Mechanism and regulation of chromosome replication

Every year, thousands of human eggs and sperm end up with the wrong number of chromosomes, a mistake that can cause miscarriage, Down’s Syndrome, or infertility. This problem is strikingly common—more so in eggs than sperm, and far more frequent in eggs from older mothers. Yet the underlying biology is nearly impossible to study directly in humans. This project will create new genetically modified mice to watch how chromosomes behave inside developing eggs and sperm. By tracking these movements, the researchers aim to uncover why errors become more frequent with age, and why certain genetic mutations can derail the process so severely that people become infertile. This is fundamental science. It will not produce a test or treatment tomorrow. But understanding the precise molecular mechanics of chromosome segregation is a necessary first step. If the work succeeds, it could eventually point toward ways to improve chromosome behaviour in human eggs and sperm—potentially reducing the number of inherited genetic diseases passed to children. Past discoveries in this area have already transformed prenatal screening; deeper knowledge could lead to interventions that prevent errors before conception.