Figure 5 .

Summary of RNAi phenotypes in the legs. (A) Functional domains of genes in the leg of D. melanogaster. For each gene, colored bars represent the region on the corresponding adult leg in which the gene is expressed and/or functions, focusing on the late third instar larval imaginal leg disc. Dll, EGF, and dpp are also required in the embryo for initiation of imaginal leg disc primordia. odd-related genes are expressed more broadly in the tarsus earlier in development, and are required for proper formation of tarsomere joints. In D. melanogaster, ab has been observed in the leg discs, but its expression pattern has not been described in detail (Hu et al. 1995). ^*Lim1 expression has also been detected in multiple domains in the proximal imaginal leg disc, including the femur (Tsuji et al. 2000). (B) Patterning of the pro- and mesothoracic legs of T. castaneum. Intensity of expression indicates phenotypic penetrance of RNAi effects. The tibial spur is represented by the column at right. (B′) The metathoracic leg has only four tarsomeres, and its patterning of the intermediate tarsomeres (t2-t3) differs from the more anterior legs.