利用聚合酶链式反应技术研究单粒古代稻谷(公元800年)离体DNA片段的扩增

Amplification of DNA Fragments Isolated from a Single Seed ofAncient Rice (AD 800) by Polymerase Chain Reaction

在东南亚地区已发掘出很多古代稻谷,如果能从这些古稻谷中把DNA提出加以分析,可以得到有关栽培稻的系统分化和地理传播方面的直接信息。古代稻种的基因型相当复杂,必须要能从单粒种子开始分析,方能得到有价值的资料。为此,我们进行了从单粒古稻谷中提取DNA的研究工作。本研究采用通常提取植物组织中DNA的方法。从在日本挖掘出的古代稻谷单粒种子中提取出了50—100ng左右的DNA片段。以这些DNA作为模板,用聚合酶链式反应(Polymerase Chain Reaction,PCR)技术将DNA加以扩增。由其中几个DNA片段初步合成了相当于水稻光敏色素基因的DNA序列。

We report here that isolation of DNA from ancient rice seed found in the archaeological ex- cavation (1,200 years old), which were preserved in a low amount of oxidants. A single ancient rice seed con- tained 50--100 ng of DNA which was half the amount of DNA extractable from a single living seed using the same extraction procedure. The DNA fragments from the ancient seed were recovered as 15--20 kbp frag- ments which were a little smaller than intact DNA. The extracted DNA was used as template of PCR reac- tion with primers against the rice phytochrome gene. Although the expected and unknown fragments were amplified at the same time, this result showed that the ancient DNA was active as a template of thermostable DNA polymerase. This suggests that PCR will be useful for the analysis of ancient rice seeds.