Chicken neural crest and neural plate

Neural cest cells are a transient stem cell-like population appearing during vertebrate embryonic development. Generation of the cranial neural crest is known to require a balanced combination of FGF and BMP levels. However, it is poorly understood how the functions of such growth factors are controlled in the extracellular spaces. Anosmin is an extracellular matrix protein implicated in FGF signaling and mutated in Kallmann syndrome. Here, we demonstrate that anosmin (Gga.14976.1.S1_at, clone ChEST132d10) is synthesized locally in the cranial neural crest of chicken embryos and is essential for cranial neural crest formation. Anosmin upregulates FGF8 and BMP5 gene expression; it also enhances FGF8 activity while inhibiting BMP5 and WNT3a signaling. Taken together, our data establish that the matrix protein anosmin is required for cranial neural crest formation, with funtional modulation of FGF, BMP, and WNT. Cranial neural folds (NF) and ventral neural plates (NP) were dissected from Hamburger & Hamilton stage 8 (HH8) embryos (80 to 114 embryos, n=4), and total RNA was analyzed using a GeneChip chicken genome arrays (Affymetrix)