Animals vary in their rates of energy expenditure for self-maintenance (standard metabolic rate [SMR]). Yet we still lack a thorough understanding of the determinants of SMR, potentially because of complex interactions among environmental, life-history, and physiological factors. Thus, we used a factorial design in female sand field crickets (Gryllus firmus) to investigate the independent and interactive effects of food availability (unlimited or limited access), acclimation temperature (control or simulated heat wave), life-history strategy (flight-capable or flight-incapable wing morphology), and immune status (control or chronic immune activation) on SMR (CO2 production rate) measured at 28°C. Both environmental factors independently affected SMR where heat wave and food limitation reduced SMR. Furthermore, wing morphology and immune status mediated the plasticity of SMR to food and temperature. For example, the hypermetabolic effect of food availability was greater in flight-capable crickets and reduced in immune-challenged crickets. Therefore, although SMR was directly affected by food availability and acclimation temperature, interactive effects on SMR were more common, meaning several factors (e.g., life history and immune status) influenced metabolic plasticity to food and temperature. We encourage continued use of factorial experiments to reveal interaction dynamics, which are critical to understanding emergent physiological processes.

中文翻译：

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生活史和免疫挑战影响代谢可塑性对食物供应和适应温度的影响。

动物的自我维持能量消耗率（标准代谢率[SMR]）各不相同。然而，由于环境，生活史和生理因素之间的复杂相互作用，我们仍然对SMR的决定因素缺乏透彻的了解。因此，我们在雌性沙田（Gryllus firmus）中使用了阶乘设计，研究了食物供应量（无限制或限制进入），适应温度（控制或模拟热浪），生活史策略（飞行-能力或无法飞行的机翼形态），以及在28°C下测得的SMR的免疫状态（控制或慢性免疫激活）（CO2产生率）。两种环境因素均独立影响SMR，其中热浪和食物限制降低了SMR。此外，机翼形态和免疫状态介导了SMR对食物和温度的可塑性。例如，食物的可代谢性在具有飞行能力的中更大，而在免疫挑战性中则降低。因此，尽管SMR直接受食物供应量和环境温度的影响，但对SMR的交互作用更为普遍，这意味着几个因素（例如，生活史和免疫状态）影响了食物和温度对代谢的可塑性。我们鼓励继续使用阶乘实验来揭示相互作用动力学，这对于理解新兴的生理过程至关重要。尽管SMR直接受食物供应量和环境温度的影响，但对SMR的交互作用更为普遍，这意味着几个因素（例如，生活史和免疫状况）影响了食物和温度对代谢的可塑性。我们鼓励继续使用阶乘实验来揭示相互作用动力学，这对于理解新兴的生理过程至关重要。尽管SMR直接受食物供应量和环境温度的影响，但对SMR的交互作用更为普遍，这意味着几个因素（例如，生活史和免疫状况）影响了食物和温度对代谢的可塑性。我们鼓励继续使用阶乘实验来揭示相互作用动力学，这对于理解新兴的生理过程至关重要。