Legs and antennae are considered to be homologous appendages. The fundamental patterning mechanisms that organize spatial pattern are conserved,yet appendages with very different morphology develop. A genetic hierarchy for specification of antennal identity has been partly elucidated. We report identification of a novel family of genes with roles in antennal development. The distal antenna (dan) and distal antenna-related(danr) genes encode novel nuclear proteins that are expressed in the presumptive distal antenna, but not in the leg imaginal disc. Ectopic expression of dan or danr causes partial transformation of distal leg structure toward antennal identity. Mutants that removedan and danr activity cause partial transformation of antenna toward leg identity. Therefore we suggest that dan anddanr contribute to differentiation of antenna-specific characteristics. Antenna-specific expression of dan and danrdepends on a regulatory hierarchy involving homothorax andDistal-less, as well as cut and spineless. We propose that dan and danr are effector genes that act downstream of these genes to control differentiation of distal antennal structures.