Question

1. How do you suppose that the two migration methods of migration for neural crest cells (mesenchymal cells) and cranial neural crest (cephalic) interact in a development?

Answer 1

The neural crest is a stem cell population, unique to vertebrates, that gives rise to a vast array of derivatives, ranging from peripheral ganglia to the facial skeleton. This population is induced in the early embryo at the border of the neural plate, which will form the central nervous system (CNS). After neural tube closure, neural crest cells depart from the dorsal CNS via an epithelial to mesenchymal transition (EMT), forming a migratory mesenchymal cell type that migrates extensive to diverse locations in the embryo.

In the early embryo, the neural crest forms at the border between the neural plate, which will become central nervous system (CNS) and the non-neural ectoderm, the future epidermis. The neural plate invaginates such that the elevating neural folds, containing neural crest precursors, form the leading edges of the closing neural tube . As a consequence, premigratory neural crest cells initially reside within the neuroepithelium.

They subsequently undergo a transition, known as an epithelial to mesenchymal transition (EMT) to delaminate from the neuroepithelium and migrate throughout the embryo.