Antibody:	Anti-Hmga2
Detection system:	Biotinylated secondary antibody/[Strept]avidin coupled to horseradish peroxidase
Assay notes:	Supplementary table 1 was interpreted as follows: +++, strong; ++, present; +, weak; +/-, ambiguous; -, absent.

Structure	Cell Type	Level	Pattern	Image	Note
TS21: intestine		Strong		1A whole embryo	Strong expression in nuclei.
TS21: lung		Strong		1A whole embryo	Strong expression in nuclei.
TS21: metanephros		Strong		1A whole embryo	Strong expression in nuclei.
TS21: oral region		Strong		1A whole embryo	Strong expression in nuclei.
TS21: pituitary gland		Strong		1A whole embryo	Strong expression in nuclei.
TS21: tail		Strong		1A whole embryo	Strong expression in nuclei.
TS21: face		Strong	Regionally restricted	1A whole embryo	Strong expression in nuclei. Perichondrium-like chondrogenic layer of the face was stained.
TS21: face	mesenchyme condensation cell	Strong	Regionally restricted	1A whole embryo	Strong expression in nuclei. Mesenchymal cells condensing at ossifying area were stained.
TS21: limb	mesenchyme condensation cell	Strong	Regionally restricted	1A whole embryo	Strong expression in nuclei. Mesenchymal cells condensing at ossifying area were stained.
TS21: vertebral cartilage condensation	mesenchyme condensation cell	Strong	Regionally restricted	1A whole embryo	Strong expression in nuclei. Mesenchymal cells condensing at ossifying area were stained.

Structure	Level	Pattern	Image	Note
TS21: pituitary gland	Strong		1A pituitary	Strong expression in nuclei.

Structure	Cell Type	Level	Pattern	Image	Note
TS21: oral region epithelium	epithelial cell	Present		1A mouth
TS21: oral region mesenchyme	mesenchymal cell	Present		1A mouth

Structure	Cell Type	Level	Pattern	Image	Note
TS21: lung epithelium	epithelial cell of lung	Present		1A lung
TS21: lung mesenchyme	mesenchymal cell	Present		1A lung

Structure	Cell Type	Level	Pattern	Image	Note
TS21: metanephros epithelium	kidney epithelial cell	Present		1A kidney
TS21: mesenchyme of metanephros	mesenchymal cell	Present		1A kidney

Structure	Cell Type	Level	Pattern	Image	Note
TS21: intestine epithelium	intestinal epithelial cell	Present		1A intestine
TS21: intestine mesenchyme	mesenchymal cell	Present		1A intestine

Structure	Cell Type	Level	Pattern	Image	Note
TS21: vertebral cartilage condensation	mesenchyme condensation cell	Present		1A vertebra

Structure	Level	Pattern	Image	Note
TS21: tail	Strong		1A tail	Strong expression in nuclei.

Structure	Level	Pattern	Image	Note
TS22: intestine	Weak		1B whole embryo
TS22: metanephros	Weak		1B whole embryo
TS22: pituitary gland	Weak		1B whole embryo
TS22: lung	Moderate		1B whole embryo
TS22: tail	Moderate		1B whole embryo
TS22: oral region epithelium	Ambiguous		1B whole embryo	Primitive mouth epithelium was stained negligibly.
TS22: tooth	Strong		1B whole embryo

Structure	Level	Pattern	Image	Note
TS22: pituitary gland	Weak		1B pituitary

Structure	Level	Pattern	Image	Note
TS22: oral region epithelium	Ambiguous		1B mouth	Primitive mouth epithelium was stained negligibly.
TS22: tooth	Strong		1B mouth

Structure	Level	Pattern	Image	Note
TS22: lung	Moderate		1B lung

Structure	Level	Pattern	Image	Note
TS22: metanephros	Weak		1B kidney

Structure	Level	Pattern	Image	Note
TS22: intestine	Weak		1B intestine

Structure	Level	Pattern	Image	Note
TS22: vertebral cartilage condensation	Weak		1B vertebra

Structure	Level	Pattern	Image	Note
TS22: tail	Moderate		1B tail

Structure	Level	Pattern	Image	Note
TS20: oral epithelium	Present	Widespread	1C upper 12 dpc	Widespread expression in primitive mouth epithelium.
TS20: dental placode	Present	Widespread	1C upper 12 dpc
TS20: oral region mesenchyme	Present	Regionally restricted	1C upper 12 dpc	Expression was detected in the underlying mesenchyme of the dental placode.

Structure	Cell Type	Level	Pattern	Image	Note
TS21: dental placode		Present		1C upper 13 dpc
TS21: molar dental lamina		Present		1C upper 13 dpc
TS21: lower jaw mesenchyme	mesenchymal cell	Present	Non-Uniform	1C upper 13 dpc	In contrast to the observed staining of mesenchymal cells away from dental lamina, mesenchymal cells juxtaposing to dental lamina were marginally stained.

