Y Chromosome Notes

Y Chromosome Loss and Health Risks

• Y chromosome loss in immune cells of older men is linked to higher rates of heart disease, cancer, and Alzheimer’s.
• CRISPR gene-editing was used to remove the Y chromosome from male mice immune cells, leading to heart problems.
• Men with Y chromosome loss in over 40% of immune cells had a 31% higher risk of dying from circulatory disease.
• Immune cells lacking a Y chromosome infiltrated heart muscle, releasing transforming growth factor beta.
• Treating mice with an antibody blocking this growth factor reduced harmful effects.

Evolution and Importance of the Y Chromosome

• The Y chromosome has been shrinking for 180 million years, losing genes.
• The modern Y chromosome is a highly evolved part of men’s genetic makeup, responsible for more than just maleness.
• The Y chromosome decay seems to have halted, with no gene loss in the oldest part of the human Y in the past 44 million years.
• Regulatory genes are retained on the Y chromosome because their protein production needs to be precisely calibrated.
• Men who lose the Y chromosome in their bone marrow have a higher risk of cancer and shorter lifespans.