Probe:	Gas2 probe1
Probe preparation:	Antisense labelled with digoxigenin RNA
Visualized with:	Alkaline phosphatase

Structure	Level	Pattern	Image	Note
TS19: hindlimb bud mesenchyme	Weak	Regionally restricted	3A	Weak expression in mesenchymal cell surrounding presumptive chondrogenic regions.

Structure	Level	Pattern	Image	Note
TS20: hindlimb mesenchyme	Strong	Regionally restricted	3B	Strong expression in cells surrounding developing chondrogenic primordia of digits, metatarsals, tibia, fibula and femur.
TS20: hindlimb pre-cartilage condensation	Absent		3B	No expression in chondrogenic primordia.
TS20: hindlimb interdigital region mesenchyme	Present		3B	Expression in soft connective tissue of interdigital regions.
TS20: hindlimb digit mesenchyme	Present	Regionally restricted	3B	No or very low levels of expression in soft connective tissue distant from chondrogenic elements.
TS20: hindlimb epithelium	Absent		3B	No expression in ectoderm or apical ectodermal ridge.

Structure	Level	Pattern	Image	Note
TS22: hindlimb mesenchyme	Present	Regionally restricted	3E	Expression in mesenchymal cells in the process of condensing to form tendons.

Structure	Level	Pattern	Image	Note
TS22: forelimb mesenchyme	Present	Regionally restricted	3K	Expression in developing tendons.
TS22: forelimb joint	Present	Regionally restricted	3K	Expression in mesenchymal cells in joint forming region.

Structure	Level	Pattern	Image	Note
TS22: carpus cartilage condensation	Present	Regionally restricted	3L	Expression in carpals restricted to chondrocytes.

Structure	Level	Pattern	Image	Note
TS22: future tarsus	Present	Regionally restricted		Expression in tarsal restricted to chondrocytes.