Abstract:
Sleep is broadly conserved across the animal kingdom but can vary widely between species. It is currently unclear which selective pressures and regulatory mechanisms influence differences in sleep between species. The fruit fly Drosophila melanogaster has become a successful model system for examining sleep regulation and function, but little is known about the sleep patterns in many related fly species. Here, we find that fly species with adaptations to extreme desert environments, including D. mojavensis, exhibit strong increases in baseline sleep compared with D. melanogaster. Long-sleeping D. mojavensis show intact homeostasis, indicating that desert flies carry an elevated drive for sleep. In addition, D. mojavensis exhibit altered abundance or distribution of several sleep/wake-related neuromodulators and neuropeptides that are consistent with their reduced locomotor activity and increased sleep. Finally, we find that in a nutrient-deprived environment, the sleep patterns of individual D. mojavensis are strongly correlated with their survival time and that disrupting sleep via constant light stimulation renders D. mojavensis more sensitive to starvation. Our results demonstrate that D. mojavensis is a novel model for studying organisms with high sleep drive and for exploring sleep strategies that provide resilience in extreme environments.
摘要:
在整个动物界,睡眠是广泛保守的,但物种之间的差异可能很大。目前尚不清楚哪些选择压力和调节机制会影响物种之间的睡眠差异。果蝇果蝇已成为检查睡眠调节和功能的成功模型系统,但是对许多相关苍蝇物种的睡眠模式知之甚少。这里,我们发现苍蝇物种能够适应极端的沙漠环境,包括D.mojavensis,与D.melanogaster相比,基线睡眠表现出强烈的增加。长睡D.mojavensis显示完整的体内平衡,这表明沙漠苍蝇携带着提升的睡眠动力。此外,D.mojavensis表现出几种与睡眠/唤醒相关的神经调节剂和神经肽的丰度或分布改变,这与其运动活动减少和睡眠增加相一致。最后,我们发现在营养匮乏的环境中,个体的睡眠模式与它们的存活时间密切相关,通过持续的光刺激干扰睡眠使个体对饥饿更加敏感。我们的结果表明,D.mojavensis是研究具有高睡眠动力的生物和探索在极端环境中提供弹性的睡眠策略的新模型。