Regulating the Organelle Band Organization in Male Meiosis of Arabidopsis Yingrui Ma Meiosis is a unique cell division process for sexual reproduction in plants and animals. In the meiotic cell cycle, a single round of DNA replication is followed by two rounds of chromosome division, called meiosis I and meiosis II. After Meiosis I, the divided homologous chromosomes are separated by the newly synthesized cell wall or a cell wall like structure. In dicotyledons, instead of a real cell wall, a band structure consisting of vesicles derived from different organelles, called an organelle band, is formed after the first chromosome division. The disruption of this structure in meiosis II can result in nuclear restitution and production of unreduced gametes. The mutation that leads to the disorder of the organelle band is named jason (jas). In this study, a suppressor of jas, called pel, was obtained through forward genetic screening. PEL is a vesicle membrane located protein, and located in the cytoplasm during meiotic cell cycle. The recovered organelle band in jas pel is sensitive to exocytotic vesicle trafficking inhibitors, suggesting that exocytotic vesicle trafficking pathway is important for organelle band maintenance in jas pel. Furthermore, destabilized actin filaments are found to partially recover the jas phenotype. vesicles can be transferred through actin filament, PEL and PEL interaction proteins transfer of exocytotic vesicles through actin filaments within male meiocytes. Taken together, this research suggests a process which involved exocytotic vesicle trafficking and actin dynamic to maintain the organelle band, acting as a physical barrier to prevent nuclear restitution during male meiosis.