NEURAL CREST CELLS

NEURAL CREST CELLS NCC originate in ridges of neural folds during gastrulation Form all of PNS Coelesce into ganglia migration involves epithelial  mesenchymal transition origin = dorsal margin of neural tube, ventral to surface epithelium How is NCC fate specified? requires signals from ectoderm AND dorsal neural tube WNT-6 BMP Wnt6, BMP early expression of NOELIN-1 is a determinant of NCC diff. Noelin-1 secreted by neural folds and migrating NCC SLUG = NCC marker Slug HNK-1 = antibody for NCC Hnk-1 neolin-retrovirus will upregulate slug expression NCC fates: Cranial NCC: teeth heart septum pharyngeal cartilage cranial nerve conn. tiss. around eye dermis/hypodermis FACE (Cranial NCC  cranial mesenchyme) cranial mesenchyme Cranial/Spinal: schwann cells, glial cells melanocytes enteric ganglia arachnoid/pia matter Spinal: adrenal medulla pre-aortic ganglia dorsal root ganglia (DRG) DRG chain ganglia chain ganglia NEURAL CREST CELLS Migration: very important components of the PNS prohibited from entering caudal portions of adjacent somites due to ephrin secretion rostral portion: dorsal root ganglion sympathetic chain ganglia (more ventral) heart, adrenals, gut (most ventral) dorsal migration later to become melanocytes NCC DIFFERENTIATION: Grafting experiments: quail neural tube INTO chick embryos quail: large nuclei chick: small  can follow quail NCC migration leads to chimeras, and is evident by pigmentation patterns FATE MAP: graft quail neural tube from S5 quail S5chick fate map can determine what structures form from which a