Craniofacial Developmental Atlas of Protein Expression of the House Finch

Expression of BMP4 across the house finch beak at stages HH29/30, HH32, HH36, HH39 and HH42.

HH29/30

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 expression of all proteins at stage HH29/30 here.

HH32

BMP4 expression at HH32

BMP4 (red stain) shows weak localized cytoplasmic expression that is predominantly present in the epithelium. Hematopoietic cells show (1) high and (2) medium cytoplasmic expression. (3) Low cytoplasmic expression in the developing myogenic area next to the cartilage. Lower jaw (4) muscle tissue and (5) inner epithelium shows medium cytoplasmic expression. (6) Weak cytoplasmic expression showed in the early formed condensation that will give rise to Meckel's cartilage. Scale bars are 50µm. See expression of all proteins at stage HH32 here.

HH36

BMP4 expression at HH36

BMP4 (red stain) shows weak cytoplasmic expression across the beak but is absent at the tip. (1) Weak cytoplasmic expression in developing nasal cartilage and (2) nasal conchae, but no expression in surrounding mesenchyme. (3) Premaxillary condensation with low cytoplasmic expression. (4) High cytoplasmic expression in blood cells. (5) No expression in basihyal cartilage and medium expression in (5, 6) muscle tissue. Scale bars are 50µm. See expression of all proteins at stage HH36 here.

HH39

BMP4 expression at HH39

BMP4 (red stain) widely distributed weak cytoplasmic expression except for absence of expression at the tip. No expression in (1) upper region of nasal, (4) paraglossal or (6) Meckel's cartilage, while (2) nasal cartilage and surrounding mesenchyme shows weak cytoplasmic expression. (3) Nasal conchae with moderate cytoplasmic expression and weak cytoplasmic expression in adjacent developing cartilage. (5) No expression in mesenchyme accumulated in the epithelial prominence. Blood cells show moderate to high cytoplasmic expression. Scale bars are 50µm. See expression of all proteins at stage HH39 here.

HH42

BMP4 expression at HH42

BMP4 (red stain) shows overall weak cytoplasmic expression and no expression at the tip. Blood cells with weak to strong cytoplasmic expression. (1) Nasal cartilage with no expression and weak cytoplasmic expression in surrounding mesenchyme. (2) Moderate expression in nasal conchae but no expression in surrounding cartilage. (3) Emerging osteogenic region and mesenchyme show no expression, but pockets of blood cells show medium cytoplasmic expression. (4) Paraglossal cartilage with no expression and weak cytoplasmic expression in myogenic area. (5) Low cytoplasmic expression in mesenchyme and salivary glands but no expression in dermal condensations. (6) Meckel's cartilage and surrounding mesenchyme shows no expression, epithelium and periosteogenic area shows weak cytoplasmic expression. Scale bars are 50µm. See expression of all proteins at stage HH42 here.