Antibody:	anti-Hoxa-2
Detection system:	Biotinylated secondary antibody/[Strept]avidin coupled to horseradish peroxidase

Structure	Level	Pattern	Image	Note
TS20: nasal cavity epithelium	Present		2
TS20: oral epithelium	Present		2
TS20: primary palate epithelium	Present		2
TS20: nasal mesenchyme	Weak	Uniform	2
TS20: oral region mesenchyme	Weak	Uniform	2
TS20: primary palate mesenchyme	Weak	Uniform	2
TS20: tongue epithelium	Present	Regionally restricted	2	Expressed in the epithelial cells on the lateral and inferior surface.

Structure	Level	Pattern	Image	Note
TS21: tongue epithelium	Present	Regionally restricted	3	Increased expression in comparison to E12.5 embryos. More pronounced on the inferior surface.
TS21: primary palate epithelium	Present		3	With the strongest levels detected at the tips of the palatal shelves. Increased expression in comparison to E12.5 embryos.
TS21: primary palate mesenchyme	Present		3	With the strongest levels detected at the tips of the palatal shelves. Increased expression in comparison to E12.5 embryos.

Structure	Level	Pattern	Image	Note
TS22: primary palate epithelium	Strong	Regionally restricted	4a , 4b	Intense expression in the vertically directed palatal shelves.
TS22: primary palate mesenchyme	Strong	Regionally restricted	4a , 4b	Intense expression in the vertically directed palatal shelves.

Structure	Level	Pattern	Image	Note
TS22: primary palate epithelium	Present	Regionally restricted	5a , 5b	Expressed primarily in the medial edge epithelia. Expression had substantially decreased compared to the expression at the E14.

Structure	Level	Pattern	Image	Note
TS23: nasal cavity epithelium	Present		6b , 6a
TS23: primary palate epithelium	Present		6b , 6a
TS23: nasal mesenchyme	Weak		6a , 6b
TS23: primary palate mesenchyme	Weak		6a , 6b
TS23: tongue epithelium	Weak		6a , 6b

Structure	Level	Pattern	Image	Note
TS22: primary palate epithelium	Present	Regionally restricted	7	Expressed primarily in the medial edge epithelia.

Structure	Level	Pattern	Image	Note
TS23: primary palate epithelium	Present	Regionally restricted	8	Expressed in the fusing midline cells of the epithelial seam.
TS23: primary palate mesenchyme	Present		8	Decreased expression.