Probe:	alpha2(XI) probe
Probe preparation:	Antisense labelled with digoxigenin RNA
Visualized with:	Alkaline phosphatase

Structure	Level	Pattern	Image	Note
TS19: notochord	Strong		1B	Significant expression in notochord.

Structure	Level	Pattern	Image	Note
TS19: sclerotome	Strong		1D	Significant expression in sclerotome.

Structure	Level	Pattern	Image	Note
TS20: notochord	Strong		1F	High level of expression in notochord.
TS20: sclerotome	Weak		1F	Low level of expression in perinotochordal sclerotome.

Structure	Level	Pattern	Image	Note
TS20: nasal mesenchyme	Present	Regionally restricted	2C	Expression in mesenchymal condensation forming nasal capsule.
TS20: nasal septum	Present		2C

Structure	Level	Pattern	Image	Note
TS21: limb	Strong		2D	High level of expression detectable at 13.0 dpc.

Structure	Level	Pattern	Image	Note
TS23: Meckel's cartilage	Strong		3B	Prominent expression in all cartilaginous tissues; such as chondrocranium, primordial cartilage of vertebral bodies, sternum, ribs, tracheal rings, hyoid cartilage, Meckel's cartilage, and limb cartilage.
TS23: chondrocranium	Strong		3B	Prominent expression in all cartilaginous tissues; such as chondrocranium, primordial cartilage of vertebral bodies, sternum, ribs, tracheal rings, hyoid cartilage, Meckel's cartilage, and limb cartilage.
TS23: hyoid	Strong		3B	Prominent expression in all cartilaginous tissues; such as chondrocranium, primordial cartilage of vertebral bodies, sternum, ribs, tracheal rings, hyoid cartilage, Meckel's cartilage, and limb cartilage.
TS23: limb cartilage condensation	Strong		3B	Prominent expression in all cartilaginous tissues; such as chondrocranium, primordial cartilage of vertebral bodies, sternum, ribs, tracheal rings, hyoid cartilage, Meckel's cartilage, and limb cartilage.
TS23: rib	Strong		3B	Prominent expression in all cartilaginous tissues; such as chondrocranium, primordial cartilage of vertebral bodies, sternum, ribs, tracheal rings, hyoid cartilage, Meckel's cartilage, and limb cartilage.
TS23: sternum	Strong		3B	Prominent expression in all cartilaginous tissues; such as chondrocranium, primordial cartilage of vertebral bodies, sternum, ribs, tracheal rings, hyoid cartilage, Meckel's cartilage, and limb cartilage.
TS23: trachea cartilaginous ring	Strong		3B	Prominent expression in all cartilaginous tissues; such as chondrocranium, primordial cartilage of vertebral bodies, sternum, ribs, tracheal rings, hyoid cartilage, Meckel's cartilage, and limb cartilage.
TS23: vertebral cartilage condensation	Strong		3B	Prominent expression in all cartilaginous tissues; such as chondrocranium, primordial cartilage of vertebral bodies, sternum, ribs, tracheal rings, hyoid cartilage, Meckel's cartilage, and limb cartilage.
TS23: humerus	Strong		3B
TS23: radius	Strong		3B
TS23: ulna	Strong		3B

Structure	Level	Pattern	Image	Note
TS23: radius	Present	Regionally restricted	4C
TS23: long bone epiphyseal plate proliferative zone	Strong	Regionally restricted	4C	Strong expression in resting and proliferating chondrocytes.
TS23: long bone epiphyseal plate resting zone	Strong	Regionally restricted	4C	Strong expression in resting and proliferating chondrocytes.
TS23: perichondrium	Present	Regionally restricted	4C	Expression in perichondrium around hypertrophic zone.
TS23: long bone epiphyseal plate hypertrophic zone	Absent		4C	No expression in cells of hypertrophic zone.
TS23: periosteum	Present	Regionally restricted	4C	Expression in immature periosteum around primary ossification center.
TS23: long bone epiphyseal plate ossification zone	Absent		4C	Expression absent from primary ossification center.

Structure	Level	Pattern	Image	Note
TS23: perichondrium	Strong	Regionally restricted	5B	High level of expression in mesenchymal cell layers differentiating into osteoblasts.

Structure	Level	Pattern	Image	Note
TS23: eye	Absent		6B	No expression in any ocular tissues.

Structure	Level	Pattern	Image	Note
TS23: forelimb tendon primordium	Absent		6D