: somite	Present	Regionally restricted	2D	Expression is in the anterior half that will become the sclerotomal compartment.

Structure	Level	Pattern	Image	Note
TS14: sclerotome	Present		2E
TS14: trunk unsegmented mesenchyme	Present	Regionally restricted	2E	Expression is in two anterior stripes destined to become the sclerotome.
TS14: head paraxial mesenchyme	Present		2E
TS14: heart	Very strong	Regionally restricted	2E	Expression is in the proepicardial region.
TS14: septum transversum	Very strong	Regionally restricted	2E	Expression is in the splanchnich mesoderm.
TS14: forelimb bud mesenchyme	Weak	Regionally restricted	2E	Expression is in the anterior-proximal region.
TS14: genitourinary system	Weak	Regionally restricted	2E	Expression is in the emerging genital ridge.

Structure	Level	Pattern	Image	Note
TS15: heart	Strong	Regionally restricted	2F	Expression is in the cells that will form the epicardium.

Structure	Level	Pattern	Image	Note
TS15: heart	Strong	Regionally restricted	2G	Expression is in cells that will form the epicardium.

Structure	Level	Pattern	Image	Note
TS17: heart	Present	Regionally restricted	2H
TS17: tail paraxial mesenchyme	Present		2H
TS17: trunk paraxial mesenchyme	Present		2H
TS17: forelimb bud	Strong		2H
TS17: hindlimb bud	Strong		2H
TS17: gonad primordium	Present	Regionally restricted	2H	Expression is in the genital ridge.
TS17: pericardio-peritoneal canal mesothelium	Present		2H

Structure	Level	Pattern	Image	Note
TS19: head mesenchyme	Present	Regionally restricted	2I	Expression is in mesenchyme surrounding the maxillar-mandibular cleft.

Structure	Level	Pattern	Image	Note
TS20: head mesenchyme	Present	Regionally restricted	2J	Expression is in the mesenchyme surrounding the maxillar-mandibular cleft.
TS20: vibrissa epithelium	Present	Regionally restricted	2J	Expression is in the dermal sheath.

Structure	Level	Pattern	Image	Note
TS15: head mesenchyme	Present	Regionally restricted	3A	Expression is in cranial paraxial mesenchyme.

Structure	Level	Pattern	Image	Note
TS15: heart	Present	Regionally restricted	3B	Expression is in the proepicardial organ.
TS15: trunk sclerotome	Present		3B

Structure	Level	Pattern	Image	Note
TS17: trunk sclerotome	Present		3C
TS17: arterial system	Weak	Regionally restricted	3C	Expression is in the intersomitic arteries.

Structure	Level	Pattern	Image	Note
TS17: gonad primordium	Present	Regionally restricted	3D	Expression is in the genital ridge.

Structure	Level	Pattern	Image	Note
TS17: heart	Present	Regionally restricted	3E	Expression is in the epicardium, covering the ventricular and atrial myocardium.

Structure	Level	Pattern	Image	Note
TS20: visceral pericardium	Present		3F

Structure	Level	Pattern	Image	Note
TS20: head mesenchyme	Present	Regionally restricted	3G	Expression is in mesenchyme surrounding the cleft between the maxilla and the mandible.

Structure	Level	Pattern	Image	Note
TS15: forelimb bud mesenchyme	Present	Regionally restricted	4A	Expression is in the anterior-proximal region.

Structure	Level	Pattern	Image	Note
TS17: forelimb bud mesenchyme	Present	Regionally restricted	4B	Expression is strong in the proximal mesenchyme and weak in a wedge in the distal-poserior region of the handplate.

Structure	Level	Pattern	Image	Note
TS19: future arm mesenchyme	Strong		4C
TS19: handplate mesenchyme	Weak	Regionally restricted	4C	Expression is in a wedge.

Structure	Level	Pattern	Image	Note
TS20: forelimb mesenchyme	Present		4D	Expression is present in mesenchyme surrounding precartilagenous condensations.
TS20: humerus pre-cartilage condensation	Absent		4D
TS20: radius-ulna pre-cartilage condensation	Absent		4D