Federal Bureau of Investigation Laboratory, DNA Support Unit, Quantico, VA 22135, USA.
Department of Forensic Genetics and Forensic Toxicology, National Board of Forensic Medicine, SE-587 58 Linkoping, Sweden.
Genes (Basel). 2022 Jan 23;13(2):202. doi: 10.3390/genes13020202.
This study describes an optimized DNA extraction protocol targeting ultrashort DNA molecules from single rootless hairs. It was applied to the oldest samples available to us: locks of hairs that were found in relics associated with the Romanov family. Published mitochondrial DNA genome sequences of Tsar Nicholas II and his wife, Tsarina Alexandra, made these samples ideal to assess this DNA extraction protocol and evaluate the types of genetic information that can be recovered by sequencing ultrashort fragments. Using this method, the mtGenome of the Tsarina's lineage was identified in hairs that were concealed in a pendant made by Karl Fabergé for Alexandra Feodorovna Romanov. In addition, to determine if the lock originated from more than one individual, two hairs from the locket were extracted independently and converted into Illumina libraries for shotgun sequencing on a NextSeq 500 platform. From these data, autosomal SNPs were analyzed to assess relatedness. The results indicated that the two hairs came from a single individual. Genetic testing of hairs that were found in the second artifact, a framed photograph of Louise of Hesse-Kassel, Queen of Denmark and maternal grandmother of Tsar Nicholas II, revealed that the hair belonged to a woman who shared Tsar Nicholas' maternal lineage, including the well-known point heteroplasmy at position 16169.
本研究描述了一种从无根单根头发中靶向超短 DNA 分子的优化 DNA 提取方案。该方案应用于我们所能获得的最古老的样本：在与罗曼诺夫家族有关的文物中发现的头发。已公布的沙皇尼古拉二世及其妻子亚历山德拉皇后的线粒体 DNA 基因组序列使这些样本成为评估该 DNA 提取方案并评估通过测序超短片段可恢复的遗传信息类型的理想选择。使用这种方法，在卡尔·法贝热 (Karl Fabergé) 为亚历山德拉·费奥多罗夫娜·罗曼诺夫 (Alexandra Feodorovna Romanov) 制作的吊坠中隐藏的头发中鉴定出了皇后的 mtGenome。此外，为了确定锁是否来自一个以上的个体，从吊坠中提取了两根头发，并将其分别转化为 Illumina 文库，以便在 NextSeq 500 平台上进行 shotgun 测序。从这些数据中，分析了常染色体 SNP 以评估相关性。结果表明，这两根头发来自同一个体。对在第二个文物——丹麦王后黑森-卡塞尔的路易丝的相框照片中发现的头发进行基因检测，显示该头发属于与沙皇尼古拉二世的母系血统相同的女性，包括位置 16169 处著名的点异质性。
