23D2;23E3
23D;23F
23D2;23E3
bk1 << toc << bk2
Heterozygosity for Df(2L)S2590 results in 0.6% X chromosome nondisjunction and 0.5% fourth chromosome nondisjunction in In(1)FM7/X ; svspa-pol females.
The Df(2L)S2590 chromosome acts as a dominant weak suppressor of telomeric silencing (assayed using the effect of the chromosome on the eye colour phenotype of flies carrying "P{wvar}KR3-2", a stable "brown-red" variant of the P{3'WP-2,wvar}2Lt insertion), but this is a false positive result (the suppressor is not within the bounds of the deficient region) because the suppressor maps to the tip of 2L rather than to the site of the deficiency. In addition, the 2L TAS array on the chromosome is missing (as assayed by in situ hybridization) and it has previously been shown (FBrf0137248, FBrf0158986) that partial or complete deficiency of the 2L TAS array on the homologue suppresses silencing of brown-red variants of P{3'WP-2,wvar}2Lt.
"23D2;23E3" was stated as revision.
Although the distal break falls in toc, the Mad gene is also missing, presumably because of a second, as yet undefined deficiency.
All limits from polytene analysis (FBrf0106082)