Coyle Susan M, Huntingford Felicity A, Peichel Catherine L
The Division of Evolutionary and Environmental Biology, Graham Kerr Building, University of Glasgow, Scotland, UK.
J Hered. 2007 Sep-Oct;98(6):581-6. doi: 10.1093/jhered/esm066. Epub 2007 Aug 9.
Little is known about the genetic and molecular mechanisms that underlie adaptive phenotypic variation in natural populations or whether similar genetic and molecular mechanisms are utilized when similar adaptive phenotypes arise in independent populations. The threespine stickleback (Gasterosteus aculeatus) is a good model system to investigate these questions because these fish display a large amount of adaptive phenotypic variation, and similar adaptive phenotypes have arisen in multiple, independent stickleback populations. A particularly striking pattern of parallel evolution in sticklebacks is reduction of skeletal armor, which has occurred in numerous freshwater locations around the world. New genetic and genomic tools for the threespine stickleback have made it possible to identify genes that underlie loss of different elements of the skeletal armor. Previous work has shown that regulatory mutations at the Pitx1 locus are likely responsible for loss of the pelvic structures in independent stickleback populations from North America and Iceland. Here we show that the Pitx1 locus is also likely to underlie pelvic reduction in a Scottish population of threespine stickleback, which has apparently evolved pelvic reduction under a different selection regime than the North American populations.
对于自然种群中适应性表型变异背后的遗传和分子机制，或者当独立种群中出现相似的适应性表型时是否利用了相似的遗传和分子机制，我们了解得还很少。三刺鱼（Gasterosteus aculeatus）是研究这些问题的一个很好的模型系统，因为这些鱼表现出大量的适应性表型变异，并且在多个独立的三刺鱼种群中出现了相似的适应性表型。三刺鱼中一个特别显著的平行进化模式是骨骼盔甲的减少，这在世界上许多淡水区域都有发生。用于三刺鱼的新的遗传和基因组工具使得识别骨骼盔甲不同元素缺失背后的基因成为可能。先前的研究表明，Pitx1基因座的调控突变可能是北美和冰岛独立三刺鱼种群中骨盆结构缺失的原因。在这里，我们表明Pitx1基因座也可能是苏格兰三刺鱼种群中骨盆减少的基础，该种群显然是在与北美种群不同的选择机制下进化出骨盆减少的。
