cE3c - Centre for Ecology, Evolution and Environmental Changes, Faculdade de Ciências, Universidade de Lisboa, Lisboa, Portugal.
CESAM, Centre for Environmental and Marine Studies, Universidade de Aveiro and Faculdade de Ciências, Universidade de Lisboa, Portugal.
J Therm Biol. 2021 Jan;95:102794. doi: 10.1016/j.jtherbio.2020.102794. Epub 2020 Nov 28.
Phenotypic plasticity can help organisms cope with changing thermal conditions and it may depend on which life-stage the thermal stress is imposed: for instance, exposure to stressful temperatures during development can trigger a positive plastic response in adults. Here, we analyze the thermal plastic response of laboratory populations of Drosophila subobscura, derived from two contrasting latitudes of the European cline. We measured reproductive performance through fecundity characters, after the experimental populations were exposed to five thermal treatments, with different combinations of developmental and adult temperatures (14 °C, 18 °C, or 26 °C). Our questions were whether (1) adult performance changes with exposure to higher (or lower) temperatures during development; (2) flies raised at lower temperatures outperform those developed at higher ones, supporting the "colder is better" hypothesis; (3) there is a cumulative effect on adult performance of exposing both juveniles and adults to higher (or lower) temperatures; (4) there is evidence for biogeographical effects on adult performance. Our main findings were that (1) higher developmental temperatures led to low reproductive performance regardless of adult temperature, while at lower temperatures reduced performance only occurred when colder conditions were persistent across juvenile and adult stages; (2) flies raised at lower temperatures did not always outperform those developed at other temperatures; (3) there were no harmful cumulative effects after exposing both juveniles and adults to higher temperatures; (4) both latitudinal populations showed similar thermal plasticity patterns. The negative effect of high developmental temperature on reproductive performance, regardless of adult temperature, highlights the developmental stage as very critical and most vulnerable to climate change and associated heat waves.
表型可塑性可以帮助生物应对不断变化的热条件，它可能取决于热应激施加的生命阶段：例如，在发育过程中暴露于应激温度下可以在成年期引发积极的可塑性反应。在这里，我们分析了来自欧洲渐变群两个不同纬度的实验室种群的黑腹果蝇（Drosophila subobscura）的热塑性反应。我们通过生育特征测量了繁殖性能，在实验种群暴露于五个不同的热处理后，这些处理具有不同的发育和成年温度组合（14°C、18°C 或 26°C）。我们的问题是：（1）成年表现是否随发育过程中暴露于较高（或较低）温度而变化；（2）在较低温度下饲养的果蝇是否比在较高温度下饲养的表现更好，支持“冷更好”假说；（3）同时暴露于较高（或较低）温度下的幼体和成虫对成虫表现有累积效应；（4）是否有生物地理效应影响成虫表现。我们的主要发现是：（1）较高的发育温度导致无论成年温度如何，繁殖性能都较低，而在较低温度下，仅当较冷条件持续存在于幼体和成年阶段时才会降低表现；（2）在较低温度下饲养的果蝇并不总是比在其他温度下饲养的表现更好；（3）同时暴露于较高温度下的幼体和成虫没有累积的有害影响；（4）两个纬度种群都表现出相似的热塑性模式。高发育温度对繁殖性能的负面影响，无论成年温度如何，都突出了发育阶段非常关键，最容易受到气候变化和相关热浪的影响。
