I tend to be a pretty easy going guy.

But like most people,

I occasionally get somewhat irritable,

and that usually happens when one of two things happen:

Either I'm hungry, or I'm really stressed out.

Note that you do not want to be around me when I'm both hungry and really stressed out.

There are a number of ways that I can deal with these situations:

I eat, I exercise. Sometimes I just scream.

One thing I cannot do, though,

it would be really nice,

would be to revert back to a simpler time,

back to when I was eight-year-old Hank.

But there is an organism, in this great wide world of ours,

that can do that very thing.

[intro music]

This, my friends, is Turritopsis Dohrnii.

Otherwise known as Turritopsis Nutricula.

Other, otherwise known as The IMMORTAL JELLYFISH.

You heard me correctly; this little guy is the only animal that we know of

that is capable of reverting back to a younger version of itself.

And it does this, you've probably guessed,

when it's facing starvation or other stresses in its environment.

The question, though, is how does this happen,

and how can I get me some of it?

Okay, so because I know you are super curious, here is the typical life cycle of a jellyfish.

We've got the fertilized egg, which becomes a larva,

which sinks to the bottom of the ocean,

attaches itself to something and becomes a polyp,

which over time transforms itself into a free-swimming bell-shaped Medusa,

AKA a jellyfish, with 80 to 90 tentacles. Simple, right?

Since our friend, The Turritopsis, is a kind of Plankton...

Plankton is, by the way, a word for anything that doesn't really move itself around in the ocean;

it just gets moved around by the ocean:

Drifting organisms.

And Turritopsis is a source of nutrition,

so it often gets eaten by other organisms

or, you know, killed off by disease,

so it's technically not immortal if it gets eaten.

But the amazing stuff happens when this dime sized jellyfish

somehow avoids getting eaten but then can't find enough food or is injured or

is otherwise stressed by the environment this is the point that the jellyfish

goes all benjamin button on is throwing its life cycle into reverse the bell and

all those tentacles deteriorate and it eventually becomes assist this cyst has

the ability to reactivate genetic instructions from earlier in its life

cycle and actually starts creating new polyp cells and from there the life

cycle process begins again as the polyp through the beauty of asexual

reproduction releases many identical copies of itself scientists have said

that in theory this process could repeat indefinitely making the jellyfish

technically immortal it may seem like science fiction like there could be only

one jellyfish

what's actually happening here as the jellyfish transformed cells into a

younger state is called transdifferentiation this is one mature

cells that have already been assigned to function like lung cells or skin cells

become different kinds of cells in the case of this jellyfish that might mean

converting a muscle cell into a nerve cell or even a sperm and egg cell among

animals transdifferentiation is not

unique to these jellyfish for example if you take the lens out of the eye of a

chicken

the iris cells will actually develop into Lens cells unlike the jellyfish

though the chicken cannot revert its entire body back into an egg

though yeah that would be pretty awesome. the story of the turritopsis is important to

scientists because we're constantly looking for ways to regenerate new

tissue

usually that process involves stem cells or unassigned cells that haven't been

given genetic instructions to become a nerve cell or a bone cell or a liver cell

turns differentiation doesn't require that the problem is we have no idea what

signals are being sent to these cells to to change their type we just don't

understand how it works and it's not entirely clear that even possible

in mammals like us of course that doesn't mean that studying this

jellyfish isn't going to be tremendously useful for us if this thing has cells

that can switch themselves on and off when they're in peril prove very useful

for cancer research

imagine if we could isolate a cancer cell and just turn on their young and

healthy cell instructions again for now the turritopsis remains the only animal

that we know of that can regenerate its entire body which might go a little ways

to explain why the population of this jellyfish is exploding worldwide of course it is

it's practically immortal always so much good information here youtube.com slash

scishow you can go and subscribe right now if you haven't and you will get this

good stuff in your subscription box constantly if you have questions or

suggestions for us you can hook up with us on facebook or on twitter and always

of course in the YouTube comments below

goodbye!

[Outro Music]