Lyon Hypothesis

The Lyon Hypothesis explains how females, who have two X chromosomes, balance gene activity with males, who have one. Early in development, one of the female's X chromosomes is randomly inactivated in each cell, forming a condensed structure called a Barr body. This inactivation occurs differently in different cells, resulting in a mosaic pattern of gene expression across the body. This process ensures that females don't have a double dose of X-linked genes and plays a role in traits and conditions linked to these genes, helping maintain genetic balance between sexes.