Structure	Cell Type	Level	Pattern	Image	Note
TS22: enamel organ		Present	Regionally restricted	1C upper 14 dpc	Expression in enamel organ was deflected on the lingual side.
TS22: dental papilla		Weak	Regionally restricted	1C upper 14 dpc	Dental papilla cells bounded by inner enamel epithelium were marginally stained.
TS22: lower jaw molar mesenchyme	mesenchymal cell	Weak	Regionally restricted	1C upper 14 dpc	Mesenchymal cells away from the enamel organ were marginally stained.
TS22: dental sac		Present	Regionally restricted	1C upper 14 dpc	Staining was detected in dental follicle cells that were arranged in lamina surrounding the enamel organ.

Structure	Cell Type	Level	Pattern	Image	Note
TS23: enamel organ		Present	Regionally restricted	1C upper 15 dpc	Expression in enamel organ was deflected on the lingual side.
TS23: dental papilla		Weak	Regionally restricted	1C upper 15 dpc	Dental papilla cells bounded by inner enamel epithelium were marginally stained.
TS23: lower jaw molar mesenchyme	mesenchymal cell	Weak	Regionally restricted	1C upper 15 dpc	Mesenchymal cells away from the enamel organ were marginally stained.
TS23: dental sac		Present	Regionally restricted	1C upper 15 dpc	Staining was detected in dental follicle cells that were arranged in lamina surrounding the enamel organ.

Structure	Cell Type	Level	Pattern	Image	Note
TS24: enamel organ		Strong	Regionally restricted	1C upper 16 dpc	Staining in enamel organ on the lingual side, especially outer enamel epithelium, was most prominent.
TS24: outer enamel epithelium		Strong	Regionally restricted	1C upper 16 dpc	Staining in enamel organ on the lingual side, especially outer enamel epithelium, was most prominent.
TS24: inner enamel epithelium	epithelial cell	Weak		1C upper 16 dpc
TS24: cervical loop		Present		1C upper 16 dpc
TS24: dental sac		Present		1C upper 16 dpc
TS24: lower jaw molar mesenchyme		Ambiguous	Regionally restricted	1C upper 16 dpc	A rapid loss of the surrounding mesenchyme staining was noted.

Structure	Cell Type	Level	Pattern	Image	Note
TS25: enamel organ		Strong	Regionally restricted	1C upper 17 dpc	Staining in enamel organ on the lingual side, especially outer enamel epithelium, was most prominent.
TS25: outer enamel epithelium		Strong	Regionally restricted	1C upper 17 dpc	Staining in enamel organ on the lingual side, especially outer enamel epithelium, was most prominent.
TS25: inner enamel epithelium	epithelial cell	Weak		1C upper 17 dpc
TS25: cervical loop		Present		1C upper 17 dpc
TS25: dental sac		Present		1C upper 17 dpc
TS25: lower jaw molar mesenchyme		Ambiguous		1C upper 17 dpc	A rapid loss of the surrounding mesenchyme staining was noted.

Structure	Cell Type	Level	Pattern	Image	Note
TS26: enamel organ		Strong	Regionally restricted	1C upper 18 dpc	Staining in enamel organ on the lingual side, especially outer enamel epithelium, was most prominent.
TS26: outer enamel epithelium		Strong	Regionally restricted	1C upper 18 dpc	Staining in enamel organ on the lingual side, especially outer enamel epithelium, was most prominent.
TS26: inner enamel epithelium	epithelial cell	Weak		1C upper 18 dpc
TS26: cervical loop		Present		1C upper 18 dpc
TS26: dental sac		Present		1C upper 18 dpc
TS26: lower jaw molar mesenchyme		Ambiguous		1C upper 18 dpc	A rapid loss of the surrounding mesenchyme staining was noted.

Structure	Level	Pattern	Image	Note
TS27: lower jaw 1st molar	Weak		1C upper NB

Structure	Level	Pattern	Image	Note
TS27: lower jaw 1st molar	Weak		1C upper 1 pp

Structure	Level	Pattern	Image	Note
TS27: lower jaw 1st molar	Weak		1C upper 2 pp

Structure	Level	Pattern	Image	Note
TS27: lower jaw 1st molar	Weak		1C upper 3 pp

Structure	Level	Pattern	Image	Note
TS28: lower jaw 1st molar	Weak		1C upper 4 pp

Structure	Level	Pattern	Image	Note
TS28: lower jaw 1st molar	Weak		1C upper 5 pp

Structure	Cell Type	Level	Pattern	Image	Note
TS21: face		Strong		S3_face upper	Strong expression in nuclei.
TS21: face	mesenchymal cell	Present	Regionally restricted	S3_face upper	Mesenchymal cells condensing at ossifying area and perichondrium-like chondrogenic layer were stained.

Structure	Level	Pattern	Image	Note
TS22: face	Weak	Regionally restricted	S3_face lower	Staining became weak at ossifying area and perichondrium-like chondrogenic layer.

