Lyonization

Lyonization, also known as X-chromosome inactivation, is a process in female mammals where one of the two X chromosomes in each cell is randomly turned off early in development. This ensures that females, like males, have a single active X chromosome, maintaining balanced levels of X-linked gene products. The inactivation is stable and passed on to daughter cells. It explains why some traits linked to the X chromosome may appear differently in females, depending on which X chromosome is inactive. Overall, lyonization is a natural mechanism to regulate gene expression and prevent dosage imbalance.