unit 3

Question 1

What is a neural crest?

Answer 1

• transient, multipotent, migratory cells that differentiate into many tissues and organs
• start as 1 thing (neural crest) and go to many types
• epithelial to mesenchymal transition

Question 2

What surrounds the neural crest?

Answer 2

somites

Question 3

How does migration occur in the neural crest?

Answer 3

• neural crest to neural plate
• neural plate closes and promigratory cells close in
• delamination of neural crest cells
• then migratory cells

Question 4

What are the regions of the neural crest?

Answer 4

• cranial
• cardiac
• vagal
• trunk

Question 5

What is the cranial region of the neural crest?

Answer 5

• forms face, neck, cranial nerves, cartilage, bone, neurons

Question 6

What is the cardiac region of the neural crest?

Answer 6

• division between aorta and pulmonary artery, cartilage and connective tissue and melanocytes

Question 7

What is the vagal region of the neural crest?

Answer 7

• parasympathetic ganglia

Question 8

What is the trunk region of neural crest?

Answer 8

• medulla portion of adrenal gland, sympathetic ganglia, melanocytes, and neurons

Question 9

How do you study the neural crest?

Answer 9

• use multicolored organisms with CRE
• use mice

Question 10

How is fate determined in the neural crest?

Answer 10

• start as progenitors and use paracrine signals to determine fate

Question 11

How is the epidermis formed?

Answer 11

WNT + BMP

Question 12

How is the placodal cells formed?

Answer 12

Wnt to BMP

Question 13

How is the neural crest formed?

Answer 13

• Wnt to WNT and BMP

Question 14

How are neural cells formed?

Answer 14

straight from wnt

Question 15

What do ecadherins do?

Answer 15

• cell adhesion in stationary cells

Question 16

What do n cadherins do?

Answer 16

• cell adhesion in migratory cells

Question 17

What does C6B do?

Answer 17

• stabilizes neural crest

Question 18

What does SOX2 do?

Answer 18

• keeps neural crest in progenitor stage as delamination progresses allowing for specification

Question 19

What does snail 2 do?

Answer 19

• TF promoting epithelial to mesenchymal transition

Question 20

What do lamelpodia and fillipodia do?

Answer 20

• directs growth with RAC1

Question 21

What do actin and myosin do?

Answer 21

• retract with RHO1

Question 22

What is contact inhibition?

Answer 22

• if they touch each other they repress and run the other way

Question 23

What is the contact inhibition pathway?

Answer 23

• touching to cells rearranging to cells looking for vacant openings to populate to proper distribution

Question 24

What is the premigratory domain?

Answer 24

• high BMP WNT SNAIL2
• repression of E+N cadherin
• SNAIL 1 and C6B upregulated

Question 25

What do chase and run placodes do?

Answer 25

• form streams and keep cells from mixing

Question 25

How is collective migration regulated?

Answer 25

• cell to cell adhesion is mediated by low N cadherin
• migratory crest cells secrete attractive signals delineated by chemical cues on the way to target

Question 25

How does the chase and run placodes work?

Answer 25

• placodes release SEF1 (Chemoattractor) to receptors CXCR4
• placodes attract than the chase begins
• repellants (semaphorins and ephrins keep the cells in line
• contact forms co-inhibition there is a stop of signals so they repel, then they chase again

Question 26

Where is beta galactosidase expressed?

Answer 26

expressed with WNT and mesoderm derived cells