Data from: Effects of photoperiod on life-history and thermal stress resistance traits across populations of Drosophila subobscura

Intro: Organisms use environmental cues to match their phenotype with the
future availability of resources and environmental conditions. Changes in
the magnitude and frequency of environmental cues such as photoperiod and
temperature along latitudes can be used by organisms to predict seasonal
changes. While the role of temperature variation on the induction of
plastic and seasonal responses is well established, the importance of
photoperiod for predicting seasonal changes is less explored. M&M:
Here we studied changes in life-history and thermal stress resistance
traits in Drosophila subobscura in response to variation in photoperiod
(6:18, 12:12 and 18:6 light:dark cycles) mimicking seasonal variations in
daylength. Populations of D. subobscura were collected from five locations
along a latitudinal gradient (from North Africa and Europe). These
populations were exposed to different photoperiods for two generations,
whereafter egg-to-adult viability, productivity, dry body weight, thermal
tolerance, and starvation resistance were assessed. Results: We found
strong effects of photoperiod, origin of populations, and their
interactions on life-history and stress resistance traits. Thermal
resistance varied between the populations and the effect of photoperiod
depended on the trait and the method applied for the assessment of thermal
resistance. Perspectives: Our results show a strong effect of the origin
of population and photoperiod on a range of fitness related traits and
provide evidence for local adaptation to environmental cues (photoperiod
by population interaction). The findings emphasize an important and often
neglected role of photoperiod in studies on thermal resistance and suggest
that cues induced by photoperiod may provide some buffer enabling
populations to cope with a more variable and unpredictable future climate.

引言：生物体借助环境线索，将自身表型与未来的资源可获得性及环境条件相匹配。沿纬度梯度分布的光周期与温度等环境线索的强度与频率变化，可被生物体用以预测季节更替。尽管温度波动诱导表型可塑性与季节响应的作用已得到充分证实，但光周期在预测季节变化中的重要性却较少被探索。材料与方法：本研究以暗果蝇（Drosophila subobscura）为对象，探究其生活史与热胁迫抗性性状在模拟季节昼长变化的光周期（6:18、12:12及18:6光暗循环）处理下的变化。暗果蝇种群采集自沿纬度梯度分布的5个采样点（覆盖北非与欧洲区域）。将这些种群在不同光周期条件下饲养两代后，对其卵至成虫存活率、繁殖力、干体重、热耐受性以及饥饿抗性进行测定。结果：研究发现光周期、种群起源及其交互作用对生活史与胁迫抗性性状均存在显著影响。不同种群间的热抗性存在差异，且光周期的影响因性状类型与热抗性测定方法而异。研究展望：本研究结果表明，种群起源与光周期对一系列适合度相关性状存在显著影响，并为生物体对环境线索的局部适应（光周期×种群交互作用）提供了证据。本研究凸显了热抗性研究中常被忽视的光周期的重要作用，并表明光周期诱导的环境线索可提供一定缓冲能力，帮助种群应对未来更加多变且不可预测的气候。