Understanding the limits to generalizability of experimental evolutionary models
Understanding the limits to generalizability of experimental evolutionary models
复制标题
DOI：
10.1038/nature07152
复制
发表时间：
2008-09-11
期刊：
影响因子：
64.8
通讯作者：
Hurst, Laurence D.
中科院分区：
文献类型：
--
作者：
Forde, Samantha E.;Beardmore, Robert E.;Hurst, Laurence D.
考虑到在原位测试进化和生态理论的困难，体外模型系统是有吸引力的替代方案（1）;然而，我们能否评估实验结果是否特定于体外模型，如果是这样，描述可能表现不同的系统并理解为什么？本文以T7 -大肠杆菌共进化系统中表型多样性与资源投入之间的关系为例，研究了这些问题。我们建立了这种相互作用的数学模型，框架作为一个超级类的宿主-寄生虫共同进化模型的一个实例，并表明它捕捉实验结果。通过调整这个模型，我们接着问多样性作为资源投入的函数，对于可供选择的共同进化伙伴（例如，E。大肠杆菌与λ噬菌体）。与缺乏噬菌体的种群相反，在共同进化的种群中，总是发现多样性随资源差异而变化，这支持了共同进化的地理镶嵌理论（2）。然而，这种变化的形式并不普遍。感染性的细节是关键：在T7 - E中。在高资源输入条件下，基因间相互作用修饰的大肠杆菌的多样性较低，而在高资源输入条件下，匹配等位基因间相互作用修饰的大肠杆菌的多样性最高。体外系统和适当配置的数学模型的组合是一种有效的手段，以隔离特定于体外系统的结果，表征可能表现不同的系统，并了解这些替代品的生物学基础。
Given the difficulty of testing evolutionary and ecological theory in situ, in vitro model systems are attractive alternatives(1); however, can we appraise whether an experimental result is particular to the in vitro model, and, if so, characterize the systems likely to behave differently and understand why? Here we examine these issues using the relationship between phenotypic diversity and resource input in the T7 - Escherichia coli co- evolving system as a case history. We establish a mathematical model of this interaction, framed as one instance of a super- class of host - parasite co- evolutionary models, and show that it captures experimental results. By tuning this model, we then ask how diversity as a function of resource input could behave for alternative co- evolving partners ( for example, E. coli with lambda bacteriophages). In contrast to populations lacking bacteriophages, variation in diversity with differences in resources is always found for co- evolving populations, supporting the geographic mosaic theory of co- evolution(2). The form of this variation is not, however, universal. Details of infectivity are pivotal: in T7 - E. coli with a modified gene- for- gene interaction, diversity is low at high resource input, whereas, for matching- allele interactions, maximal diversity is found at high resource input. A combination of in vitro systems and appropriately configured mathematical models is an effective means to isolate results particular to the in vitro system, to characterize systems likely to behave differently and to understand the biology underpinning those alternatives.