The pug coding region is fused to approximately 1kb of highly repetitive DNA. Transcription and translation of both parts are required for the mutant phenotype. The repetitive DNA consists of ~140 nearly perfect repeats of AGAGAGA, a significant component of centric heterochromatin.
Eye pigment phenotype whereby pigment is more intense at the eye periphery. Variegation occurs such that more pigmented patches occur internal to the eye, revealed dramatically in a mutant background for v, where pugD is revealed to almost completely remove pteridines in the middle of the eye. The periphery of the eye remains pigmented. A small portion of the mutant flies have concave dents in the eye as if it were structurally weak. Homozygotes sometimes have rough eyes.
Affects pteridine (red) and ommochrome (brown) pigments. Pteridine is eliminated in the middle of the eye so that eyes are pigmented only at the edge. Causes a variegated reduction in ommochrome pigmentation.
Eliminates pteridines in the middle of the eye. Also causes variegated reduction in ommochrome level.
The repetitive DNA of the fusion allele may be responsible for the variegated aspect of the mutant phenotype - by association of the pug locus with centric heterochromatin.