中国东北第四纪晚期哺乳动物化石样品的古DNA损伤分析

二代测序技术的进步推动了古DNA研究的发展,古DNA研究在人类起源、动物演化等领域已经做出突出贡献。如何针对特定地点的古DNA样品特征,有效提取挖掘其中蕴含的古生物遗传信息,是发挥古代生物样品在诸多研究领域重要作用的前提。本研究将DNA损伤的两个主要指标(末端碱基替换率、平均片段长度)与样品的埋藏时间、所属地质时期、样品材料类型和建库方法相联系,分析不同因素对古DNA损伤的影响。结果表明:中国东北古脊椎动物样品中的古DNA分子的末端碱基替换率与埋藏点的含水量、样品埋藏时间呈正相关;不同地质时期的样品之间古DNA末端碱基替换率有显著差异;不同样品材料类型对于古DNA的末端碱基替换率未见明显影响;样品古DNA的平均片段长度与以上所研究的因素均无明显关系。研究结果为探明中国东北古脊椎动物样品的古DNA特征提供了分子依据,为有效选取不同地区的古脊椎动物样品及样品发掘后的合理保存提供了借鉴和参考。

Ancient DNA Damage Analysis of Late Quaternary Mammalian Fossil Samples in Northeast China

The advancement of the next generation sequencing (NGS) technology has promoted the development of ancient DNA research. Ancient DNA has made outstanding contributions in various fields such as human origin, animal evolution,etc. How to effectively extract and mine the genetic information from fossil and sub-fossil remains excavated from specific locations is a prerequisite for optimizing their important roles in many fields. In this study, we correlated the two main indicators of DNA damage (terminal base replacement rate, average fragment length) with the possible factors such as the burial time, geological epochs, tissue types, and sequencing library construction methods. The results show that the end base replacement rate of ancient DNA from Northeastern China is positively correlated with the water content of the environment and the ages of the samples. Among samples of different geological epochs, ancient DNA end base replacement rates have significant differences. On the contrary, different tissue types of the remains have no significant effects on the end base replacement rate of ancient DNA. The average fragment size of the molecules has no obvious correlation with the factors mentioned above. The results provide both solid data for investigating the characteristics of ancient DNA from specimens collected in Northeastern China, and valuable information for collecting appropriate samples from different geographical locations and the downstream storage before wet lab procedures after excavation.