Polytene chromosomes normal.
pb27 Scr2 hth5E04 clones in the labium result in transformation of the labium to a compact leg appendage identified by claws and bracted bristles in 81% of cases, while in the remaining 19% of cases the transformed structure contains a mix of leg and antennal tissue.
Clones triple mutant for pb27, Scr2 and exd1 generated 30-60 hours after egg laying show transformations of arista to tarsus, antenna to second leg and rostrum to ectopic eye, with associated leg. Both pb27 and pb27, Scr2 clones of ectodermal proboscis cells adopt aristal identity. However, both pb27, exd1 and pb27, Scr2, exd1 clones of ectodermal proboscis cells adopt tarsal (second leg) identity. Clones of pb27 cells in the proboscis form sex combs. Clones of pb27, exd1 cells in the proboscis are transformed to tarsal identity and in addition they form sex combs. When the clones are of the genotype pb27, Scr2, exd1, no sex combs form.