Researchers at the Technical University of Munich have made a groundbreaking discovery that could explain gender differences in age-related diseases. According to a statement released by the university on Tuesday, the genes on the inactive second X-chromosome in female mice are reactivated in old age. This process may also play a role in human females, who possess two X-chromosomes, with one typically being inactivated.
The study found that in older animals, up to nine percent of the genes on this chromosome are reactivated. Genes linked to diseases such as lung fibrosis and autoimmune disorders are particularly affected.
The discovery could help explain why women are more likely to develop certain diseases at an older age, such as heart and circulatory diseases and neurodegenerative disorders like dementia and Parkinson’s. Previous explanations for these differences focused on hormones and lifestyle, but the new study opens up alternative explanations, the researchers said.
It has long been known that some genes can escape the inactivation of the Barr body, leading to higher gene activity in women, which is suspected of influencing the development of diseases. “We have now for the first time shown that with increasing age, an ever greater number of genes escape the inactivation of the Barr body” said Daniel Andergassen, group leader at the Institute of Pharmacology and Toxicology at the TUM. The study was published in the scientific journal “Nature Aging”.