Constitutes an element of the transverse filaments of the synaptonemal complex (SC), formed between homologous chromosomes during meiotic prophase I, and is required for the assembly of the central region of the SC (PubMed:19798442, PubMed:21840865). Required for chromosome synapsis and chiasma formation between homologous chromosomes during meiosis, mechanisms that are crucial for crossover formation and meiotic recombination (PubMed:19798442). Localizes to chromosomes during meiotic prophase I (PubMed:19798442). During leptotene and zygotene, localizes in foci on chromosomes (PubMed:19798442). Localizes to the central region of the synaptonemal complex at the interface between synapsed chromosomes throughout pachytene (PubMed:19798442, PubMed:28346135, PubMed:21840865). During diplotene, becomes concentrated towards one end of each chromosome (PubMed:19798442). Localizes to the short axes of the bivalents during diakinesis and disappears from chromosomes by the end of diakinesis (PubMed:19798442). Phosphorylated at Ser-269 by plk-1 and plk-2. Phosphorylation starts at the pachytene stage during oogenesis and depends on crossover precursor formation. Phosphorylation negatively regulates meiotic DNA double-strand break (DSB) formation. High levels of embryonic lethality and a high percentage of males among the surviving progeny (PubMed:19798442). Failure to localize syp-1 and syp-3, components of the synaptonemal complex central region, to chromosomes (PubMed:19798442). Failure to form chromosome synapses and lack of synaptonemal complex formation leading to a delay in meiotic progression (PubMed:19798442). Impaired stabilization of homologous pairing interactions (PubMed:19798442). Lack of chiasmata formation during diakinesis (PubMed:19798442). Reduced crossover frequency (PubMed:19798442). Increased rad-51 foci during pachytene indicating impaired DNA double-strand break (DSB) repair progression (PubMed:19798442). Elevated germ cell apoptosis (PubMed:19798442). Disruption of plk-2 localization to synapsed chromosomes during pachytene (PubMed:28346135).