Plays a role in the maintenance of the undifferentiated state of germ cells regulating the spermatogonia cell cycle and inducing a prolonged transit in G1 phase. Affects cell proliferation probably by repressing translation of specific mRNAs. Maintains the germ cell lineage by suppressing both Bax-dependent and -independent apoptotic pathways. Essential in the early stage embryo to protect the migrating primordial germ cells (PGCs) from apoptosis. Binds mRNA from germ cells. Interacts with PUM2 (By similarity). Co-localizes with PUM2, EIF2S1 and TIAL1 in the stress granules. Co-localizes with DCP1A in the P-body. Ovary, testis and brain (at protein level). In the ovaries, expressed during multiple stages of oogenesis, including primordial, primary, secondary and antral follicles with the highest expression in the oocytes. In the testis, expressed in germ cells, type A spermatogonia (SA), primary spermatocytes (S1), round spermatids (S3) and elongated spermatids. Fetal ovary and fetal testis (at protein level). The Nanos-type zinc finger is composed of two C2HC motifs, each motif binding one molecule of zinc. It is essential for the translation repression activity of the protein. Belongs to the nanos family.