Is amino acid racemization a useful tool for screening for ancient DNA in bone?
Is amino acid racemization a useful tool for screening for ancient DNA in bone?
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DOI：
10.1098/rspb.2009.0563
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发表时间：
2009-08-22
期刊：
影响因子：
--
通讯作者：
Hofreiter M
中科院分区：
文献类型：
--
作者：
Collins MJ;Penkman KE;Rohland N;Shapiro B;Dobberstein RC;Ritz-Timme S;Hofreiter M
许多稀有和珍贵的古代标本现在都带有古代DNA研究的伤疤，因为人口遗传学和地理学的问题需要更大的样本集。这刺激了对可靠技术的需求，以在破坏性采样之前筛选DNA保存。只有一种这样的技术已被广泛采用：天冬氨酸外消旋（AAR）的程度。AAR的动力学被认为与DNA脱嘌呤的速率相似，因此是DNA存活可能性的良好量度。此外，AAR分析仅具有最小的破坏性。我们报告了第一次全面的测试AAR使用91骨和牙齿样本从温带和高纬度地区进行了DNA分析。虽然所有标本的AAR范围都很低（0.02-0.17），但AAR的程度与DNA扩增成功率之间没有相关性。额外的加热实验和文献调查表明，d/l Asx在骨中很低，直到几乎所有的胶原蛋白丢失。这是因为天冬氨酸被保留在骨中的胶原三螺旋的约束环境中，在那里由于空间原因它不能外消旋化。只有当螺旋变性为可溶性明胶时，Asx才容易外消旋化，但这种可溶性明胶在大多数埋葬环境中很容易丢失。我们的结论是，Asx d/l是不是一个有用的筛选技术从骨古DNA。
Many rare and valuable ancient specimens now carry the scars of ancient DNA research, as questions of population genetics and phylogeography require larger sample sets. This fuels the demand for reliable techniques to screen for DNA preservation prior to destructive sampling. Only one such technique has been widely adopted: the extent of aspartic acid racemization (AAR). The kinetics of AAR are believed to be similar to the rate of DNA depurination and therefore a good measure of the likelihood of DNA survival. Moreover, AAR analysis is only minimally destructive. We report the first comprehensive test of AAR using 91 bone and teeth samples from temperate and high-latitude sites that were analysed for DNA. While the AAR range of all specimens was low (0.02–0.17), no correlation was found between the extent of AAR and DNA amplification success. Additional heating experiments and surveys of the literature indicated that d/l Asx is low in bones until almost all the collagen is lost. This is because aspartic acid is retained in the bone within the constrained environment of the collagen triple helix, where it cannot racemize for steric reasons. Only if the helix denatures to soluble gelatin can Asx racemize readily, but this soluble gelatine is readily lost in most burial environments. We conclude that Asx d/l is not a useful screening technique for ancient DNA from bone.
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影响因子：
2.7
作者：
Penkman KE;Kaufman DS;Maddy D;Collins MJ
通讯作者：
Collins MJ
DOI：
10.1098/rstb.1999.0359
发表时间：
1999-01-29
影响因子：
6.3
作者：
Collins, MJ;Waite, ER;van Duin, ACT
通讯作者：
van Duin, ACT
影响因子：
2.8
作者：
Cappellini, E;Chiarelli, B;Caramelli, D
通讯作者：
Caramelli, D
影响因子：
64.8
作者：
MATSUURA, S;UETA, N
通讯作者：
UETA, N
DOI：
10.1073/pnas.96.15.8426
发表时间：
1999-07-20
影响因子：
11.1
作者：
Poinar, HN;Stankiewicz, BA
通讯作者：
Stankiewicz, BA