[Music]
good evening here you see a little petri
dish that we use in the lab with a dry
leaf completely dry and on there there
are females why do I say females because
that’s their way of life they live and
evolve without males they got rid of
males and also they are dry they can dry
up and we can wait for years put them in
the freezer and get the back tonight we
will do a live experiment with one of my
scientists Boris to resurrect these
animals for you these females thanks
Boris so look around you there is an
amazing diversity of living organism on
this planet from bacteria to Fonzi to
plans to animals to human nothing looks
alike but do you know that all these
diversity arose once from a universal
ancestor around 3.5 billion years ago
and this ancestor of all living
organisms a single simple cell something
like a bacteria but how do we know that
all life has evolved from a single cell
we know this because we all share the
same alphabet we have the same DNA code
DNA is a magic molecule of life and DNA
is only made up of four chemical
building blocks citizen guanine adenine
teaming so only four letters that make
the whole alphabet of life so yes from
bacteria to human we only need four
letters but then what’s our DNA
instruction book looking like in each of
ourselves we have around three billions
of those letters organized on 23 pairs
of chromosomes so you see here it’s a
compaction of these four letters but
what makes you different from me is that
these letters changes these letters
changed between all the
individuals so if we all have the same
genetic code it means we are all related
yes we are we all cousins from each
other
but then you may wonder how did we
evolve to so many complex forms from
such a single cell long time ago
and that’s when I want you remember the
card game we have been playing what’s
essential for evolution is genetic
variation it’s changes in these letters
so these letters change randomly and
most of these changes are neutral they
have no effect on the fitness of the
individual but if a change is advantage
it can be selected
remember we select if a positive
mutation appears why is it selected
because the individual gets an advantage
and it might reproduce more than the
others so the mutation is transmitted
and we know that natural selection is
cumulative that we can accumulate this
positive mutation which is important for
adaptation and evolution so as I said
during the card game there is nothing of
intelligent or Creator out there for
evolution and look at cancer development
cancer development is also an
evolutionary process it follows this
same mechanism each of our cells
accumulate randomly these changes these
mutations but if one of these normal
cells suddenly gets a growth advantage a
mutation that gives it a growth
advantage compared to the other cells it
will start to grow quicker an
uncontrolled proliferation and cancer
can occur and of course it’s a problem
to human we know it but you know animals
also get cancer but do all of them get
cancer there are a few mysterious
species that don’t develop cancer what
are they
the most notorious one is this naked
mole rat very cute animal no for
scientists it’s a very interesting
animal it’s very small it’s like a mouse
but it lives 30 years
and mouse lives for years what’s also
interesting is if you inject the cancer
cell in this in this animal it will not
develop and why scientists have searched
for this for years and found that they
have this kind of molecule a high
molecular mass here luolan it’s a kind
of ship super sugar that they secreted
around the cells of these animals and it
makes their tissue very elastic and why
is it important because this animal they
dig into the soul
they make these burrows and so that
tissue need to be very elastic so it’s
not updation to this but what’s
interesting is that it this molecule
when it’s secreted around the cell it
prevents the cell from dividing or
proliferating further so you immediately
see the interesting application of the
discovery of such a molecule but if you
think this is the only interesting
animal out there it’s wrong nature is
full of mysterious species where we can
discover so much nature has been an
inspiration to scientists for so many
years like Albert Einstein said we know
less than 1,000 of 1% of what nature has
to reveal to us and if we do start to
destroy our nature will will not even
discover all everything that’s out there
look at this gecko this gecko we know
they can run quickly on vertical glasses
but how how can this these animals Adi
are so strongly to glass and then just
run on it and so for long scientists
looked at a molecule what kind of
molecule is secreted that makes them
like a glue like a strong adhesion and
in fact by looking at these fingers they
found is nothing of a molecule that is
secreted but it’s a structure what they
discovered is that underneath these
figures there are these hairlike
structures millions of them and if you
look even at the nanoscopic level you
see that at the end of all of these
hairs you have hundreds of these spatula
likes structures and when these are in
strong contact with glass it creates a
strong adhesion just through simple
Vander Waals forces the simple forces
that
make this strong addition and when they
rotate their fingers this force releases
