Ellis J R, Burke J M
Department of Biological Sciences, Vanderbilt University, Nashville, TN 37232, USA.
Heredity (Edinb). 2007 Aug;99(2):125-32. doi: 10.1038/sj.hdy.6801001. Epub 2007 May 23.
Simple-sequence repeats (SSRs) have increasingly become the marker of choice for population genetic analyses. Unfortunately, the development of traditional 'anonymous' SSRs from genomic DNA is costly and time-consuming. These problems are further compounded by a paucity of resources in taxa that lack clear economic importance. However, the advent of the genomics age has resulted in the production of vast amounts of publicly available DNA sequence data, including large collections of expressed sequence tags (ESTs) from a variety of different taxa. Recent research has revealed that ESTs are a potentially rich source of SSRs that reveal polymorphisms not only within the source taxon, but in related taxa, as well. In this paper, we review what is known about the transferability of EST-SSRs from one taxon to another with particular reference to the potential of these markers to facilitate population genetic studies. As an example of the utility of these resources, we then cross-reference existing EST databases against lists of rare, endangered and invasive plant species and conclude that half of all suitable EST databases could be exploited for the population genetic analysis of species of conservation concern. We then discuss the advantages and disadvantages of EST-SSRs in the context of population genetic applications.
简单序列重复（SSRs）越来越成为群体遗传学分析的首选标记。不幸的是，从基因组DNA开发传统的“匿名”SSRs成本高且耗时。在缺乏明确经济重要性的分类群中，资源匮乏使这些问题更加复杂。然而，基因组学时代的到来导致了大量公开可用的DNA序列数据的产生，包括来自各种不同分类群的大量表达序列标签（ESTs）集合。最近的研究表明，ESTs是SSRs的一个潜在丰富来源，不仅能揭示源分类群内的多态性，还能揭示相关分类群内的多态性。在本文中，我们回顾了关于EST-SSRs从一个分类群转移到另一个分类群的已知情况，特别提及这些标记促进群体遗传学研究的潜力。作为这些资源实用性的一个例子，我们随后将现有的EST数据库与珍稀、濒危和入侵植物物种列表进行交叉引用，并得出结论，所有合适的EST数据库中有一半可用于对受保护关注物种的群体遗传学分析。然后，我们在群体遗传学应用的背景下讨论了EST-SSRs的优缺点。
