Acts as a translational repressor. Can mediate repression affecting different steps in the translation process: cap-driven, IRES-driven, polyadenylated RNAs or nonpolyadenylated RNAs. Essential for the development of primordial germ cells (PGCs) by ensuring their proper migration and survival. Interacts with ccnb1. During early cleavage and blastula stages found close to the cell periphery in a germ plasm-like pattern. From gastrula stage on, detected predominantly in a perinuclear region. Ovary and testis. Very abundant in the oocyte and early embryo and reduced to very low levels by gastrulation. 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.