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The Undying Hydra: A Freshwater Mini-Monster That Defies Aging | Deep Look - YouTube
Channel: Deep Look
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Everything that lives, must one day die, right?
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Well, maybe not everything.
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Consider the hydra.
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It’s named after a many-headed monster from
Greek mythology.
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Chop off one head and two grow in its place.
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That myth isn’t too far from the real hydra’s
death-defying abilities.
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They’re cousins to jellyfish -- see the
resemblance?
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But hydra live in freshwater.
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Its body is a hollow column with walls only
two cells thick.
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Its head is just a bunch of tentacles surrounding
a mouth, no eyes or brain.
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The whole thing is about as long as a grain
of rice.
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The hungry hydra stretches out its tentacles
to snag swimming prey.
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Microscopic harpoons hook the water flea injecting
it with paralyzing neurotoxins.
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Then, it’s down the hatch.
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The hydra uses those nutrients to make more
hydra.
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Check out this bud.
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It’s a clone sprouting right from the hydra’s
side.
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Hydra can reproduce sexually too, but most
often, they just clone themselves.
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A chip off the old block!
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Hydra are constantly regenerating their own
bodies too, replacing all of their cells every
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twenty days.
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They can do that because roughly half of the
cells in their bodies are stem cells which
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can develop into all the different types of
specialized cells you need to build, or re-build
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a body.
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Stem cells only make up a tiny percentage
of our bodies.
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And our stem cells degrade over time -- that’s
why we age.
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But a hydra can make near-perfect copies of
its stem cells … basically forever.
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It’s called non-senescence -- biological
immortality.
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Having all those stem cells allows hydra to
recover from all kinds of... damage.
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Alright, here we go.
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No body?
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Not to worry.
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No head?
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No problem.
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As long as the chopped off chunk has some
stem cells, it's ready to regrow.
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In a couple days, the severed head has a new
body.
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And the foot?
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It’s got a brand new head!
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Soon, they’ll both be as good as new…
except for maybe some lingering trust issues.
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To test the limits of their ability to recover,
researchers came up with an experiment.
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This hydra is genetically engineered so that
under ultraviolet light its exterior cells
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glow purple and interior ones glow green.
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Scientists basically blend up a bunch of these
hydra.
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Leaving a heap of mixed-up cells.
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Right away, the cells start re-organizing.
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Those purple outer layer cells migrate out.
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The cells from the inside squirm back into
the center.
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The hydra dumps cells from the interior to
restore its hollow shape.
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The stem cells start dividing - and differentiating
- to rebuild the rest of the animal.
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Soon a head starts to form, sometimes a few
little heads compete to be the new top.
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After a few tumultuous days what was once
a mixed up pile of cells
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takes on a familiar shape.
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Researchers hope to harness hydra’s ability
to regenerate to someday slow human aging,
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or even regrow damaged organs.
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Maybe this tiny monster will one day show
us the way to the mythical fountain of youth.
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Hey Deep Peeps - our PBS friends here on YouTube
are celebrating Earth Day
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with a ton of special episodes.
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Head over to Above the Noise, where host Myles
Bess asks... can we make room for wildlife
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in our cities?
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Thanks and tell 'em Deep Look sent you!
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