Timing of locomotor recovery modulated by the white gene in Drosophila

Locomotor recovery from anoxia follows the restoration of disordered ion distributions and neuronal excitability. The time taken for locomotor recovery after 30 s anoxia (around 10 min) is longer than the time for the propagation of action potentials to be restored (less than 1 min) in Drosophila wild-type. We report here that the white (w) gene modulates the timing of locomotor recovery. Wild-type flies displayed fast and consistent recovery of locomotion from anoxia, whereas mutants of w showed significantly delayed recovery. Genetic analysis including serial backcrossing revealed a strong association between the w locus and the timing of locomotor recovery, and haplo-insufficient function of w+ in promoting fast locomotor recovery. The locomotor recovery phenotype was independent of classic eye pigmentation, although both are associated with the w gene. Introducing up to four copies of mini-white (mw+) into w1118 was insufficient to promote fast and consistent locomotor recovery. However, flies carrying w+ duplicated to Y chromosome showed wild-type-like fast locomotor recovery. Furthermore, RNAi knockdown of w in neurons but not glia delayed locomotor recovery, and specifically, knockdown of w in putative subsets of serotonin neurons was sufficient to delay the locomotor recovery. These data reveal an additional role for w in modulating the timing of locomotor recovery from anoxia.