Genotype data for 60 SNP genetic markers associated with eye, hair, skin color, ABO blood group, sex, core Y-chromosome haplogroups in Kazakh population.

OBJECTIVES: The collection of genotype data was conducted as an essential part of a pivotal research project with the goal of examining the genetic variability of skin, hair, and iris color among the Kazakh population. The data has practical application in the field of forensic DNA phenotyping (FDA). Due to the limited size of forensic databases from Central Asia (Kazakhstan), it is practically impossible to obtain an individual identification result based on forensic profiling of short tandem repeats (STRs). However, the pervasive use of the FDA necessitates validation of the currently employed set of genetic markers in a variety of global populations. No such data existed for the Kazakhs. The Phenotype Expert kit (DNA Research Center, LLC, Russia) was used for the first time in this study to collect data. DATA DESCRIPTION: The present study provides genotype data for a total of 60 SNP genetic markers, which were analyzed in a sample of 515 ethnic Kazakhs. The dataset comprises a total of 41 single nucleotide polymorphisms (SNPs) obtained from the HIrisPlex-S panel. Additionally, there are 4 SNPs specifically related to the AB0 gene, 1 marker associated with the AMELX/Y genes, and 14 SNPs corresponding to the primary haplogroups of the Y chromosome. The aforementioned data could prove valuable to researchers with an interest in investigating genetic variability and making predictions about phenotype based on eye color, hair color, skin color, AB0 blood group, gender, and biogeographic origin within the male lineage.

Population dataset for 23 Y-STR in the Merkit clan form Kazakh population.

This study presents a comprehensive analysis of 23 Y-STR data for the Merkit clan, a subgroup within the Kerey tribe of the Kazakh people. A total of 64 complete haplotypes were generated using the PowerPlex Y23 System. The data obtained using 23 Y-STR markers has been submitted to the Y Chromosome Haplotype Reference Database (YHRD) at yhrd.org, which will significantly enhance the forensic database for the Kazakh population in Kazakhstan. The research focuses on the distribution of haplotypes within the clan and their genealogical lines, which were visualized using a Median-joining network and Multidimensional scaling plot. The study identifies four distinct haplogroup clusters, revealing important insights into the genetic makeup and historical lineage of the Merkits. This dataset not only enriches our understanding of Kazakh genetic structure but also holds significant value for anthropological and population genetic research, as well as for forensic genetics. This work bridges a notable gap in genetic research on the Merkit clan, contributing to a deeper understanding of Central Asian nomadic tribes.

Genetic polymorphism of Y-chromosome in Kazakh populations from Southern Kazakhstan.

BACKGROUND: The Kazakhs are one of the biggest Turkic-speaking ethnic groups, controlling vast swaths of land from the Altai to the Caspian Sea. In terms of area, Kazakhstan is ranked ninth in the world. Northern, Eastern, and Western Kazakhstan have already been studied in relation to genetic polymorphism 27 Y-STR. However, current information on the genetic polymorphism of the Y-chromosome of Southern Kazakhstan is limited only by 17 Y-STR and no geographical study of other regions has been studied at this variation. RESULTS: The Kazakhstan Y-chromosome Haplotype Reference Database was expanded with 468 Kazakh males from the Zhambyl and Turkestan regions of South Kazakhstan by having their 27 Y-STR loci and 23 Y-SNP markers analyzed. Discrimination capacity (DC = 91.23%), haplotype match probability (HPM = 0.0029) and haplotype diversity (HD = 0.9992) are defined. Most of this Y-chromosome variability is attributed to haplogroups C2a1a1b1-F1756 (2.1%), C2a1a2-M48 (7.3%), C2a1a3-F1918 (33.3%) and C2b1a1a1a-M407 (6%). Median-joining network analysis was applied to understand the relationship between the haplotypes of the three regions. In three genetic layer can be described the position of the populations of the Southern region of Kazakhstan-the geographic Kazakh populations of Kazakhstan, the Kazakh tribal groups, and the people of bordering Asia. CONCLUSION: The Kazakhstan Y-chromosome Haplotype Reference Database was formed for 27 Y-STR loci with a total sample of 1796 samples of Kazakhs from 16 regions of Kazakhstan. The variability of the Y-chromosome of the Kazakhs in a geographical context can be divided into four main clusters-south, north, east, west. At the same time, in the genetic space of tribal groups, the population of southern Kazakhs clusters with tribes from the same region, and genetic proximity is determined with the populations of the Hazaras of Afghanistan and the Mongols of China.

Genetic polymorphism of 27 Y-STR loci in Kazakh populations from Eastern Kazakhstan.

