Biologists answer fundamental question about cell size
MIT biologists have discovered the answer to a fundamental biological question: Why are cells of a given type all the same size? In humans, cell size can vary more than 100-fold, ranging from tiny red blood cells to large neurons. However, within each cell type, there is very little deviation from a standard size. In studies of yeast, MIT researchers grew cells to 10 times their normal size and found that their DNA could not keep up with the demands of producing enough protein to maintain normal cell functions. Furthermore, the researchers found that this protein shortage leads the cells into a nondividing state known as senescence, suggesting a possible explanation for how cells become senescent as they age. “There are so many hypotheses out there that try to explain why senescence happens, and I think this data provides a beautiful and simple explanation for senescence,” says Angelika Amon, the Kathleen and Curtis...