Antibody:	anti-Six2
Detection system:	Secondary antibody coupled to horseradish peroxidase

Structure	Level	Pattern	Image	Note
TS13: head mesenchyme	Present	Regionally restricted	3A	Expressed in mesoderm cells at the hindbrain level.

Structure	Level	Pattern	Image	Note
TS15: head mesenchyme	Present	Regionally restricted	3B	Particularly in the frontal region.
TS15: trunk mesenchyme	Present	Regionally restricted	3B	Expressed in the mesenchyme of the thoracic region.
TS15: 1st branchial arch	Present		3B
TS15: foregut mesenchyme	Present	Regionally restricted	3B	Expressed in the esophageal-pharyngeal and midgut mesenchymes corresponding to stomach anlage.
TS15: midgut mesenchyme	Present	Regionally restricted	3B	Expressed in the esophageal-pharyngeal and midgut mesenchymes corresponding to stomach anlage.

Structure	Level	Pattern	Image	Note
TS17: 1st branchial arch	Present		3C
TS17: head mesenchyme	Present		3C
TS17: stomach mesenchyme	Present		3C
TS17: trunk mesenchyme	Present		3C
TS17: nephrogenic cord	Present	Regionally restricted	3C	Expressed in the mesenchyme.
TS17: trunk somite	Present		3C	thoracic somite

Structure	Level	Pattern	Image	Note
TS17: hindbrain	Present	Regionally restricted	4A	Expressed in a small cell population at the anterior part, overlapping with Six4 positive region.

Structure	Level	Pattern	Image	Note
TS19: nasal epithelium	Present		4B	Increased expression.

Structure	Level	Pattern	Image	Note
TS19: otocyst	Present		4C	Increased expression.

Structure	Level	Pattern	Image	Note
TS19: forelimb bud mesenchyme	Present		4D	Increased expression.

Structure	Level	Pattern	Image	Note
TS20: myotome	Present		4E
TS20: sclerotome	Present		4E
TS20: mesenchyme of metanephros	Present	Regionally restricted	4E	Expressed in the mesenchyme of nephrogenic cords which forms the peripheral part of the kidney.
TS20: genital tubercle	Strong		4E

Structure	Level	Pattern	Image	Note
TS11: embryo	Absent

Structure	Level	Pattern	Image	Note
TS13: foregut diverticulum	Present
TS13: heart	Present	Regionally restricted		Expressed in a limited area.

Structure	Level	Pattern	Image	Note
TS15: Rathke's pouch	Present

Structure	Level	Pattern	Image	Note
TS17: Rathke's pouch	Present
TS17: forelimb bud mesenchyme	Present
TS17: nasal epithelium	Present
TS17: otocyst epithelium	Present

Structure	Level	Pattern	Image	Note
TS19: 1st branchial arch	Present	Regionally restricted		Increased expression in cells in the tip.
TS19: olfactory epithelium	Present	Regionally restricted		Expressed in the same region containing Six4 positive cells.

Structure	Level	Pattern	Image	Note
TS20: stomach mesenchyme	Present
TS20: somite	Present	Regionally restricted		Expressed in thoracic somites.

Structure	Level	Pattern	Image	Note
TS21: head mesenchyme	Present	Regionally restricted		Expressed in the fronfal region.
TS21: trunk mesenchyme	Present
TS21: forelimb	Present	Regionally restricted		Expressed at the tip.
TS21: hindlimb	Present	Regionally restricted		Expressed at the tip.

Structure	Level	Pattern	Image	Note
TS22: embryo	Ambiguous			Most of the staining in E13.5 had disappeared.