最近,爱尔兰和英国的科学家利用6,700年前的古代野牛的前肢骨骼样本,成功地测序出完整的线粒体DNA基因组序列。这篇文章发表在最近一期的PLoS ONE杂志上。
都柏林大学的研究人员利用一种最近开发出来的DNA测序技术从野牛的骨骼中提取出大量的遗传信息。虽然线粒体DNA基因组序列为母系遗传,但研究人员希望下一步研究能够完整地获得野牛的核DNA基因组。该论文的合著者Dr Ceiridwen Edwards说,这项发现意味着我们可以对野牛以及现代家畜的进化史以及起源的研究提供新的希望。这不仅对考古学家有重要影响,而且对现代畜牧业的也有重要意义。
原始出处:
PLoS ONE 5(2): e9255. doi:10.1371/journal.pone.0009255
A Complete Mitochondrial Genome Sequence from a Mesolithic Wild Aurochs (Bos primigenius)
Ceiridwen J. Edwards1#¤a, David A. Magee2#, Stephen D. E. Park2#, Paul A. McGettigan2, Amanda J. Lohan3, Alison Murphy3, Emma K. Finlay1, Beth Shapiro4¤b, Andrew T. Chamberlain5, Martin B. Richards6, Daniel G. Bradley1, Brendan J. Loftus3, David E. MacHugh2,3*
1 Smurfit Institute of Genetics, Trinity College, Dublin, Ireland, 2 Animal Genomics Laboratory, School of Agriculture, Food Science and Veterinary Medicine, College of Life Sciences, University College Dublin, Dublin, Ireland, 3 Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Dublin, Ireland, 4 Henry Wellcome Ancient Biomolecules Centre, Department of Zoology, Oxford University, Oxford, United Kingdom, 5 Department of Archaeology, University of Sheffield, Sheffield, United Kingdom, 6 Institute of Integrative and Comparative Biology, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
Background
The derivation of domestic cattle from the extinct wild aurochs (Bos primigenius) has been well-documented by archaeological and genetic studies. Genetic studies point towards the Neolithic Near East as the centre of origin for Bos taurus, with some lines of evidence suggesting possible, albeit rare, genetic contributions from locally domesticated wild aurochsen across Eurasia. Inferences from these investigations have been based largely on the analysis of partial mitochondrial DNA sequences generated from modern animals, with limited sequence data from ancient aurochsen samples. Recent developments in DNA sequencing technologies, however, are affording new opportunities for the examination of genetic material retrieved from extinct species, providing new insight into their evolutionary history. Here we present DNA sequence analysis of the first complete mitochondrial genome (16,338 base pairs) from an archaeologically-verified and exceptionally-well preserved aurochs bone sample.
Methodology
DNA extracts were generated from an aurochs humerus bone sample recovered from a cave site located in Derbyshire, England and radiocarbon-dated to 6,738±68 calibrated years before present. These extracts were prepared for both Sanger and next generation DNA sequencing technologies (Illumina Genome Analyzer). In total, 289.9 megabases (22.48%) of the post-filtered DNA sequences generated using the Illumina Genome Analyzer from this sample mapped with confidence to the bovine genome. A consensus B. primigenius mitochondrial genome sequence was constructed and was analysed alongside all available complete bovine mitochondrial genome sequences.
Conclusions
For all nucleotide positions where both Sanger and Illumina Genome Analyzer sequencing methods gave high-confidence calls, no discrepancies were observed. Sequence analysis reveals evidence of heteroplasmy in this sample and places this mitochondrial genome sequence securely within a previously identified aurochsen haplogroup (haplogroup P), thus providing novel insights into pre-domestic patterns of variation. The high proportion of authentic, endogenous aurochs DNA preserved in this sample bodes well for future efforts to determine the complete genome sequence of a wild ancestor of domestic cattle.