Required for normal meiosis in male and female gametophytes. Acts with ASY1 at the interface between the developing chromosome axes and the recombination machinery to ensure interhomolog recombination. Required for synaptonemal complex formation during meiosis. Interacts with ASY1. During interphase-early leptotene, distributed as numerous punctuate foci throughout the chromatin. At zygotene and pachytene, shows a continuous localization along chromosomal axes.