svr¹ mutant flies recover more quickly from cold-induced sleep than control flies.

When tested for their response to ethanol, svr¹ mutants show a tendency for greater sensitivity than wild-type controls, although the differences are not statistically significant

svr¹ mutant males exhibit normal naive courtship behaviour when paired with virgin females. The failure of svr¹ mutants to suppress courtship with previously mated females indicates deficits in long-term memory.

Mutants have pointed wings. The proximal segments of the third and fourth longitudinal wing veins are shorter than normal, while the distal segments of these veins are longer than normal. The anterior and posterior crossveins are shorter than normal in the mutant wings. The wing edge between the second and third longitudinal wing veins is longer than normal, while the wing edge between the third and fourth veins is shorter than normal. The distal segment of longitudinal vein 5 is longer than normal.

There is no substantial effect of the lighting conditions on mating ability of svr¹ males; svr¹ males introduced to virgin females for several days result in the same number of offspring as control males introduced to virgin females whether under conditions of constant bright light, constant dark or regular ambient light.

Homozygous third instar larvae show an abnormal response to UVC radiation.

Body colour: light, with a metallic sheen. N-acetyldopamine levels are elevated 5-10 times in homozygous flies compared to wild-type. High levels of N-acetyldopamine are excreted compared to wild-type. Homozygotes usually survive to adulthood. In vitro induction of pigmentation in unpigmented svr¹ pharate adults by incubation with dopamine mimics the svr¹ phenotype in all cuticle structures.

Tyrosinase active in adult.

RK2. Body colour: legs, wings, veins and integument pale and silvery; bristles and trident pattern on thorax dark. Wings of all males and some females pointed. Viability fair. Larval mouth part colour: wild-type.