ISTOCK, JEZPERKLAUZENTwo studies in Science today (December 7)—one that focuses on prenatal development in humans, the other on infancy to old age—provide insights into the extent of DNA sequence errors that the average human brain cell accumulates over a lifetime. Together, they reveal that mutations become more common as fetuses develop, and over a lifetime a person may rack up more than 2,000 mutations per cell.
“I think these are both very powerful technical papers, and they demonstrate how single-cell sequencing . . . can reliably detect somatic changes in the genomes of human neurons,” says neuroscientist Fred Gage of the Salk Institute in La Jolla who was not involved in either study.
“What’s cool about [the papers] is that they show two different ways that one can look at somatic mutations in single human neurons . . . and yet they get consistent results,” says neuroscientist Michael McConnell of the University of Virginia School of Medicine.
Cells of the human body acquire mutations over time, whether because of errors introduced during DNA replication or damage incurred during transcription and other cellular processes. But, until recent technological developments enabled whole genome ...
