Fun30-Myc ChIP-seq in Spo11 wild type and spo11-yf mutants

Resection, nucleolytic processing of DSB ends is necessary to generate 3' single-stranded DNA tails (ssDNA) for homologous recombination (HR). Meiotic recombination initiated by Spo11 induced double-strand breaks (DSBs) is essential for the accurate segregation of homologous chromosomes. After cleavage, Spo11 stays covalently linked to the DSB ends, which requires MRX/Sae2 incision on broken molecules to allow following Exo1-mediated resection. Exonuclease I activity is inhibited by nucleosome bound DNA in vitro. To ensure resection proceeds, resection machineries must overcome chromatin barrier. Here we show that DSB dependent enrichment of Fun30 proteins at hotspots and meiotic axes.双链断裂（double-strand break, DSB）末端的核酸酶解加工即末端切除（resection），是生成3'单链DNA（single-stranded DNA, ssDNA）尾巴以介导同源重组（homologous recombination, HR）的必要过程。由Spo11诱导产生的双链断裂所起始的减数分裂重组，对于同源染色体的精准分离至关重要。切割完成后，Spo11会与DSB末端共价结合，这一过程需要断裂分子上的MRX/Sae2切口活性参与，以允许后续外切酶1（exonuclease I, Exo1）介导的末端切除过程。体外实验表明，结合于核小体的DNA会抑制外切酶I的活性。为确保末端切除顺利进行，切除相关的分子机器必须克服染色质屏障。本研究证实，Fun30蛋白会依赖双链断裂在重组热点区域与减数分裂轴部位发生富集。