Probe:	m-Frzb1 cDNA
Probe preparation:	labelled with digoxigenin RNA
Visualized with:	Alkaline phosphatase

Structure	Level	Pattern	Image	Note
TS11: primitive streak	Present		2A

Structure	Level	Pattern	Image	Note
TS11: embryo mesoderm	Present	Regionally restricted	2B	Expression in the prospective cardiac mesoderm.

Structure	Level	Pattern	Image	Note
TS14: prosencephalon	Present	Regionally restricted	2C	Expression in dorsal cells of the presumptive forebrain, just anterior to the forebrain-midbrain junction.
TS14: future midbrain	Present		2C

Structure	Level	Pattern	Image	Note
TS13: future midbrain	Strong	Regionally restricted	2E	Continued strong dorsal stripes of expression in forebrain and midbrain.
TS13: future prosencephalon	Strong	Regionally restricted	2E	Continued strong dorsal stripes of expression in forebrain and midbrain.
TS13: branchial arch mesenchyme	Present		2E	Expression in branchial arches first detected, restricted to mesenchymal tissue.

Structure	Level	Pattern	Image	Note
TS14: trunk unsegmented mesenchyme	Present		2F
TS14: somite	Present	Regionally restricted	2F	Expression in cranial half of newly formed somites.
TS14: primitive streak	Absent		2F

Structure	Level	Pattern	Image	Note
TS15: future forebrain	Weak	Regionally restricted		Expression in dorsal forebrain is weaker but still easily detectable.

Structure	Level	Pattern	Image	Note
TS15: hindlimb ridge	Present			Expression in hindlimb detected as early as 9.5 dpc.

Structure	Level	Pattern	Image	Note
TS15: head mesenchyme	Present	Regionally restricted	3A	Expression in ventral facial mesenchyme.
TS15: 1st branchial arch maxillary component	Present	Regionally restricted	3A	Expression at inferior border of maxillary division of first branchial arch.
TS15: 1st branchial arch mandibular component	Present	Regionally restricted	3A	Expression at superior border of mandibular division of first branchial arch.
TS15: forelimb bud mesenchyme	Present	Regionally restricted	3A	Expression becomes more restricted to ventral mesenchyme
TS15: forelimb bud presumptive apical ectodermal ridge	Absent		3A	Expression appears to be excluded from the developing AER.

Structure	Level	Pattern	Image	Note
TS17: head mesenchyme	Strong	Regionally restricted	3B	Intense expression in ventral facial mesenchyme adjacent to the maxillary arch.
TS17: 1st branchial arch mesenchyme	Present	Widespread	3B	Expression throughout mesenchyme of first branchial arch.
TS17: 2nd branchial arch mesenchyme	Present		3B	Expression into mesenchyme of hyoid or second arch.
TS17: forelimb bud	Present	Regionally restricted	3B	Expression begins to lose its strictly ventral pattern.
TS17: hindlimb bud	Present	Regionally restricted	3B	Expression remains ventral.

Structure	Level	Pattern	Image	Note
TS20: face mesenchyme	Present	Regionally restricted		Expression in ventral facial mesenchyme.
TS20: mandibular process mesenchyme	Present
TS20: maxillary process mesenchyme	Present

Structure	Level	Pattern	Image	Note
TS20: mandibular process mesenchyme	Present	Regionally restricted	3C	Expression restricted to condensing ectomesenchyme around the presumptive tooth bud.
TS20: maxillary process mesenchyme	Present	Regionally restricted	3C	Expression restricted to condensing ectomesenchyme around the presumptive tooth bud.
TS20: jaw primordium	Present	Regionally restricted	3C	No expression within epithelial placode.

Structure	Level	Pattern	Image	Note
TS20: mandibular process mesenchyme	Present	Regionally restricted	3D	Expression restricted to condensing ectomesenchyme around the presumptive tooth bud.
TS20: jaw primordium	Present	Regionally restricted	3D	No expression within epithelial placode.

Structure	Level	Pattern	Image	Note
TS15: forelimb bud	Present	Regionally restricted	4A	Expression is initially ventral-specific.

Structure	Level	Pattern	Image	Note
TS17: hindlimb bud	Present	Regionally restricted	4C	Expression extends more dorsally.

Structure	Level	Pattern	Image	Note
TS19: forelimb bud	Present	Regionally restricted	4D	Expression no longer detected in the ventral portion of the limb.
TS19: forelimb bud mesenchyme	Present	Regionally restricted	4D	Expression in distal mesenchyme. Expression primarily in prechondrial region surrounding condensing mesenchyme.

Structure	Level	Pattern	Image	Note
TS21: humerus cartilage condensation	Present	Regionally restricted	4G	Expression in chondroblasts at the proximal and distal ends, but not at the center, of condensing cartilaginous anlage,
TS21: upper arm rest of mesenchyme	Absent		4G	No expression in the surrounding mesenchyme (perichondrium).