Antibody:	anti-FRG1 (Fl-258) (sc-135066)
Detection system:	Secondary antibody coupled to Alexa Fluor 568

Structure	Cell Type	Level	Pattern	Image	Note
TS17: oral region epithelium		Present	Regionally restricted	1D , 1B	Expression in epithelial layer at predicted first molar region.
TS17: oral region	blood vessel endothelial cell	Strong	Regionally restricted	1B , 1D	Strong expression in mesenchyme around tooth germs, appeared to be located in vascular endothelial cells.

Structure	Cell Type	Level	Pattern	Image	Note
TS20: dental placode		Present	Regionally restricted	1H , 1F	Expression in oral epithelium and mesenchymal cells.
TS20: jaw primordium mesenchyme		Present	Regionally restricted	1H , 1F	Expression in oral epithelium and mesenchymal cells.
TS20: jaw primordium	blood vessel endothelial cell	Strong	Regionally restricted	1H , 1F	Strong expression in vascular endothelial cells.

Structure	Cell Type	Level	Pattern	Image	Note
TS22: tooth bud		Present	Regionally restricted	1L , 1J	At bud stage, expression in epithelial cells of tooth bud.
TS22: tooth epithelium		Present	Regionally restricted	1L , 1J	At bud stage, expression in epithelial cells of tooth bud.
TS22: jaw mesenchyme		Present	Regionally restricted	1L , 1J	At bud stage, expression in surrounding mesenchymal cells. Intensity weaker than in vascular endothelial cells.
TS22: jaw	blood vessel endothelial cell	Strong	Regionally restricted	1L , 1J	Strong expression in vascular endothelial cells.

Structure	Cell Type	Level	Pattern	Image	Note
TS22: jaw	blood vessel endothelial cell	Strong	Regionally restricted	S1C , S1A	Strong expression in mesenchyme around tooth germs, localized to vascular endothelial cells.

Structure	Cell Type	Level	Pattern	Image	Note
TS23: cap stage tooth		Present	Widespread	1P , 1N	At cap stage, expression pattern almost the same as that of Frg1 mRNA. Expression in whole enamel organ.
TS23: enamel organ		Present	Widespread	1P , 1N	At cap stage, expression pattern almost the same as that of Frg1 mRNA. Expression in whole enamel organ.
TS23: cervical loop		Strong		1P , 1N
TS23: inner enamel epithelium		Strong		1P , 1N
TS23: outer enamel epithelium		Strong		1P , 1N
TS23: primary enamel knot		Strong		1P , 1N
TS23: tooth	blood vessel endothelial cell	Present	Regionally restricted	1N , 1P	Expression in vascular endothelial cells around enamel organ.

Structure	Cell Type	Level	Pattern	Image	Note
TS24: cervical loop		Strong		1T , 1R
TS24: enamel knot		Strong		1T , 1R
TS24: inner enamel epithelium		Strong		1T , 1R
TS24: outer enamel epithelium		Strong		1T , 1R
TS24: enamel organ		Present	Regionally restricted	1T , 1R	Decreased expression in central cells of enamel organ.
TS24: dental papilla		Weak		1R , 1T	Expression reduced compared with that on E15.
TS24: dental sac		Weak		1R , 1T	Expression reduced compared with that on E15.
TS24: tooth	blood vessel endothelial cell	Present	Regionally restricted	1T , 1R	Expression in vascular endothelial cells around enamel organ.

Structure	Level	Pattern	Image	Note
TS26: enamel knot	Present		1V , 1X
TS26: inner enamel epithelium	Present		1V , 1X
TS26: dental sac	Weak		1V , 1X
TS26: outer enamel epithelium	Weak		1V , 1X
TS26: dental papilla	Weak	Regionally restricted	1X , 1V	Weak expression in cells of dental papilla facing inner enamel epithelium.
TS26: tongue muscle	Present		1X , 1V

Structure	Level	Pattern	Image	Note
TS26: cervical loop	Strong		S2C , S2A
TS26: inner enamel epithelium	Strong		S2C , S2A
TS26: outer enamel epithelium	Strong		S2C , S2A

Structure	Cell Type	Level	Pattern	Image	Note
TS27: inner enamel epithelium		Strong	Regionally restricted	2B-1 , 2B-3	Strong expression in inner enamel epithelium at central groove region.
TS27: tooth	preameloblast	Strong	Regionally restricted	2B-3 , 2B-1	Strong expression in preameloblasts and preodontoblasts at lingual cusp site.
TS27: tooth	preodontoblast	Strong	Regionally restricted	2B-3 , 2B-1	Strong expression in preameloblasts and preodontoblasts at lingual cusp site.
TS27: dental papilla		Absent		2B-1 , 2B-3	Expression not noted in cells of dental papilla facing inner enamel epithelium.

