Stage HH29/30

β-catenin

β-catenin expression at HH29/30

β-catenin (brown stain) shows overall weak cytoplasmic and nuclear expression across the upper and lower jaws with (1) high nuclear expression at the tip in mesenchymal cells and both high cytoplasmic and nuclear epithelial expression. No expression in blood cells. (2) Low cytoplasmic and nuclear expression in the upper jaw. (3) Low cytoplasmic and nuclear expression in the lower jaw, with Meckel's cartilage condensation not formed yet. (4) Mediumnuclear expression along the outer edge of the tip in the mesenchyme cells and medium cytoplasmic and nuclear epithelial expression. (5) Medium cytoplasmic and nuclear expression in condensations that will become future myogenic areas. Scale bars are 50µm. See β-catenin expression across all stages here.

BMP4

BMP4 expression at HH29/30

Bmp4 (red stain) is rarely present in the upper beak except for some areas (1) that show very weak cytoplasmic expression. Low cytoplasmic expression across the lower beak with (2 , 3, 4) medium cytoplasmic expression in cell condensations that will form future myogenic areas. (5) Weak cytoplasmic expression in the mesenchyme while the endoderm shows medium cytoplasmic expression. Medium and high cytoplasmic expression in blood cells. Scale bars are 50µm. See BMP4 expression across all stages here.

CaM

CaM expression at HH29/30

CaM (brown stain) shows weak cytoplasmic and nuclear expression across both the upper (1) and lower jaw. (2) Blood cells show high nuclear expression. (3) No expression at the tip of the upper jaw. (4) Medium cytoplasmic and nuclear expression in myogenic condensation. (5) Weak cytoplasmic and nuclear expression in contact with low nuclear expression that is present at the mesenchyme of the outer edge in the lower jaw. Scale bars are 50µm. See CaM expression across all stages here.

DKK3

DKK3 expression at HH29/30

DKK3 (red stain) shows medium cytoplasmic expression in the upper jaw (1) and specially in the lower jaw. (2) Weak cytoplasmic expression in some areas of the upper jaw with (3) high cytoplasmic expression at the tip. (4 ,5) High cytoplasmic expression in potential myogenic areas. Scale bars are 50µm. See DKK3 expression across all stages here.

FGF8

FGF8 expression at HH29/30

FGF8 (brown stain) is weakly expressed in (2) both the cytoplasm and nucleus at half of the upper jaw and across the whole lower jaw with (1) medium and low nuclear expression in the mesenchyme and medium cytoplasmic and nuclear expression in the epithelium at the tip of the upper jaw and (5) no expression at the outer edge of the lower jaw. (3) Low nuclear expression in cell condensation and (4) medium cytoplasmic and nuclear expression in potential myogenic area. Scale bars are 50µm. See FGF8 expression across all stages here.

IHH

IHH expression at HH29/30

IHH (red stain) expression is localized with weak cytoplasmic expression in both (2) the upper jaw and (6) the lower jaw. (1) Blood cells show medium cytoplasmic expression. Most expression is localized in potential myogenic areas that show (3) medium and (4, 5) high cytoplasmic expression. Scale bars are 50µm. See IHH expression across all stages here.

TGFβ2

TGFβ2 expression at HH29/30

TGFβ2 (brown stain) shows low cytoplasmic and perinuclear expression across the upper and lower jaw with weak cytoplasmic expression at the tip of the (3) upper and (1) lower jaw. (2) High cytoplasmic and perinuclear expression in the upper jaw and medium expression in (4) potential muscle tissue and (5) cell condensation in the lower jaw. Scale bars are 50µm. See TGFβ2 expression across all stages here.

WNT4

WNT4 expression at HH29/30

WNT4 (red stain) is rarely present in the upper jaw and highly localized in the lower jaw. (1) blood cells show weak cytoplasmic expression. Low cytoplasmic expression in (2, 3) future myogenic areas and (4) endoderm in the lower jaw. Scale bars are 50µm. See WNT4 expression across all stages here.