The mutation impairs circadian locomotor activity.

We investigated effects of mutation ap on circadian locomotor activity, eclosion rhythms, and transcript levels of and in . We investigated circadian locomotor activity and eclosion rhythms in and wild-type flies, their F1 and F2 offspring, and wingless mutants and show that disrupts circadian locomotor rhythms in a genetically recessive manner, that is not caused by the absence of wings. The strain also showed impaired circadian activity rhythms, providing independent evidence for a significant role of in circadian locomotor rhythm expression. The mutation did not disrupt a circadian eclosion rhythm or rhythmic expression of the and clock genes, indicating that is not essential for circadian clock function, but is necessary for coupling locomotor activity to a circadian clock. transcription was reduced in flies in 12:12 LD, suggesting that may modulate core clock gene expression.