Macronutrient balance mediates the growth of sexually selected weapons but not genitalia in male broad-horned beetles
Macronutrient balance mediates the growth of sexually selected weapons but not genitalia in male broad-horned beetles
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DOI：
10.1111/1365-2435.12567
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发表时间：
2016-05-01
影响因子：
5.2
通讯作者：
Hunt, John
中科院分区：
文献类型：
--
作者：
House, Clarissa M.;Jensen, Kim;Hunt, John
1. 条件被定义为个人可用的可分配给增强健康特征的资源池。因此，如果发生任何情况，条件可能会影响发育权衡。尽管许多研究通过控制饮食来证明条件依赖性性状表达，但很少有研究确定特定营养素对条件或权衡的贡献。2．我们使用营养几何学来量化膳食蛋白质和碳水化合物含量对幼虫性能和成虫形态发育的影响，包括体型以及雄性宽角甲虫 Gnatocerus cornutus 的主要和次要性选择特征。3。我们发现，后代的存活率、发育速度和形态特征很大程度上受膳食碳水化合物含量的影响，而蛋白质含量的影响较小，并且在蛋白质与碳水化合物的比例约为 1:2 时，所有性状均得到最大化。第二性征（下颌骨）的绝对大小对两种常量营养素的可用性和比例的增加有更大的反应。相比之下，男性生殖器对常量营养素可用性的增加相对不敏感。4。总体而言，虽然营养影响性状表达，但发育速度和形态性状的营养需求基本相同，并且资源获取似乎仅在该物种中实现了弱权衡。5。这一发现与一些资源限制预测形成鲜明对比，因为甲虫似乎能够同时满足大多数性状的营养需求。
1. Condition is defined as the pool of resources available to an individual that can be allocated to fitness-enhancing traits. Consequently, condition could influence developmental trade-offs if any occur. Although many studies have manipulated diet to demonstrate condition-dependent trait expression, few studies have determined the contribution of specific nutrients to condition or trade-offs.2. We used nutritional geometry to quantify the effects of dietary protein and carbohydrate content on larval performance and the development of adult morphology including body size as well as a primary and secondary sexually selected trait in male broad-horned beetles, Gnatocerus cornutus.3. We found that offspring survival, development rate and morphological traits were highly affected by dietary carbohydrate content and to a lesser extent by protein content and that all traits were maximized at a protein-to-carbohydrate ratio around 1:2. The absolute size of a secondary sexual character, the mandibles, had a heightened response to the increased availability and ratio of both macronutrients. Male genitalia, in contrast, were relatively insensitive to the increased availability of macronutrients.4. Overall, while nutrition influenced trait expression, the nutritional requirements of development rate and morphological traits were largely the same and resource acquisition seems to implement only weak trade-offs in this species.5. This finding contrasts with some resource constraint predictions, as beetles seem able to simultaneously meet the nutritional requirements of most traits.