Min Kyeong Woon, Jang Taehwan, Lee Kwang Pum
Department of Agricultural Biotechnology Seoul National University Seoul Korea.
Ecol Evol. 2020 Nov 24;11(1):443-457. doi: 10.1002/ece3.7064. eCollection 2021 Jan.
Environments experienced during development have long-lasting consequences for adult performance and fitness. The "environmental matching" hypothesis predicts that individuals perform best when adult and developmental environments match whereas the "silver spoon" hypothesis expects that fitness is higher in individuals developed under favorable environments regardless of adult environments. Temperature and nutrition are the two most influential determinants of environmental quality, but it remains to be elucidated which of these hypotheses better explains the long-term effects of thermal and nutritional histories on adult fitness traits. Here we compared how the temperature and nutrition of larval environment would affect adult survivorship and reproductive success in the fruit fly, . The aspect of nutrition focused on in this study was the dietary protein-to-carbohydrate (P:C) ratio. The impact of low developmental and adult temperature was to improve adult survivorship. High P:C diet had a negative effect on adult survivorship when ingested during the adult stage, but had a positive effect when ingested during development. No matter whether adult and developmental environments matched or not, females raised in warm and protein-enriched environments produced more eggs than those raised in cool and protein-limiting environments, suggesting the presence of a significant silver spoon effect of larval temperature and nutrition. The effect of larval temperature on adult egg production was weak but persisted across the early adult stage whereas that of larval nutrition was initially strong but diminished rapidly after day 5 posteclosion. Egg production after day 5 was strongly influenced by the P:C ratio of the adult diet, indicating that the diet contributing mainly to reproduction had shifted from larval to adult diet. Our results highlight the importance of thermal and nutritional histories in shaping organismal performance and fitness and also demonstrate how the silver spoon effects of these aspects of environmental histories differ fundamentally in their nature, strength, and persistence.
发育过程中所经历的环境对成年个体的表现和适应性具有长期影响。“环境匹配”假说预测，当成年环境与发育环境相匹配时，个体表现最佳；而“银汤匙”假说则认为，无论成年环境如何，在有利环境中发育的个体适应性更高。温度和营养是环境质量的两个最具影响力的决定因素，但究竟哪种假说能更好地解释热历史和营养历史对成年适应性特征的长期影响，仍有待阐明。在此，我们比较了果蝇幼虫环境的温度和营养如何影响成年个体的存活率和繁殖成功率。本研究关注的营养方面是饮食中蛋白质与碳水化合物（P:C）的比例。发育阶段和成年期低温的影响是提高成年个体的存活率。高P:C饮食在成年期摄入时对成年个体的存活率有负面影响，但在发育期间摄入时则有正面影响。无论成年环境与发育环境是否匹配，在温暖且富含蛋白质的环境中饲养的雌性果蝇比在凉爽且蛋白质受限的环境中饲养的雌性果蝇产卵更多，这表明幼虫温度和营养存在显著的“银汤匙”效应。幼虫温度对成年果蝇产卵的影响较弱，但在成年早期持续存在；而幼虫营养的影响最初较强，但在羽化后第5天迅速减弱。羽化后第5天的产卵量受成年果蝇饮食P:C比例的强烈影响，这表明主要影响繁殖的饮食已从幼虫饮食转变为成年果蝇饮食。我们的研究结果突出了热历史和营养历史在塑造生物体表现和适应性方面的重要性，同时也证明了环境历史这些方面的“银汤匙”效应在本质、强度和持续性上存在根本差异。
