ZEP1 orchestrates template choice and crossover pathways to ensure meiotic genome integrity in rice.

Loss of rice ZEP1 protein causes asynapsis, multivalent formation, and chromosome fragmentation, disrupting meiotic genome integrity in rice.

• Why it matters: Maintaining proper crossover regulation is essential for accurate chromosome segregation during meiosis, but how the synaptonemal complex coordinates homologous recombination remains unclear, risking genome instability.
• What they did: Researchers examined ZEP1, a transverse filament protein, using null mutants, interaction assays, and genetic analyses to assess its role in recombination and synapsis, focusing on HEI10-marked crossovers and associated factors.
• The result: ZEP1 deficiency leads to persistent DMC1/RAD51 signals and chromosome abnormalities, with impaired recombination homeostasis, suggesting ZEP1's role in coordinating anti-crossover factors and recombination intermediate processing to ensure genome stability.