immediately and they can run further and
of course laboratories have now been
interested to just reconstruct these
nano structures to make strong adhesives
and that’s what I want to show you it’s
so interesting to study biology because
there’s so much to discover because
there has been such a long evolution of
all kinds of specimens with all kinds of
different adaptations and what is
puzzled me is reproduction you know that
for life it’s essential to reproduce we
need to reproduce or the species will go
extinct but do you know that sexual
reproduction the one we all know it’s
the queen of problems in evolutionary
biology first scientist it’s really a
puzzle and why think about all the
energy you need to spend to find a
partner all the strategies the male’s
developed to try to attract a female to
try to fertilize her to the point that
there is a battle of sexes believe me
man penis is boring compared to this
insect penis this is a penis of a bean
level full of spines and the males with
the longest spines are those that
fertilize most of the eggs of course the
female cannot reproduce anymore
afterwards but least the male is sure he
transmitted his genes a look at this
fruit fly you might have many fruit
flies in summer around your trash bin
this fruit fly Drosophila belukha
produces giant sperm 20 times its body
it’s like you man you would have a pee
urge a sperm that is twenty times your
body like a building of 12 stages Wow
but at least when it transmits this to
the female the receptacle of the female
is filled there is no space space for
another sperm so it’s sure to transmit
its genes but then why did such a
complicated mode of reproduction evolved
and is so omnipresent is it not just
simpler to clone yourself one individual
makes a new individual
so why is sexual reproduction so
prevalent in nature
in fact for us biologists sex is just
about mixing genetic material of one
individual with another individual to
create each generation of Springs that
are all different and that’s a force of
sexual reproduction
it creates every generation this genetic
variability that is essential for
evolution so does it mean that animals
that lose sexual reproduction or that
abandon in order have no sexual
reproduction cannot evolve cannot adapt
that’s what we thought until we
discovered what has been called an
evolutionary scandal or an ancient
sexual scandal it’s a microscopic world
of animals the DeLuise rat first these
are females cloning themselves never has
any male been discovered they exist
since millions of years and we found
them everywhere and they are not only
interesting because they can reproduce
without males and if off without males
we can also dry them out I showed you we
can just take them here in the park a
piece of Flickr no dry lickin bring it
back to the lab and what you see that’s
also what you see on the microscope this
dry lickin’s and then they are in turns
but when we add water they start to live
again so these animals we can dry them
out at any stage in their life and we
can keep them dry we can put them in the
-80 freezer we can send them to
collaborators in the US and if they add
water they live again and off and it’s
not only one species you could take yeah
but it’s just this rare animal no it’s
more than 400 species being described
having diversified into many
morphological forms all females
reproducing without males most of them
being able to dry out and of course this
makes the newspaper so reproduce not
sexy possible yes it’s possible but then
of course you might think how did these
females evolve how do they create
variability because we know
it’s essential for evolution so if they
just cloned themselves how do they ever
evolve and adapt and so as a scientist
is important to have these hypothesis to
think of so our hypothesis is it’s easy
to work with this animal you take a
female in the wild you start to clone it
in the lab you have millions of
identical females we dry them up and
then our question was do these females
what happens to the genetic material of
these females when we dry them up
we know from bacteria that drying up
breaks their genetic material into
pieces is this also happening in these
animals and then what if they don’t
repair perfectly these pieces is this a
way to create variability meaning if you
replace males by drying up
you might also evolve and so that’s what
we tested so boys has designed a very
nice protocol in the lab to dry them up
with a high survival rate and what
happens what to do these females when
they are dried up you see the longer
they are dried up the more their DNA is
broken the simple gel and the DNA
migrates through it the smaller the
pieces and when we hydrate them what you
see is that they start to repair so they
can come out of drying they have their
broken DNA but they can survive with
broken DNA apparently and then they
start to repair and you know if you have
a cancer cell it’s known that the cancer
cells sometimes during a division some
DNA brokes and it repairs this broken
DNA but not perfectly and you can have
an aggressive cancer that appears what
they do in proton therapy is use proton
radiation to completely destroy the DNA
of cancer cells so the DSA cells gets
completely broken the DNA and the
molecules too and so we thought if we do
proton radiation to these animals what
