Table 6 Suppression of the brown variegated dominant phenotype by different amounts of the second chromosome heterochromatin
Female Progeny
Second Chromosome Heterochromatic Free Duplicationsy/ywf; bwv/+/Dp(2)*y+ (E)y/ywf; bwv/+ (C)
O.D.O.D.ΔO.D.a± SE%b
Dp(2) e510.188890.057780.131110.02229.2
Dp(2) e580.318690.056940.261750.01258.3
Dp(2) e970.376890.033350.343540.01276.5
Y0.488400.039120.449280.016100.0
  • The results are of crosses of ywf/ywf females carrying the different second chromosome heterochromatic free duplications, or y+Y chromosome, for males y/Y; bwv/Cy.

  • Optical density (O.D. 480 nm) levels were measured in y/ywf; bwv/+/Dp(2)y+ (E) and y/ywf; 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, 5 samples were analyzed.

  • a ΔO.D. = O.D. (E) − O.D. (C).

  • b % = O.D. Dp(2)y+/O.D. of the Y chromosome.