Mutants have thin textured, slightly smaller, sometimes crumpled wings with the ends bent slightly upward or downward. Hemizygotes and homozygotes have fairly high viability and fertility. Flies sometimes have a m phenotype (due to position effect variegation of m).

position-effect; enhanced by In(2LR)Rev^B = In(2LR)40;52C-E; in turn enhances Rev^B (Wargent and Hartmann-Goldstein, 1974). Wings thin textured, smaller than normal, sometimes crumpled, with tips bent slightly upward or downward. Sometimes, fly has m phenotype. m^K/m female varies from m-like to nearly normal. Viability and fertility high.