flam piRNA precursors channel from the nucleus to the cytoplasm in a temporally regulated manner along Drosophila oogenesis.

Our findings show a spatio-temporal regulation of the piRNA biogenesis in the follicle cells of Drosophila ovaries, that involves coordinated control of both piRNA precursors and components of the piRNA processing machinery. This newly unveiled regulation establishes another level of complexity in the production of piRNAs and suggests a stage-dependent involvement of the piRNA biogenesis in the mechanism of transposable elements silencing along oogenesis.