Polytene chromosomes normal.
Point mutation.
General enhancer of position effect variegation: significantly enhances the mutant variegated phenotype of In(1)wm4, In(1)y3P, C(1;YL)wmMc and T(1;4)wm5. Position effect variegation at the w locus is not seen when E(var)88DE95 is combined with In(1)wm4rv5, In(1)wm4rv6 or In(1)wm4rv26.