Differentiation of neural crest cells
The first neural crest cells to differentiate are in the mesencephalon region and in the secretory neural crest group. These cells migrate separately from the nerve folds before the anterior neuroporus closes, but the coronary nerve cells migrate after the neural tube closes, the fetal cadaveric nerve cells originating from the medullary cord. They migrate on the 26th day after the closure of the posterior neuropur.
The second cells of the coronary nerve separate from the diencephalon and the front of the brain and migrate upward and forward to the cephalic sphincter, creating a nasal forehead bulge. The olfactory placodes and protrusions of the nose then form on both sides. The ridges of the nose fuse together and a bridge of the nose is created. The olfactory platelets penetrate and differentiate the olfactory epithelium
Schwann and melanocyte cell development from neural crest cells
A distinct fate awaits Schwann melanocytes and cells. These neural crest derivatives are very strong. Neural progenitor cells are bipolar, the fate of these cells is largely controlled by pax3 (survival factor) and other factors such as growth. Transformation of PMS into melanocytes or immature Schwann cells occurs on days 12 to 16. At this stage, during mitosis, immature Schwann cells arrange radial axons. At this stage, pax3 is temporarily silent and apoptosis occurs, resulting in the required ratio of glia cells to axons. Pax3 plays an important role in regulating the differentiation of lateral posterior melanocytes. Simultaneously, some PMS cells move toward the fate of melanocytes. Prevents axon contact by increasing IGF and PDGF levels. The fate of Schwann cells is twofold. A number of Schwann cells in which the pax3 gene is expressed undergo a program to inhibit the myelination gene. Another class of Schwann cells that depend on oct6 expression Primary myelination occurs in Schwann cells
Development of neural crest cells
At the junction of the epidermis and the neural plate, certain concentrations of BMP4, BMP7, wnt, and FgF are produced by the induction of the neural plate, the epidermis, and the paraxial mesoderm, activating an area called the peripheral neural plate. The Pax3 and Distalless5 genes are expressed. These two genes inhibit the formation of the neural plate and the epidermis, and the induction of the slug and FoxD3 genes, which are specific genes for neural crest cells, differentiate into specific regions of neural crest cells. The FoXD3 gene causes ectoderm cells to specialize in neural crest cells, and the slug gene causes the coronary cells to migrate. Corneal cells are altered by their adjacent cells and become characteristic of a migratory cell