Fig. 1. (A) The Drosophila Musashi protein. Musashi contains two RNA-recognition motifs (RRM). RNP-1 and RNP-2 are conserved amino acid sequences that are commonly contained in RRM-type RNA-binding domains. (B) The Drosophila msi mutant phenotype. The left panels show the external bristle phenotype by light microscopy; the central panels show the strucure of the adult mechanosensory organ of the indicated genotypes; the right panels show the mechanosensory bristle cell lineage of the indicated genotypes. Upper panels, wild-type. Lower panels, msi¹ mutant. Abbreviations: G, Glia; N, Neuron; Sf, shaft cell; Sh, Sheath cell; So, Socket cell; SOP, sensory organ precursor cell.