Physiological climatic limits in Drosophila: patterns and implications
Physiological climatic limits in Drosophila: patterns and implications
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DOI：
10.1242/jeb.037630
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发表时间：
2010-03-15
影响因子：
2.8
通讯作者：
Hoffmann, A. A.
中科院分区：
文献类型：
--
作者：
Hoffmann, A. A.
生理极限决定了对环境变化的敏感性，并可在个人、种群或物种/谱系水平上进行评估。在这里，我讨论果蝇体内的这些水平，并考虑对确定物种对气候变化的敏感性的影响。果蝇个体水平的限制取决于实验技术和评估特征的背景。在种群水平上，来自选择实验的证据，特别是涉及黑腹果蝇的证据表明，在应对热应激和干旱方面，可遗传变异和进化水平很高。一个例外是对高温的抗性，这种抗性在选择实验中达到平台期，当温度上升到压力水平时，遗传力/进化力较低。在热带果蝇物种中，种群进化出更强的干燥性和抗寒性的能力有限。种群限制可能来自性状和基因的交互作用，但不同实验室研究的结果是不一致的，而且可能低估了田间条件下的交互作用强度。物种和谱系比较表明，在抗热极端和其他胁迫方面具有系统发育保守性。塑料反应设定了个体的极限，但在果蝇身上似乎进化得很慢。与上限相比，温度下限和干燥抗性在物种水平上的差异更大，这可能反映了不同的选择压力和/或低的进化性。与最近的猜测相反，当考虑到极端情况时，热带果蝇物种似乎并不比温带物种受到与全球变暖相关的更高温度的威胁。然而，如果来自潮湿热带的物种不能从基因上适应更干燥的条件，它们可能会受到威胁。
Physiological limits determine susceptibility to environmental changes, and can be assessed at the individual, population or species/lineage levels. Here I discuss these levels in Drosophila, and consider implications for determining species susceptibility to climate change. Limits at the individual level in Drosophila depend on experimental technique and on the context in which traits are evaluated. At the population level, evidence from selection experiments particularly involving Drosophila melanogaster indicate high levels of heritable variation and evolvability for coping with thermal stresses and aridity. An exception is resistance to high temperatures, which reaches a plateau in selection experiments and has a low heritability/evolvability when temperatures are ramped up to a stressful level. In tropical Drosophila species, populations are limited in their ability to evolve increased desiccation and cold resistance. Population limits can arise from trait and gene interactions but results from different laboratory studies are inconsistent and likely to underestimate the strength of interactions under field conditions. Species and lineage comparisons suggest phylogenetic conservatism for resistance to thermal extremes and other stresses. Plastic responses set individual limits but appear to evolve slowly in Drosophila. There is more species-level variation in lower thermal limits and desiccation resistance compared with upper limits, which might reflect different selection pressures and/or low evolvability. When extremes are considered, tropical Drosophila species do not appear more threatened than temperate species by higher temperatures associated with global warming, contrary to recent conjectures. However, species from the humid tropics may be threatened if they cannot adapt genetically to drier conditions.