Expression of Spn28D^NIG.cUa under the control of Scer\GAL4^Act5C occasionally results in small black or brown spots on the cuticle of larvae. These animals die at the pupal stage when raised at 25[o] or 29[o]C.

If young pupae expressing Spn28D^NIG.cUa under the control of Scer\GAL4^Act5C are moved to 23[o]C (to preclude pupal lethality), approximately 10% of adult escapers are obtained, that can then be studied at 29[o]C. These animals show almost no melanised spots at the time of eclosion, but develop melanised spots several hours after eclosion. In addition to dispersed melanotic spots and extensive blackening of cuticle areas, specific body parts are also found to be melanised in 50-70% of the mutant flies. This blackening is not located in the body cavity, but rather in proximity to the cuticle and especially in areas potentially in contact with air, with melanisation often extending from the spiracles to the surrounding cuticle. Melanisation is also seen on the foramen of the halteres. The ptilinal suture and surrounding area between the eyes is melanised to a variable extent in 80% of the flies and the ptilinum itself is blackened in young flies. 50% of the flies show an underpigmented abdomen, which in most apparent in males.

Adults expressing Spn28D^NIG.cUa under the control of Scer\GAL4^da.G32 show melanisation of the spiracles. These flies do not show pigmentation defects.

Flies expressing Spn28D^NIG.cUa under the control of Scer\GAL4^Act5C show a strongly reduced melanisation reaction at a wound site 16 hours after septic injury compared to control flies.