Mitochondrial DNA sequence analysis of ancient human remains found in a 2000-year-old elite Xiongnu cemetery in northeast Mongolia

The Xiongnu empire was a dominating nomadic tribe in the east of southern Siberia between the third century BC and first century AD. Archeological sites and artifacts of the Xiongu have been found primarily in Mongolia and scattered in Russia and the northern part of China. The historical sites are mainly tombs. Rectangular terrace tombs with satellite graves-small circular tombs around the main large terrace tombs-have been found throughout Xiongnu cemeteries. This is the first study to report a genetic analysis of the relationship among individuals in these satellite tombs. The ancient DNA samples were extracted following a strict decontamination protocol in a dedicated laboratory using a silica-based method. The mitochondrial DNA segments required for haplogrouping were assessed using multiplex and nested real-time polymerase chain reaction-based methods to amplify multiple target segments simultaneously. This reduced the consumption of valuable samples, labor, and time. Mitochondrial DNA haplotypes were analyzed from the skeletons excavated from six satellite tombs found in a 2000-year-old Xiongnu elite cemetery at Duurlig nars, Mongolia. Interestingly, the different mitochondrial haplotypes (A, C4, D4, G1, G2, W) of six satellite tombs did not reveal any maternal kinship among the six individuals in the tombs. Two sacrifice tombs had two females in their twenties within them. Future studies should assess Y haplotypes, Y chromosomal short tandem repeats, autosomal short tandem repeats, and phenotype and biogeography ancestry-informative DNA.