Figure 8.

A model for 9-1-1 complex in meiotic recombination. Black and red lines indicate dsDNA molecules of two nonsister chromatids. Only key steps and proteins mentioned in this article are labeled. Meiotic recombination starts with the formation of DSBs mediated by SPO11. These DSBs are processed by proteins including COM1 to yield the 3′ single-stranded tails, which can suppress DSB repair by C-NHEJ. Under the catalyzation of RAD51C and DMC1, the 3′ tails invade the homolog. Then ZMMs (such as HEI10 and MER3) promote the generation of COs. We propose that the 9-1-1 complex may reinforce meiotic recombination in two processes: (1) stimulating DNA resection and thereby inhibiting C-NHEJ; and (2) assisting end invasion to restrain ectopic recombination or Alt-EJ.