HIM-17 regulates the position of recombination events and GSP-1/2 localization to establish short arm identity on bivalents in meiosis

Significance Recombination and chromosome remodeling are tightly regulated to ensure accurate chromosome segregation during meiosis. However, how these important steps are regulated remains poorly understood. Here, we show that RAD-51 foci, which form at the sites of meiotic DNA double-strand breaks (DSBs), exhibit a biased distribution toward off-centered positions alongCaenorhabditis elegans chromosomes, and we identify two meiotic roles for chromatin-associated protein HIM-17. During early prophase I, HIM-17 regulates the distribution of DSB-dependent RAD-51 foci and crossovers on chromosomes. During late prophase I, HIM-17 promotes the normal localization of protein phosphatases GSP-1/GSP-2 and potentially GSP-1 phosphorylation, thereby antagonizing Aurora B kinase/AIR-2. Therefore, HIM-17 plays distinct roles during meiotic progression that converge to promote normal chromosome remodeling and accurate chromosome segregation.