L6 GOK

Question 1

Neural patterning is ?

Answer 1

a biological process by which cells in the developing
nervous system acquire distinct identities according to their specific spatial
positions.

Question 2

what is a major determinant of cell fate in the sc ?

Answer 2

Dorsal(D)-ventral(V) positioning

Question 3

what does the roof plate secrete ?

whats does the floor plate secrete ?

Answer 3

roof - BMPs

floor - shh

Question 4

what are morphgens ?

and examples ?

Answer 4

signaling molecules that elicits different cellular responses depending on its concentration

BMP & shh

Question 5

where are the roof and floor plate located ?

Answer 5

roof = dorsally 
floor = ventrally

Question 6

what does the absolute conc of a morphogen acting on a cell determine?

Answer 6

developmental fate

Question 7

what is BMPs and shh’s gradients ?

Answer 7

BMPs = D/v
shh = V/D

Question 8

how do these gradients divid NPC?

Answer 8

subdivide neural progenitor cells into discrete domains

-> which then produce all subclasses of motor & sensory neurons

Question 9

what do these opposing gradients led to the expression of ?

Answer 9

homeobox TFs
Nkx6.1 ventrally,
Pax6 medially,
Pax3/Pax7 dorsally

Question 10

what does the V-D gradient of shh do to the basal plate ?

Answer 10

it partitions it into 5 discrete progenitor domains that wil generate 6 different classes of neurons

progen domains = V0,V1,V2,V3 and pMN

Question 11

what do the motor neuron progenitors express ? (pMN)

Answer 11

Nkx6.1

Question 12

what do the NP in other ventral domains become ?

Answer 12

interneurons

Question 13

what do V3 neuron progenitors express ?

and what dont they express ?

Answer 13

express = nkx2.2

dont express = Pax6 and oligo 2

Question 14

what do pMN express ?

and what dont they express ?

Answer 14

express = nkx6.1 and oligo 2

dont express = nkx2.2 and Irx 3

Question 15

what does nkx6.1 turn on the express of ?

and what does this lead to ?

Answer 15

oligo2 = basic helix loop helix TF (bHLH)

oligo 2 induces motor neuron diffrin by activating Hb9 and Isl 1/2

Question 16

what Ngn2 ? and whats it coexpressed with ?

Answer 16

its a gene for neural differentiation

coexpressed with - Oligo 2

Question 17

are oligo 2 and Nkx6.1 coexpressed ?

Answer 17

yes

Question 18

is NKx2.2 coexpressed with Oligo 2?

Answer 18

no, because Nkx2.2 is expressed in the most ventral domain where interneurons are expressed and oligo2 is involved in neuron diffrin

Question 19

the D/V BMP gradient divides the alar plate into ?

Answer 19

two progenitor regions

most dorsal region = 2 progenitor domains = Class A dI1-dI3 interneurons.

intermediate region = 6 progenitor domains = Class B dI4-dI6 interneurons

Question 20

what does BMPs dimers binding to their BMPr cause ?

Answer 20

to the recruitment and phosphorylation of
receptor-regulated smad proteins (Smad1/5)

when phosphorylated these complex with Smad-4
and translocate to the nucleus where they regulate
gene expression

Question 21

What class of inter neurons neural diffrin is dependent on wnt/ Bmp signalling ?
which class isnt ?

Answer 21

dependent = Class A dl1-dl3

independent = Class B dl4-dl6

Question 22

Patterning of the dorsal sc inter neurons is dependent on what signalling ?

Answer 22

BMP/ smad

Question 23

BMP/Wnt signalling turn on expression on which cell specific determinants of class A progenitors dl1-dl3

Answer 23

Olig3, Atoh1, Neurog1/2 & Ascl1

Question 24

Oligo 3 is expressed by all Class A progenitors what does it repress ?

Answer 24

it represses Lbx1 to specify
dI1-dI3 interneurons.

Atoh1 = dI1; Neurog1/2 = dI2 & Ascl1 = dI3.

Question 25

what are the first born cells in the retina ?

Answer 25

retinal ganglion cells

Question 26

morphogen expression is controlled by ?

Answer 26

homeobox genes

Question 27

what does the retina arise from ?

Answer 27

neuroepithelial progenitors of anterior neural plat

Question 28

order of retinal cell expression ???

Answer 28

RGC, amacrine/ horizontal, cone ,bipolar, rod and muller glia cells

Question 29

what gen do retinal ganglion cells require for proper development ?

Answer 29

Atoh7 bHLH

Question 30

neural promoting bHLH genes invovled in genesis of specific retinal cell types ?

Answer 30

Atoh7, Neurog2, Neurod1 and Ascl1.