Scientists at The University of Manchester have made a major discovery that could change what we’ve believed—and taught—about how cells divide for over a century.
In a study published in Science, they found that cells don’t always become round before they split into two, challenging what many of us learned in school biology classes.
Traditionally, students are taught that when a cell divides, it first becomes a perfect sphere.
It then splits into two equal parts—called daughter cells—that are the same size and shape. But this new research shows that’s not always true in living organisms.
The team discovered that many cells in the body don’t actually round up at all before they divide.
Instead, they stay in their original shape and divide in a way that produces two daughter cells that are different—not just in size, but also in function. This type of division is called “asymmetric division.”
Asymmetric division is important because it helps the body produce different types of cells that go on to form different tissues and organs.
Until now, scientists thought that this only happened with stem cells—special cells that can become many different cell types. But the Manchester team found that asymmetric division happens more widely in the body.
Their findings also reveal something surprising: the shape of a parent cell before it divides plays a big role in how it splits. If a cell is short and wide, it usually rounds up and divides into two similar daughter cells.
But if the cell is long and thin, it doesn’t round up—it divides asymmetrically, making one daughter cell that’s different from the other.
This discovery could help us better understand diseases like cancer. In cancer, cells divide quickly and in unpredictable ways.
The study suggests that irregularly shaped cancer cells might divide asymmetrically, producing daughter cells with different behaviors. Some of these differences might help cancer spread to other parts of the body, a process called metastasis.
The research could also benefit regenerative medicine, which focuses on repairing or growing new tissues and organs.
If scientists can control the shape of cells before they divide, they may be able to guide what kind of daughter cells are produced. That could help in creating specific cell types for healing injuries or treating diseases.
The scientists made their discovery by using live imaging on tiny, see-through zebrafish embryos just one day old. These fish are often used in research because their bodies are transparent, making it easier to see what’s happening inside.
In one experiment, the researchers watched as special fast-moving cells at the front of growing blood vessels divided. Instead of becoming round, these “tip” cells divided while keeping their shape and created two different types of daughter cells—one fast and one slow.
They also used a technique called micropatterning, which lets them control the shape of human cells in the lab. By using a special UV laser to print tiny protein patterns smaller than a human hair, they made cells take on specific shapes and then watched how they divided.
This discovery changes how we think about one of life’s most basic processes—and it might soon change what students learn in classrooms too.
