Genetic of Ageing Flashcards
What is ageing characterised by?
Changes in appearance.
A lower metabolic rate.
Longer reaction times.
Declines memory functions.
Declines in sexual activity.
What are the changes in appearance in ageing?
A gradual reduction in height and weight loss due to loss of muscle and bone mass.
Why is C. elegans a good model system for ageing?
Goes through the embryonic part of the cycle in 3 days and the whole cycle is 2.5 weeks.
What happens to C. Elegans when under stress (low level of food and/or overcrowding?
They enter their Dauer larva stage.
Why does C.Elegans enter the Dauer larva stage?
They can survive several months, this stage delays ageing.
What is the gene which induces the dauer larva stage in C.Elegans?
A knockout gene which prevents certain bodily functions.
How does the gene which induces the dauer larva stage in C.Elegans work within the pathway shown?
Downregulate the activity of the transcription factor DAF-16.
What happens when you combine a DAF-16 mutation with any ageing mutation?
Causes the test subject to have a longer life span.
What happens when you combine the DAF-28 and DAF-16?
No increase to life span.
Who proposed the disposable soma theory?
Tom Cartilage
What is the disposable soma theory?
A trade-off of energy between maintenance and reproduction.
How can we mimic oxidative stress when testing the life span of C.Elegans?
Adding hydrogen peroxide to the petri dish.
What happens to C.Elegans wild types under oxidative stress?
Die much faster.
What happens to reproduction when C.elegans are put under oxidative stress?
Have less and less offspring per generation until they no longer reproduce.
Why do C.Elegans generations gradually lose the ability to reproduce in generations under oxidative stress?
They dedicate all their energy to survival and maintenance and none to reproduction.
What are S. Cerevisiae?
Yeast cells
What kind of organism are S. Cerevisiae?
Eukaryotic single cell organism.
Why do S. Cerevisiae make good ageing models?
Divide to make daughter cells so you can add mutations and observe what impact it has on ageing in a short period of time.
How do increase the life span in a mouse?
Knock out of certain kinases, insulin receptor mutations and inactive IR S1.
How much does life expectancy increase when mutations are applied in a mouse?
15%
What happens when you deactivate the S6K1 pathway in female mice?
Increase in life span.
What happens when you deactivate the S6K1 pathway in male mice?
Increase in health life span.
What types of ageing gene are conserved in pretty much every species?
Insulin signalling
Signalling through mechanistic target of rapamycin. (mTOR).
Nutrient sensing and utilisation.
What are insulin and mTOR pathways both inhibited by?
Lack of nutrients during calorie restriction, this occurs because there is a disruption of mitochondrial function.
What is progeria syndrome?
Increased ageing with serious symptoms, can start in very young children.
What is the Werner syndrome?
Ageing disease is involved in multiple parts of DNA metabolism.
Reduced repair and telomere defects.
What is Hutchinson-Gilford progeria syndrome?
Disruption of nuclear morphology and DNA repair,
increased ROS and DNA damage.
What are link analysis studies?
Showed that during crossover genes which cause gene ageing are close together and are move together.
