For those who took high school biology, the concept of cell division, also known as mitosis, is likely familiar. This fundamental process, crucial to all life forms, has been taught for over a century with the understanding that a parent cell becomes spherical before splitting into two identical daughter cells. However, a recent study may necessitate a revision of many biology textbooks.

Researchers have made a groundbreaking discovery that challenges the conventional wisdom on mitosis. According to their findings, cell division does not always involve the parent cell becoming spherical, which means the resulting daughter cells may not be symmetrical or have the same function. The details of this study, published in the journal Science, have significant implications for understanding cell division in diseases like cancer.

Shane Herbert, co-lead author of the study and a researcher at the University of Manchester’s faculty of Biology, Medicine, and Health, noted, “The traditional teaching is that when a cell divides, it takes on a uniform spherical shape. Our research shows that, in reality, the process is more complex.” This statement was made in a university announcement.

The study focused on the formation of blood vessels in zebrafish embryos, where the growth of new vessels is led by a fast-moving cell. When this lead cell undergoes mitosis, it does not become spherical, resulting in an asymmetrical division that produces two distinct cells: one slow-moving and one fast-moving. This challenges the previous association of asymmetric cell division primarily with specialized stem cells.

Holly Lovegrove, co-lead author and lecturer in cardiovascular sciences at The University of Manchester, highlighted the advantages of using transparent zebrafish embryos: “This allows us to study cell division within a living organism and capture the process on film, revealing new insights into tissue growth.”

The researchers also observed that the shape of the parent cell plays a crucial role in determining whether the division will be symmetrical or asymmetrical. For instance, shorter, wider cells tend to become spherical and divide into similar daughter cells, whereas longer, thinner cells do not “round up” and divide asymmetrically.

To further investigate, the team manipulated the size of human parent cells using micropatterning techniques. Georgia Hulmes, co-first author and postdoctoral research associate, explained, “Micropatterning enables us to create microscopic patches of proteins that cells can adhere to, allowing us to control the shape of the cells and study how this affects cell division.”

According to Herbert, “Our findings suggest that the parent cell’s shape before division can influence whether it becomes spherical and whether the resulting daughter cells are symmetrical or asymmetrical in both size and function.”

This discovery could potentially allow scientists to generate cells with specific functions by controlling the shape of their parent cells. Moreover, it highlights the importance of asymmetric divisions in the development of tissues and organs. The study also has significant implications for diseases like cancer, where asymmetric division could contribute to the progression of the disease by leading to diverse cell behaviors.

In conclusion, the findings of this study may soon render current biology textbooks outdated, leaving students, parents, and educators facing the prospect of purchasing updated editions.