P29P29/+ ; Df(4)G/+ and P29P29/Y ; Df(4)G/+ flies show extensive bristle loss on the abdomen, a phenotype not seen in either P29P29/+ or Df(4)G/+ flies. P29P29 shows loss of bristles on the adult abdomen in double heterozygous combination with sv5, sv6, sv7 or sv8.