Fig. 5. Morpholino antisense oligonucleotides directed against sox9a inhibit splicing and transport of sox9a transcript. (A) RNase protection assays of sox9a transcript in 28 hpf wild-type animals injected at the one-cell stage with 2 nl of different concentrations of MO, normalized against odc. (B) RNase protection assays of sox9a transcript in animals 28 hpf or 4 dpf either treated (+) or not treated (-) with 5.0 ng MO, normalized against odc. Graphs show the amount of RNA present as a percent of untreated controls. (C) Transcript for sox9a accumulates in the cytoplasm in wild type, but in the nucleus in splice-directed MO injected embryos at 28 hpf. In jef^tw37 embryos, transcript is visible both in the cytoplasm and in the nucleus. Dorsal views, anterior is upwards. Equal amounts of MO directed against the donor sites for intron 1 and 2. Scale bars: 100 µm.