Revising mtDNA haplotypes of the ancient Hungarian conquerors with next generation sequencing

As part of the effort to create a high resolution representative sequence database of the medieval Hungarian conquerors we have resequenced the entire mtDNA genome of 24 published ancient samples with Next Generation Sequencing, whose haplotypes had been previously determined with traditional PCR based methods. We show that PCR based methods are prone to erroneous haplotype or haplogroup determination due to ambiguous sequence reads, and many of the resequenced samples had been classified inaccurately. The SNaPshot method applied with published ancient DNA authenticity criteria is the most straightforward and cheapest PCR based approach for testing a large number of coding region SNP-s, which greatly facilitates correct haplogroup determination

Correction: Mitogenomic data indicate admixture components of Central-Inner Asian and Srubnaya origin in the conquering Hungarians.

[This corrects the article DOI: 10.1371/journal.pone.0205920.]

Mitogenomic data indicate admixture components of Central-Inner Asian and Srubnaya origin in the conquering Hungarians.

It has been widely accepted that the Finno-Ugric Hungarian language, originated from proto Uralic people, was brought into the Carpathian Basin by the conquering Hungarians. From the middle of the 19th century this view prevailed against the deep-rooted Hungarian Hun tradition, maintained in folk memory as well as in Hungarian and foreign written medieval sources, which claimed that Hungarians were kinsfolk of the Huns. In order to shed light on the genetic origin of the Conquerors we sequenced 102 mitogenomes from early Conqueror cemeteries and compared them to sequences of all available databases. We applied novel population genetic algorithms, named Shared Haplogroup Distance and MITOMIX, to reveal past admixture of maternal lineages. Our results show that the Conquerors assembled from various nomadic groups of the Eurasian steppe. Population genetic results indicate that they had closest connection to the Onogur-Bulgar ancestors of Volga Tatars. Phylogenetic results reveal that more than one third of the Conqueror maternal lineages were derived from Central-Inner Asia and their most probable ultimate sources were the Asian Scythians and Asian Huns, giving support to the Hungarian Hun tradition. The rest of the lineages most likely originated from the Bronze Age Potapovka-Poltavka-Srubnaya cultures of the Pontic-Caspian steppe. Available data imply that the Conquerors did not have a major contribution to the gene pool of the Carpathian Basin

Chromatogram of two HVR-I sequence fragments of the Karos-III/16 sample from [9].

<p>Arrows label double peaks, correct reads according to NGS data are listed above the arrows.</p

Details of NGS data for each sample.

<p>Details of NGS data for each sample.</p

Electropherograms of two SNaPshot SBE-II reactions from two extracts of the same Karos-III/6 sample [9].

<p>Characters at the top indicate Hg-s defined by the corresponding peaks. Black characters indicate peaks defining the ancestral allele, read characters indicate peaks defining the derived allele. Arrows point at double peaks. As each dye has a different influence on DNA mobility, positions of identical fragments with different dyes are not the same. Black arrows point at peaks taken into account, while blue arrows indicate neglected peaks, considered to have been derived from contamination. Orange peaks are size standards (GeneScan-120 LIZ, Applied Biosystems).</p

Comparison of Haplogroups identified with different PCR based methods and NGS.

<p>Comparison of Haplogroups identified with different PCR based methods and NGS.</p