نتایج جستجو برای: ancient dna
تعداد نتایج: 542037 فیلتر نتایج به سال:
Much of what we know about extinct organisms comes from traits that are not preserved in the fossil record. Until recently, morphological analysis was the only tool available for scientists to determine relationships for extinct fossil organisms. We now know that "ancient' DNA can be preserved in the remains of extinct organisms. By targeting specific gene sequences, it may be possible to deduc...
In the early 1990s, when studies of ancient DNA became possible, new perspectives of analyzing archaeological data also developed. Nowadays, because the methodology related to ancient DNA research is well developed, it has been used to reveal several aspects of human history and interaction. Here we review the basic concepts, methodologies, and recent developments in the fi eld of ancient DNA s...
About 20 years ago, DNA sequences were separately described from the quagga (a type of zebra) and an ancient Egyptian individual. What made these DNA sequences exceptional was that they were derived from 140- and 2400-year-old specimens. However, ancient DNA research, defined broadly as the retrieval of DNA sequences from museum specimens, archaeological finds, fossil remains, and other unusual...
DNA sequences determined from ancient organisms have high error rates, primarily due to uracil bases created by cytosine deamination. We use synthetic oligonucleotides, as well as DNA extracted from mammoth and Neandertal remains, to show that treatment with uracil-DNA-glycosylase and endonuclease VIII removes uracil residues from ancient DNA and repairs most of the resulting abasic sites, leav...
Second-generation sequencing platforms have revolutionized the field of ancient DNA, opening access to complete genomes of past individuals and extinct species. However, these platforms are dependent on library construction and amplification steps that may result in sequences that do not reflect the original DNA template composition. This is particularly true for ancient DNA, where templates ha...
Since the appearance of the first reports describing the isolation and cloning of DNA from a 140-year-old preserved quagga [1] and from a 2 400 year-old Egyptian mummy [2], ancient DNA has been extracted from a number of organisms preserved in a variety of ways. Sources include preserved museum specimens, frozen mammoths, a 17 million year-old Magnolia leaf, and a 130 million yearold weevil ent...
Ligation Bias in Illumina Next-Generation DNA Libraries: Implications for Sequencing Ancient Genomes
Ancient DNA extracts consist of a mixture of endogenous molecules and contaminant DNA templates, often originating from environmental microbes. These two populations of templates exhibit different chemical characteristics, with the former showing depurination and cytosine deamination by-products, resulting from post-mortem DNA damage. Such chemical modifications can interfere with the molecular...
The publication of partial and complete paleogenomes within the last few years has reinvigorated research in ancient DNA. No longer limited to short fragments of mitochondrial DNA, inference of evolutionary processes through time can now be investigated from genome-wide data sampled as far back as 700,000 years. Tremendous insights have been made, in particular regarding the hominin lineage. Wi...
We extracted the DNA contained in samples of bones and teeth from 10 skeletons excavated from the Gravette site (400-1000 AD, south of France). Ancient DNA was analysed by autosomal short tandem repeats (STRs). The DNA present in these ancient remains appeared very degraded, but nevertheless, better conserved in tooth than in bone samples. Moreover, we showed that the DNA extracted from ancient...
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