Download Neural Crest

Migrations in Development
Neural Crest Migration
• The peripheral nervous system is created by
a spatiotemporally coordinated migratory
process during which the precursor cells,
the neural crest (NC) cells, traverse the
embryo to reach distantly located sites.
• Homing of peripheral neurons and
their supportive cells might be
dictated by a delicate equilibrium
between the multiple actions of
stimulatory and inhibitory molecules,
which is modulated further by defined
responses of the dispersing cells to
these ECM components during their
successive phases of phenotypic
diversification.
Epithelial-Mesenchyme Transition
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In the first phase of neural crest cell migration, neural
crest cells separate from the neural epithelium via an
epithelial-mesenchymal transformation. We present
three models to account for this process:
• (1) separation by asymmetric mitosis,
• (2) separation by generating tractional force in order to
rupture cell adhesions
• (3) loss of expression or function of cell-cell adhesion
molecules that keep the presumptive neural crest cells
tethered to the neural epithelium.
Steps In NC Migration
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Initiation of migration
Migration
Homing
Differentiation
Initiation of Migration
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Transition from tissue ball to migration
Loss of cadherins
Acquisition of Integrins
Acquisition of motile machinery
Stimulus to migrate