WEBVTT
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I'm standing here in a very beautiful
spot, as you might see.
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It's not only beautiful, it's also
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a reason to think about what is going
on with the oceans these days.
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And if I
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look at where I'm standing right now,
I remember that I was collecting
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hydrozoans at a high diversity 30 years ago
and the one main species I was interested in
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I couldn't find five years ago and
I couldn't find this week so that
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makes me sad and that should make
us think about what is going on.
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Clearly there's a threat to the oceans,
there's global warming, increasing
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acidification, and a threat to the oceans
is a threat to the whole planet.
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And what we urgently need is reliable,
sensitive biomonitoring systems,
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modern biomarkers, and these modern
biomarkers require that they can use the
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whole set of genetic tools we have available
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We need to identify the genes under stress
immediately when the stress occurs,
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and interestingly, these genes we're
interested in for stress response
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related genes we also use for other
applications, even for biomedical research
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we can use related gene families to study
cancer, and actually our Trichoplax
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from here is also used in cancer research.
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Placozoans might be very promising bio
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marker systems for biomonitoring. So
environmental change related to global
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warming or ocean acidification
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might be something we could easily
measure, detect by watching placozoans
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and their genetics. We have all the tools
to do that, and I think there's some hope
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we can develop placozoans into very
promising biomonitoring systems.
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What makes a good, promising
biomarker, biomonitoring system?
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Well it's genetics. Genetic
tools are so powerful
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that we can use them now, and we can
detect changes in the response of an
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animal system almost immediately.
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So if we know the expression patterns
under normal conditions, we can follow
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the expression patterns under
changing conditions in real time.
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And this is just one way we can use
genetics in a powerful and good way.
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We now also have the genetic tools to
study the setup of polarity in an animal
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bauplan. Polarity is very important, we
know already that the placozoan bauplan
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only has polarity, not symmetry,
just the top-bottom polarity.
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This polarity is important for the behaviour
for feeding and as we see later also for
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studying cancer genes.
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So we have the tools to study polarity
and polarity is the start for all higher
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animal bodies, so we use polarity also
to analyse or to study the evolution
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of higher animal bauplans. So another
nice thing we can do with genetics is to
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study the origin or the setup of polarity
and there's all the standard polarity
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genes we know from higher animals,
also present in placozoans.
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One of these genes could be trox-2,
the parahox gene trox-2.
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We have seen what it might be doing in
the videos before when we talked about
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the evolution of higher animal bauplans from
the placula the so-called placula hypothesis
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and the essential role of this gene is
also seen if you knock it out so we could
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do knock-downs of this gene and
we find as a result that the animals
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immediately stop dividing.
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So it's a very essential function and there's
a lot of work to do with these knock-downs.
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We've heard a lot of exciting stuff about
Trichoplax. But now one more exciting stuff
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is cancer, we mentioned it before. How
can we use Trichoplax to fight cancer?
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Well it's very simple: we know Trichoplax
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the only thing it has with respect to
body plan organisation is polarity.
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It has a top and a bottom. But we have
seen it has polarity genes and these
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polarity genes are the exact genes we
are interested in, because cancer cells
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the first thing cancer cells
do is they lose polarity.
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If cancer cells lose polarity, they
grow in all different directions.
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If they grow in all different directions, it
becomes a clump of cells and we call it
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a tumor. So we need to know what goes on
in the very beginning of losing polarity,
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that we can learn from Trichoplax.
What we have to do, we take Trichoplax
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polar Trichoplax, study the polarity
genes under normal conditions
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and then we eliminate gravity. If we
don't have gravity, well then we lose
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the signal for polarity.
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We can do it in two ways: we can do it
here in the lab in a clinostat in a machine
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which is kind of a simulation of zero
gravity, or we can do it in reality and
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shoot Trichoplax into space. That's
what we're going to do in a few weeks.
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And what do we do with the genetics?
We just collect the RNA at different stages:
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before losing gravity, after losing gravity
let's say 10 seconds after losing gravity,
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a minute, 5 minutes, 10 minutes. So then
we get the first steps of losing polarity.
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We get the very first genes involved and
by RNA expression studies, we can find
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all the genes the medical guys are
interested in to fight cancer.