Chromosome 4 – How a worm is unlocking the secrets of ageing

The great thing about living
in today’s world is that we get to live longer. Unfortunately, the downside is
that with older age comes a higher risk of age related
diseases, such as Alzheimer’s, Parkinson’s, heart diseases,
or cancer. In order to understand human
health span, we need to get to know more about biology
of ageing. There is no hiding it,
it’s complicated. It has genetic components, it
has environmental components, and there is an extensive
interplay between the two. One part of the human genome
that has been shown to be linked to longevity is part
of chromosome four. Because individual genes can
affect lifespan, we need a simple model to study it. So what we use is a nematode
worm called C. elegans. On this plate, there are
thousands of worms. They’re really small, about a
millimetre long, which is why we need to use the microscope
in order to study them. Their genetic makeup is really
similar to our own, so studying genes in the worm that
control lifespan will also tell us a lot about
our own lifespan. They live for about two
to three weeks. They’re really easy to look
after, and we can also manipulate their genes
very, very easily. Even though they’re so small,
we can tell the difference between a young worm and an old
worm just by looking at them down a microscope. On the left is a young worm,
and on the right is a much older worm. The older worm can no longer
move around the plate searching for food, and you
might be able to see it looks a lot sicker. As with humans, there is much
variation between individuals in terms of how long they live,
which means when we study ageing in a worm, we
need to look at a whole population of worms rather
than just one or two individuals. So you can ask, how do you
measure ageing in a population of worms? What we do, we start with let’s
say 100 worms, and we put each and every single one
of them on a separate plate. And we check up on them every
single day until they die. So we need a way to assess
whether they stop moving because they are dead, or
because they just don’t want to move anymore. So what we do we essentially
poke them with a stick. In our case it’s a
platinum wire. And if they respond, that means
they’re alive, if they don’t we count them as dead. So this way, we can
draw a graph. If we start, let’s say, with 100
worms alive at day zero, we have to check every single
day how many worms have died. We can draw a really nice
parallel to humans in here, because just as us, worms can
live to different age. In our lab, we are particularly
interested in genes that cause changes in
how long the worms live. If they live shorter,
the whole curve is shifted to the left. And if they live longer,
the whole curve is shifted to the right. The aim of research in our lab
is to eventually develop drugs that will influence the genetic
control of ageing, and therefore delay or even prevent
many of the age related diseases in humans. So in this way, we are using the
worm to reveal the secrets of a long and healthy life.

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