演題：Single molecule sequencing of DSB repair synthesis reveals hidden properties of homologous recombination

演者：Dr. Valérie Borde
        (Institut Curie, Centre de Recherche, CNR, Paris, France
         CNRS Research Director)
 
抄録：
DNA double-strand breaks (DSB) threaten genome integrity and must be faithfully repaired. During meiosis, homologous recombination (HR) repairs programmed DSBs to promote homolog pairing and crossovers. We combine long-read sequencing with BrdU detection to directly map HR-associated DNA synthesis on single yeast DNA molecules at near-nucleotide resolution. We reveal striking asymmetry between the two DSB ends, consistent with distinct repair modes: strand-displacement and fill-in synthesis. Polymorphism analysis uncovers frequent sister-chromatid repair and extensive template switching within individual synthesis tracts. Remarkably, virtually all crossover events involve extensive branch migration, retaining both synthesis tracts on the repaired chromatid. These findings provide new mechanistic insights into meiotic recombination and the generation of genetic diversity. We extend this single-molecule approach to human cells to investigate canonical and alternative DSB repair pathways. 
 
日　時：２０２６年 １１月 １９日（木） １５：３０〜１６：３０
場　所：吉田記念講堂