Fig. 6. Ectopic DISCO alters the trunk segments. In an early stage 13 wild-type embryo (A) note the regular appearance of salm mRNA in the dorsal tracheal cells (vertical arrows) and the oenocytes (angled arrowheads). (B) In a similarly staged prddisco embryo dorsal tracheal cells and oenocytes are missing in the segments ectopically expressing disco. (C,D) The trunk sensory neurons are remodeled by ectopic disco expression. Embryo `fillets' are shown where the gut has been removed and the embryos have been flattened so the neurons are in the same approximate focal plane. Anterior is upwards and dorsal is towards the right in both images. (C) Wild-type sensory neurons of the first abdominal segment. A similar pattern is found in all abdominal segments. Several characteristic neurons and sensory structures are labeled. isn, intersegmental neuron; sn, segmental neuron; vg, ventral sensory organ group; vch, ventral chordotonal organ; lch, lateral chordotonal organ; dg, dorsal sensory group; dg-t3, dorsal group from t3. In prddisco embryos (D), both unaffected (a2, bottom) and affected (a1, top) segments are shown. Note the absence of chordotonal organs in a1, and that the neurons do not extend as far dorsally. The position of the sensory cells in affected segments does not match those in the unaffected or normal trunk segments.