Constant, cycling, hot and cold thermal environments: strong effects on mean viability but not on genetic estimates

It has frequently been suggested that trait heritabilities are environmentally sensitive, and there are genetic trade-offs between tolerating different environments such as hot and cold or constant and fluctuating temperatures. Future climate predictions suggest an increase in both temperatures and their fluctuations. How species will respond to these changes is uncertain, particularly as there is a lack of studies which compare genetic performances in constant vs. fluctuating environments. In this study, we used a nested full-sib/half-sib breeding design to examine how the genetic variances and heritabilities of egg-to-adult viability differ at high and low temperatures with and without daily fluctuations in temperatures using Drosophila melanogaster as a model organism. Although egg-to-adult viability was clearly sensitive to developmental temperatures, heritabilities were not particularly sensitive to developmental temperatures. Moreover, we found that egg-to-adult viabilities at dif...已有研究多次指出，性状遗传力（heritability）具有环境敏感性，且生物在耐受不同环境（如冷热环境、恒定与波动温度环境）时存在遗传权衡（genetic trade-offs）。未来气候预测表明，全球气温及其波动幅度均将上升。目前学界尚不清楚物种将如何响应这些气候变化，尤其是现有研究缺乏对恒定与波动环境下遗传表现的对比分析。本研究以黑腹果蝇（Drosophila melanogaster）为模式生物，采用巢式全同胞/半同胞繁育设计（nested full-sib/half-sib breeding design），探究在存在/不存在每日温度波动的高低温环境下，卵至成虫存活率（egg-to-adult viability）的遗传方差与遗传力的变化差异。尽管卵至成虫存活率明显受发育温度影响，但遗传力并未对发育温度表现出显著敏感性。此外，本研究发现，不同温度条件下的卵至成虫存活率……