Plays a key role in meiotic progression. Regulates 3 different functions during meiosis: ensures that sufficient numbers of processed DNA double-strand breaks (DSBs) are available for successful homology search by increasing the steady-state numbers of single-stranded DSB ends. Promotes synaptonemal-complex formation independently of its role in homology search. Plays a key role in the male mid-pachytene checkpoint and the female meiotic prophase checkpoint: required for efficient build-up of ATR activity on unsynapsed chromosome regions, a process believed to form the basis of meiotic silencing of unsynapsed chromatin (MSUC) and meiotic prophase quality control in both sexes. Interacts with HORMAD2. Interacts with IHO1. Preferentially localizes to unsynapsed or desynapsed chromosomal regions during the prophase I stage of meiosis. TRIP13 is required for depletion from synapsed chromosomes. The expression of the phosphorylated form at Ser-377 is restricted to unsynapsed chromosomal regions (By similarity). Testis-specific. Over-expressed in carcinomas. Phosphorylated at Ser-377 in a SPO11-dependent manner.