Department of Biology, Dalhousie University, 1355 Oxford Street, Halifax, Nova Scotia B3H 4J1, Canada.
Mol Ecol. 2010 Nov;19(22):4852-62. doi: 10.1111/j.1365-294X.2010.04822.x. Epub 2010 Sep 17.
Molecular markers, such as mitochondrial DNA and microsatellite loci, are widely studied to assess population genetics and phylogeography; however, the selective neutrality of these markers is increasingly being questioned. Given the importance of molecular markers in fisheries science and conservation, we evaluated the neutrality of both mtDNA and microsatellite loci through their associations with population size. We surveyed mtDNA and microsatellite data from the primary literature and determined whether genetic diversity increased with abundance across a total of 105 marine and freshwater fishes, with both global fisheries catch data and body size as proxies for abundance (with an additional 57 species for which only body size data were assessed). We found that microsatellite data generally yielded higher associations with abundance than mtDNA data, and within mtDNA analyses, number of haplotypes and haplotype diversity were more strongly associated with abundance than nucleotide diversity, particularly for freshwater fishes. We compared genetic diversity between freshwater and marine fishes and found that marine fishes had higher values of all measures of genetic diversity than freshwater fishes. Results for both mtDNA and microsatellites generally conformed to neutral expectations, although weaker relationships were often found between mtDNA nucleotide diversity and 'abundance' compared to any other genetic statistic. We speculate that this is because of historical events unrelated to natural selection, although a role for selection cannot be ruled out.
分子标记物，如线粒体 DNA 和微卫星位点，被广泛用于评估种群遗传学和系统地理学；然而，这些标记物的选择中性正越来越受到质疑。鉴于分子标记物在渔业科学和保护中的重要性，我们通过其与种群大小的关系来评估 mtDNA 和微卫星位点的中性。我们调查了来自主要文献的 mtDNA 和微卫星数据，并确定了遗传多样性是否随着丰度的增加而增加，总共涵盖了 105 种海洋和淡水鱼类，丰度的代表是全球渔业捕捞数据和体型（另外还有 57 种仅评估了体型数据的物种）。我们发现，微卫星数据通常比 mtDNA 数据与丰度的相关性更强，在 mtDNA 分析中，单倍型数量和单倍型多样性与丰度的相关性比核苷酸多样性更强，特别是对于淡水鱼类。我们比较了淡水鱼和海水鱼之间的遗传多样性，发现海水鱼的所有遗传多样性衡量标准都高于淡水鱼。mtDNA 和微卫星的结果通常符合中性预期，尽管与任何其他遗传统计数据相比，mtDNA 核苷酸多样性与“丰度”之间的关系往往较弱。我们推测这是由于与自然选择无关的历史事件造成的，尽管不能排除选择的作用。
