Human sperm rewrites DNA earlier than previously thought

Researchers at the Wellcome Sanger Institute and University of Cambridge found that some genetic reshuffling in human sperm occurs before meiosis. Long-read sequencing of 15 sperm samples revealed 7,143 crossovers and 2,382 non-crossover gene conversion events.

• 15 sperm samples from 13 donors aged 24–74 were analyzed
• 7,143 crossovers and 2,382 gene conversion events found
• Some conversions formed before meiosis and resemble DNA repair
• Differences appeared even between identical twins