Involved in and required for double-strand break repair by meiotic and mitotic homologous recombination. During meiosis, has a dual role in the repair of meiotic double-stranded breaks and the efficient activation of the meiotic recombination checkpoint (By similarity). Interacts with Rad9 and spn-A/Rad51. Brca2 and spn-A become recruited to nuclear foci after DNA damage.