Neuronal Specification

Question 1

What are important steps in cell specification/determination?

Answer 1

1. development of neural progenitor cells/neuroblasts
2. Production of neuronal and glial progenitor/precursor cells through asymmetric cell division of neuroblasts
3. Differentiation of neurons and glial cells from neuronal and glial progenitor/precursor, respectively

Question 2

How to study cell lineages?

Answer 2

1. fluorescent marker molecules
2. green fluorescent proteins (GFP)
3. C. elegans model

Question 3

What happens in Drosophila neurogenesis?

Answer 3

1. neuroectoderm moves to ventral side of embryo during gastrulation
2. 60 proneural clusters form
3. one cell per cluster develops into a neuroblast
4. neuroblast divides into a neuroblast and ganglion mother cell
5. ganglion mother cell become neuronal and glial progenitor cells

Question 4

What happens during Drosophila transformation?

Answer 4

neuroectoderm becomes neuroblast

Question 5

What happens during symmetric cell division?

Answer 5

cell divides to make two of itself

Question 6

What happens during asymmetric cell division?

Answer 6

a cell divides in a way that it makes a clone of itself but also makes differentiated cell

Question 7

What happens during vertebrate neurogenesis?

Answer 7

1. neuroectoderm undergoes transformation into a neuroblast
2. neuroblasts multiply through symmetric cell division
   3a. neuroblasts become neuronal progenitor cell
   3b. neuroblasts become glial progenitor cell

Question 8

imbalance of delta notch signaling results in what?

Answer 8

lateral inhibition

Question 9

what are proneural gene products? what do they do?

Answer 9

achaete-scrute protein activates delta expression

Question 10

What does delta activate?

Answer 10

activates notch signaling in neighboring cells and less achaete-scute

Question 11

What do cells with high level of notch signaling become?

Answer 11

epidermal

Question 12

What do cells with high levels of delta and achaete-scute become?

Answer 12

neuroblasts

Question 13

What is the proneural gene in vertebrates?

Answer 13

neurogenin which also promotes neuroblast determination

Question 14

What do cell polarity factors do?

Answer 14

determine apical side of the neuralblast

Question 15

What are cytoplasmic determinants?

Answer 15

factors localized to the basal side of the cell

Question 16

What side of the neuroblast becomes ganglion mother cell?

Answer 16

basal side

Question 17

How many layers of cells does the cerebral cortex contain?

Answer 17

6 layers of cells via migrating neurons through radial glial cells

Question 18

What cortex layer is first?

Answer 18

proliferative/ventricular zone; rest migrate away