ATZ ‐1 promotes DNA replication efficiency to maintain normal meiotic function

Precise coordination of DNA replication and meiotic progression is essential for germline genome stability, yet a complete understanding of this interplay remains unknown. In this study, we show that the absence of Abnormal Transition Zone 1 (atz-1) in Caenorhabditis elegans results in abnormal germline architecture and oocyte development. Specifically, atz-1 mutants display depleted S-phase DNA replication and acute sensitivity to depletion of the checkpoint kinase 1 (chk-1), but not chk-2. These findings suggest that ATZ-1 promotes replication efficiency during premeiotic S-phase, potentially suppressing replication stress and enabling timely meiotic progression. Collectively, this work demonstrates that ATZ-1 contributes to germline genome integrity by influencing cell cycle processes, which, if disrupted, result in numerous downstream germline defects.