HYPOTHESIS. “Perhaps the most interesting hypothesis for why replication occurs before meiotic recombination in meiosis I is that in the pre-Spo11 era, the sister-chromatid copies served as the source of double strand breaks. Double strand breaks are formed by replication of nicked DNA, in which the nicks might have been incurred by UV or gamma rays before Spo11, and double strand breaks (but not nicks) are potent stimulators of homologous recombination.”
https://lnkd.in/ebVhXPf