Tudor domain-containing protein involved in germ cell development, more specifically the formation of chromatoid body (during spermiogenesis), Balbiani body (during oogenesis), germ plasm (upon fertilization), and for proper miRNA expression and spliceosome maturation (By similarity) (PubMed:30086300). Required for Balbiani body and germ plasm formation and mobility through interaction with dimethylated arginines in the prion-like protein Bucky ball (buc) (PubMed:30086300). Coordinates transcript deposition into future primordial germ cells (PubMed:30086300). Interacts with known germ plasm mRNAs such as vasa, dazl, nanos3 and hook2 (PubMed:30086300). Interacts (via Tudor domain) with buc (when dimethylated on arginine residues); and may be responsible for recruitment of different protein complexes to germ plasm. Presents in chromatoid body (CB) of spermatids, also named processing bodies (P-bodies) in somatic cells. Detected in the multilobular cytoplasmic CBs (also called intermitochondrial cementin) in pachytene spermatocytes and as a single perinuclear CB in haploid round spermatids (By similarity). Localizes to nuage, the Balbiani body during oogenesis, and in the grem plasm upon fertilization (PubMed:30086300). Expressed in the ovary, where it localizes to nuage and to the Balbiani body (PubMed:30086300). Maternally provided and localized to the germ plasm in 4-cell stage embryos (PubMed:30086300). 24 hours post-fertilization, restricted to primordial germ cells, where it localizes to nuage (a peri-nuclear protein-RNA aggregate that associates closely with mitochondria) (PubMed:30086300). The tudor domains recognize and bind to proteins with dimethylated arginine or lysine residues (Probable). Plays an important role in the protein functions through its direct binding to the target proteins (Probable). Knockout oocytes exhibit significant defects in germ cell development, leading to reduction in primordial germ cell number in the offspring, irrespective of the genotype of the father (PubMed:30086300). Barely affects piRNA populations (PubMed:30086300).