Required for chromosome synapsis and regulates crossover frequency during meiosis. Acts as transverse filament protein and constitutes the central element of the synaptonemal complex. Interacts with CRC1. During zygotene in meiocytes, initially localizes onto the chromosomes as punctate foci and quickly extends into linear signals (PubMed:20154151, PubMed:22393242). Associates with chromosomal axes at zygotene (PubMed:27436711). Highly expressed in panicles. Decreased pollen fertility due to abnormal synaptic behaviors and increased crossover formation during prophase I.