Genetic of Ageing

Question 1

What is ageing characterised by?

Answer 1

Changes in appearance.
A lower metabolic rate.
Longer reaction times.
Declines memory functions.
Declines in sexual activity.

Question 2

What are the changes in appearance in ageing?

Answer 2

A gradual reduction in height and weight loss due to loss of muscle and bone mass.

Question 3

Why is C. elegans a good model system for ageing?

Answer 3

Goes through the embryonic part of the cycle in 3 days and the whole cycle is 2.5 weeks.

Question 4

What happens to C. Elegans when under stress (low level of food and/or overcrowding?

Answer 4

They enter their Dauer larva stage.

Question 5

Why does C.Elegans enter the Dauer larva stage?

Answer 5

They can survive several months, this stage delays ageing.

Question 6

What is the gene which induces the dauer larva stage in C.Elegans?

Answer 6

A knockout gene which prevents certain bodily functions.

Question 7

How does the gene which induces the dauer larva stage in C.Elegans work within the pathway shown?

Answer 7

Downregulate the activity of the transcription factor DAF-16.

Question 8

What happens when you combine a DAF-16 mutation with any ageing mutation?

Answer 8

Causes the test subject to have a longer life span.

Question 9

What happens when you combine the DAF-28 and DAF-16?

Answer 9

No increase to life span.

Question 10

Who proposed the disposable soma theory?

Answer 10

Tom Cartilage

Question 11

What is the disposable soma theory?

Answer 11

A trade-off of energy between maintenance and reproduction.

Question 12

How can we mimic oxidative stress when testing the life span of C.Elegans?

Answer 12

Adding hydrogen peroxide to the petri dish.

Question 13

What happens to C.Elegans wild types under oxidative stress?

Answer 13

Die much faster.

Question 14

What happens to reproduction when C.elegans are put under oxidative stress?

Answer 14

Have less and less offspring per generation until they no longer reproduce.

Question 15

Why do C.Elegans generations gradually lose the ability to reproduce in generations under oxidative stress?

Answer 15

They dedicate all their energy to survival and maintenance and none to reproduction.

Question 16

What are S. Cerevisiae?

Answer 16

Yeast cells

Question 17

What kind of organism are S. Cerevisiae?

Answer 17

Eukaryotic single cell organism.

Question 18

Why do S. Cerevisiae make good ageing models?

Answer 18

Divide to make daughter cells so you can add mutations and observe what impact it has on ageing in a short period of time.

Question 19

How do increase the life span in a mouse?

Answer 19

Knock out of certain kinases, insulin receptor mutations and inactive IR S1.

Question 20

How much does life expectancy increase when mutations are applied in a mouse?

Answer 20

15%

Question 21

What happens when you deactivate the S6K1 pathway in female mice?

Answer 21

Increase in life span.

Question 22

What happens when you deactivate the S6K1 pathway in male mice?

Answer 22

Increase in health life span.

Question 23

What types of ageing gene are conserved in pretty much every species?

Answer 23

Insulin signalling
Signalling through mechanistic target of rapamycin. (mTOR).
Nutrient sensing and utilisation.

Question 24

What are insulin and mTOR pathways both inhibited by?

Answer 24

Lack of nutrients during calorie restriction, this occurs because there is a disruption of mitochondrial function.

Question 25

What is progeria syndrome?

Answer 25

Increased ageing with serious symptoms, can start in very young children.

Question 26

What is the Werner syndrome?

Answer 26

Ageing disease is involved in multiple parts of DNA metabolism.
Reduced repair and telomere defects.

Question 27

What is Hutchinson-Gilford progeria syndrome?

Answer 27

Disruption of nuclear morphology and DNA repair,
increased ROS and DNA damage.

Question 28

What are link analysis studies?

Answer 28

Showed that during crossover genes which cause gene ageing are close together and are move together.