Instituto Gulbenkian de Ciência, Oeiras, Portugal.
Current address: Atlantic Technical University (UTA), Mindelo, São Vicente island, Cabo Verde.
Evolution. 2021 Jul;75(7):1805-1819. doi: 10.1111/evo.14271. Epub 2021 Jun 19.
Developmental plasticity can match organismal phenotypes to ecological conditions, helping populations to deal with the environmental heterogeneity of alternating seasons. In contrast to natural situations, experimental studies of plasticity often use environmental conditions that are held constant during development. To explore potential interactions between day and night temperatures, we tested effects of circadian temperature fluctuations on thermally plastic traits in a seasonally plastic butterfly, Bicyclus anynana. Comparing phenotypes for four treatments corresponding to a full-factorial analysis of cooler and warmer temperatures, we found evidence of significant interaction effects between day and night temperatures. We then focused on comparing phenotypes between individuals reared under two types of temperature fluctuations (warmer days with cooler nights, and cooler days with warmer nights) and individuals reared under a constant temperature of the same daily mean. We found evidence of additive-like effects (for body size), and different types of dominance-like effects, with one particular period of the light cycle (for development time) or one particular extreme temperature (for eyespot size) having a larger impact on phenotype. Differences between thermally plastic traits, which together underlie alternative seasonal strategies for survival and reproduction, revealed their independent responses to temperature. This study underscores the value of studying how organisms integrate complex environmental information toward a complete understanding of natural phenotypic variation and of the impact of environmental change thereon.
发育可塑性可以使生物个体的表型适应生态条件，帮助种群应对季节交替带来的环境异质性。与自然情况不同，可塑性的实验研究通常使用在发育过程中保持不变的环境条件。为了探索昼夜温度之间的潜在相互作用，我们测试了昼夜温度波动对季节性可塑性蝴蝶 Bicyclus anynana 的热可塑性特征的影响。通过比较对应于更凉爽和更温暖温度的完全析因分析的四个处理的表型，我们发现昼夜温度之间存在显著的相互作用效应。然后，我们专注于比较在两种温度波动（温暖的白天和凉爽的夜晚，以及凉爽的白天和温暖的夜晚）下饲养的个体和在相同日平均温度下饲养的个体之间的表型。我们发现存在类似加性的效应（对于体型），以及不同类型的优势类似效应，其中光周期的一个特定时期（对于发育时间）或一个特定的极端温度（对于眼斑大小）对表型有更大的影响。热可塑性特征的差异，这些差异共同构成了生存和繁殖的替代季节性策略，揭示了它们对温度的独立响应。这项研究强调了研究生物体如何整合复杂的环境信息以全面理解自然表型变异及其对环境变化的影响的价值。
