Gravity affects us in ways we didn’t expect.
We know this by observing frogs.
That’s right, frogs.
Hi all.
I’m Ian O’Neill, space producer for Discovery News, and I wanted to chat a little about
a frog named Xenopus Laevis and a force called gravity.
The Xenopus is also known at the African clawed frog and biologists have been astonished by
how big its cells are.
On average, animal cells on Earth are around 10 microns wide, but the Xenopus cells are
much, much larger.
If a human cell was the size of a house, a Xenopus cell would be the size of the Empire
State Building!
Why is there such a wild size difference?
In a new study published in Nature Cell Biology, researchers studied the architecture of the
cells found inside Xenopus eggs.
These huge cells are markedly different from human cells in that they contain many membrane-less
compartments inside the nucleus.
These compartments are liquid-like drops filled with RNA and proteins known as “nuclear
bodies.”
In human cells, these nuclear bodies are supported by membranes that provide structure, preventing
them from turning to mush.
But with few membranes to support the nuclear bodies inside Xenopus cells, why doesn’t
gravity take over, causing all the stuff inside the nucleus to sink to the bottom?
There must be something countering this gravitational effect.
After injecting a magnetized microscopic bead into one of the cells, the researchers were
able to exert a magnetic field on that bead and observe how it moved.
They found that the bead (and nuclear bodies) were being held in place by a web of proteins
known as an “actin mesh”.
When the magnetic field was switched off, the bead returned to its original position
as if it were embedded inside a cube of Jello.
As a space scientist I’ve always been fascinated by how the space environment can impact biology
-- simply removing the force of gravity in experiments on the International Space
Station has led to breakthroughs in medicine, cell growth and developments in new therapies
for disease.
But as demonstrated by this little frog, Nature has a few tricks up its sleeve to mimic a
gravity-less environment inside the Xenopus cells, thereby boosting its size, making it
more durable and more adept at supporting life.
Wouldn’t it be cool if we could develop this microscopic mesh for industrial purposes,
maybe it would make a good shock absorber?
Who knows!
What do you think we could learn from this fascinating research?
Let me know in the comments below and please subscribe for more DNews every day of the
week.