Ancient and modern DNA reveal dynamics of domestication and cross-continental dispersal of the dromedary
Ancient and modern DNA reveal dynamics of domestication and cross-continental dispersal of the dromedary
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DOI：
10.1073/pnas.1519508113
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发表时间：
2016-06-14
影响因子：
11.1
通讯作者：
Burger, Pamela A.
中科院分区：
文献类型：
--
作者：
Almathen, Faisal;Charruau, Pauline;Burger, Pamela A.
3000 年来，单峰骆驼一直是人类社会在干旱地区发展和穿越恶劣炎热地区的长途贸易的基础。如今，它们仍然是边缘农业生态区的重要牲畜资源。然而，单峰骆驼驯化的历史以及古代贸易网络对其遗传结构的影响仍然难以捉摸。我们将来自干旱地区的野生和早期驯化的单峰骆驼样本的古代 DNA 序列与从该物种范围内收集的 1,083 只现存动物的核微卫星和线粒体基因型信息结合起来。我们在现代种群中几乎观察不到系统发育地理学信号，这表明基因流动广泛，并且几乎影响了除东非以外的所有地区，东非的单峰骆驼种群仍然相对孤立。与考古发现一致，我们确定来自阿拉伯半岛东南部的野生单峰骆驼是国内单峰骆驼基因库的创始人之一。近似贝叶斯计算进一步支持“从野生重新放养”假说，即最初的驯化，然后是来自现已灭绝的野生种群的个体的渗入。与其他牲畜相比，它们与野生祖先有着悠久的基因流动历史，我们发现，相对于阿拉伯半岛野生祖先的本地分布以及早期驯化和野生个体的短暂共存，我们发现了较高的初始多样性。这项研究还证明了从炎热干燥的沙漠环境中挖掘出的骨骸中检索古代 DNA 序列的潜力。
Dromedaries have been fundamental to the development of human societies in arid landscapes and for long-distance trade across hostile hot terrains for 3,000 y. Today they continue to be an important livestock resource in marginal agro-ecological zones. However, the history of dromedary domestication and the influence of ancient trading networks on their genetic structure have remained elusive. We combined ancient DNA sequences of wild and early-domesticated dromedary samples from arid regions with nuclear microsatellite and mitochondrial genotype information from 1,083 extant animals collected across the species' range. We observe little phylogeographic signal in the modern population, indicative of extensive gene flow and virtually affecting all regions except East Africa, where dromedary populations have remained relatively isolated. In agreement with archaeological findings, we identify wild dromedaries from the southeast Arabian Peninsula among the founders of the domestic dromedary gene pool. Approximate Bayesian computations further support the "restocking from the wild" hypothesis, with an initial domestication followed by introgression from individuals from wild, now-extinct populations. Compared with other livestock, which show a long history of gene flow with their wild ancestors, we find a high initial diversity relative to the native distribution of the wild ancestor on the Arabian Peninsula and to the brief coexistence of early-domesticated and wild individuals. This study also demonstrates the potential to retrieve ancient DNA sequences from osseous remains excavated in hot and dry desert environments.