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

Structure	Level	Pattern	Image	Note
TS21: tibia-fibula pre-cartilage condensation	Absent		1B	Expression not detected at this stage.

Structure	Cell Type	Level	Pattern	Image	Note
TS22: bone		Strong	Regionally restricted	2D	Strong expression in osteogenic cells of bone collar.
TS22: tibia cartilage condensation	chondrocyte	Weak	Regionally restricted	2D	Weak expression in chondrocytes adjacent to bone collar.

Structure	Level	Pattern	Image	Note
TS23: tibia epiphysis	Present	Regionally restricted	3B	Expression on osteogenic cells of bone collar.
TS23: epiphyseal plate hypertrophic zone	Weak	Regionally restricted	3B	Weak expression in chondrocytes of lower hypertrophic cell zone.

Structure	Level	Pattern	Image	Note
TS22: mandible	Present	Regionally restricted	4B	Expression in osterogenic cells of bone tissue.
TS22: mandible condylar condensation	Absent		4B	No expression in cells with condylar anlage.

Structure	Cell Type	Level	Pattern	Image	Note
TS23: mandible		Present	Regionally restricted	5B	Expression in osterogenic cells of bone collar.
TS23: mandible condylar process	chondrocyte	Present		5B	Widely expressed in newly formed chondrocytess.

Structure	Cell Type	Level	Pattern	Image	Note
TS24: mandible		Present	Regionally restricted	6B	Expression in osteogenic cells of bone collar.
TS24: mandible condylar process	chondrocyte	Present	Regionally restricted	6B	Expression in chondrocytes of entire hypertrophic cell zone. Slightly weaker expression in lower hypertrophic cell zone.