Institute of Evolutionary Biology and Environmental Sciences, University of Zurich, Zurich, Switzerland.
PLoS One. 2010 Jun 2;5(6):e10927. doi: 10.1371/journal.pone.0010927.
Chytridiomycosis is a fungal disease linked to local and global extinctions of amphibians. Susceptibility to chytridiomycosis varies greatly between amphibian species, but little is known about between- and within-population variability. However, this kind of variability is the basis for the evolution of tolerance and resistance evolution to disease.
METHODOLOGY/PRINCIPAL FINDINGS: In a common garden experiment, we measured mortality after metamorphosis of Alytes obstetricans naturally infected with Batrachochytrium dendrobatidis. Mortality rates differed significantly among populations and ranged from 27 to 90%. Within populations, mortality strongly depended on mass at and time through metamorphosis.
CONCLUSIONS/SIGNIFICANCE: Although we cannot rule out that the differences observed resulted from differences in skin microbiota, different pathogen strains or environmental effects experienced by the host or the pathogen prior to the start of the experiment, we argue that genetic differences between populations are a likely source of at least part of this variation. To our knowledge, this is the first study showing differences in survival between and within populations under constant laboratory conditions. Assuming that some of this intraspecific variation has a genetic basis, this may suggest that there is the potential for the evolution of resistance or tolerance, which might allow population persistence.
壶菌病是一种真菌疾病，与两栖动物的局部和全球灭绝有关。两栖动物对壶菌病的易感性在物种间差异很大，但对种群间和种群内的变异性知之甚少。然而，这种变异性是对疾病的耐受和抗性进化的基础。
方法/主要发现：在一个共同的园林实验中，我们测量了自然感染壶菌的 A. obstetricans 在变态后死亡率。死亡率在种群之间有显著差异，范围从 27%到 90%。在种群内，死亡率与变态时的体重和时间有很强的依赖性。
结论/意义：虽然我们不能排除观察到的差异是由于皮肤微生物群、不同的病原体菌株或宿主和病原体在实验开始前经历的环境效应的差异造成的，但我们认为种群之间的遗传差异是这种变异性的至少部分来源。据我们所知，这是第一项在恒定的实验室条件下显示种群间和种群内生存差异的研究。假设这种种内变异的一部分具有遗传基础，这可能表明存在抗性或耐受性进化的潜力，这可能允许种群的持续存在。
