Exam 3: Neural Crest

Question 1

Neural crest cells originate from the _____ _____ of the neural plate.

Answer 1

Lateral margins

Question 2

Neural crest cells transform into mesenchymal from _____ cells.

Answer 2

Epithelial

Question 3

What signals are expressed on epithelial side that prevent some epithelial cells from becoming neural crest cells?

Answer 3

BMPs & Wnts

Question 4

What signal is expressed by the mesoderm to create neural crest cells?

Answer 4

FGF-8

Question 5

What factors are important in allowing cells to break free for migration?

Answer 5

Snail-1, Snail-2, & Foxd3

Question 6

The first emigrating neural crest cells take which path?

Answer 6

Ventral/sympathoadrenal path

Question 7

The second emigrating neural crest cells take which path?

Answer 7

Ventrolateral path

Question 8

The last wave of emigrating neural crest cells take which path?

Answer 8

Dorsolateral path

Question 9

What are the 3 ligand/receptor pair guidance molecules?

Answer 9

Robo/Slit
Neuropilin/Semaphorin
Ephrin/Eph

Question 10

T/F: Later migratory neural crest cells form spinal ganglia.

Answer 10

True

Question 11

T/F: Early migratory neural crest cells can only form melanoblasts.

Answer 11

False, Late

Question 12

What happens if you expose rat neural crest cells to glial growth factor in vitro?

Answer 12

They become schwann cells

Question 13

How do single neural crest cells grown in culture compare to dye-injected neural crest cells in vivo?

Answer 13

Both produce progeny with 2 or more phenotypes

Question 14

What happens if you transplant trunk neural crest cells into the cranial region?

Answer 14

Forms sympathetic and parasympathetic neurons instead of just sympathetic for the trunk and parasympathetic for the cranial region

Question 15

What signals promote the differentiation of sympathetic neurons?

Answer 15

Phox-2 & Mash-1

Question 16

In the sensory lineage pathway, _____ & _____ form sensory neurons, whereas _____ forms schwann cells

Answer 16

Wnt & Catenin

Glial growth factor

Question 17

What factor/receptor duo is critical in the dispersal of premelanocytes?

Answer 17

Steel factor/c-kit

Question 18

_____ is characteristic of melanocyte precursors.

Answer 18

Mitf

Question 19

What inhibits neural crest cells from arising anterior to the diencephalon?

Answer 19

Dickkopf-1

Question 20

T/F: Cells from R4 & posteriorly do NOT express Hox genes.

Answer 20

False, DO express Hox genes

Question 21

Which Hox gene is expressed from R4 to pharyngeal arch 2 to prevent if from becoming the first arch?

Answer 21

Hoxa2

Question 22

Which Hox gene is expressed from R6/R7 to pharyngeal arch 3?

Answer 22

Hox3

Question 23

Neural crest cells from where form the cardia crest?

Answer 23

Somites 1-3

Question 24

Neural crest cells from where make the vagal crest & parasympathetic innervation for the digestive tract?

Answer 24

R4-7

Question 25

Which somites give rise to vagal neural crest?

Answer 25

Somites 1-7

Question 26

Expression of what prevents trunk neural crest cells to enter the gut?

Answer 26

Slit-2

Question 27

What do vagal crest cells not express that allows them to enter the gut?

Answer 27

Robo

Question 28

Pax-3 mutations leading to pigmentation defects, deafness, cleft palate, & ocular hypertelorism are characteristic of what disease?

Answer 28

Waardenburg’s syndrome

Question 29

A deletion of chromosome 22 characterized by hypoplasia, reduced thymus, thyroid, & parathyroid function, and cardiovascular defects are characteristic of what disease?

Answer 29

DiGeorge syndrome

Question 30

What is a common genetic disease manifested by multiple neural crest tumors on the skin?

Answer 30

Neurofibromas