Anti-SPO11 initiator of meiotic double stranded breaks antibodies are used for the immunodetection of the protein encoded by the SPO11 gene. In humans, the canonical protein has a reported length of 396 amino acid residues and a mass of 44.5 kDa. Its subcellular localization is in the nucleus. Alternative splicing is reported to yield 2 different isoforms for this protein. It is reported to be highly expressed in the testis. A member of the TOP6A protein family, it is a known component of the topoisomerase 6 complex specifically required for meiotic recombination. Other names for this target antigen include SPATA43, TOPOVIA, TOPVIA, meiotic recombination protein SPO11, SPO11 meiotic protein covalently bound to DSB homolog, and CT35. Gene orthologs have been identified in the mouse, rat, bovine, frog, zebrafish, chimpanzee and chicken species.