Genomics and museum specimens
Genomics and museum specimens
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基因组学和博物馆标本
DOI：
10.1111/mec.12563
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发表时间：
2013
影响因子：
4.9
通讯作者：
M. Nachman
中科院分区：
文献类型：
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作者：
M. Nachman
大约25年前，Allan Wilson及其同事从博物馆的袋鼠标本中分离出DNA序列，并将这些序列与新鲜收集的动物进行了比较（托马斯等人）。博物馆的标本是在78年前收集的，因此这两个样本提供了遗传变异模式的直接时间比较。这不是第一次从保存的材料中分离出DNA序列，但这是第一次用人口样本进行。群体遗传学家经常试图推断历史过程的影响，如选择，漂移，突变和迁移对目前遗传变异模式的影响。威尔逊及其同事的工作之所以重要，部分是因为它提出了一种方法，使群体遗传学家能够真正研究自然群体随时间的遗传变化，就像实验学家在实验室中研究人工群体一样。事实上，托马斯等人（）的工作催生了数十项研究，其中博物馆标本被用来比较历史和当今的遗传多样性（在Wandeler等人中进行了评论）。然而，所有这些研究都受到同一个基本问题的限制：旧DNA被降解成短片段。因此，这些研究主要涉及短模板的PCR扩增，通常是线粒体DNA或微卫星的短片段。在这一期中，毕等（）报道了一项突破，这将为博物馆标本的基因组变异研究打开大门。他们使用目标富集（外显子捕获）和下一代（Illumina）测序来比较高山花栗鼠（Tamias alpinus）历史和现代种群样本的遗传变异模式（图1）。历史样本来自1915年收集的标本，因此这次比较的时间跨度近100年。
Nearly 25 years ago, Allan Wilson and colleagues isolated DNA sequences from museum specimens of kangaroo rats (Dipodomys panamintinus) and compared these sequences with those from freshly collected animals (Thomas et al. ). The museum specimens had been collected up to 78 years earlier, so the two samples provided a direct temporal comparison of patterns of genetic variation. This was not the first time DNA sequences had been isolated from preserved material, but it was the first time it had been carried out with a population sample. Population geneticists often try to make inferences about the influence of historical processes such as selection, drift, mutation and migration on patterns of genetic variation in the present. The work of Wilson and colleagues was important in part because it suggested a way in which population geneticists could actually study genetic change in natural populations through time, much the same way that experimentalists can do with artificial populations in the laboratory. Indeed, the work of Thomas et al. ( ) spawned dozens of studies in which museum specimens were used to compare historical and present‐day genetic diversity (reviewed in Wandeler et al. ). All of these studies, however, were limited by the same fundamental problem: old DNA is degraded into short fragments. As a consequence, these studies mostly involved PCR amplification of short templates, usually short stretches of mitochondrial DNA or microsatellites. In this issue, Bi et al. ( ) report a breakthrough that should open the door to studies of genomic variation in museum specimens. They used target enrichment (exon capture) and next‐generation (Illumina) sequencing to compare patterns of genetic variation in historic and present‐day population samples of alpine chipmunks (Tamias alpinus) (Fig. 1). The historic samples came from specimens collected in 1915, so the temporal span of this comparison is nearly 100 years.