gain of function allele
Insertion of a P{UAS-lacZ.B} element 21bp upstream of the transcriptional start site of the melt gene.
photoreceptor cell R8 of pale ommatidium | increased number
photoreceptor cell R8 of yellow ommatidium
In meltBg4-2-4b eyes, about 90% of R8 photoreceptor cells adopt a p fate, while only 30% adopt this fate in wild-type eyes.