neural crest cells

Question 1

what do ncc form?

Answer 1

Neurons and glia of PNS, cartilage and bone, connective tissue, sympatho-adrenal cells, sensory neurons and glia, pigment cells

Question 2

ncc are derived from ____derm

Answer 2

ectoderm

Question 3

how are neural plate boarder genes induced

Answer 3

intermediate BMP + Wnts & FGF -> neural plate boarder genes induced

Question 4

_____ BMP activity = neural plate boarder

Answer 4

intermediate

Question 5

overexpressed BMP =

Answer 5

ectoderm

Question 6

low BMP = (neural plate border)

Answer 6

NP border expands

Question 7

trans factors at neural plate border

Answer 7

Pax3/7, Msx, Zic

Question 8

epithelial -> mesenchymal transition

Answer 8

Changes in cell-cell adhesion - Loss of tight junctions
- Loss of adherens junctions - Changes in cadherin expression

• Loss of apical-basal polarity
• Changes in cell shape
• actin cytoskeleton
• Lamellipodia and filopodia
• Changes in cell-matrix adhesion - Expression of receptors for extracellular matrix molecules
• Expression of matrix metalloproteases
• Loss of association with basal lamina

Question 9

EMT promoted by

Answer 9

BMP and Wnt

Question 10

microRNA

Answer 10

bind to target mrna and repress / promote translation

Question 11

migration of NCC - order

Answer 11

1. cranial
2. vagal
3. trunk
4. sacral

Question 12

failure to migrate - cranial NCC

Answer 12

craniofacial defecits
treacher collins syndrome: failure of ncc to migrate to brachial arch 1 to survive

Question 13

trunk ncc migration

Answer 13

there are somites at this level
DL pathway (around); melanocytes only
V pathwway (between and through); symp gang, dorsal root gang, schwann cells, melanocytes, adrenal chromaffin cells

Question 14

formation of dorsal root ganglia
ventral pathway

Answer 14

caudal halves of somites are inhibitory to ncc
class 3 semaphorins bind to neuropilin receptors -> INHIBIT migration
= NCC in posterior somite halves
= cell bundles = dorsal root ganglia

Question 15

how do ncc migrate

Answer 15

Lamellipodia: respond to signals (attraction = protrusion, attachment and traction)

Question 16

ENS formation -> ncc

Answer 16

took out vagal = no ens
saw migration of ncc through quail chick chimeras
if trunk ncc put in vagal -> wont function as well

Question 17

ablating regions of nc

Answer 17

Ablating regions of the NC
And then seeing what doesn’t form
Can see importance for particular regions
Can’t see how cells get to locations
Or if other cells compensate for loss
Requires high skill

Question 18

quail chick

Answer 18

Chick Quail Chimeras
Can identify cells during migration
Cells are permanently identified
Can’t image live cells in embryo

Question 19

label pre migratory cells

Answer 19

Image cells in live embryos
Label a variable number of cells
Label different groups of cells (or in precise locations)
Labels are not permanent (Dilute out)

Question 20

intrinsic markers of ncc ->immunohist and ish

Answer 20

Label specific genes / populations of NC
Can use antibodies to label multiple concurrently
See how specific NC genes affected from manipulation
Can only label fixed tissue (not live)

Question 21

transgenic animals expressing reporter genes

Answer 21

Label specific genes / populations of NC
Can use antibodies to label multiple concurrently
See how specific NC genes affected from manipulation
Can only label fixed tissue (not live)

Question 22

light microscopy

Answer 22

allows imaging of whole embryod