happens so we took again a female we dry
it up we add proton radiation and what
happens the
make it completely broken and this 800
gray of proton radiations are huge doses
there are no living cells that can
survive this but what’s amazing here is
you really see the dean is completely
broken and when we rehydrate these
females 99 percent of them survive so
they come up of drying with a completely
broken Chilean DNA without problem and
then they start to repair and of course
the question is do they really repair
perfectly or so do they put all the
pieces of DNA back together into their
12 chromosomes because we found they had
12 chromosomes or is that just creating
some variability and so we have to here
preliminary results that I’m just
showing you tonight where we did this
experiments so where we dry them up we
irradiate them and then we look at
genomic structure not going too much
into detail but what you see here is for
example pieces of the reach of the
genome from a female before she was
radiated or dried up then we dry it up
we irradiate it and we look at whether
these pieces come back you see here
everything is destroyed and whether we
get these pieces back showing that it’s
stitching back all these DNA pieces
together into these 12 chromosomes so
they can do this they reconstruct their
genome as before or at least that’s what
it seems to look like and even the
descendants have that same structure as
a parent align so is there no genetic
scrambling going on that’s possible
maybe they don’t indeed make a
completely new genome they keep their
genome but what we then ask us question
is how can you survive when you are
irradiated because not only your DNA is
broken but also your molecules must be
broken but they must keep their
molecules somehow intact because you
need these MOC molecules to repair your
DNA so what do they have what’s their
secret what we found by sequencing the
first genome so really sequencing the
entire alphabet of this animal
we found that they have a huge amount of
antioxidants antioxidants are essential
to protect yourself from these damaged
cells we all have antioxidants that’s
because our cells accumulate damages a
kind of what we call a oxidative stress
and your proteins your DNA everything
gets damages that’s why we get older and
that’s why you put all these creams on
full of antioxidants to try to prevent
the aging of your cells but it will not
but here these animals have a huge
amount of these antioxidants so next
time think about it don’t buy all these
expensive creams full of antioxidants
just drink some rat AFER’s you find them
in the nature and might help but of
course these are all things we discover
but as a scientist when you discover
things you have even much more questions
and so recently I obtained two a grant
from the European Research Council to
really try to demystify all these
mysteries we found we found they have
this huge amount of antioxidants but are
they really effective how do they repair
this broken genome what are the
molecules the mechanism a have to repair
such a broken genome to survive drying
freezing and then one last thing we
discovered is by sequencing their genome
we found between their genetic material
genetic material from bacteria plants
fungi so they seem to integrate DNA from
their environment and that’s of course
bustling but we also thought if they can
integrate this foreign DNA can they also
integrate DNA from other females out
there are the rotifer that also dry up
and the first results we got on this is
that we found some signatures of DNA
exchange between these females and we
think it’s not conventional sex because
we never found males so they are not
using the strategy that all animals do a
sperm and an oversight to exchange DNA
so what is the strategy we have no idea
we called it’s a for mixes it’s a mixing
of genetic material between females and
you immediately see here and that’s why
it’s so beautiful to be a scientist if
you discover a lot but you have even
more questions but what’s for sure is
that we have a very interesting model
organism here to understand how can they
evolve without males
how does suffer mix this happen and how
can they survive such extreme conditions
as drying up freezing and high doses of
radiation there’s so much still to
discover there and one of our next
challenges is to send them to space we
got a grant from the European research
agency to send in 2019 Rati first to
space rice why because space is also an
extreme environment we have no idea at
the moment what these extreme
environments has as pressure on
astronauts or any living animal this is
a very interesting model Organists to
send out there and to understand much
better
what’s space like and of course I cannot
end this presentation without thanking
all the funding but especially all the
people in my lab many are here there
this work is never done by one person a
lab is really a group of person working
tackling these questions a lot of
frustrations they know it better than me
right now and then I would like to thank
the rotifer and Boris with the whole
experiment because thanks to these rat
AFER’s I’m really happy to go every day
or almost every day to my work at least
when I know I can do science and I can
work with a rotifers I’m a happy person
thank you
[Applause]
[Music]
good evening here you see a little petri
