Antibody:	Gas2 antibody
Detection system:	alkaline phosphatase

Structure	Level	Pattern	Image	Note
TS19: head mesenchyme	Strong	Regionally restricted	2A	Strong expression in soft connective tissue of face and trunk.
TS19: trunk mesenchyme	Strong	Regionally restricted	2A	Strong expression in soft connective tissue of face and trunk.
TS19: axial skeleton	Strong	Regionally restricted	2A	Strong expression in intervertebral tissues, but not in vertebral cartilage.
TS19: brain	Weak		2A	Low level of expression in brain and neural tube.
TS19: future spinal cord	Weak		2A	Low level of expression in brain and neural tube.

Structure	Level	Pattern	Image	Note
TS21: axial skeleton	Strong	Regionally restricted	2D	Strong expression in intervertebral tissues and soft connective tissues of head and trunk.
TS21: head mesenchyme	Strong	Regionally restricted	2D	Strong expression in intervertebral tissues and soft connective tissues of head and trunk.
TS21: trunk mesenchyme	Strong	Regionally restricted	2D	Strong expression in intervertebral tissues and soft connective tissues of head and trunk.
TS21: lens	Weak		2D	Low levels of expression in developing lung, cortex of kidney and lens of eye.
TS21: lung	Weak		2D	Low levels of expression in developing lung, cortex of kidney and lens of eye.
TS21: renal cortex	Weak		2D	Low levels of expression in developing lung, cortex of kidney and lens of eye.
TS21: vertebral cartilage condensation	Weak	Regionally restricted	2D	Low levels of expression in vertebral cartilage located cranially.

Structure	Level	Pattern	Image	Note
TS20: hindlimb interdigital region	Present	Regionally restricted	3C	Expression in interdigital tissues. authors state protein expression pattern was essentially similar to that of RNA expression.

Structure	Level	Pattern	Image	Note
TS21: hindlimb interdigital region	Present	Regionally restricted	3D	Expression restricted to proximal regions of interdigital tissues. No expression detected distally.
TS21: femur cartilage condensation	Present	Regionally restricted	3D	Expression in some chondrocytes in the stylopod.
TS21: foot pre-cartilage condensation	Absent		3D	No expression in autopod and zygopod.
TS21: tibia-fibula pre-cartilage condensation	Absent		3D	No expression in autopod and zygopod.
TS21: foot mesenchyme	Strong	Regionally restricted	3D	Strong expression in mesenchymal cells surrounding cartilage in autopod and zygopod.
TS21: lower leg rest of mesenchyme	Strong	Regionally restricted	3D	Strong expression in mesenchymal cells surrounding cartilage in autopod and zygopod.

Structure	Level	Pattern	Image	Note
TS21: humerus cartilage condensation	Strong	Regionally restricted	3F	Strong expression in chondrocytes in pre-hypertrophic and hypertrophic regions of developing cartilage of humerus, radius and ulna.
TS21: radius cartilage condensation	Strong	Regionally restricted	3F	Strong expression in chondrocytes in pre-hypertrophic and hypertrophic regions of developing cartilage of humerus, radius and ulna.

Structure	Level	Pattern	Image	Note
TS22: humerus cartilage condensation	Strong	Regionally restricted	3G	Strong expression in chondrocytes in hypertrophic regions of developing cartilage of humerus, radius and ulna.
TS22: radius cartilage condensation	Strong	Regionally restricted	3G	Strong expression in chondrocytes in hypertrophic regions of developing cartilage of humerus, radius and ulna.
TS22: ulna cartilage condensation	Strong	Regionally restricted	3G	Strong expression in chondrocytes in hypertrophic regions of developing cartilage of humerus, radius and ulna.

Structure	Level	Pattern	Image	Note
TS22: future tarsus	Present	Regionally restricted		Expression in cartilages forming tarsals.

Structure	Level	Pattern	Image	Note
TS23: ulna	Absent		3H	No expression after hypertrophic chondrocytes die and become mineralized.

Structure	Level	Pattern	Image	Note
TS21: hindlimb muscle	Present	Regionally restricted	3I	In proximal myogenic regions, expression in some myogenic cells (myoblasts).

Structure	Level	Pattern	Image	Note
TS22: hindlimb muscle	Present	Regionally restricted	3J	Expression restricted to myotubules in mature myogenic regions.