Figure 1. Wild type and mutant leg and antenna phenotypes.

Micrographs show the normal morphology of the tarsal structures of the wild type Canton S, ss^a40ahm and milkah-1 flies. Antennal structures of the milkah-1 mutant flies do not show any difference from the wild type. The distal segment of the antenna – the arista - of the ss^a40ahm flies presents a certain thickening of the proximal end. The arista of the ss^a40ahmmilkah-1 hybrid flies suffered homeotic transformation into an unsegmented tarsus. The tarsal structures of the ss^a40ahmmilkah-1 hybrids show altered segment fusion.