Exam 2: Chapter 4

Question 1

How do you know if neuron development is intrinsic or extrinsic factors?

Answer 1

Transplant in dish
If changes due to knew environment: extrinsic
No change: intrinsic

Question 2

Elegans and Chalfie’s touch insensitive mutants. What is normal?

Answer 2

Q –> Q 1 A and Q1P

Q1P goes on to become touch cell and interneuron

Question 3

Unc-86 Elegans mutant

Answer 3

Q’ instead of Q1P
This makes Q7’a and Q’’
No touch cells, no interneurons

Question 4

Mec-3 Elegans mutant

Answer 4

Q –> Q1P
Interneurons, but no touch cells
Touch sensitive but don’t differentiate

Question 5

Mec-7, 12, 17

Answer 5

Defective touch cell, touch insensitive

Question 6

Huckebein is activated by ___ and inhibited by __-

Answer 6

activated: Wnt/shh
inhibited: engrailed/gooseberry

Question 7

homobox genes: msh, ind, vnd follow

Answer 7

Dpp gradient D-V

msh: high Dpp concentration, most Dorsal

Question 8

What are the differences between 1st and later GMCs?

Answer 8

Earlier: deep in CNS, long axons
Later: Short axons, on edge

Question 9

Order neuroblasts send to mother cells:

Pdm, Krueppel, Hb, Castor

Answer 9

Hb -> KR -> Pdm –> Cas

Question 10

Ko Hb

Answer 10

no hunchback, but others are ok

Question 11

Ko Kr

Answer 11

Skip that step

Question 12

Pdm too early

Answer 12

Skip Kr

Question 13

Asymmetric cell division

Answer 13

1) Par complex apical side
2) Localized Numb
3) Inscruitible and PINS
4) LGL replaces Baz
5) Miranda traps prospero, which turns on GMC genes

Question 14

Par complex made up of

Answer 14

1) Bazooka
2) Par-6
3) aPKC

Question 15

Why does Numb need to go to GMC?

Answer 15

inhibits other pathways to let mother cells divide and make 2 neurons. If it stays, inhibits neuroblast division.

Question 16

What does inscrutable and PINS do?

Answer 16

attract miotic spindle fibers that direction and orient division.

Question 17

What phosphorylates Baz so it leaves?

Answer 17

Aurdura A

Question 18

What phosphorylates LGL so it can replace Baz?

Answer 18

aPKC

Question 19

Why does LGL replace Baz and Numb-phosphorylated?

Answer 19

Numb-P and has oriented spindles, but needs everything on GMC side.

Numb-P inhibits notch pathway

Question 20

What traps prospero and what does prospero do?

Answer 20

Miranda

Prospero- turns on GMC genes

Question 21

What inhibits Numb/Prospero on basal?

Answer 21

GMC

Question 22

What pulls up phosphorylated Numb?

Answer 22

PON

Question 23

Sp1 (SOP)–>

Answer 23

Sp2b- anterior (dominant)

Sp2a- posterior

Question 24

Sp2b vs. Sp2a

Answer 24

Sp2b inhibits Sp2a by notch pathway

if ablated, Sp2a becomes Sp2b

Question 25

Sp2a/b in notch mutant (KO notch)

Answer 25

2x Sp2B

Question 26

Sp2a/b in notch increase mutant

Answer 26

2x Sp2a

Question 27

Sp2b -->

Answer 27

Neuron and support cell | Neuron inhibits support cell by notch

Question 28

Sp2a -->

Answer 28

Socket and Shaft | Socket inhibits Shaft via notch

Question 29

What is Sp2b not effected by notch?

Answer 29

NUMB in Sp2B inhibits it.

Question 30

Sevenless Pathway

Answer 30

Boss - ligand Sev- receptor Boss --> Sev --> MapK (erk) --> Yan and Prkd --> R7 program.

