Maxat Zhabagin

Deep Phylogenetic Analysis of Haplogroup G1 Provides Estimates of SNP and STR Mutation Rates on the Human Y-Chromosome and Reveals Migrations of Iranic Speakers

Y-chromosomal haplogroup G1 is a minor component of the overall gene pool of South-West and Central Asia but reaches up to 80% frequency in some populations scattered within this area. We have genotyped the G1-defining marker M285 in 27 Eurasian populations (n= 5,346), analyzed 367 M285-positive samples using 17 Y-STRs, and sequenced ~11 Mb of the Y-chromosome in 20 of these samples to an average coverage of 67X. This allowed detailed phylogenetic reconstruction. We identified five branches, all with high geographical specificity: G1-L1323 in Kazakhs, the closely related G1-GG1 in Mongols, G1-GG265 in Armenians and its distant brother clade G1-GG162 in Bashkirs, and G1-GG362 in West Indians. The haplotype diversity, which decreased from West Iran to Central Asia, allows us to hypothesize that this rare haplogroup could have been carried by the expansion of Iranic speakers northwards to the Eurasian steppe and via founder effects became a predominant genetic component of some populations, including the Argyn tribe of the Kazakhs. The remarkable agreement between genetic and genealogical trees of Argyns allowed us to calibrate the molecular clock using a historical date (1405 AD) of the most recent common genealogical ancestor. The mutation rate for Y-chromosomal sequence data obtained was 0.78×10-9 per bp per year, falling within the range of published rates. The mutation rate for Y-chromosomal STRs was 0.0022 per locus per generation, very close to the so-called genealogical rate. The “clan-based” approach to estimating the mutation rate provides a third, middle way between direct farther-to-son comparisons and using archeologically known migrations, whose dates are subject to revision and of uncertain relationship to genetic events.

Genetic differentiation between upland and lowland populations shapes the Y-chromosomal landscape of West Asia

Y-chromosomal variation in West Asian populations has so far been studied in less detail than in the neighboring Europe. Here, we analyzed 598 Y-chromosomes from two West Asian subregions—Transcaucasia and the Armenian plateau—using 40 Y-SNPs and 17 Y-STRs and combined them with previously published data from the region. The West Asian populations fell into two clusters: upland populations from the Anatolian, Armenian and Iranian plateaus, and lowland populations from the Levant, Mesopotamia and the Arabian Peninsula. This geographic subdivision corresponds with the linguistic difference between Indo-European and Turkic speakers, on the one hand, and Semitic speakers, on the other. This subdivision could be traced back to the Neolithic epoch, when upland populations from the Anatolian and Iranian plateaus carried similar haplogroup spectra but did not overlap with lowland populations from the Levant. We also found that the initial gene pool of the Armenian motherland population has been well preserved in most groups of the Armenian Diaspora. In view of the contribution of West Asians to the autosomal gene pool of the steppe Yamnaya archaeological culture, we sequenced a large portion of the Y-chromosome in haplogroup R1b samples from present-day East European steppe populations. The ancient Yamnaya samples are located on the “eastern” R-GG400 branch of haplogroup R1b-L23, showing that the paternal descendants of the Yamnaya still live in the Pontic steppe and that the ancient Yamnaya population was not an important source of paternal lineages in present-day West Europeans.

Population biobanks: Organizational models and prospects of application in gene geography and personalized medicine

Population biobanks are collections of thoroughly annotated biological material stored for many years. Population biobanks are a valuable resource for both basic science and applied research and are essential for extensive analysis of gene pools. Population biobanks make it possible to carry out fundamental studies of the genetic structure of populations, explore their genetic processes, and reconstruct their genetic history. The importance of biobanks for applied research is no less significant: they are essential for development of personalized medicine and genetic ecological monitoring of populations and are in high demand in forensic science. Establishment of an efficient and representative biobank requires strict observance of the principles of sample selection in populations, protocols of DNA extraction, quality control, and storage and documentation of biological materials. We reviewed regional biobanks and presented the organizational model of population biobank establishment based on the Biobank of Indigenous Population of Northern Eurasia created under supervision of E.V. Balanovska and O.P. Balanovsky. The results obtained using the biobanks in transdisciplinary research and prospective applications for the purposes of genogeography, genomic medicine, and forensic science are presented.