BACKGROUND: The establishment of a national haplotype database is important for forensic and genetic applications and requires studying genetic polymorphisms at Y-STR sites. However, the genetic structure of the Eastern Kazakhstan population is poorly characterised. AIM: To investigate the genetic polymorphisms of 27 Y-STR loci in the Kazakh population from Eastern Kazakhstan and analyse the population genetic relationships of the Eastern Kazakhs with other populations. SUBJECTS AND METHODS: The Yfiler Plus kit was utilised to genotype 246 healthy, unrelated males from Eastern Kazakhstan. Based on the raw data, haplotype and allele frequencies along with forensic parameters were calculated, and an MDS plot was constructed. RESULTS: A total of 207 haplotypes were detected, of which 186 were unique. The haplotype diversity and discrimination capacity were 0.997 and 0.841, respectively. Population comparisons showed that Eastern Kazakhs have close genetic relationships with Kazakhs from Xinjiang, China. At the same time, a difference was found between the studied population and the previous one in the same part of Kazakhstan. CONCLUSIONS: The obtained haplotypes will help to expand the Kazakhstan Y-chromosome reference database and will be useful for future genetic research and forensic applications.

Kazak mitochondrial genomes provide insights into the human population history of Central Eurasia.

As a historical nomadic group in Central Asia, Kazaks have mainly inhabited the steppe zone from the Altay Mountains in the East to the Caspian Sea in the West. Fine scale characterization of the genetic profile and population structure of Kazaks would be invaluable for understanding their population history and modeling prehistoric human expansions across the Eurasian steppes. With this mind, we characterized the maternal lineages of 200 Kazaks from Jetisuu at mitochondrial genome level. Our results reveal that Jetisuu Kazaks have unique mtDNA haplotypes including those belonging to the basal branches of both West Eurasian (R0, H, HV) and East Eurasian (A, B, C, D) lineages. The great diversity observed in their maternal lineages may reflect pivotal geographic location of Kazaks in Eurasia and implies a complex history for this population. Comparative analyses of mitochondrial genomes of human populations in Central Eurasia reveal a common maternal genetic ancestry for Turko-Mongolian speakers and their expansion being responsible for the presence of East Eurasian maternal lineages in Central Eurasia. Our analyses further indicate maternal genetic affinity between the Sherpas from the Tibetan Plateau with the Turko-Mongolian speakers.

Ancient Components and Recent Expansion in the Eurasian Heartland: Insights into the Revised Phylogeny of Y-Chromosomes from Central Asia.

In the past two decades, studies of Y chromosomal single nucleotide polymorphisms (Y-SNPs) and short tandem repeats (Y-STRs) have shed light on the demographic history of Central Asia, the heartland of Eurasia. However, complex patterns of migration and admixture have complicated population genetic studies in Central Asia. Here, we sequenced and analyzed the Y-chromosomes of 187 male individuals from Kazakh, Kyrgyz, Uzbek, Karakalpak, Hazara, Karluk, Tajik, Uyghur, Dungan, and Turkmen populations. High diversity and admixture from peripheral areas of Eurasia were observed among the paternal gene pool of these populations. This general pattern can be largely attributed to the activities of ancient people in four periods, including the Neolithic farmers, Indo-Europeans, Turks, and Mongols. Most importantly, we detected the consistent expansion of many minor lineages over the past thousand years, which may correspond directly to the formation of modern populations in these regions. The newly discovered sub-lineages and variants provide a basis for further studies of the contributions of minor lineages to the formation of modern populations in Central Asia.

Genetic Polymorphism of 27 Y-STR Loci in the Western Kazakh Tribes from Kazakhstan and Karakalpakstan, Uzbekistan.

Data on the genetic polymorphism of 27 Y-STR in Kazakhs of the Junior Zhuz has been presented and analyzed in relation to forensic features. A total of 464 representatives of the Western Kazakh tribes of Kazakhstan (Western Kazakhs, n = 405) and Uzbekistan (Karakalpakstan Kazakhs, n = 59) were examined by the Yfiler Plus set. The data are available in the YHRD under accession numbers YA006010 and YA006009. Genetic analysis (AMOVA and MDS) did not show significant differences between the two groups (Kazakhstan and Karakalpakstan Kazakhs) in terms of Y-chromosome diversity. Both groups are characterized by haplogroup C2a1a2 as a founder effect, which dominated two of the three tribes: Alimuly (67%), Baiuly (74.6%), and Zhetiru (25.8%). At the same time, the phylogenetic network for each tribe found its own clusters within C2a1a2. Western Kazakhs and Karakalpakstan Kazakhs present high values of unique haplotypes (84.44% and 96.61%), discrimination capacity (90.37% and 98.30%), and haplotype diversity (0.9991 and 0.9994). A set of 27 Y-STR loci distinguishes closely related individuals within the Western Kazakh tribes quite well. It is suitable for forensic application, and is also optimal for population genetics studies.

Whole-Genome Sequencing and Genomic Variant Analysis of Kazakh Individuals.