Structure	Cell Type	Level	Pattern	Image	Note
TS27: tooth	ameloblast	Strong	Regionally restricted	2D-3 , 2D-1	Strong expression in ameloblasts and odontoblasts at lingual cusp site.
TS27: tooth	odontoblast	Strong	Regionally restricted	2D-3 , 2D-1	Strong expression in ameloblasts and odontoblasts at lingual cusp site.
TS27: tooth	preameloblast	Strong	Regionally restricted	2D-1 , 2D-3	Strong expression in preameloblasts and preodontoblasts at central groove region.
TS27: tooth	preodontoblast	Strong	Regionally restricted	2D-1 , 2D-3	Strong expression in preameloblasts and preodontoblasts at central groove region.

Structure	Cell Type	Level	Pattern	Image	Note
TS27: inner enamel epithelium		Strong	Regionally restricted	2F-1 , 2F-3	Strong expression in inner enamel epithelium at central groove region.
TS27: tooth	preameloblast	Strong	Regionally restricted	2F-3 , 2F-1	Strong expression in preameloblasts and preodontoblasts at lingual cusp site.
TS27: tooth	preodontoblast	Strong	Regionally restricted	2F-3 , 2F-1	Strong expression in preameloblasts and preodontoblasts at lingual cusp site.

Structure	Cell Type	Level	Pattern	Image	Note
TS27: tooth	ameloblast	Strong	Regionally restricted	2I-3 , 2I-1	Strong expression in ameloblasts and odontoblasts at lingual cusp site.
TS27: tooth	odontoblast	Strong	Regionally restricted	2I-3 , 2I-1	Strong expression in ameloblasts and odontoblasts at lingual cusp site.

Structure	Cell Type	Level	Pattern	Image	Note
TS27: inner enamel epithelium		Strong	Regionally restricted	2L-3 , 2L-1	Strong expression in inner enamel epithelium at central groove region.
TS27: tooth	preameloblast	Strong	Regionally restricted	2L-1 , 2L-3	Strong expression in preameloblasts and preodontoblasts at lingual cusp site.
TS27: tooth	preodontoblast	Strong	Regionally restricted	2L-1 , 2L-3	Strong expression in preameloblasts and preodontoblasts at lingual cusp site.
TS27: dental papilla		Absent		2L-1 , 2L-3	No expression in cells of dental papilla facing inner enamel epithelium.

Structure	Cell Type	Level	Pattern	Image	Note
TS27: tooth	preameloblast	Strong	Regionally restricted	2O-1 , 2O-3	Strong expression in preameloblasts and preodontoblasts at central groove region.
TS27: tooth	preodontoblast	Strong	Regionally restricted	2O-1 , 2O-3	Strong expression in preameloblasts and preodontoblasts at central groove region.

Structure	Cell Type	Level	Pattern	Image	Note
TS27: tooth	ameloblast	Strong	Regionally restricted	3F , 3D	Strong expression in ameloblasts and odontoblasts at cusp cites, similar to that on P1.
TS27: tooth	odontoblast	Strong	Regionally restricted	3F , 3D	Strong expression in ameloblasts and odontoblasts at cusp cites, similar to that on P1.

Structure	Cell Type	Level	Pattern	Image	Note
TS27: tooth	preameloblast	Strong	Regionally restricted	3G	Strong expression in preameloblasts and preodontoblasts, expecially on lateral sides of tooth crown.
TS27: tooth	preodontoblast	Strong	Regionally restricted	3G	Strong expression in preameloblasts and preodontoblasts, expecially on lateral sides of tooth crown.
TS27: stratum intermedium		Present

Structure	Cell Type	Level	Pattern	Image	Note
TS28: tooth	ameloblast	Strong		4F , 4D	Expression pattern similar to that of Frg1 mRNA. Strong expression in odontoblasts and ameloblasts secreting enamel matrix.
TS28: tooth	odontoblast	Strong		4F , 4D	Expression pattern similar to that of Frg1 mRNA. Strong expression in odontoblasts and ameloblasts secreting enamel matrix.

Structure	Level	Pattern	Image	Note
TS28: enamel epithelium	Weak	Regionally restricted	4G	Reduced expression in enamel epithelium at presumptive lingual cusp sites where ameloblast have become reduced enamel epithelium.

Structure	Cell Type	Level	Pattern	Image	Note
TS28: tooth	preodontoblast	Present		4H
TS28: Hertwig's epithelial root sheath		Weak		4H

Structure	Cell Type	Level	Pattern	Image	Note
TS28: tooth	odontoblast	Strong		4L , 4N	Expression pattern similar to that of Frg1 mRNA.

Structure	Cell Type	Level	Pattern	Image	Note
TS28: tooth	odontoblast	Strong		4O	Expression pattern similar to that of Frg1 mRNA.