Latta Leigh C, Peacock Mica, Civitello David J, Dudycha Jeffry L, Meik Jesse M, Schaack Sarah
Department of Biology, Reed College, Portland, Oregon 97202.
Am Nat. 2015 Feb;185(2):243-52. doi: 10.1086/679501.
Understanding the context dependence of mutation represents the current frontier of mutation research. In particular, understanding how traits vary in their abilities to accrue mutational variation and how the environment influences expression of mutant phenotypes yields insight into evolutionary processes. We conducted phenotypic assays in four environments using a set of Daphnia pulex mutation accumulation lines to examine the context dependence of mutation. Life-history traits accrued mutational variance faster than morphological traits when considered in individual environments. Across environments, the mutational variance in plasticity was also greater for life-history traits than for morphological traits, although this pattern was less robust. In addition, the expression of mutational variance depended on the environment, which resulted in changes in the rank order of genotype performance across environments in some cases. Such cryptic genetic variation resulting from mutation may maintain genetic diversity and allow for rapid adaptation in spatially or temporally variable environments.
理解突变的环境依赖性是当前突变研究的前沿领域。特别是，了解性状在积累突变变异能力方面的差异以及环境如何影响突变表型的表达，有助于深入了解进化过程。我们使用一组大型溞突变积累品系在四种环境中进行了表型分析，以研究突变的环境依赖性。在个体环境中考虑时，生活史性状比形态性状积累突变方差的速度更快。在不同环境中，生活史性状的可塑性突变方差也比形态性状更大，尽管这种模式不太稳定。此外，突变方差的表达取决于环境，这在某些情况下导致基因型表现的排名顺序在不同环境中发生变化。这种由突变产生的隐藏遗传变异可能维持遗传多样性，并允许在空间或时间变化的环境中快速适应。
