Thomas W K, Pääbo S, Villablanca F X, Wilson A C
Division of Biochemistry and Molecular Biology, University of California, Berkeley 94720.
J Mol Evol. 1990 Aug;31(2):101-12. doi: 10.1007/BF02109479.
The advent of direct sequencing via the polymerase chain reaction (PCR) has opened up the possibility of molecular studies on museum specimens. Here we analyze genetic variation in populations over time by applying PCR to DNA extracted from museum specimens sampled from populations of one species over the last 78 years. Included in this study were 43 museum specimens of the Panamint kangaroo rat Dipodomys panamintinus from localities representing each of three geographically distinct subspecies. These specimens were originally collected and prepared as dried skins in 1911, 1917, or 1937. For each specimen, a 225-bp segment of the mitochondrial genome was sequenced. These mitochondrial DNA sequences were compared to those of 63 specimens collected at the same localities in 1988. The three subspecies were nearly completely distinct. Only 2 of the 106 individuals shared mitochondrial types between subspecies. For all three localities, the diversity levels were maintained between the two temporal samples. The concordance observed between the two temporally separate phylogenies supports the use of museum specimens for phylogenetic inference. This study demonstrates the accuracy and routine nature of the use of museum specimens in the analysis of mitochondrial sequence variation in natural populations and, importantly, that a temporal aspect can now be added to such studies.
通过聚合酶链反应（PCR）进行直接测序技术的出现，为对博物馆标本开展分子研究开辟了可能性。在此，我们通过对从过去78年间取自一个物种不同种群的博物馆标本中提取的DNA应用PCR技术，来分析种群随时间推移的遗传变异情况。本研究纳入了43份来自代表三个地理上不同亚种的巴拿马袋鼠鼠（Dipodomys panamintinus）的博物馆标本。这些标本最初于1911年、1917年或1937年采集并制成干皮标本。对于每个标本，对线粒体基因组的一个225碱基对片段进行了测序。将这些线粒体DNA序列与1988年在相同地点采集的63份标本的序列进行了比较。这三个亚种几乎完全不同。在106个个体中，只有2个个体在亚种间共享线粒体类型。对于所有三个地点，两个时间样本之间的多样性水平得以维持。在两个时间上分开的系统发育树之间观察到的一致性，支持了利用博物馆标本进行系统发育推断。本研究证明了在分析自然种群线粒体序列变异时使用博物馆标本的准确性和常规性，并且重要的是，现在可以在这类研究中加入时间维度。
