Responses of the variegating transgenes on the fourth chromosome to different genetic modifiers. (A) Homozygous females from V lines were crossed to males carrying modifiers of PEV as indicated. Female progeny carrying both the transgene and the modifier mutation were photographed. (B) Eye pigmentation levels for these flies (values 10 × OD480). The number under each bar indicates that the transgene is present with y w67c23 (control) (bar 1), Su(var)2-101 (bar 2), Su(var)2-502 (bar 3), Su(var)3-7 (bar 4), E(var)3-93E (bar 5), or E(var)3-93D (bar 6).