Table 3 Suppression of the brown variegated dominant phenotype by different amounts of the X chromosome heterochromatin
Female Progeny
X Chromosome Heterochromatic Free Duplicationsy/ywf; bwv/+/Dp(2)*y+ (E)y/ywf; bwv/+ (C)
X duplicationO.D.O.D.ΔO.D.a± SE%b
Dp(1) 11870.083150.068600.014550.0063.2
Dp(1) 12050.100800.075400.025400.0065.7
Dp(1) 13460.137290.087500.049790.00811.1
Dp(1) 11730.163600.050900.112700.00925.1
Dp(1) A1400.286900.045300.241600.01054.0
  • The results are of crosses of ywf/ywf females carrying the different X heterochromatic free duplications, or a y+Y chromosome, for males y/Y; bwv/Cy.

  • Optical density (O.D. 480 nm) levels were measured in ywf/y/Dp(1)*y+; bwv/+ (E) and ywf/y; bwv/+ (C) female offspring.

  • The pigment assay was based on samples of 10 heads collected 3 d after eclosion of the flies. For each duplication, 10 samples were analyzed.

  • a ΔO.D. = O.D. (E) - O.D. (C).

  • b Percent of suppression = O.D. Dp(1)y+/O.D. of the Y chromosome.