Structure	Cell Type	Level	Pattern	Image	Note
TS21: limb		Strong		S3_limb bud upper	Strong expression in nuclei.
TS21: limb cartilage condensation	mesenchyme condensation cell	Present		S3_limb bud upper	Mesenchymal cells condensing at ossifying area and perichondrium-like chondrogenic layer were stained.

Structure	Level	Pattern	Image	Note
TS22: limb cartilage condensation	Weak	Regionally restricted	S3_limb bud lower	Staining became weak at ossifying area and perichondrium-like chondrogenic layer.

Structure	Level	Pattern	Image	Note
TS20: dental placode	Strong
TS20: oral region mesenchyme	Strong
TS20: oral epithelium	Present	Non-Uniform		Expression in primitive mouth epithelium was listed as +++ ~ +.

Structure	Level	Pattern	Image	Note
TS21: dental lamina	Strong
TS21: lower jaw mesenchyme	Strong
TS21: oral region epithelium	Present	Non-Uniform		Expression in primitive mouth epithelium was listed as +++ ~ +.

Structure	Level	Pattern	Image	Note
TS22: cervical loop	Present
TS22: enamel organ	Present
TS22: outer enamel epithelium	Present
TS22: dental papilla	Weak
TS22: dental sac	Weak
TS22: inner enamel epithelium	Present			Expression was labeled as ++ ~ + in the table.
TS22: lower jaw molar mesenchyme	Weak			Expression was labeled as + - +/- in the table.
TS22: oral region epithelium	Ambiguous			Primitive mouth epithelium expression was labeled as +/- ~ - in the table.

Structure	Level	Pattern	Image	Note
TS23: cervical loop	Present
TS23: enamel organ	Present
TS23: outer enamel epithelium	Present
TS23: dental papilla	Weak
TS23: dental sac	Weak
TS23: inner enamel epithelium	Present			Expression was labeled as ++ ~ + in the table.
TS23: lower jaw molar mesenchyme	Weak			Expression was labeled as + - +/- in the table.
TS23: oral epithelium	Ambiguous			Primitive mouth epithelium expression was labeled as +/- ~ - in the table.

Structure	Level	Pattern	Image	Note
TS24: dental sac	Present
TS24: outer enamel epithelium	Present
TS24: cervical loop	Present	Non-Uniform		Expression was labeled as ++ - + in the table.
TS24: enamel organ	Present	Non-Uniform		Expression was labeled as ++ - + in the table.
TS24: inner enamel epithelium	Weak	Non-Uniform		Expression was labeled as + - - in the table.
TS24: dental papilla	Weak
TS24: lower jaw molar mesenchyme	Absent
TS24: oral epithelium	Absent			Primitive mouth epithelium was negative.

Structure	Level	Pattern	Image	Note
TS26: dental sac	Present
TS26: outer enamel epithelium	Present
TS26: cervical loop	Present	Non-Uniform		Expression was labeled as ++ - + in the table.
TS26: enamel organ	Present	Non-Uniform		Expression was labeled as ++ - + in the table.
TS26: inner enamel epithelium	Weak	Non-Uniform		Expression was labeled as + - - in the table.
TS26: dental papilla	Weak
TS26: lower jaw molar mesenchyme	Absent
TS26: oral epithelium	Absent			Primitive mouth epithelium was negative.

Structure	Level	Pattern	Image	Note
TS27: cervical loop	Weak
TS27: dental sac	Weak
TS27: enamel organ	Weak
TS27: outer enamel epithelium	Weak
TS27: dental papilla	Ambiguous			Expression was labeled as +/- ~ - in the table.
TS27: inner enamel epithelium	Absent
TS27: lower jaw molar mesenchyme	Absent
TS27: oral epithelium	Absent			Primitive mouth epithelium was negative.

Structure	Level	Pattern	Image	Note
TS27: cervical loop	Ambiguous			Expression was labeled as +/- ~ - in the table.
TS27: dental papilla	Ambiguous			Expression was labeled as +/- ~ - in the table.
TS27: dental sac	Ambiguous			Expression was labeled as +/- ~ - in the table.
TS27: enamel organ	Ambiguous			Expression was labeled as +/- ~ - in the table.
TS27: inner enamel epithelium	Absent
TS27: lower jaw molar mesenchyme	Absent
TS27: outer enamel epithelium	Absent
TS27: oral epithelium	Absent			Primitive mouth epithelium was negative.

Structure	Level	Pattern	Image	Note
TS28: cervical loop	Ambiguous			Expression was labeled as +/- ~ - in the table.
TS28: dental papilla	Ambiguous			Expression was labeled as +/- ~ - in the table.
TS28: dental sac	Ambiguous			Expression was labeled as +/- ~ - in the table.
TS28: enamel organ	Ambiguous			Expression was labeled as +/- ~ - in the table.
TS28: inner enamel epithelium	Absent
TS28: lower jaw molar mesenchyme	Absent
TS28: outer enamel epithelium	Absent
TS28: oral epithelium	Absent			Primitive mouth epithelium was negative.