dish that we use in the lab with a dry
leaf completely dry and on there there
are females why do I say females because
that’s their way of life they live and
evolve without males they got rid of
males and also they are dry they can dry
up and we can wait for years put them in
the freezer and get the back tonight we
will do a live experiment with one of my
scientists Boris to resurrect these
animals for you these females thanks
Boris so look around you there is an
amazing diversity of living organism on
this planet from bacteria to Fonzi to
plans to animals to human nothing looks
alike but do you know that all these
diversity arose once from a universal
ancestor around 3.5 billion years ago
and this ancestor of all living
organisms a single simple cell something
like a bacteria but how do we know that
all life has evolved from a single cell
we know this because we all share the
same alphabet we have the same DNA code
DNA is a magic molecule of life and DNA
is only made up of four chemical
building blocks citizen guanine adenine
teaming so only four letters that make
the whole alphabet of life so yes from
bacteria to human we only need four
letters but then what’s our DNA
instruction book looking like in each of
ourselves we have around three billions
of those letters organized on 23 pairs
of chromosomes so you see here it’s a
compaction of these four letters but
what makes you different from me is that
these letters changes these letters
changed between all the
individuals so if we all have the same
genetic code it means we are all related
yes we are we all cousins from each
other
but then you may wonder how did we
evolve to so many complex forms from
such a single cell long time ago
and that’s when I want you remember the
card game we have been playing what’s
essential for evolution is genetic
variation it’s changes in these letters
so these letters change randomly and
most of these changes are neutral they
have no effect on the fitness of the
individual but if a change is advantage
it can be selected
remember we select if a positive
mutation appears why is it selected
because the individual gets an advantage
and it might reproduce more than the
others so the mutation is transmitted
and we know that natural selection is
cumulative that we can accumulate this
positive mutation which is important for
adaptation and evolution so as I said
during the card game there is nothing of
intelligent or Creator out there for
evolution and look at cancer development
cancer development is also an
evolutionary process it follows this
same mechanism each of our cells
accumulate randomly these changes these
mutations but if one of these normal
cells suddenly gets a growth advantage a
mutation that gives it a growth
advantage compared to the other cells it
will start to grow quicker an
uncontrolled proliferation and cancer
can occur and of course it’s a problem
to human we know it but you know animals
also get cancer but do all of them get
cancer there are a few mysterious
species that don’t develop cancer what
are they
the most notorious one is this naked
mole rat very cute animal no for
scientists it’s a very interesting
animal it’s very small it’s like a mouse
but it lives 30 years
and mouse lives for years what’s also
interesting is if you inject the cancer
cell in this in this animal it will not
develop and why scientists have searched
for this for years and found that they
have this kind of molecule a high
molecular mass here luolan it’s a kind
of ship super sugar that they secreted
around the cells of these animals and it
makes their tissue very elastic and why
is it important because this animal they
dig into the soul
they make these burrows and so that
tissue need to be very elastic so it’s
not updation to this but what’s
interesting is that it this molecule
when it’s secreted around the cell it
prevents the cell from dividing or
proliferating further so you immediately
see the interesting application of the
discovery of such a molecule but if you
think this is the only interesting
animal out there it’s wrong nature is
full of mysterious species where we can
discover so much nature has been an
inspiration to scientists for so many
years like Albert Einstein said we know
less than 1,000 of 1% of what nature has
to reveal to us and if we do start to
destroy our nature will will not even
discover all everything that’s out there
look at this gecko this gecko we know
they can run quickly on vertical glasses
but how how can this these animals Adi
are so strongly to glass and then just
run on it and so for long scientists
looked at a molecule what kind of
molecule is secreted that makes them
like a glue like a strong adhesion and
in fact by looking at these fingers they
found is nothing of a molecule that is
secreted but it’s a structure what they
discovered is that underneath these
figures there are these hairlike
structures millions of them and if you
look even at the nanoscopic level you
see that at the end of all of these
hairs you have hundreds of these spatula
likes structures and when these are in
strong contact with glass it creates a
strong adhesion just through simple
Vander Waals forces the simple forces
that
make this strong addition and when they
rotate their fingers this force releases
immediately and they can run further and
