LAUSR

Homologs of PUTATIVE RECOMBINATION INITIATION DEFECT 1 (PRD1) are essential for meiotic double-strand break (DSB) formation in mouse (Mus musculus), Arabidopsis (Arabidopsis thaliana), and rice (Oryza sativa). Latest work reveals that the rice PRD1 also plays an unanticipated role in meiotic bipolar spindle assembly, highlighting multiple functions of PRD1 in plant meiosis. In this work, we characterize the meiotic function of PRD1 in maize (Zea mays; ZmPRD1). The Zmprd1 mutant plants display normal vegetative growth but complete male and female sterility. Meiotic DSB formation is fully abolished in mutant meiocytes, leading to the failure in homologous pairing, synapsis, and recombination. ZmPRD1 exhibits distinct pattern of chromosome localization as its rice homologs, and interacted with several DSB-forming proteins, but not directly interacts with kinetochore protein REC8 and SGO1. Possibly as a result, there are no significant abnormalities of bipolar spindle assembly in Zmprd1 meiocytes. Overall, our results demonstrate that ZmPRD1 is essential for DSB formation and homologous recombination in maize meiosis. However, the newly-identified function of PRD1 in bipolar spindle assembly during rice meiosis is not conserved in term of different plant species.