Question 31

R7 in 7less path

Answer 31

UV sensitive, last to join/differentiate | Has the Sev receptor, needs BOSS ligand from R8

Question 32

Neural lineage in drosophilia is determined by

Answer 32

``` lateral inhibition (notch/delta) neuronal fate = transcription factors ```

Question 33

Why asymmetric division?

Answer 33

Allow for functionally linked cells with identity

Question 34

Chicken and Quail transplant of cholinergic and adrenergic neurons

Answer 34

V: S7, Cholinergic (para) T (low): S18, adrenergic neurons (sym) If transplants to wrong area, respond to environment cues to become the other.

Question 35

Wnt (late)

Answer 35

Sensory

Question 36

BMP2/4 and CTGF beta 1-3

Answer 36

ANS

Question 37

Nrg-1

Answer 37

Schwann (glia)

Question 38

Nrg vs. Ngn

Answer 38

Nrg- neuregulin, secreted by neurons | Ngn- neurogenin, proneural

Question 39

BMPs in dorsal aorta (sym ganglia) -->

Answer 39

Mash1 and Phox26

Question 40

Mash 1

Answer 40

proneural bHLH transcription factor creates neuron specific stuff turns on neuron program, gets neurofilaments/microtubules you need to stabilize axons/dendrites

Question 41

Phox26 -->

Answer 41

TH- rate limited step in dopamine production | D-beta-H: makes NE

Question 42

Early Wnt

Answer 42

Sensory and BHLH/Nrgn2, needs early wnt to get here

Question 43

FGF

Answer 43

Neurites to come off. Encourages microtubules Encourages TH/DBH Turns on NGF Receptor - Can't Skip this step!

Question 44

Once FGF activates NGF, what does that do?

Answer 44

acts on NGFR, fully differentiate/survivor | sym neuron survival

Question 45

Fully differentiate neurons release ___ for next cells

Answer 45

Neurogenin

Question 46

Remove wnt in environment;

Answer 46

no sensory neurons, but you can make everything else respond to future signals even though you missed the first.

Question 47

Don't control duration/location of signals:

Answer 47

wnt too big/long signal, more cells stuck and can't migrate on, lose too many neurons, stuck in wnt cycle.

Question 48

If you culture Arota + neural crest OR BMP7 + neural crest, what happens?

Answer 48

Adrenergic neurons (NE)

Question 49

Rodent Feet: Hairy vs. Foot Pads

Answer 49

Hair- no sweat, NE | Foot Pad- sweat, acetyl

Question 50

How does foot pad work?

Answer 50

release NE, stop at target Food pad releases CNT/LIF to change phenotype acetyl program on: CAT (acetyltransferase) NE program off (TH/DBH)

Question 51

Experiment with sweat glands on hairy skin and parotid gland tissue:

Answer 51

sweat glands: cholinergic parotid: NE (adrenergic) Matches transplant

Question 52

Nrg-1 makes glia by...

Answer 52

telling newcomers you're too late: no more neurons. More Nrg-1= more likely glia. More neurons = more cells making it.

Question 53

Experiment: Crest cell ganglia treated with +Nrg-1 or delta

Answer 53

Mostly Glia, 10% neuron

Question 54

Experiment: crest cell ganglia, treated with -NRG-1 and +BMP2

Answer 54

Mostly Neuron, 80%

Question 55

Cortical Layer Experiment: Layer 6 --> Layer 321

Answer 55

Becomes 321

Question 56

Cortical Layer Experiment: Layer 321 --> Layer 6

Answer 56

Becomes, 321, too late to change, fate is becoming determined

Question 57

Cortical Layer Experiment: Layer 54 --> 321

Answer 57

Becomes 321

Question 58

Cortical Layer Experiment: Layer54 --> Layer 6

Answer 58

Becomes 54

Question 59

Lateral/Dorsal

Answer 59

Sensory

Question 60

Medial/Ventral

Answer 60

Motor

Question 61

___ and Ultimately ____ will turn on certain classes of homodomain genes which repress to one subdivison, new regions, newfactors, things slide around, add across board, see what you can make where.

Answer 61

BMP and ultimately RA