of course laboratories have now been
interested to just reconstruct these
nano structures to make strong adhesives
and that’s what I want to show you it’s
so interesting to study biology because
there’s so much to discover because
there has been such a long evolution of
all kinds of specimens with all kinds of
different adaptations and what is
puzzled me is reproduction you know that
for life it’s essential to reproduce we
need to reproduce or the species will go
extinct but do you know that sexual
reproduction the one we all know it’s
the queen of problems in evolutionary
biology first scientist it’s really a
puzzle and why think about all the
energy you need to spend to find a
partner all the strategies the male’s
developed to try to attract a female to
try to fertilize her to the point that
there is a battle of sexes believe me
man penis is boring compared to this
insect penis this is a penis of a bean
level full of spines and the males with
the longest spines are those that
fertilize most of the eggs of course the
female cannot reproduce anymore
afterwards but least the male is sure he
transmitted his genes a look at this
fruit fly you might have many fruit
flies in summer around your trash bin
this fruit fly Drosophila belukha
produces giant sperm 20 times its body
it’s like you man you would have a pee
urge a sperm that is twenty times your
body like a building of 12 stages Wow
but at least when it transmits this to
the female the receptacle of the female
is filled there is no space space for
another sperm so it’s sure to transmit
its genes but then why did such a
complicated mode of reproduction evolved
and is so omnipresent is it not just
simpler to clone yourself one individual
makes a new individual
so why is sexual reproduction so
prevalent in nature
in fact for us biologists sex is just
about mixing genetic material of one
individual with another individual to
create each generation of Springs that
are all different and that’s a force of
sexual reproduction
it creates every generation this genetic
variability that is essential for
evolution so does it mean that animals
that lose sexual reproduction or that
abandon in order have no sexual
reproduction cannot evolve cannot adapt
that’s what we thought until we
discovered what has been called an
evolutionary scandal or an ancient
sexual scandal it’s a microscopic world
of animals the DeLuise rat first these
are females cloning themselves never has
any male been discovered they exist
since millions of years and we found
them everywhere and they are not only
interesting because they can reproduce
without males and if off without males
we can also dry them out I showed you we
can just take them here in the park a
piece of Flickr no dry lickin bring it
back to the lab and what you see that’s
also what you see on the microscope this
dry lickin’s and then they are in turns
but when we add water they start to live
again so these animals we can dry them
out at any stage in their life and we
can keep them dry we can put them in the
-80 freezer we can send them to
collaborators in the US and if they add
water they live again and off and it’s
not only one species you could take yeah
but it’s just this rare animal no it’s
more than 400 species being described
having diversified into many
morphological forms all females
reproducing without males most of them
being able to dry out and of course this
makes the newspaper so reproduce not
sexy possible yes it’s possible but then
of course you might think how did these
females evolve how do they create
variability because we know
it’s essential for evolution so if they
just cloned themselves how do they ever
evolve and adapt and so as a scientist
is important to have these hypothesis to
think of so our hypothesis is it’s easy
to work with this animal you take a
female in the wild you start to clone it
in the lab you have millions of
identical females we dry them up and
then our question was do these females
what happens to the genetic material of
these females when we dry them up
we know from bacteria that drying up
breaks their genetic material into
pieces is this also happening in these
animals and then what if they don’t
repair perfectly these pieces is this a
way to create variability meaning if you
replace males by drying up
you might also evolve and so that’s what
we tested so boys has designed a very
nice protocol in the lab to dry them up
with a high survival rate and what
happens what to do these females when
they are dried up you see the longer
they are dried up the more their DNA is
broken the simple gel and the DNA
migrates through it the smaller the
pieces and when we hydrate them what you
see is that they start to repair so they
can come out of drying they have their
broken DNA but they can survive with
broken DNA apparently and then they
start to repair and you know if you have
a cancer cell it’s known that the cancer
cells sometimes during a division some
DNA brokes and it repairs this broken
DNA but not perfectly and you can have
an aggressive cancer that appears what
they do in proton therapy is use proton
radiation to completely destroy the DNA
of cancer cells so the DSA cells gets
completely broken the DNA and the
molecules too and so we thought if we do
proton radiation to these animals what
happens so we took again a female we dry
