SUMMARY
Cell fate generation can rely on the unequal distribution of molecules during progenitor cell division in the nervous system of vertebrates and invertebrates. Here we address asymmetric fate determinant localization in the developing Drosophila nervous system, focusing on the control of asymmetric Miranda distribution in mitotic larval neuroblasts. Two models have been put forward to explain Miranda asymmetry. One proposed that actomyosin drives basal Miranda localization. Later, it was proposed that spatially controlled aPKC dependent phosphorylation of Mira can explain its polarized localization. We reveal now that both the actomyosin network and aPKC phosphorylation of Miranda are required, but operate at distinct phases of the cell cycle. Using live imaging of neuroblast polarity reporters at endogenous levels of expression we show that displacement of Miranda by phospho-regulation by aPKC at the onset of mitosis and differential binding to the actomyosin cortex after nuclear envelope breakdown establishes asymmetric Miranda localization.