Department of Biological Sciences, Florida Atlantic University, Jupiter, FL 33458, USA.
Departments of Psychiatry and Neuroscience, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA.
J Exp Biol. 2019 Feb 8;222(Pt 3):jeb191049. doi: 10.1242/jeb.191049.
Food shortage represents a primary challenge to survival, and animals have adapted diverse developmental, physiological and behavioral strategies to survive when food becomes unavailable. Starvation resistance is strongly influenced by ecological and evolutionary history, yet the genetic basis for the evolution of starvation resistance remains poorly understood. The fruit fly provides a powerful model for leveraging experimental evolution to investigate traits associated with starvation resistance. While control populations only live a few days without food, selection for starvation resistance results in populations that can survive weeks. We have previously shown that selection for starvation resistance results in increased sleep and reduced feeding in adult flies. Here, we investigate the ontogeny of starvation resistance-associated behavioral and metabolic phenotypes in these experimentally selected flies. We found that selection for starvation resistance resulted in delayed development and a reduction in metabolic rate in larvae that persisted into adulthood, suggesting that these traits may allow for the accumulation of energy stores and an increase in body size within these selected populations. In addition, we found that larval sleep was largely unaffected by starvation selection and that feeding increased during the late larval stages, suggesting that experimental evolution for starvation resistance produces developmentally specified changes in behavioral regulation. Together, these findings reveal a critical role for development in the evolution of starvation resistance and indicate that selection can selectively influence behavior during defined developmental time points.
食物短缺是生存面临的主要挑战，动物已经适应了多样化的发育、生理和行为策略，以在食物匮乏时生存。抗饥饿能力受生态和进化历史的强烈影响，但抗饥饿能力进化的遗传基础仍知之甚少。果蝇为利用实验进化来研究与抗饥饿能力相关的特征提供了一个强大的模型。虽然对照种群在没有食物的情况下只能存活几天，但对抗饥饿能力的选择导致了能够存活数周的种群。我们之前曾表明，对饥饿抵抗的选择导致成年果蝇的睡眠增加和进食减少。在这里，我们研究了这些经过实验选择的果蝇中与抗饥饿能力相关的行为和代谢表型的个体发生。我们发现，对饥饿抵抗的选择导致幼虫发育延迟和代谢率降低，这些特征在成虫中持续存在，这表明这些特征可能允许在这些选择种群中积累能量储备并增加体型。此外，我们发现，幼虫的睡眠基本上不受饥饿选择的影响，而在幼虫后期进食增加，这表明，为抗饥饿能力进行的实验进化会导致行为调节的发育特异性变化。总之，这些发现揭示了发育在抗饥饿能力进化中的关键作用，并表明选择可以在特定的发育时间点选择性地影响行为。
