In many animal species, germ cell fate determination depends on the maternal inheritance of the germ plasm, a specialized cytoplasm composed of ribonucleoparticles (RNPs) and enriched in cytoskeletal elements. Germ plasm RNPs are typically inherited as particles within the egg, which during early embryogenesis become aggregated into large masses. These become segregated into primordial germ cells (PGCs), where they are thought to promote the initiation of the germ cell transcriptional program. In zebrafish, as in a number of other vertebrate species, gathering and segregation of germ plasm RNPs is coupled to cell division. We have previously delineated specific steps during cell division that result in germ plasm RNP recruitment to the furrows for the first several cycles, with subsequent compaction at the furrow distal ends. These steps entail a gradual increase in GP RNP aggregation and result in the stabilization of four large germ plasm masses. These masses are inherited by PGCs, to eventually disperse through the cytoplasm during PGC specification. Our overarching hypothesis is that germ plasm RNP gathering, segregation and activity are mediated by adaptations of the cellular machinery, relying on RNP fluid phase properties.