Córdoba-Aguilar A, Nava-Sánchez A, González-Tokman D M, Munguía-Steyer R, Gutiérrez-Cabrera A E
Depto de Ecología Evolutiva, Instituto de Ecología, Univ Nacional Autónoma de México, Ciudad Universitaria, Mexico, D.F., Mexico.
CONACyT Research Fellow, Instituto de Ecología, Xalapa, Mexico.
Neotrop Entomol. 2016 Aug;45(4):404-10. doi: 10.1007/s13744-016-0391-0. Epub 2016 Apr 1.
Some insect species are capable of producing an enhanced immune response after a first pathogenic encounter, a process called immune priming. However, whether and how such ability is driven by particular diet components (protein/carbohydrate) have not been explored. Such questions are sound given that, in general, immune response is dietary dependent. We have used adults of the house cricket Acheta domesticus L. (Orthoptera: Gryllidae) and exposed them to the bacteria Serratia marcescens. We first addressed whether survival rate after priming and nonpriming treatments is dietary dependent based on access/no access to proteins and carbohydrates. Second, we investigated how these dietary components affected fat reserves, muscle mass, and body weight, three key traits in insect fitness. Thus, we exposed adult house crickets to either a protein or a carbohydrate diet and measured the three traits. After being provided with protein, primed animals survived longer compared to the other diet treatments. Interestingly, this effect was also sex dependent with primed males having a higher survival than primed females when protein was supplemented. For the second experiment, protein-fed animals had more fat, muscle mass, and body weight than carbohydrate-fed animals. Although we are not aware of the immune component underlying immune priming, our results suggest that its energetic demand for its functioning and/or consequent survival requires a higher demand of protein with respect to carbohydrate. Thus, protein shortage can impair key survival-related traits related to immune and energetic condition. Further studies varying nutrient ratios should verify our results.
一些昆虫物种在首次遭遇病原体后能够产生增强的免疫反应，这一过程称为免疫致敏。然而，这种能力是否以及如何由特定的饮食成分（蛋白质/碳水化合物）驱动尚未得到探索。鉴于一般来说免疫反应依赖于饮食，这些问题是合理的。我们使用家蟋蟀Acheta domesticus L.（直翅目：蟋蟀科）的成虫，并将它们暴露于粘质沙雷氏菌中。我们首先根据是否能获取蛋白质和碳水化合物来探讨致敏和未致敏处理后的存活率是否依赖于饮食。其次，我们研究了这些饮食成分如何影响脂肪储备、肌肉质量和体重，这三个是昆虫健康状况的关键特征。因此，我们将成年家蟋蟀暴露于蛋白质或碳水化合物饮食中，并测量这三个特征。在提供蛋白质后，致敏的动物比其他饮食处理的动物存活时间更长。有趣的是，这种影响也与性别有关，当补充蛋白质时，致敏雄性的存活率高于致敏雌性。对于第二个实验，喂食蛋白质的动物比喂食碳水化合物的动物有更多的脂肪、肌肉质量和体重。虽然我们不知道免疫致敏背后的免疫成分，但我们的结果表明，其功能和/或后续存活的能量需求相对于碳水化合物需要更高的蛋白质需求。因此，蛋白质短缺会损害与免疫和能量状况相关的关键生存相关特征。进一步改变营养比例的研究应该验证我们的结果。
