Survival and recovery of DNA from ancient teeth and bones
Survival and recovery of DNA from ancient teeth and bones
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DOI：
10.1016/j.jas.2010.11.010
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发表时间：
2011-05-01
影响因子：
2.8
通讯作者：
Cooper, A.
中科院分区：
文献类型：
--
作者：
Adler, C. J.;Haak, W.;Cooper, A.
从保存完好的硬骨骼遗骸中回收遗传物质是古代 DNA、考古和法医研究的重要组成部分。然而，人们对不同组织内 DNA 的相对浓度、采样方法对提取的 DNA 的影响或环境决定的降解率对样本中 DNA 存活的作用知之甚少。我们通过使用实时 PCR 表征 42 个古代人类和牛科动物标本中不同片段长度 (77-235 bp) 的线粒体 DNA (mtDNA) 含量来研究这些问题。值得注意的是，与骨磨机中的粉碎相比，用于骨骼材料采样的标准钻速（约 1000 RPM）被发现可将 mtDNA 产量降低多达 30 倍（平均减少 3.1 x 10(5) mtDNA 拷贝）。这种巨大的负面影响似乎与热损伤有关，并且在非常低的钻速（例如 100 RPM）下消失。因此，许多古代 DNA 和法医研究可能获得了假阴性结果，尤其是重要标本，这些标本通常使用钻头取样，以尽量减少损坏迹象。牙骨质的 mtDNA 含量被发现比常用的牙本质高出五倍（141 bp，p = 0.01），使得富含牙骨质的根尖成为古代人类材料的最佳样本。最后，mtDNA被发现在许多沉积环境中表现出一致的指数碎片模式，不同地理区域和组织类型的碎片率不同，从而提高了预测和理解保存标本中DNA存活率的能力。 Crown 版权所有 (C) 2010 由 Elsevier Ltd 出版。保留所有权利。
The recovery of genetic material from preserved hard skeletal remains is an essential part of ancient DNA, archaeological and forensic research. However, there is little understanding about the relative concentrations of DNA within different tissues, the impact of sampling methods on extracted DNA, or the role of environmentally-determined degradation rates on DNA survival in specimens. We examine these issues by characterizing the mitochondrial DNA (mtDNA) content of different hard and soft tissues in 42 ancient human and bovid specimens at a range of fragment lengths (77-235 bp) using real-time PCR. Remarkably, the standard drill speeds used to sample skeletal material (c. 1000 RPM) were found to decrease mtDNA yields up to 30 times (by 3.1 x 10(5) mtDNA copies on average) compared to pulverization in a bone mill. This dramatic negative impact appears to relate to heat damage, and disappeared at very low drill speeds (e.g. 100 RPM). Consequently, many ancient DNA and forensic studies may have obtained false negative results, especially from important specimens which are commonly sampled with drills to minimize signs of damage. The mtDNA content of tooth cementum was found to be five times higher than the commonly used dentine (141 bp, p = 0.01), making the cementum-rich root tip the best sample for ancient human material. Lastly, mtDNA was found to display a consistent pattern of exponential fragmentation across many depositional environments, with different rates for geographic areas and tissue types, improving the ability to predict and understand DNA survival in preserved specimens. Crown Copyright (C) 2010 Published by Elsevier Ltd. All rights reserved.