it up we add proton radiation and what
happens the
make it completely broken and this 800
gray of proton radiations are huge doses
there are no living cells that can
survive this but what’s amazing here is
you really see the dean is completely
broken and when we rehydrate these
females 99 percent of them survive so
they come up of drying with a completely
broken Chilean DNA without problem and
then they start to repair and of course
the question is do they really repair
perfectly or so do they put all the
pieces of DNA back together into their
12 chromosomes because we found they had
12 chromosomes or is that just creating
some variability and so we have to here
preliminary results that I’m just
showing you tonight where we did this
experiments so where we dry them up we
irradiate them and then we look at
genomic structure not going too much
into detail but what you see here is for
example pieces of the reach of the
genome from a female before she was
radiated or dried up then we dry it up
we irradiate it and we look at whether
these pieces come back you see here
everything is destroyed and whether we
get these pieces back showing that it’s
stitching back all these DNA pieces
together into these 12 chromosomes so
they can do this they reconstruct their
genome as before or at least that’s what
it seems to look like and even the
descendants have that same structure as
a parent align so is there no genetic
scrambling going on that’s possible
maybe they don’t indeed make a
completely new genome they keep their
genome but what we then ask us question
is how can you survive when you are
irradiated because not only your DNA is
broken but also your molecules must be
broken but they must keep their
molecules somehow intact because you
need these MOC molecules to repair your
DNA so what do they have what’s their
secret what we found by sequencing the
first genome so really sequencing the
entire alphabet of this animal
we found that they have a huge amount of
antioxidants antioxidants are essential
to protect yourself from these damaged
cells we all have antioxidants that’s
because our cells accumulate damages a
kind of what we call a oxidative stress
and your proteins your DNA everything
gets damages that’s why we get older and
that’s why you put all these creams on
full of antioxidants to try to prevent
the aging of your cells but it will not
but here these animals have a huge
amount of these antioxidants so next
time think about it don’t buy all these
expensive creams full of antioxidants
just drink some rat AFER’s you find them
in the nature and might help but of
course these are all things we discover
but as a scientist when you discover
things you have even much more questions
and so recently I obtained two a grant
from the European Research Council to
really try to demystify all these
mysteries we found we found they have
this huge amount of antioxidants but are
they really effective how do they repair
this broken genome what are the
molecules the mechanism a have to repair
such a broken genome to survive drying
freezing and then one last thing we
discovered is by sequencing their genome
we found between their genetic material
genetic material from bacteria plants
fungi so they seem to integrate DNA from
their environment and that’s of course
bustling but we also thought if they can
integrate this foreign DNA can they also
integrate DNA from other females out
there are the rotifer that also dry up
and the first results we got on this is
that we found some signatures of DNA
exchange between these females and we
think it’s not conventional sex because
we never found males so they are not
using the strategy that all animals do a
sperm and an oversight to exchange DNA
so what is the strategy we have no idea
we called it’s a for mixes it’s a mixing
of genetic material between females and
you immediately see here and that’s why
it’s so beautiful to be a scientist if
you discover a lot but you have even
more questions but what’s for sure is
that we have a very interesting model
organism here to understand how can they
evolve without males
how does suffer mix this happen and how
can they survive such extreme conditions
as drying up freezing and high doses of
radiation there’s so much still to
discover there and one of our next
challenges is to send them to space we
got a grant from the European research
agency to send in 2019 Rati first to
space rice why because space is also an
extreme environment we have no idea at
the moment what these extreme
environments has as pressure on
astronauts or any living animal this is
a very interesting model Organists to
send out there and to understand much
better
what’s space like and of course I cannot
end this presentation without thanking
all the funding but especially all the
people in my lab many are here there
this work is never done by one person a
lab is really a group of person working
tackling these questions a lot of
frustrations they know it better than me
right now and then I would like to thank
the rotifer and Boris with the whole
experiment because thanks to these rat
AFER’s I’m really happy to go every day
or almost every day to my work at least
when I know I can do science and I can
work with a rotifers I’m a happy person
thank you
[Applause]
[Music]
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