Axn^h mutant clones in the eye disc show considerable overgrowth and do not differentiate as ommatidia. In the adult, the clones in the eye induce differentiation of frons cuticle corresponding to the dorsal head and also induced naked cuticle and tube-like overgrowths with macrochaetae. Mutant cells in mosaic eye-antennal discs show a significant increase in the proportion of cells in S and G2 at the expense of cells in G1 when compared to wild type. Excess BrdU incorporation is seen posterior to the furrow in mutant clones in the eye disc.