Phase separation determining meiotic interference-sensitive meiotic crossover formation

In sexual reproduction, meiosis creates new combinations between homologs and diversifies the genetic information among gametes and progenies. Most meiotic crossovers (COs) are mediated by a group of ZMM factors, including HUMAN ENHANCER of INVASION-10 (HEI10), which is suggested to concentrate at CO sites to form larger foci for crossover interference. However, how HEI10 is recruited to the CO site is still unclear. Here, Wang et al. showed Arabidopsis HEI10 undergoes liquid-liquid phase separation (LLPS) and its condensation depends on its residue Ser70. The HEI10 promoted the ubiquitination-dependent degradation of the interacting REPLICATION PROTEIN A (RPA1a) in the LLPS of CO sites through the early pachytene phase. This study also provides clues about how HEI10 controls class I meiotic crossover formation and can be relevant in most eukaryotes. (Summary by Yueh Cho @YuehCho1984) PNAS. 10.1073/pnas.2310542120.