Cell division is one of the most fundamental biological functions, vital to life – but there's still so much about it that we don't understand. In an attempt to find out more, researchers at the University of Chicago have now managed to recreate cell division outside of a cell for the first time, surprising even themselves.
From the time we're conceived as just a single cell, to our wounds healing themselves in adulthood, cell division is a key part of how living organisms grow and survive. While we understand how this works on the broad scale, the nuances are still somewhat lost on us.
So the researchers on the new study set out to investigate the process further. To do so, they removed the "ingredients" from a cell and reconstructed them outside. But what they didn't expect was that this makeshift cell would undergo division like a normal cell.
First the team separated out actin, a protein that's key to the cellular division process. The actin proteins, which are long and rod-shaped, tended to clump together in parallel lines, forming a kind of almond-shaped droplet.
The real magic happened when the researchers added myosin, a motor protein that plays a part in muscle contraction. Surprisingly, the myosin moved towards the center of the actin droplets, then pinched them off from the middle, forming two separate "cells."
"There's no precedent for this," says Margaret Gardel, lead researcher on the study. "It looks exactly like the spindles that drive cell division."
Modelling the physics behind the process, the team got a better understanding of why the scenario played out the way it did. The researchers found that the actin organized themselves into parallel lines because that's where they find the least resistance. The myosin tries to do the same, gathering in the middle, but if too many collect in one spot the cluster instead breaks off the droplet.
While it's not a perfect replica of how a natural cell divides, the team says it's a good model for understanding the fundamentals. It could also inspire artificial cells and other medical breakthroughs down the track.
"This is the kind of thing you need to know to imagine building things like artificial tissue for a wound," says Gardel. "Ultimately, a great deal of problems in biology are about how ensembles of molecules work together, and because these are often materials with chemical reactions going on inside, they're very hard to model. These kinds of studies allow us the opportunity to explore the basic principles of the forces at play."
The research was published in the journal PNAS.
Source: University of Chicago