Phylogeography of human Y-chromosome haplogroup Q3-L275 from an academic/citizen science collaboration

BackgroundThe Y-chromosome haplogroup Q has three major branches: Q1, Q2, and Q3. Q1 is found in both Asia and the Americas where it accounts for about 90% of indigenous Native American Y-chromosomes; Q2 is found in North and Central Asia; but little is known about the third branch, Q3, also named Q1b-L275. Here, we combined the efforts of population geneticists and genetic genealogists to use the potential of full Y-chromosome sequencing for reconstructing haplogroup Q3 phylogeography and suggest possible linkages to events in population history.ResultsWe analyzed 47 fully sequenced Y-chromosomes and reconstructed the haplogroup Q3 phylogenetic tree in detail. Haplogroup Q3-L275, derived from the oldest known split within Eurasian/American haplogroup Q, most likely occurred in West or Central Asia in the Upper Paleolithic period. During the Mesolithic and Neolithic epochs, Q3 remained a minor component of the West Asian Y-chromosome pool and gave rise to five branches (Q3a to Q3e), which spread across West, Central and parts of South Asia. Around 3–4 millennia ago (Bronze Age), the Q3a branch underwent a rapid expansion, splitting into seven branches, some of which entered Europe. One of these branches, Q3a1, was acquired by a population ancestral to Ashkenazi Jews and grew within this population during the 1st millennium AD, reaching up to 5% in present day Ashkenazi.ConclusionsThis study dataset was generated by a massive Y-chromosome genotyping effort in the genetic genealogy community, and phylogeographic patterns were revealed by a collaboration of population geneticists and genetic genealogists. This positive experience of collaboration between academic and citizen science provides a model for further joint projects. Merging data and skills of academic and citizen science promises to combine, respectively, quality and quantity, generalization and specialization, and achieve a well-balanced and careful interpretation of the paternal-side history of human populations.

The Connection of the Genetic, Cultural and Geographic Landscapes of Transoxiana

We have analyzed Y-chromosomal variation in populations from Transoxiana, a historical region covering the southwestern part of Central Asia. We studied 780 samples from 10 regional populations of Kazakhs, Uzbeks, Turkmens, Dungans, and Karakalpaks using 35 SNP and 17 STR markers. Analysis of haplogroup frequencies using multidimensional scaling and principal component plots, supported by an analysis of molecular variance, showed that the geographic landscape of Transoxiana, despite its distinctiveness and diversity (deserts, fertile river basins, foothills and plains) had no strong influence on the genetic landscape. The main factor structuring the gene pool was the mode of subsistence: settled agriculture or nomadic pastoralism. Investigation of STR-based clusters of haplotypes and their ages revealed that cultural and demic expansions of Transoxiana were not closely connected with each other. The Arab cultural expansion introduced Islam to the region but did not leave a significant mark on the pool of paternal lineages. The Mongol expansion, in contrast, had enormous demic success, but did not impact cultural elements like language and religion. The genealogy of Muslim missionaries within the settled agricultural communities of Transoxiana was based on spiritual succession passed from teacher to disciple. However, among Transoxianan nomads, spiritual and biological succession became merged.

Vitamin D Receptor Gene Polymorphisms in Susceptibility to Tuberculosis in the Kazakh Population in Almaty and Almaty Area

Introduction Vitamin D receptor (VDR) plays an important role in activating the immune response against various infectious agents. It is known that the active metabolite of ligand receptor Vitamin D (1,25 – dihydroxyvitamin D) is encoded by VDR and helps mononuclear phagocytes to suppress the intracellular growth of M. tuberculosis. The VDR gene harbors approximately 200 polymorphisms, some of which are linked to differences in receptor Vitamin D uptake and therefore can be considered as candidate disease risk variants. The relation between VDR gene polymorphisms and susceptibility to TB has been studied in different populations. There is not a great deal of information regarding the association of these SNPs with TB risk in the Kazakh population. The four most commonly investigated VDR polymorphisms in association with different diseases, including susceptibility to tuberculosis, are located in exon 2 (rs2228570 or FokI), intron 8 (rs1544410 or BsmI and rs7975232 or ApaI), and exon 9 (rs731236 or TaqI). The aim of our study was to determine whether these four VDR gene single nucleotide polymorphisms were associated with TB and whether they were a risk for the development of TB in the Kazakh Population in Almaty city and Almaty area. Methods This study was a hospital-based case-control analysis of 283 individuals (99 TB patients and 184 healthy controls). Genotyping was performed by Taqman SNP allelic discrimination using commercial TaqMan SNP Genotyping assays. Statistical analysis was conducted using SPSS Version 19.0 software. Results Genotype frequencies for the Kazakh population are close to world (HapMap) data on Asian populations. FokI and ApaI polymorphisms genotypes tend to be associated with TB risk under the co-dominant model [OR=1.18; 95%CI: (0.68, 2.07), p=0.15] for FokI and [OR=1.33; 95%CI: (0.61, 2.91), p=0.6] for ApaI. No significant association between the disease and TaqI, BsmI genotypes was observed. Conclusions In summary, we explored potential associations between SNPs in the VDR (FokI, ApaI) gene and susceptibility to tuberculosis in the Kazakh Population, which requires further detailed analysis with a larger sample size and greater geographic diversity including other regions of Kazakhstan.

Whole genome sequencing of M.tuberculosis in Kazakhstan: preliminary data

Background Tuberculosis is a major public health problem which infects one third of the world’s population, resulting in more than two million deaths every year. The emergence of whole genome sequencing (WGS) technologies as a primary research tool has allowed for the detection of genetic diversity in Mycobacterium tuberculosis (MTB) with unprecedented resolution. WGS has been used to address a broad range of topics, including the dynamics of evolution, transmission, and treatment. To our knowledge, studies involving WGS of Kazakhstani strains of M. tuberculosis have not yet been performed. Aim To perform whole genome sequencing of M. tuberculosis strains isolated in Kazakhstan and analyze sequence data (first experience and preliminary data). Results In the present report, we announce the whole-genome sequences of the two clinical isolates of Mycobacterium tuberculosis, MTB-489 and MTB-476, isolated from the Almaty region. These strains were part of a repository that was created during our project “Creating prerequisites of personalized approach in the diagnosis and treatment of tuberculosis, based on whole genome-sequencing of M. tuberculosis”. Two strains were isolated from sputum samples of patients P1 and P2. Phenotypically, two isolates were drug-susceptible M. tuberculosis. Sequence data was compared with the publicly available data on M. tuberculosis laboratory strain H37Rv and others. The sequencing of the strains was performed on a Roche 454 GS FLX+ next-generation sequencing platform using a standard protocol for a shotgun genome library. The whole genome sequencing was performed for two M.tuberculosis isolates MTB-476 and MTB-489. 96 M bp with an average read length of 520 bp, approximately 21.8X coverage and 104.2 M bp with an average read length of 589 bp and approximately 23.7X coverage were generated for the MTB-476 and MTB-489, respectively. The genome of MTB-476 consists of 257 contigs, 4204 CDS, 46 tRNAs and 3 rRNAs. MTB-489 has 187 contigs, 4183 CDS, 45 tRNAs and 3rRNAs. Conclusion The results of genome assembling have been submitted into NCBI GenBank and are available for public access under the accession numbers AZBA00000000 and AZAZ00000000. These genome assemblies can be useful for comparative genome analysis and for identification of novel SNPs and gene variants in genomes of M.tuberculosis.

Characterizing the genetic history of admixture across inner Eurasia

The indigenous populations of inner Eurasia, a huge geographic region covering the central Eurasian steppe and the northern Eurasian taiga and tundra, harbor tremendous diversity in their genes, cultures and languages. In this study, we report novel genome-wide data for 763 individuals from Armenia, Georgia, Kazakhstan, Moldova, Mongolia, Russia, Tajikistan, Ukraine, and Uzbekistan. We furthermore report genome-wide data of two Eneolithic individuals (∽5,400 years before present) associated with the Botai culture in northern Kazakhstan. We find that inner Eurasian populations are structured into three distinct admixture clines stretching between various western and eastern Eurasian ancestries. This genetic separation is well mirrored by geography. The ancient Botai genomes suggest yet another layer of admixture in inner Eurasia that involves Mesolithic hunter-gatherers in Europe, the Upper Paleolithic southern Siberians and East Asians. Admixture modeling of ancient and modern populations suggests an overwriting of this ancient structure in the Altai-Sayan region by migrations of western steppe herders, but partial retaining of this ancient North Eurasian-related cline further to the North. Finally, the genetic structure of Caucasus populations highlights a role of the Caucasus Mountains as a barrier to gene flow and suggests a post-Neolithic gene flow into North Caucasus populations from the steppe.

Development of the Kazakhstan Y-chromosome haplotype reference database: analysis of 27 Y-STR in Kazakh population

To improve available databases of forensic interest, all Y-STR haplotypes from Kazakh population were presented in this study. The reference database accumulated almost 3650 samples from academic and citizen science. Additionally, 27 Y-STR from Yfiler Plus System were first analyzed in 300 males from Kazakh (Qazaq) populations residing in Kazakhstan. The data is available in the YHDR under accession numbers YA004316 and YA004322. A total of 270 unique haplotypes were observed. Discrimination capacity was 90%. Obtained Y-STR haplotypes exhibited a high intra-population diversity. Analysis of pairwise genetic distances showed lowest RST values from Uighur and Mongolian populations.

[Gene pool of Siberian Tatars: Five ways of origin for five subethnic groups].

Siberian Tatars form the largest Turkic-speaking ethnic group in Western Siberia. The group has a complex hierarchical system of ethnographically diverse populations. Five subethnic groups of Tobol–Irtysh Siberian Tatars (N = 388 samples) have been analyzed for 50 informative Y-chromosomal SNPs. The subethnic groups have been found to be extremely genetically diverse (FST = 21%), so the Siberian Tatars form one of the strongly differentiated ethnic gene pools in Siberia and Central Asia. Every method employed in our studies indicates that different subethnic groups formed in different ways. The gene pool of Isker–Tobol Tatars descended from the local Siberian indigenous population and an intense, albeit relatively recent gene influx from Northeastern Europe. The gene pool of Yalutorovsky Tatars is determined by the Western Asian genetic component. The subethnic group of Siberian Bukhar Tatars is the closest to the gene pool of the Western Caucasus population. Ishtyak–Tokuz Tatars have preserved the genetic legacy of Paleo-Siberians, which connects them with populations from Southern, Western, and Central Siberia. The gene pool of the most isolated Zabolotny (Yaskolbinsky) Tatars is closest to Ugric peoples of Western Siberia and Samoyeds of the Northern Urals. Only two out of five Siberian Tatar groups studied show partial genetic similarity to other populations calling themselves Tatars: Isker–Tobol Siberian Tatars are slightly similar to Kazan Tatars, and Yalutorovsky Siberian Tatars, to Crimean Tatars. The approach based on the full sequencing of the Y chromosome reveals only a weak (2%) Central Asian genetic trace in the Siberian Tatar gene pool, dated to 900 years ago. Hence, the Mongolian hypothesis of the origin of Siberian Tatars is not supported in genetic perspective.