Mitochondrial and Y-chromosomal profile of the Kazakh population from East Kazakhstan

Aim

To study the genetic relationship of Kazakhs from East Kazakhstan to other Eurasian populations by examining paternal and maternal DNA lineages.

Methods

Whole blood samples were collected in 2010 from 160 unrelated healthy Kazakhs residing in East Kazakhstan. Genomic DNA was extracted with Wizard® genomic DNA Purification Kit. Nucleotide sequence of hypervariable segment I of mitochondrial DNA (mtDNA) was determined and analyzed. Seventeen Y-short tandem repeat (STR) loci were studied in 67 samples with the AmpFiSTR Y-filer PCR Amplification Kit. In addition, mtDNA data for 2701 individuals and Y-STR data for 677 individuals were retrieved from the literature for comparison.

Results

There was a high degree of genetic differentiation on the level of mitochondrial DNA. The majority of maternal lineages belonged to haplogroups common in Central Asia. In contrast, Y-STR data showed very low genetic diversity, with the relative frequency of the predominant haplotype of 0.612.

Conclusion

The results revealed different migration patterns in the population sample, showing there had been more migration among women. mtDNA genetic diversity in this population was equivalent to that in other Central Asian populations. Genetic evidence suggests the existence of a single paternal founder lineage in the population of East Kazakhstan, which is consistent with verbal genealogical data of the local tribes.In terms of population genetics, Central Asia is one of the least studied regions in the world. The studies conducted in the region, based on scarce genetic data, indicate that the Central Asia population is a mix of Eastern and Western populations (1,2). Kazakhstan is a vast country, which has throughout history been inhabited by different nomadic tribes such as the Argyn, Dughlat, Jalayir, Kerei, Kipchak, Madjar, Naiman, and others (3). The Kazakh ethnic group was formed in the 15th century under a huge infulence of the Mongol Empire (4). We expected the genetic profile of Kazakhs to be heterogeneous because of the different tribes and ethnicities (5).The current study focused on the Kazakh population of the East Kazakhstan Province, because recently there have been many reports on the neighboring populations of Xinjiang Uyghur Autonomous Region and Altai regions. East Kazakhstan is populated by the Naiman tribe. Their genealogical narrative, “shezhire,” states that the Naiman people living in Tarbagatay region are descendants of one ancestor, named Toktar-kozha, who came from the territory of modern Uzbekistan and was a Sart by origin. Based on the data from “shezhire,” we formed a hypothesis of uniform paternal descent of the Naiman tribe. The aim of this study was to better understand the origins and differentiation of the Kazakh ethnic group and to investigate the genetic relationship between this population and other Eurasian populations.