Whole lotta leg

Watch: 14-legged lifeform walks without a brain, and scientists finally know how it pulls of the feat

How cells move is a longstanding mystery — but new research has some clues.

by Jennifer Walter
Updated: 
Originally Published: 
Current Biology/Larson et al

Current Biology/Larson et al

What has 14 legs and crawls around without a brain or nervous system?

That would be the single-celled organism Euplotes eurystomus, a microscopic protist that thrives in water.

The microscopic world of Euplotes and other single-celled organisms has long fascinated scientists.

Individual cells can do animal-like things such as hunt and solve mazes, despite their simple anatomy and lack of brains.

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How they pull off these feats is not completely understood.

Even the simplest tasks, like walking and swimming, require animals to use muscles — which Euplotes doesn’t even have.

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Writing this week in the journal Current Biology, researchers investigated the movements of Euplotes under a microscope to determine how it walks.

Here’s Euplotes moving across a surface using its 14 leg-like appendages, called cirri.

Current Biology/Larson et al

In order to get around, Euplotes has a few different gaits that it switches between to coordinate all of its cirri.

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And in lieu of a brain, the researchers found that the cells use an interconnected network of fibers called microtubules to get around.

This reconstruction shows the network of fibers that run through a Euplotes cell.

Current Biology/Larson et al

Some of the fibers are thick and linear, and others are thin and splayed out.

But they all connect to the cell’s cirri.

Current Biology/Larson et al

When the researchers exposed Euplotes cells to chemicals that inhibited microtubule function, they found that it made it difficult for them to walk.

So it’s likely that microtubules are playing a significant role in carrying cells like Euplotes from point A to B — solving a mystery about how they travel with such simple anatomy.

DE AGOSTINI PICTURE LIBRARY/De Agostini/Getty Images

DE AGOSTINI PICTURE LIBRARY/De Agostini/Getty Images

“Our work lays a foundation for studying sensorimotor behavior in Euplotes, which will shed light on principles of cellular behavior.”