Lecture 6.2 C. elegans Flashcards

You may prefer our related Brainscape-certified flashcards:
1
Q

How is the chemosensory cilia in contact with the outside world? What can it do?

A

Chemosensory cilia: in contact with the outside world at the ends of dendrites of axons.
-> Can detect chemicals, pheromones, etc.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

How long is it? What does it exist of?

A

Cilium =hair-like structure with a membrane. Core = microtubule structure that forms a pipe from the base to the tip. 7-8 microm long. Different parts:

1) Dendrite & PCMC
2) transition zone (diffusion barrier keeping certains proteins inside the cilium different from the rest)
3) Proximal segment: microtubules are doublets, specific for C. elegans
4) distal segment where microtubules are singlets, tip is on contact with outside world.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

3 motor proteins that make up the transport mechanism, essential for building the cilia structure/function. What are they called? In what direction do they transport?

A

OSM3 and kinesin: transport base to tip

Dynein = takes care of transport tip to base

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are IFT-A and -B used for?

A

required for building maintenance & functioning of cilia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What was done to visualize single-motor tracking & cargo handover?

A

Modified worms were made that fluoresce. Single-motor tracking: color imaging. Cargo handover from kinesin-2 to OSM-3: change in fluorescence colour.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What does the IFT-train velocity (=snelheid) vary with? How does it vary?

A

Varies with location.
>IFT-trains accelerate gradually
>IFT-train intensity stays constant

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

How does Kinesin-2 (slow motor) hand over cargo and to who?

A

> Kinesin-II(slow motor) graduallyhands overIFT-cargo toOSM-3(fastmotor)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Visualization & tracking of individual kinesins: what was discovered about the motors?

A

They switch directions: turn from drivers into passengers and vice versa

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Where does kinesin-2 cycle and where does OSM-3 cycle?

A

Kinesin-2: between base and start proximal segment
OSM3: between transition zone & tip

Driver-to passenger switch almost instantaneous: hardly free motors (except for base)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Current view on IFT in c. Elegans?

A
  • Train backbone moves in one go

- Motors dock on and off trains

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is OCR-2?

A
  • OCR-2 is a TRPV cation channel involved in signaling
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

How is IFT trans-membrane cargo, OCR-2, transported?

A

In dendrite: active transport driven by dynein. It is embedded in RAB-8 vesicles.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What kind of transport takes place across the transition zone?

A

Active

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what kind of movement takes place in the proximal & distal segment?

A

Saltatory movement (=Saltatory conduction (from the Latin saltare, to hop or leap) is the propagation of action potentials along myelinated axons from one node of Ranvier to the next node, increasing the conduction velocity of action potentials.)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Choosing between mostly IFT, normal diffusion, subdiffusion and little IFT, what kind of transport takes place in the TZ (transition zone), PS (proximal segment), DS (distal segment) and the Tip?

A

> TZ: mostly IFT
PS: normal diffusion + a bit of IFT
DS: subdiffusion + IFT
Tip: subdiffusion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly