Petit Rémy J, Deguilloux Marie-France, Chat Joëlle, Grivet Delphine, Garnier-Géré Pauline, Vendramin Giovanni G
UMR Biodiversity, Genes & Ecosystems, Institut National de la Recherche Agronomique, 69 route d Arcachon, F-33612 Cestas cedex, France.
Mol Ecol. 2005 Mar;14(3):885-90. doi: 10.1111/j.1365-294X.2005.02446.x.
Mutation rates at microsatellites tend to increase with the number of repeats of the motif, leading to higher levels of polymorphism at long microsatellites. To standardize levels of diversity when microsatellites differ in size, we investigate the relationship between tract length and variation and provide a formula to adjust allelic richness to a fixed mean number of repeats in the specific case of chloroplast microsatellites. A comparison between 39 loci from eight species of conifers (where chloroplast DNA is paternally inherited) and 64 loci from 12 species of angiosperms (where chloroplast DNA is generally predominantly maternally inherited) indicates that the greater allelic richness found in conifers remains significant after controlling for number of repeats. The approach stresses the advantage of reporting variation in number of repeats instead of relative fragment sizes.
微卫星的突变率往往会随着基序重复次数的增加而上升，从而导致长微卫星具有更高水平的多态性。为了在微卫星大小不同时标准化多样性水平，我们研究了序列长度与变异之间的关系，并给出了一个公式，用于在叶绿体微卫星的特定情况下，将等位基因丰富度调整到固定的平均重复次数。对来自8种针叶树（叶绿体DNA通过父系遗传）的39个位点和来自12种被子植物（叶绿体DNA通常主要通过母系遗传）的64个位点进行比较，结果表明，在控制重复次数后，针叶树中发现的更高等位基因丰富度仍然显著。该方法强调了报告重复次数变异而非相对片段大小的优势。
