Department of Entomology, College of Agriculture, Food, and Environment, University of Kentucky, Lexington 40546, United States of America.
Department of Entomology, College of Agriculture, Food, and Environment, University of Kentucky, Lexington 40546, United States of America; Department of Biology, College of Arts & Sciences, University of Louisiana at Lafayette, Lafayette, LA 70506, United States of America.
Comp Biochem Physiol A Mol Integr Physiol. 2021 Jul;257:110948. doi: 10.1016/j.cbpa.2021.110948. Epub 2021 Apr 2.
Cold stress can reduce insect fitness and is an important determinant of species distributions and responses to climate change. Cold tolerance is influenced by genotype and environmental conditions, with factors such as day length and temperature having a particularly strong influence. Recent studies also indicate that diet impacts cold tolerance, but it is unclear whether diet-mediated shifts in cold tolerance are consistent across distinct genotypes. The goal of this study was to determine the extent to which commonly used artificial diets influence cold tolerance in Drosophila melanogaster, and whether these effects are consistent across genetically distinct lines. Specifically, we tested the impact of different fly diets on 1) ability to survive cold stress, 2) critical thermal minimum (CT), and 3) the ability to maintain reproduction after cold stress. Experiments were conducted across six isogenic lines from the Drosophila Genetic Reference Panel, and these lines were reared on different fly diets. Cold shock survival, CT, and reproductive output pre- and post-cold exposure varied considerably across diet and genotype combinations, suggesting strong genotype by environment interactions shape nutritionally mediated changes in cold tolerance. For example, in some lines cold shock survival remained consistently high or low across diets, while in others cold shock survival ranged from 5% to 75% depending on diet. Ultimately, these results add to a growing literature that cold tolerance is shaped by complex interactions between genotype and environment and inform practical considerations when selecting a laboratory diet for thermal tolerance experiments in Drosophila.
冷应激会降低昆虫的适应能力，是决定物种分布和对气候变化响应的重要因素。低温耐受性受基因型和环境条件的影响，其中日长和温度等因素的影响尤为强烈。最近的研究还表明，饮食会影响低温耐受性，但饮食介导的低温耐受性变化是否在不同的基因型之间一致尚不清楚。本研究的目的是确定常用人工饲料在多大程度上影响黑腹果蝇的低温耐受性，以及这些影响是否在遗传上不同的品系之间一致。具体而言，我们测试了不同的果蝇饮食对 1）在冷应激下生存的能力，2）临界热最小值（CT），以及 3）在冷应激后维持繁殖的能力的影响。实验在来自果蝇遗传参考面板的六个同基因系中进行，这些系在不同的果蝇饮食中繁殖。冷休克生存、CT 和冷暴露前后的生殖输出在饮食和基因型组合之间差异很大，这表明强烈的基因型与环境相互作用塑造了营养介导的低温耐受性变化。例如，在一些品系中，冷休克生存在不同的饮食中保持一致的高低，而在其他品系中，冷休克生存则根据饮食从 5%到 75%不等。最终，这些结果增加了越来越多的文献表明，低温耐受性是由基因型和环境之间的复杂相互作用塑造的，并为在果蝇中进行热耐受性实验时选择实验室饮食提供了实际考虑因素。
