Polytene chromosomes normal.
One copy of Psc1.d19 is unable to suppress position effect variegation (PEV) at the w locus caused by In(1)wm4.
One copy of Psc1.d19 weakly suppresses the telomeric position effect (TPE) in stocks carrying a variegating P{hsp26-pt-T}39C-5 insertion at the telomere of the left arm of chromosome two.
Can show a dominant suppression on telomeric Position Effect Variegation (PEV) in stocks carrying a variegating w+mW.hs allele at the telomeres of the second and third chromosomes. Has no effect on pericentric and fourth chromosome insertions.