Deletion of 5' sequences to -91bp.
5' regulatory region deletion derivative of y, 91 nucleotides remain upstream of the transcription start site.
yD91 males have significantly reduced mating success compared to control males. The Dp(1;f)1187 minichromosome rescues the mating success of these mutants. Larval mouth-part pigmentation is reduced in yD91 mutants. In adults, pigmentation is reduced on the body and wings and partially reduced in the tarsal claws.
Larval mouth part colour: mutant Larval denticle belt colour: mutant Body colour: mutant, wing colour mutant, sex combs and bristles wild-type.
Allelic series of reduced male mating success phenotype: y59b = yD91 >= y3d > ya77 >= y2S.