Unique Self-Sustaining Circadian Oscillators Within the Brain of Drosophila melanogaster

摘要

In Drosophila circadian rhythms persist in constant darkness (DD). The small ventral Lateral Neurons (s-LN_v) mainly control the behavioral circadian rhythm in consortium with the large ventral Lateral Neurons (l-LN_v) and dorsal Lateral Neurons (LN_d). It is believed that the molecular oscillations of clock genes are the source of this persistent behavior. Indeed the s-LN_v, LN_d, Dorsal Neurons (DN)-DN_2 and DN_3 displayed self-sustained molecular oscillations in DD both at RNA and protein levels, except the DN_2 oscillates in anti-phase. In contrast, the l-LN_v and DN_1 displayed self-sustained oscillations at the RNA level, but protein oscillations quickly dampened. Having self-sustained and dampened molecular oscillators together in the DN groups suggested that they play different roles. However, all DN groups seemed to contribute together to the light-dark (LD) behavioral rhythm. The LD entrainment of LN oscillators is achieved through Rhodopsin (RH) and Cryptochrome (CRY). CRY's expression in all DN groups implicates also its role in LD entrainment of DN, like in DN_1. However, mutations in cry and glass that did not inflict LD synchronization of the DN_2, DN_3 oscillator implicate the existence of a novel photoreceptor at least in DN_3.