Antibody:

anti-Lbx1

Structure	Level	Pattern	Image	Note
TS16: forelimb bud mesenchyme	Present	Regionally restricted	1C	Expression in migrating muscle progenitors of dorsal and ventral limb.

Structure	Level	Pattern	Image	Note
TS17: mesenchyme derived from somites 01-04	Present	Regionally restricted	2G	Co-expression with Cxcr4 xpression in muscle progenitors migrating along hypoglossal cord and in muscle progenitors in tongue anlage.
TS17: 1st branchial arch mesenchyme derived from head mesoderm	Present	Regionally restricted	2G	Expression in muscle progenitors colonizing mesenchyme of first branchial arch.

Structure	Level	Pattern	Image	Note
TS17: dermomyotome	Present	Regionally restricted	3A	Expression in progenitors prior to delamination from ventrolateral dermomyotome. Co-expression with Cxcr4 only after migrating progenitors cells have moved away from the dermomyotome.
TS17: forelimb bud mesenchyme	Present	Regionally restricted	3A	Co-expression with Cxcr4 in muscle masses. All Cxcr4-expressing cells in premuscle masses also expressing Lbx1, but not every Lbx1-expressing cell expresses Cxcr4.

Structure	Level	Pattern	Image	Note
TS18: forelimb bud mesenchyme	Present	Regionally restricted	3B	Co-expression with Cxcr4 in muscle masses. All Cxcr4-expressing cells in premuscle masses also expressing Lbx1, but not every Lbx1-expressing cell expresses Cxcr4.

Structure	Level	Pattern	Image	Note
TS19: forelimb bud mesenchyme	Present	Regionally restricted	3C	Co-expression with Cxcr4 in muscle masses. All Cxcr4-expressing cells in premuscle masses also expressing Lbx1, but not every Lbx1-expressing cell expresses Cxcr4.

Structure	Level	Pattern	Image	Note
TS17: forelimb bud mesenchyme	Present	Regionally restricted	3D	Expression in all Cxcr4-expressing muscle progenitor cell, but not expressed in all Cxcr4-expressing cells.

Structure	Level	Pattern	Image	Note
TS18: mesenchyme derived from somites 01-04	Present	Regionally restricted	5A	Expression in stream of muscle progenitors along hypoglossal cord.
TS18: 1st branchial arch mesenchyme derived from head mesoderm	Present	Regionally restricted	5A	Expression in muscle progenitors colonizing mesenchyme of first branchial arch.

Structure	Level	Pattern	Image	Note
TS18: 1st branchial arch mesenchyme derived from head mesoderm	Present	Regionally restricted	5B	Number of expressing muscle progenitor cells in first branchial arch reduced compared to control.

Structure	Level	Pattern	Image	Note
TS18: 1st branchial arch mesenchyme derived from head mesoderm	Present	Regionally restricted	5C	Number of expressing muscle progenitor cells in first branchial arch reduced compared to control.

Structure	Level	Pattern	Image	Note
TS18: 1st branchial arch mesenchyme derived from head mesoderm	Absent		5D	Authors report absence of muscle progenitors in first branchial arch.

Structure	Level	Pattern	Image	Note
TS19: branchial arch mesenchyme derived from head mesoderm	Absent			Authors report absence of muscle progenitors in first branchial arch.

Structure	Level	Pattern	Image	Note
TS18: forelimb bud mesenchyme	Present	Regionally restricted	6A	Expression in muscle progenitor cells.

Structure	Level	Pattern	Image	Note
TS18: forelimb bud mesenchyme	Present	Regionally restricted	6B	Reduction in number of expressing cells compared to control embryos, more pronounced in distal than in proximal domain of dorsal limb.

Structure	Level	Pattern	Image	Note
TS18: forelimb bud mesenchyme	Present	Regionally restricted	6C	Expression in muscle progenitor cells.

Structure	Level	Pattern	Image	Note
TS18: forelimb bud mesenchyme	Present	Regionally restricted	6D	In dorsal and ventral limb, number of expressing cells further reduced compared to Gab1-/- mutant embryos.