The splice and cryptic splice sites in the sphinx intron-exon boundaries are mutated.
sphinx729RW mutants do not exhibit any morphological differences to wild-type.
Both wild-type and sphinx729RW mutant flies show the full range of normal mating behaviour, including orienting, tapping, wing extension/vibration, licking, attempting, and copulation. The mutant and wild-type males do not differ significantly in their courtship scores when mating with wild-type females.
Homozygous sphinx729RW mutant males pursue each other for a significantly longer time compared with wild-type males. Heterozygotes show some level of male-male courtship behaviors, but much weaker than homozygote mutants, suggesting partial heterozygote insufficiency. Mutant males go through all stages of normal male-female courtship except the final stage, that of copulation, but with other males. Similar male-male courtship is observed when two homozygous mutant males and one female are placed together. Furthermore, when many males are present, mutant males form courtship chains and circles, a typical male-male courtship behavior that is not seen in wild-type flies.
Courtship behavior does not appear to be affected in sphinx729RW mutant females.
