Fig. 3. Abnormal diurnal and circadian locomotor behavior in Clk^ar flies. Normalized plots of locomotor activity in LD (A and B) and first two days of constant darkness (C and D; see Materials and methods) for wild type (+; A and C; n = 16) and Clk^ar flies (B and D; n = 16). Light and dark bars correspond to times of lights-on and -off. Error bars indicate SEM.