Probe:	Hey2 probe5
Probe preparation:	Antisense labelled with digoxigenin RNA

Structure	Level	Pattern	Image	Note
TS20: dental placode	Absent		1C

Structure	Level	Pattern	Image	Note
TS21: molar epithelium	Ambiguous		1F	Hardly detectable.
TS21: molar mesenchyme	Ambiguous		1F	Hardly detectable.

Structure	Level	Pattern	Image	Note
TS22: molar	Ambiguous		1I	Almost negative, or at a quite low level.

Structure	Level	Pattern	Image	Note
TS23: molar	Ambiguous		1L	Almost negative, or at a quite low level.

Structure	Level	Pattern	Image	Note
TS24: inner enamel epithelium	Present	Regionally restricted	2C	Restricted to the undifferentiatedundifferentiated inner enamel epithelium
TS24: molar mesenchyme	Ambiguous		2C	Absent, or at a very low level.

Structure	Level	Pattern	Image	Note
TS25: inner enamel epithelium	Present	Regionally restricted	2G' , 2G	Most intense expression in the undifferentiated inner enamel epithelium.
TS25: molar mesenchyme	Ambiguous		2G' , 2G	Absent, or at a very low level.

Structure	Level	Pattern	Image	Note
TS26: inner enamel epithelium	Present	Regionally restricted	2K , 2K'	Peaked out expression in the undifferentiated inner enamel epithelium.
TS26: molar mesenchyme	Ambiguous		2K , 2K'	Absent, or at a very low level.

Structure	Level	Pattern	Image	Note
TS27: molar epithelium	Ambiguous		3C' , 3C	Barely identified.
TS27: molar mesenchyme	Ambiguous		3C' , 3C	Barely identified.

Structure	Level	Pattern	Image	Note
TS27: molar epithelium	Ambiguous		3G , 3G'	Barely identified.
TS27: molar mesenchyme	Ambiguous		3G , 3G'	Barely identified.

Structure	Level	Pattern	Image	Note
TS28: molar epithelium	Ambiguous		3K' , 3K	Barely identified.
TS28: molar mesenchyme	Ambiguous		3K' , 3K	Barely identified.

Structure	Level	Pattern	Image	Note
TS26: lower jaw incisor enamel organ	Present	Regionally restricted	5C2 , 5C1 , 5C3 , 5C4	Expressed in the undifferentiated inner enamel epithelium in the apical bud, and barely detectable in preameloblasts and ameloblasts.
TS26: inner enamel epithelium	Present	Regionally restricted	5C1 , 5C4 , 5C3 , 5C2	Expressed in the undifferentiated inner enamel epithelium in the apical bud.
TS26: lower jaw incisor dental papilla	Ambiguous		5C2 , 5C3 , 5C4 , 5C1	Barely detectable in mesenchymal cells.

Structure	Level	Pattern	Image	Note
TS28: inner enamel epithelium	Present	Regionally restricted	5G1	Expressed in the undifferentiated inner enamel epithelium in the apical bud.
TS28: upper jaw incisor enamel organ	Present	Regionally restricted	5G1	Expressed in the undifferentiated inner enamel epithelium in the apical bud.
TS28: upper jaw incisor dental papilla	Ambiguous		5G1	Barely detectable in mesenchymal cells.

Structure	Level	Pattern	Image	Note
TS28: upper jaw incisor dental papilla	Ambiguous		5G2	Barely detectable in mesenchymal cells.

Structure	Level	Pattern	Image	Note
TS28: inner enamel epithelium	Present	Regionally restricted	5K1	Expressed in the undifferentiated inner enamel epithelium in the apical bud.
TS28: upper jaw incisor enamel organ	Present	Regionally restricted	5K1	Expressed in the undifferentiated inner enamel epithelium in the apical bud.
TS28: upper jaw incisor dental papilla	Ambiguous		5K1	Barely detectable in mesenchymal cells.

Structure	Level	Pattern	Image	Note
TS28: upper jaw incisor dental papilla	Ambiguous		5K2	Barely detectable in mesenchymal cells.