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). Component of cytoplasmic mRNP particle through interaction with FRGY2, and binds to maternal mRNA related to cell cycle (RCC1, RHAMM, INCENP-A, MAD2L1, HELLS) and a germ plasm specific mRNA (Dead end/Dnd1), it is proposed a role in translational activation of the maternal mRNAs repressed in mRNP particle (PubMed:21314676). Interacts with FRGY2 (a component of messenger ribonucleoprotein (mRNP) particle)during germ cell develpoment. Localizes in the germ plasm, most precisely in the cytoplasmic mRNP particle (messenger ribonucleoprotein, which corresponds to mRNA with bound proteins). Expressed in testis. Presents exclusively in early embryonic and germline cells (PubMed:15771630, PubMed:21314676). Expressed in both spermatogenic and oogenic cells except for round spermatids and the later stage (PubMed:12112575). Expressed in early stage embryos and decrease after the gastrula stage (PubMed:12112575). The tudor domains recognize and bind to proteins with dimethylated arginine residues. Loss-of-function in embryos causes arrest of karyokinesis progression.