Project Summary: This project will examine the cellular events that occur at the end of meiosis, to better understand how these events are coordinated and regulated. Meiosis is a specialized cell division used to produce haploid cells from diploid cells. Although some aspects of meiosis are regulated as in mitotic cells, some parts of meiosis are regulated using distinct mechanisms. In the budding yeast Saccharomyces cerevisiae, meiosis occurs during sporulation, where a diploid mother cell will remodel its interior through meiosis and spore morphogenesis to create four haploid spores. As cells prepare to complete meiosis II, spindle disassembly and cytokinesis must be coordinated. In the budding yeast, meiotic cytokinesis takes place through the closure of the prospore membrane, a membrane that is synthesized during sporulation and grows to surround the newly formed 1N DNA products of meiosis. Meiosis II spindle disassembly and timely prospore membrane closure are regulated by Cdc15 (a Hippo-like kinase) acting upstream of Sps1 (a STE20-family GCKIII kinase). The regulation of exit from meiosis II is distinct from the regulation of exit from mitosis. This project will examine how cytokinesis and spindle disassembly are coordinated in meiosis II, and will also identify additional component important for regulating the exit of meiosis II. The experiments in this proposal will use yeast molecular genetics, biochemistry, and imaging studies to provide a more detailed understanding of meiosis II spindle disassembly, how this is coordinated with timely prospore membrane closure, and the molecular targets used to regulate these processes. The work in the proposal will also begin to define other components involved in regulating exit of meiosis II, and will provide a better understanding of the the signaling pathway using Cdc15 and Sps1. The knowledge gained from this project will contribute to the fundamental understanding of meiotic cell cycle regulation and how cellular processes are coordinated. These studies will also contribute to our knowledge of fungal biology, which is important because fungi are commensal organisms (as part of the fungal microbiome) and can also become pathogenic.