
How a Water Bear Survives When It’s Dry - happy-go-lucky
https://www.nytimes.com/2017/03/16/science/tardigrades-water-bears-dried-out.html
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alexholehouse
Great to see this in the NYT. I'm working with Thomas (who, in addition to
being a truly exceptional scientists is a really great guy) on understanding
the underlying biophysics of _how_ these disordered proteins facilitate stress
protection.

We have some cool stuff coming along...

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mechagodzilla
Do you know if a structure of any of these proteins is published anywhere? I
checked the PDB, but didn't find anything.

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alexholehouse
Many of these proteins are intrinsically disordered proteins (IDPs), meaning
they don't actually have a set 3D structure, but instead existing in a kind of
'cloud' (ensemble) of interconverting conformations. A consequence of this is
that there is no 'one' representative structure, due to this conformational
heterogeneity.

People used to (very reasonably) assume that 'disordered' just meant totally
random, so the thought was these disordered proteins behaved like a random
polymer. However, just like in folded proteins, the amino acid sequence of
these IDPs has a major impact on the way these clouds of conformations behave.
Happy to discuss more here or 'offline' (see my profile for contact info) -
this is basically my whole PhD, so, you know, I can go more in depth...

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mechagodzilla
Yes (that's the fun part!) - I should have specified that I was just
interested in getting an atomistic model of one of these tardigrade proteins
to play around with in an MD simulation.

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r0m4n0
Can't help but to think about a very distant future where we use these same
disordered proteins to truly freeze organic material, including ourselves.
Maybe I could be dehydrated for a few thousand years on my way to another
solar system no prob.

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vm
There's a cool element of this in the Three Body Problem, a sci-fi book, where
aliens use dehydration to survive to disastrous conditions on their home
planet. You might like the book:
[https://www.amazon.com/dp/B00IQO403K/](https://www.amazon.com/dp/B00IQO403K/)

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InclinedPlane
This is why tardigrades have such high radiation tolerance as well. It turns
out that dehydration is incredibly damaging, especially to DNA, and the same
repair/protection systems for dealing with dehydration (such as DNA repair)
tend to protect against high radiation doses as well.

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Florin_Andrei
The big question is - what's the cost? There is no free lunch. They're paying
for it, or are limited by it, somehow and somewhere.

There's a "feature budget" in any organism, and it's the main reason why you
can't have creatures that could fly, and run fast, and live underwater.

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milesvp
There's a feature budget only in that there's a cost/benefit restriction for
every living thing. Usually the big cost is how many calories does this gene
cost vs how much does this gene benefits the organism (or it's close
relatives).

What's interesting about having high radiation resistance, is that I could see
a cure or vaccine for cancer could be introducing (or possibly expressing)
genes that cause our cells to spend a lot more calories to repair its DNA than
they already do. And the skeptic in me thinks it'll probably be marketed as a
diet pill :)

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Florin_Andrei
It's gonna sell like hot cakes.

 _" High metabolism and cures cancer? I'll take five!"_

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brotoss
Trisolarans anyone?

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r00fus
I was thinking the Zerg. This is like an stepping stone to mutalisks.

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M_Grey
Just about the coolest little critters on Earth! They're cute, they can
survive just about anything reasonably thrown their way from hard vacuum to
radiation, and now this. It makes me happy to know that regardless of how
badly we as a species screw up ourselves or the biosphere, these little
tardigrades won't even notice.

~~~
johansch
Just in case you missed that delightfully weird story from last month:

Google was working on putting live tardigrades into Android phones:

[http://venturebeat.com/2017/02/24/complicated-weird-
beautifu...](http://venturebeat.com/2017/02/24/complicated-weird-beautiful-
the-secret-google-project-to-put-an-aquarium-full-of-tiny-wiggly-water-bears-
inside-your-phone/)

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M_Grey
I did miss it! Thanks, this made my day. There was a movie from the late 80's,
early 90's... and I remember a pimp with platform shoes that were also an
aquarium. This... is better.

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johansch
You made my day in return when I viewed your list of submitted stories. So
much cool stuff!

(And another sign HN needs to step up its submission/upvoting algorithms/UX. I
do think so many HN-worthy stories get lost each day just because of this.)

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M_Grey
Thanks, that's really kind of you to say.

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brilliantcode
The biggest fascinating point about Tardigrades is that they can survive in
_space_.

I think the implication of this should be explored further.

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leggomylibro
That's what the article is about; when they dry out, they produce an irregular
protein which essentially stiffens and preserves the cells while protecting
them from environmental damage. When they are rehydrated, the protein
dissolves and the cells resume their normal functions.

It's pretty cool, and could indeed lead the way to hibernative naptosis.

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xenonysf
Drying out wouldn't be the only problem in space though, there are other
problems... (Btw how long they can survive like that though?)

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known
[https://en.wikipedia.org/wiki/Camel#Ecological_and_behaviora...](https://en.wikipedia.org/wiki/Camel#Ecological_and_behavioral_adaptations)
store fat in their humps

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jondiggsit
Looks like the trisolarans weren't so bad after all.

