Schwarz Sebastian, Durisko Zachary, Dukas Reuven
Department of Psychology, Neuroscience and Behaviour, McMaster University, ON, L8S4K1, Hamilton, Canada,
Naturwissenschaften. 2014 Jan;101(1):61-8. doi: 10.1007/s00114-013-1129-z. Epub 2013 Dec 19.
Selecting food items and attaining a nutritionally balanced diet is an important challenge for all animals including humans. We aimed to establish fruit fly larvae (Drosophila melanogaster) as a simple yet powerful model system for examining the mechanisms of specific hunger and diet selection. In two lab experiments with artificial diets, we found that larvae deprived of either sucrose or protein later selectively fed on a diet providing the missing nutrient. When allowed to freely move between two adjacent food patches, larvae surprisingly preferred to settle on one patch containing yeast and ignored the patch providing sucrose. Moreover, when allowed to move freely between three patches, which provided either yeast only, sucrose only or a balanced mixture of yeast and sucrose, the majority of larvae settled on the yeast-plus-sucrose patch and about one third chose to feed on the yeast only food. While protein (yeast) is essential for development, we also quantified larval success on diets with or without sucrose and show that larvae develop faster on diets containing sucrose. Our data suggest that fruit fly larvae can quickly assess major nutrients in food and seek a diet providing a missing nutrient. The larvae, however, probably prefer to quickly dig into a single food substrate for enhanced protection over achieving an optimal diet.
选择食物并实现营养均衡的饮食对包括人类在内的所有动物来说都是一项重大挑战。我们旨在将果蝇幼虫（黑腹果蝇）建立为一个简单而强大的模型系统，用于研究特定饥饿和饮食选择的机制。在两项使用人工饲料的实验室实验中，我们发现，被剥夺蔗糖或蛋白质的幼虫后来会选择性地取食提供缺失营养素的饲料。当允许幼虫在两个相邻的食物斑块之间自由移动时，令人惊讶的是，幼虫更喜欢停留在含有酵母的斑块上，而忽略了提供蔗糖的斑块。此外，当允许幼虫在三个斑块之间自由移动时，这三个斑块分别只提供酵母、只提供蔗糖或提供酵母和蔗糖的均衡混合物，大多数幼虫停留在酵母加蔗糖的斑块上，约三分之一的幼虫选择只取食含酵母的食物。虽然蛋白质（酵母）对发育至关重要，但我们也对有无蔗糖的饲料上幼虫的生长情况进行了量化，并表明幼虫在含蔗糖的饲料上发育得更快。我们的数据表明，果蝇幼虫能够快速评估食物中的主要营养素，并寻找提供缺失营养素的饮食。然而，幼虫可能更喜欢迅速钻进单一的食物基质中，以增强保护，而不是追求最佳饮食。
