Loss of Y Chromosome
With nearly every cell division our bodies accumulate genetic mutations. By adulthood our bodies are mosaics of genetically distinct populations of cells. In some cases this genetic diversity leads to competition between cells which more closely resembles unicellular evolution than multicellular development. This process of somatic evolution opens many questions about our perception of identity and the notion that we are composed of one singular genome.
One of the most striking and common examples of somatic evolution is the loss of the Y chromosome in the blood of men. A recent study lead by John R.B. Perry and Lars A Forsberg looked at the blood of hundreds of thousands of individuals and found that 20% of men have blood cells that are missing the Y chromosome. By age 70, this number increases to 43.7%.
Tri-Institutional PhD Program in Computational Biology and Medicine
Weill Cornell Medical College
New York, NY
Thompson et al. Genetic predisposition to mosaic Y chromosome loss in blood. 2019. Nature. 575(7784):652 PubMed Link