Department of Biological Sciences, Arkansas State University, Jonesboro, AR, United States; Mississippi Department of Wildlife, Fisheries, and Parks, Mississippi Museum of Natural Science, Jackson MS, United States.
Department of Biological Sciences, Arkansas State University, Jonesboro, AR, United States.
Gen Comp Endocrinol. 2023 Nov 1;343:114350. doi: 10.1016/j.ygcen.2023.114350. Epub 2023 Jul 29.
Energy is a finite resource required for all physiological processes and must be allocated efficiently among essential activities to ensure fitness and survival. During the active season, adult organisms are expected to prioritize investment in reproduction over other energetically expensive processes, such as responding to immunological challenges. Furthermore, when encountering a stressor, the balance between reproduction and immunity might be disrupted in order to fuel the stress response. Because of the distinct differences in life histories across species, watersnakes provide a unique group of study in which to examine these tradeoffs. Over a two-year period, we captured three watersnake species throughout Northeast Arkansas. Animals were subjected to restraint stress and blood samples were collected throughout the acute stress response. Blood samples were used to assess innate immunity and steroid hormone concentrations. We found the peak in corticosterone concentration is season-specific, potentially because energetic reserves fluctuate with reproductive activities. We also found body condition was positively related to acute stress and negatively related to immunity. Watersnakes evidently prioritize reproduction over immunity, especially during the energetically intensive process of vitellogenesis. Energetic tradeoffs between reproduction, immunity, and the stress response are complex, and this study contributes to our understanding of energetic shifts in free-living organisms in the context of stress.
能量是所有生理过程所需的有限资源，必须在重要活动之间有效地分配，以确保适应和生存。在活跃季节，成年生物应优先投资于繁殖，而不是其他能量密集的过程，如应对免疫挑战。此外，当遇到压力源时，为了为压力反应提供燃料，繁殖和免疫之间的平衡可能会被打破。由于不同物种的生活史存在明显差异，水蛇为研究这些权衡提供了一个独特的群体。在两年的时间里，我们在阿肯色州东北部捕获了三种水蛇。动物受到束缚应激，在急性应激反应过程中采集血液样本。血液样本用于评估先天免疫和类固醇激素浓度。我们发现皮质酮浓度的峰值具有季节性，这可能是因为能量储备随生殖活动而波动。我们还发现身体状况与急性应激呈正相关，与免疫呈负相关。水蛇显然优先考虑繁殖而不是免疫，尤其是在卵黄生成这一能量密集的过程中。繁殖、免疫和应激反应之间的能量权衡是复杂的，本研究有助于我们理解在应激背景下自由生活生物的能量转移。
