The Geometry of Nutrient Space-Based Life-History Trade-Offs: Sex-Specific Effects of Macronutrient Intake on the Trade-Off between Encapsulation Ability and Reproductive Effort in Decorated Crickets
The Geometry of Nutrient Space-Based Life-History Trade-Offs: Sex-Specific Effects of Macronutrient Intake on the Trade-Off between Encapsulation Ability and Reproductive Effort in Decorated Crickets
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DOI：
10.1086/696147
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发表时间：
2018-04-01
影响因子：
2.9
通讯作者：
Hunt, John
中科院分区：
文献类型：
--
作者：
Rapkin, James;Jensen, Kim;Hunt, John
生活史理论假设，性状会争夺有限的资源，从而导致权衡。在实证研究中，最常被操纵的资源是饮食的数量或质量。然而，最近使用营养几何框架的研究表明，权衡取舍往往受到特定营养素摄入量的调节，但缺乏一种正式的方法来确定和量化这种权衡取舍的强度。我们认为，当生活史性状在营养空间的不同区域中最大化时，就会发生权衡，这可以通过每个性状的全局最大值的95%置信区域不重叠以及线性营养向量之间的大角度（）和全局最大值之间的欧氏距离（d）来证明。然后，我们研究了蛋白质和碳水化合物的摄入量的影响之间的权衡繁殖和免疫功能方面的男性和女性的蟋蟀。雌性包囊能力和产蛋量增加，这两种营养素的摄入量，而男性包囊能力增加蛋白质的摄入量，但调用努力增加碳水化合物的摄入量。性状之间的权衡，因此，男性比女性更大，表现出显着的负相关性之间的性状在男性，不重叠的95%置信区间，和较大的估计和d。在饮食选择，性别有类似的规定摄入量，但没有最佳调节营养摄入量最大的性状表达。我们强调的事实是，更多地考虑特定的营养摄入量时，需要审查营养空间为基础的权衡。
Life-history theory assumes that traits compete for limited resources, resulting in trade-offs. The most commonly manipulated resource in empirical studies is the quantity or quality of diet. Recent studies using the geometric framework for nutrition, however, suggest that trade-offs are often regulated by the intake of specific nutrients, but a formal approach to identify and quantify the strength of such trade-offs is lacking. We posit that trade-offs occur whenever life-history traits are maximized in different regions of nutrient space, as evidenced by nonoverlapping 95% confidence regions of the global maximum for each trait and large angles () between linear nutritional vectors and Euclidean distances (d) between global maxima. We then examined the effects of protein and carbohydrate intake on the trade-off between reproduction and aspects of immune function in male and female Gryllodes sigillatus. Female encapsulation ability and egg production increased with the intake of both nutrients, whereas male encapsulation ability increased with protein intake but calling effort increased with carbohydrate intake. The trade-offs between traits was therefore larger in males than in females, as demonstrated by significant negative correlations between the traits in males, nonoverlapping 95% confidence regions, and larger estimates of and d. Under dietary choice, the sexes had similar regulated intakes, but neither optimally regulated nutrient intake for maximal trait expression. We highlight the fact that greater consideration of specific nutrient intake is needed when examining nutrient space-based trade-offs.