Golenberg E M
Department of Biological Sciences, Wayne State University, Detroit, Michigan 48202.
Philos Trans R Soc Lond B Biol Sci. 1991 Sep 30;333(1268):419-26; discussion 426-7. doi: 10.1098/rstb.1991.0092.
Ancient DNA has been extracted and sequenced from several animal and plant specimens. Previous considerations of the damage to ancient DNA have suggested that both the age and size of DNA fragments that can be retrieved and sequenced may be limited, the former to between several thousand and at most tens of thousands of years old, and the latter to at most a few hundred bases. A recent report of a 770 base pair (b.p.) sequence from the chloroplast gene rbcL from a Miocene Magnolia latahensis leaf indicates that both estimated limitations may be too conservative. Further work has indicated that analysis of Miocene fossil DNA can be replicated, and can, therefore, open up the prospects for future development of the field of molecular palaeontology. Successful amplification of fossil DNA is sometimes confounded by factors inherent to fossil DNA or to samples with minimal amounts of target DNA. Techniques that alter denaturation, reduce inhibitors and the problem of contaminants, and repair DNA prior to polymerase chain reaction amplification can increase the probability of success.
已经从多个动植物标本中提取了古代DNA并进行了测序。先前对古代DNA损伤的研究表明，能够被检索和测序的DNA片段的年龄和大小可能都有限制，前者限制在几千年到最多几万年之间，后者最多几百个碱基。最近一份关于来自中新世大叶木兰叶片叶绿体基因rbcL的770个碱基对（bp）序列的报告表明，这两个估计的限制可能都过于保守。进一步的研究表明，对中新世化石DNA的分析可以重复进行，因此可以为分子古生物学领域的未来发展开辟前景。化石DNA的成功扩增有时会受到化石DNA本身或目标DNA含量极少的样本所固有的因素的干扰。改变变性、减少抑制剂和污染物问题以及在聚合酶链反应扩增之前修复DNA的技术可以提高成功的概率。
