Data from: Adaptive contraction of diet breadth affects sexual maturation and specific nutrient consumption in an extreme generalist omnivore

Animals balance their intake of specific nutrients, but little is known about how they do so when foraging in an environment with toxic resources and whether toxic foods promote adaptations that affect life history traits. In German cockroach (Blattella germanica) populations, glucose aversion has evolved in response to glucose-containing insecticidal baits. We restricted newly eclosed glucose averse (GA) and wild type (WT) female cockroaches to nutritionally defined diets varying in protein-to-carbohydrate (P:C) ratio (3:1, 1:1, or 1:3) or gave them free choice of the 3:1 and 1:3 diets, with either glucose or fructose as the sole carbohydrate source. We measured consumption of each diet over six days and then dissected the females to measure the length of basal oocytes in their ovaries. Our results showed significantly lower consumption by GA compared to WT cockroaches when restricted to glucose-containing diets, but also lower fructose intake by GA compared to WT cockroaches when restricted to high fructose diets or given choice of fructose-containing diets. Protein intake was regulated tightly regardless of carbohydrate intake, except by GA cockroaches restricted to glucose-containing diets. Oocyte growth was completely suppressed in GA females restricted to glucose-containing diets, but also significantly slower in GA than in WT females restricted to fructose-containing diets. Our findings suggest that GA cockroaches have adapted to reduced diet breadth through endocrine adjustments which reduce requirements for energetic fuels. Our study illustrates how an evolutionary change in the chemosensory system may affect the evolution of other traits that govern animal life histories.

动物能够精准调控特定营养素的摄入以维持平衡，但学界对其在有毒资源环境中觅食时如何实现这一调控，以及有毒食物是否会催生影响动物生活史性状的适应性演化，仍知之甚少。在德国小蠊（*Blattella germanica*）种群中，葡萄糖拒食行为正是因接触含葡萄糖的杀虫饵剂而演化形成的适应性性状。我们将刚羽化的葡萄糖拒食型（glucose averse, GA）与野生型（wild type, WT）雌性德国小蠊分为两组，分别开展两种饲喂处理：其一为限制饲喂模式，即仅允许试虫食用营养成分明确、蛋白质与碳水化合物比值（P:C）分别为3:1、1:1或1:3的人工饲料；其二为自由选择模式，即允许试虫自由选取3:1与1:3两种P:C比的饲料，且两类饲料均分别以葡萄糖或果糖作为唯一碳水化合物来源。我们连续六天记录每头试虫的取食量，随后解剖雌性个体，测量其卵巢基部的卵母细胞长度。研究结果显示：当仅能食用含葡萄糖的饲料时，GA组德国小蠊的取食量显著低于WT组；而在限制饲喂高果糖饲料或可选择含果糖饲料的条件下，GA组的果糖摄入量也显著低于WT组。除限制饲喂含葡萄糖饲料的GA组外，无论碳水化合物摄入情况如何，各组试虫的蛋白质摄入量均受到严格调控。在限制饲喂含葡萄糖饲料的GA组雌性个体中，其卵母细胞的发育完全受到抑制，生长也完全停滞；而在限制饲喂果糖饲料的GA组雌性个体中，其卵母细胞的发育速度也显著慢于WT组雌性个体。我们的研究表明，GA组德国小蠊通过内分泌调控降低了对能量燃料的需求，从而适应了食谱范围的缩减。本研究阐明了化学感受系统的演化改变，可如何影响调控动物生活史的相关性状的演化，进而为理解动物适应性演化提供了新的视角。