Signals inducing neural crest formation
FGF, BMP, Wnt6
BMP secreted by dorsal neural crest
Signals blocking Neural Crest border
MSX, Pax3, Zic, DLX
Ventrally induced by Shh secreted by notochord
Signals involving Neural Crest multipotency
Signals involving Neural Crest delamination/migration
Signals involving Neural Crest differentiation
Cadherin signalling and the neural crest
E-cadherin expressed by ectoderm
neural plate expresses N-cadherin
migrating cells express cadherin and move in long chians
Slug dissociates E-cadherins, allowing cells to migrate
Migration of neural crest cells
2 routes; dorsolateral (melanocytes) and central (ganglia, schwann)
hetergoenous developmental potential at the start
Migration timed rostro-caudally
Ephrins in ECM force cells in ventral path through anterior 1/2 of somites
Crest cells express RhoB which allows for polymerizaiton/migation
Neural crest leads to?
Dorsal root ganglia, chian ganglia, melanocytes, schwann cells.
Hox genes are expressed by neural crest cells coming into branchial arches
BMPs to attract neural crest cells for autonomic innervation of the heart
Enteric nervous system
More neurons than spine and has the greatest diversity in PNS.
Supported by glia, not schwann cells.
aganglionosis which leads to pseudo-obstruction in the bowls. Takes out part of the ENS and heart nervous system.
Comes from a bug bite.
Congenital aganglionosis in terminal colon. Defect in RET.
Found in a religious subset population
Enteric system migration
RET: receptor tyrosine kinase expressed in crest cells
GDNF binds it
RET promotes survival
GDNF is expressed in the stomach and leads neural crest cells to the cecum. Enthelin-B allows these cells to break through the cecum.
Attracts neural crest cells in the gut to the pancreatic and submucousal plexuses.
DCC is a netrin receptor and transduces a positive signal but when in contact with laminin transduces an inhibitory signal instead.