Probe:	Mtsh1 cDNA2
Probe preparation:	Antisense labelled with digoxigenin RNA
Visualized with:	Alkaline phosphatase

Structure	Level	Pattern	Image	Note
TS17: branchial arch	Present		1A
TS17: trunk	Present		1A	Higher level expression.

Structure	Level	Pattern	Image	Note
TS15: 1st branchial arch mandibular component mesenchyme	Present	Scattered	1C	Widely scattered.

Structure	Level	Pattern	Image	Note
TS16: 1st branchial arch mandibular component mesenchyme	Present	Regionally restricted	1D	Expressed at the distal portion.
TS16: 2nd branchial arch mesenchyme	Present	Regionally restricted	1D	Expressed at the distal portion of the hyoid arch.
TS16: 1st branchial arch endoderm	Present	Regionally restricted	1D	Expressed in a small population of epithelial cells located in the rostral-proximal region.

Structure	Level	Pattern	Image	Note
TS17: 1st branchial arch mandibular component mesenchyme	Present	Regionally restricted	1E	Increased expression. Became confined to the posterior-distal half.
TS17: 2nd branchial arch mesenchyme	Present	Regionally restricted	1E	Increased expression. Detected throughout the distal portion.
TS17: 1st branchial arch endoderm	Present	Regionally restricted	1E	Expressed in a small population of epithelial cells located in the rostral-proximal region.

Structure	Level	Pattern	Image	Note
TS19: auditory hillocks	Present		1F

Structure	Level	Pattern	Image	Note
TS14: forelimb bud	Present		1G

Structure	Level	Pattern	Image	Note
TS15: forelimb bud mesenchyme	Strong	Regionally restricted	1H	Expressed in the distal portion.

Structure	Level	Pattern	Image	Note
TS17: forelimb bud apical ectodermal ridge	Present		1I
TS17: forelimb bud mesenchyme	Present	Regionally restricted	1I	Expressed in the proximal part. Detected in the mesenchyme underneath the apical ectodermal ridge, the presumptive anterior and posterior necrotic zones, and near the zone of polarizing activity.

Structure	Level	Pattern	Image	Note
TS19: forelimb bud mesenchyme	Present	Regionally restricted	1J	Expressed in the distal portion of the limb, predominantly on the anterior side. Also expressed in the proximal portion.

Structure	Level	Pattern	Image	Note
TS19: forelimb bud mesenchyme	Present	Regionally restricted	1K	Expressed in the distal portion of the limb, predominantly on the anterior side. Also expressed in the proximal portion and a clear-edged band of cells on the ventral side.

Structure	Level	Pattern	Image	Note
TS21: digit mesenchyme	Present	Regionally restricted	1L	Expressed in a subset of cells of the lateral border and at the distal tip of every digit.

Structure	Level	Pattern	Image	Note
TS22: digit mesenchyme	Present	Regionally restricted	1M	Increased expression in the distal tip of every digit. Those next to the inter-digital region decreased to near undetectable levels.