Component of a topoisomerase 6 complex specifically required for meiotic recombination. Together with SPO11, mediates DNA cleavage that forms the double-strand breaks (DSB) that initiate meiotic recombination. The complex promotes relaxation of negative and positive supercoiled DNA and DNA decatenation through cleavage and ligation cycles. Heterotetramer of SPO11 and 2 TOP6BL chains (Probable). Interacts with SPO11 (PubMed:26917764). Localizes to meiotic chromosomes. In males, expressed in testis but not in other tissues. Expressed in testis from 8 days postpartum (dpp) onward, with a peak of expression around 12 to 14 dpp, at the beginning of meiotic prophase. In females, expressed in embryonic ovaries when oocytes proceed through meiotic prophase (PubMed:26917764). Despite a weak sequence similarity, retains most of the structural features of the ancestral archaeal Top6B subunit (AC O05207), including the transducer domain that interacts with the SPO11 subunit and the ATP-binding fold, also named GHKL fold. Male mice develop normally and reach adulthood but have smaller testes. Spermatogonia are present at the periphery of tubules but are strongly depleted and spermatids are absent, due to defects during meiotic prophase. Belongs to the TOP6B-like family.