Behavior of photoreceptor mutants at LI and HI. A, Average activity profiles of flies exposed to LI (black line) and HI (red line) ± SEM using the Würzburg system. Flies deficient of either compound eyes (clieya) or compound eyes and ocelli (clieya no ocelli) and flies lacking norpA (norpAP24) still react to HI, whereas the loss of rhodopsin 6 in clieya background renders the flies insensitive to light-intensity changes. B,
clieya, clieya no ocelli and norpAP24 flies show a PI significantly <1 (clieya, clieya no ocelli: p < 0.0001, norpAP24: p = 0.0014), whereas the PI of clieya;rh61 is indistinguishable from 1 (p = 0.4613). **p < 0.001.