The unicellular cell that multiplies its dimensions by 30 thanks to an origami-style structure

2024-10-03 04:00:12

This unicellular is whimsical. For Manu Prakash, professor of bioengineering at Stanford University, it was enough to see it once “forever fascinated”. It has to be said Smell of Lacrymaria plays in a category of its own. In a few seconds, a neck of… 1,500 microns emerges from its body in the form of a 40 micron drop of water (hence the name). A bit as if a human being 1.80 meters tall could stretch his head 67 meters.

With colleague Eliott Flaum, the biophysicist revealed In Scienceon June 7, the secret of this ciliate: a structure never before observed in the living world, but known among origami lovers by the name of Yoshimura. This is a triangular-based fold that allows you to extend an entire cylinder without lengthening each element. Better: both deployment and retraction can be done in only one way, allowing the single cell to withstand the approximately 20,000 extensions – and returns – made over the course of a lifetime.

A mathematical “singularity”.

Thanks to complex imaging work, the two researchers first highlighted the filaments of the unicellular cytoskeleton. These microtubules structure the cell membrane in such a way that allows it to fold inward into several layers when at rest. But when the creature comes to target prey and the accordion opens, opens, opens… The Californians have studied the complex geometry involved in this structure and have highlighted a mathematical “singularity”, i.e. the points at which the structure is both folded and unfolded.

This organization offers the advantage of being able to concentrate a gigantic amount of the skeleton, and then deploy it when necessary. But also to avoid unnecessary extensions and unwanted folds. Anyone who has handled paper maps and hated seeing them tear so quickly will understand. Manu Prakash does not seem to foresee a cartographic variant upon his discovery. On the other hand, this “very small scale distribution” it could find applications in space telescopes or surgical robots. Single cell phones and traditional paper folders certainly have a lot to teach us.