The P{lArB} insertion is at bp 6185 (where 1 is at transcription start).
Polytene chromosomes from homozygous third instar larvae show loss of a significant breakage and scattering of the normally circular-shaped nucleolus, with nucleolar material being widely spread and/or attached to many distinct sites on the euchromatic chromosome arms. The euchromatic arms are smaller than in control larvae due to reduced polytenisation.
jumuD631/+ significantly suppresses the position effect variegation of the w gene seen in the T(2;3)P(GawB)94E line, resulting in a conspicuous increase in eye pigmentation.
Dominant suppressor of PEV in In(1)wm4. In homozygous adult escapers a number of phenotypes are seen. A disordered hair and bristle arrangements are seen at the scutellum and the wing margins. In most cases flies show loss or doubling of macrochaetae, however bristles appear to be at correct positions. jumuD631/jumuD631 wings are reduced in size, hairs are irregularly places, posterior wing margins are notched and L5 is sometimes shortened. In some cases wings are extended. The eyes in jumuD631/jumuD631 mutants are smaller than wild-type and have a rough eye phenotype, adjacent ommatidia are often fused and the eyes are composed of ommatidia of variable size and shape.
jumuD631 has lethal phenotype, non-suppressible by Hsap\FOXN1UAS.cHa/Scer\GAL4hs.PB
Expression of Hsap\FOXN1Scer\UAS.cHa under the control of Scer\GAL4hs.PB does not rescue the jumuD631 homozygous phenotype; most animals die as young larvae and only a few escapers reach the third larval stage.
Strong enhancer. High spontaneous background rate of E(var) mutations in these experiments allows for the possibility that the P insertion is not the cause of the E(var) phenotype.