Geometry of compensatory feeding and water consumption in Drosophila melanogaster
Geometry of compensatory feeding and water consumption in Drosophila melanogaster
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DOI：
10.1242/jeb.066860
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发表时间：
2012-03-01
影响因子：
2.8
通讯作者：
Taylor, Phillip W.
中科院分区：
文献类型：
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作者：
Fanson, Benjamin G.;Yap, Sarsha;Taylor, Phillip W.
进食行为是动物潜在营养策略的表达。因此，对喂养决策的研究可以描述营养策略。对果蝇摄食行为的研究产生了相互矛盾的说法，而且人们对营养物质如何影响这一重要模式物种的摄食模式知之甚少。在这里，我们进行了两项实验来表征营养的优先顺序和调节。在一项选择实验中，我们通过向单只果蝇提供三个微毛细管，让雌性果蝇自我调节酵母、蔗糖和水的摄入量：一个只含有不同浓度的酵母，另一个只含有不同浓度的蔗糖，最后一个只含有水。果蝇将酵母和蔗糖严格调节到恒定比例，但代价是摄入过多的水，这表明果蝇优先考虑大量营养素的调节，而不是过量的水消耗。为了确定酵母和蔗糖的相对重要性，在一项无选择实验中，我们为果蝇提供了两个微毛细管：第一个含有 28 种酵母和蔗糖含量不同的饮食中的一种，另一个只含有水。果蝇增加的总水摄入量与酵母消耗量有关，但与蔗糖消耗量无关。此外，随着饮食浓度降低以及糖与酵母的比例均衡，果蝇的饮食摄入量增加。使用几何缩放方法，我们发现饮食摄入模式可以通过果蝇同等优先考虑蛋白质和碳水化合物以及营养素之间缺乏可替代性来解释。最后，我们通过说明我们的结果如何协调曾经在二维饮食景观中看到的文献中相互矛盾的结果来得出结论。
Feeding behaviour is an expression of an animal's underlying nutritional strategy. The study of feeding decisions can hence delineate nutritional strategies. Studies of Drosophila melanogaster feeding behaviour have yielded conflicting accounts, and little is known about how nutrients affect feeding patterns in this important model species. Here, we conducted two experiments to characterize nutrient prioritization and regulation. In a choice experiment, we allowed female flies to self-regulate their intake of yeast, sucrose and water by supplying individual flies with three microcapillary tubes: one containing only yeast of varying concentrations, another with just sucrose of varying concentrations, and the last with just water. Flies tightly regulated yeast and sucrose to a constant ratio at the expense of excess water intake, indicating that flies prioritize macronutrient regulation over excess water consumption. To determine the relative importance of yeast and sucrose, in a no-choice experiment, we provided flies with two microcapillary tubes: the first with one of the 28 diets varying in yeast and sucrose content and the other with only water. Flies increased total water intake in relation to yeast consumption but not sucrose consumption. Additionally, flies increased diet intake as diet concentration decreased and as the ratio of sugar to yeast equalized. Using a geometric scaling approach, we found that the patterns of diet intake can be explained by flies prioritizing protein and carbohydrates equally and by the lack of substitutability between the nutrients. We conclude by illustrating how our results harmonize conflicting results in the literature once viewed in a two-dimensional diet landscape.