INBREEDING DEPRESSION INCREASES WITH ENVIRONMENTAL STRESS: AN EXPERIMENTAL STUDY AND META-ANALYSIS
INBREEDING DEPRESSION INCREASES WITH ENVIRONMENTAL STRESS: AN EXPERIMENTAL STUDY AND META-ANALYSIS
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DOI：
10.1111/j.1558-5646.2010.01108.x
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发表时间：
2011-01-01
期刊：
影响因子：
3.3
通讯作者：
Reed, David H.
中科院分区：
文献类型：
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作者：
Fox, Charles W.;Reed, David H.
当近亲繁殖导致不同环境中不同的适应度损失时，就会发生近亲繁殖与环境的相互作用。近亲繁殖的个体通常比远系繁殖的个体对环境压力更敏感，这可能是因为压力增加了有害的隐性等位基因的表达，或者细胞对压力的保护措施被推到生物体的生理极限之外。我们研究了近交环境的相互作用，沿着两个环境轴（温度和饲养主机），不同的发展压力，他们施加的量，在种子喂养甲虫Callosobruchus maculatus。我们发现，近亲繁殖抑郁症（近亲繁殖负荷，L）增加与环境的压力，压力的大小解释高达66%的变化，近亲繁殖抑郁症。L和发育压力之间的这种关系是无法解释的增加，在更紧张的环境中的表型变异。为了检验这一实验结果的普遍性，我们对已发表的关于压力和近亲繁殖抑郁症的研究中的可用数据进行了荟萃分析。荟萃分析证实，环境对近亲繁殖抑郁症的影响与压力的大小呈线性关系;平均而言，压力环境导致的健康每减少30%，种群就会遭受一个额外的致命当量。使用压力较小的环境进行的研究可能缺乏统计能力来检测近亲繁殖抑郁症的微小变化。近亲繁殖衰退的程度与施加的压力的大小成比例，这对进化和保护遗传学产生了许多影响，并可能激励旨在寻找这种关系中所涉及的因果机制的研究。
Inbreeding-environment interactions occur when inbreeding leads to differential fitness loss in different environments. Inbred individuals are often more sensitive to environmental stress than are outbred individuals, presumably because stress increases the expression of deleterious recessive alleles or cellular safeguards against stress are pushed beyond the organism's physiological limits. We examined inbreeding-environment interactions, along two environmental axes (temperature and rearing host) that differ in the amount of developmental stress they impose, in the seed-feeding beetle Callosobruchus maculatus. We found that inbreeding depression (inbreeding load, L) increased with the stressfulness of the environment, with the magnitude of stress explaining as much as 66% of the variation in inbreeding depression. This relationship between L and developmental stress was not explainable by an increase in phenotypic variation in more stressful environments. To examine the generality of this experimental result, we conducted a meta-analysis of the available data from published studies looking at stress and inbreeding depression. The meta-analysis confirmed that the effect of the environment on inbreeding depression scales linearly with the magnitude of stress; a population suffers one additional lethal equivalent, on average, for each 30% reduction in fitness induced by the stressful environment. Studies using less-stressful environments may lack statistical power to detect the small changes in inbreeding depression. That the magnitude of inbreeding depression scales with the magnitude of the stress applied has numerous repercussions for evolutionary and conservation genetics and may invigorate research aimed at finding the causal mechanism involved in such a relationship.