Colosimo Pamela F, Peichel Catherine L, Nereng Kirsten, Blackman Benjamin K, Shapiro Michael D, Schluter Dolph, Kingsley David M
Department of Developmental Biology and Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, California, USA.
PLoS Biol. 2004 May;2(5):E109. doi: 10.1371/journal.pbio.0020109. Epub 2004 Mar 30.
How many genetic changes control the evolution of new traits in natural populations? Are the same genetic changes seen in cases of parallel evolution? Despite long-standing interest in these questions, they have been difficult to address, particularly in vertebrates. We have analyzed the genetic basis of natural variation in three different aspects of the skeletal armor of threespine sticklebacks (Gasterosteus aculeatus): the pattern, number, and size of the bony lateral plates. A few chromosomal regions can account for variation in all three aspects of the lateral plates, with one major locus contributing to most of the variation in lateral plate pattern and number. Genetic mapping and allelic complementation experiments show that the same major locus is responsible for the parallel evolution of armor plate reduction in two widely separated populations. These results suggest that a small number of genetic changes can produce major skeletal alterations in natural populations and that the same major locus is used repeatedly when similar traits evolve in different locations.
有多少基因变化控制着自然种群中新性状的进化？在平行进化的案例中是否能看到相同的基因变化？尽管长期以来人们对这些问题很感兴趣，但它们一直难以解决，尤其是在脊椎动物中。我们分析了三刺鱼（Gasterosteus aculeatus）骨骼盔甲三个不同方面的自然变异的遗传基础：骨侧板的图案、数量和大小。少数染色体区域可以解释侧板所有三个方面的变异，其中一个主要基因座导致了侧板图案和数量的大部分变异。遗传图谱和等位基因互补实验表明，同一个主要基因座导致了两个相距甚远的种群中盔甲板减少的平行进化。这些结果表明，少数基因变化可以在自然种群中产生主要的骨骼改变，并且当相似性状在不同位置进化时，同一个主要基因座会被反复利用。
