Plays a central role during spermatogenesis by repressing transposable elements and preventing their mobilization, which is essential for the germline integrity. Acts via the piRNA metabolic process, which mediates the repression of transposable elements during meiosis by forming complexes composed of piRNAs and Piwi proteins and governs the methylation and subsequent repression of transposons. Its association with piP-bodies suggests a participation in the secondary piRNAs metabolic process. Required for the localization of germ-cell factors to the meiotic nuage. Interacts with SMARCB1, SIN3B and DDX4. Interacts with piRNA-associated proteins TDRD1, PIWIL1 and PIWIL2. Interacts with Tex19.1 and, probably, Tex19.2 (PubMed:28254886). Component of the meiotic nuage, also named P granule, a germ-cell-specific organelle required to repress transposon activity during meiosis. Recruited to perinuclear nuage during spermatogenesis. Specifically localizes to piP-bodies, a subset of the nuage which contains secondary piRNAs. PIWIL2 is required for its localization to piP-bodies. PubMed:16787967, reported an association with the nuclear XY body, however, PubMed:18694567 showed that it is not the case because the antibody used by PubMed:16787967 still stains the nuclear XY body in spermatocytes lacking Mael. Moreover other antibodies raized against the same epitope used in PubMed:16787967 do not recognize any epitopes on XY chromosomes but show a clear localization to the meiotic nuage. Testis-specific. Present in spermatocytes and round and early elongating spermatids. Present from 12.5 dpc, although at this stage, protein levels are low. In the male, from 12.5 until 14.5 cpc, it localizes to the cytoplasm of germ cells, but from 15.5-16.5 dpc, it localizes to the nucleus as well. In the female, it is cytoplasmic in germ cells throughout embryonic gonad development (at protein level). In testis, low levels are observed in the early stages of meiotic prophase I (leptonema to midpachynema). Starts to accumulate throughout the cytoplasm and in prominent perinuclear nuage in late pachytene and diplotene spermatocytes. Meiotic metaphases and secondary spermatocytes show a high level in the cytoplasm as well as in nuage. Present in the chromatoid body and in a second smaller nuage in round spermatids (at protein level). Mice are viable but show profound defect in synapsis of homologous chromosomes in male meiosis, piRNA production defects, DNA demethylation of LINE-1 (L1) transposable elements and a 100-fold increase in L1 expression in the adult testis. In the adult testes, L1 transposon derepression occurs at the onset of meiosis. As a result, spermatocytes are flooded with L1 ribonucleoproteins (RNPs) that accumulates in large cytoplasmic enclaves and nuclei. Spermatocytes with nuclear L1 RNPs exhibit massive DNA damage and severe chromosome asynapsis. In gonocytes, PIWIL4, TDRD9, and DDX4 are lost from piP-bodies, whereas no effects on pi-body composition are observed. Belongs to the maelstrom family.