Visual impairment in ninaB mutants does not affect social suppression of aggressiveness. (A) Schematic drawing of phototaxis assay (see Materials and methods). (B) Vision index of flies was quantified (see Materials and methods). Canton-S (CS) wild-type flies prefer to stay in light zone. Whereas ninaB1 mutant flies distributed randomly in light and dark zones, indicating impairment in vision. Rescued flies in which a UAS-ninaB transgene was expressed in photoreceptors in ninaB1 mutant flies under control of the eye-specific GMR-GAL4 driver, showed light preference similar to that of wild-type flies. **p < 0.01, *p < 0.05. Number of experiments performed: CS, n = 11; ninaB1 Rescue, n = 10; ninaB1, n = 11. (C) Social suppression of aggressiveness of wild-type and ninaB1 mutant flies. The level of aggressiveness (i.e. total aggression) was quantified by counting the number of all aggressive events (i.e. lunges, wing threats, tussles, boxing, and holding) within 10-min period. Pairs of flies tested: CS, n = 27 (single housing), n = 21 (group housing); ninaB1 mutants, n = 22 (single housing), n = 20 (group housing). ***p < 0.0001. Error bars represent SEM.