The neurites of developing T4/T5 neurons lose their normal radial arrangement around the cell body cluster in atow.attR third instar larvae, showing over-fasciculation (100% penetrance), and guidance (100%) and growth (46%) defects. The dendrites of T4/T5 neurons show fasciculation and growth defects in atow.attR adults. The medulla and lobula complexes are reduced in size in the mutant adults.
The normal preference of third instar larvae for 17.5[o]C over 14[o]C in a two-way choice test is eliminated in mutant larvae.