van Treuren R, Kuittinen H, Kärkkäinen K, Baena-Gonzalez E, Savolainen O
Department of Biology, University of Oulu, Finland.
Mol Biol Evol. 1997 Mar;14(3):220-9. doi: 10.1093/oxfordjournals.molbev.a025758.
We examined microsatellite variation in two diploid, outcrossing relatives of Arabidopsis thaliana, Arabis petraea and Arabis lyrata. The primer sequences were derived from A. thaliana. About 50% (14 loci) of the A. thaliana primers could successfully amplify microsatellites in the related species. Analysis of microsatellite structure in the related species showed that there had been large changes in the microsatellites: there were large differences in repeat numbers and many of the A. thaliana simple repeats were shorter in the related species. For the loci we compared, the related species had a much lower level of variability at the microsatellites than Japanese wild populations of A. thaliana. This is presumably related to the different microsatellite structures, because allozyme data showed that the outcrossing relatives were highly polymorphic compared to other outcrossing herbaceous species. Use of microsatellites in assessing variability or phylogenetic relationships between different species requires caution, because changes in microsatellite structure may alter evolutionary rates.
我们检测了拟南芥的两个二倍体异交近缘种——岩生庭荠和琴叶岩荠中的微卫星变异情况。引物序列源自拟南芥。约50%（14个位点）的拟南芥引物能够成功扩增相关物种中的微卫星。对相关物种微卫星结构的分析表明，微卫星发生了很大变化：重复数存在很大差异，且相关物种中许多拟南芥的简单重复序列较短。对于我们比较的位点，相关物种微卫星的变异水平远低于日本野生拟南芥种群。这可能与微卫星结构的差异有关，因为等位酶数据显示，与其他异交草本物种相比，这些异交近缘种具有高度多态性。在评估不同物种间的变异性或系统发育关系时，使用微卫星需要谨慎，因为微卫星结构的变化可能会改变进化速率。
