T.C. Kaufman.

The Df(3R)Cbx^TwtLUbx^KM5R chromosome may act as a dominant suppressor of telomeric silencing (assayed using the effect of the chromosome on the eye colour phenotype of flies carrying "P{w^var}KR3-2", a stable "brown-red" variant of the P{3'WP-2,w^var}2Lt insertion), but the eye colour phenotype in the presence of Df(3R)Cbx^TwtLUbx^KM5R overlaps the eye colour phenotype in a wild-type background so it cannot be unequivocally demonstrated that the deficiency chromosome uncovers a suppressor of telomeric silencing. In addition, any suppression is a false positive result (the suppressor is not within the bounds of the deficient region) because the region of the deficiency is covered by one or more nonsuppressing deficiencies.