Figure 1.

miR-124a and dFMR1 are present in the same RNP complex in the Drosophila nervous system. A, In situ analysis shows prominent miR-124a expression in the brain and ventral nerve cord in a stage 13 Drosophila embryo. B, miR-124a-Gal4 drives GFP expression specifically in the embryonic nervous system, and the expression persists to adulthood. The axon bundles from motor neurons are visible in this image. C, Immunoprecipitation (IP) experiments demonstrate that miR-124a and dFMR1 are present in the same RNP complex independent of polyribosomes. dFMR1-containing RNP complexes were pulled down with HA antibody, and miR-124a in the immunoisolates was detected with a ³²P-labeled ribonucleotide probe. A portion of total RNA from control larvae before IP was loaded as a positive control. D, Western blot analysis of immunoisolates with HA antibody. HA-tagged dFMR1 was readily detectable in lysates isolated from larval brains or in immunoisolates after IP. The absence of tubulin in immunoisolates indicates the specificity of the IP experiment with HA antibody. In C and D, control larvae express elav-Gal4 alone, and other larvae express dFMR1 under the control of elav-Gal4.