Kazakhstan, the ninth-largest country in the world, is located along the Great Silk Road and connects Europe with Asia. Historically, its territory has been inhabited by nomadic tribes, and modern-day Kazakhstan is a multiethnic country with a dominant Kazakh population. We sequenced and analyzed the genomes of five ethnic Kazakhs at high coverage using the Illumina HiSeq2000 next-generation sequencing platform. The five Kazakhs yielded a total number of base pairs ranging from 87,308,581,400 to 107,526,741,301. On average, 99.06% were properly mapped. Based on the Het/Hom and Ti/Tv ratios, the quality of the genomic data ranged from 1.35 to 1.49 and from 2.07 to 2.08, respectively. Genetic variants were identified and annotated. Functional analysis of the genetic variants identified several variants that were associated with higher risks of metabolic and neurogenerative diseases. The present study showed high levels of genetic admixture of Kazakhs that were comparable to those of other Central Asians. These whole-genome sequence data of healthy Kazakhs could contribute significantly to biomedical studies of common diseases as their findings could allow better insight into the genotype-phenotype relations at the population level.

Determining the Area of Ancestral Origin for Individuals From North Eurasia Based on 5,229 SNP Markers.

Currently available genetic tools effectively distinguish between different continental origins. However, North Eurasia, which constitutes one-third of the world's largest continent, remains severely underrepresented. The dataset used in this study represents 266 populations from 12 North Eurasian countries, including most of the ethnic diversity across Russia's vast territory. A total of 1,883 samples were genotyped using the Illumina Infinium Omni5Exome-4 v1.3 BeadChip. Three principal components were computed for the entire dataset using three iterations for outlier removal. It allowed the merging of 266 populations into larger groups while maintaining intragroup homogeneity, so 29 ethnic geographic groups were formed that were genetically distinguishable enough to trace individual ancestry. Several feature selection methods, including the random forest algorithm, were tested to estimate the number of genetic markers needed to differentiate between the groups; 5,229 ancestry-informative SNPs were selected. We tested various classifiers supporting multiple classes and output values for each class that could be interpreted as probabilities. The logistic regression was chosen as the best mathematical model for predicting ancestral populations. The machine learning algorithm for inferring an ancestral ethnic geographic group was implemented in the original software "Homeland" fitted with the interface module, the prediction module, and the cartographic module. Examples of geographic maps showing the likelihood of geographic ancestry for individuals from different regions of North Eurasia are provided. Validating methods show that the highest number of ethnic geographic group predictions with almost absolute accuracy and sensitivity was observed for South and Central Siberia, Far East, and Kamchatka. The total accuracy of prediction of one of 29 ethnic geographic groups reached 71%. The proposed method can be employed to predict ancestries from the populations of Russia and its neighbor states. It can be used for the needs of forensic science and genetic genealogy.

Genetic polymorphism of 27 Y-STR loci in Kazakh populations from Northern Kazakhstan.

BACKGROUND: Previous studies of the genetic polymorphism of the Y-chromosome of Kazakhs were focussed on the Eastern, Central, Southern, and Western regions of Kazakhstan. In addition, many of these studies were limited to 17 Y-STR loci from the Yfiler. AIM: To enrich the existing Kazakhstan Y-chromosome Haplotype Reference Database from the Northern Kazakh population data by a wide set of 27 Y-STR and investigate the population genetic relationships with previously published data. SUBJECTS AND METHODS: Twenty-seven Y-STR loci from the Yfiler Plus PCR Amplification Kit were analysed in 382 healthy unrelated Kazakh males from Northern Kazakhstan. Genetic polymorphism was analysed using Arlequin software. RESULTS: A total of 326 distinct haplotypes of the 27 Y-STR loci were observed in 382 individuals. The discrimination capacity (0.9982) and haplotype diversity (0.8534) were computed. A total of 168 alleles at single-copy loci were observed and their frequencies ranged from 0.003-0.843. The pairwise genetic distance (RST) showed that the Northern Kazakh population is genetically distinct from the Chinese Kazakh population. CONCLUSIONS: Genetic polymorphism shows that the potential value of 27 Y-STR loci for forensic casework in the Northern Kazakh population and the current findings might be beneficial for paternal lineages in the study of population genetics.

Medieval Super-Grandfather founder of Western Kazakh Clans from Haplogroup C2a1a2-M48.

Western Kazakhstan is populated by three clans totaling 2 million people. Since the clans are patrilineal, the Y-chromosome is the most informative genetic system for tracing their origin. We genotyped 40 Y-SNP and 17 Y-STR markers in 330 Western Kazakhs. High phylogenetic resolution within haplogroup C2a1a2-M48 was achieved by using additional SNPs. Three lines of evidence indicate that the Alimuly and Baiuly clans (but not the Zhetiru clan) have a common founder placed 700 ± 200 years back by the STR data and 500 ± 200 years back by the sequencing data. This supports traditional genealogy claims about the descent of these clans from Emir Alau, who lived 650 years ago and whose lineage might be carried by two-thirds of Western Kazakhs. There is accumulation of specific haplogroups in the subclans representing other lineages, confirming that the clan structure corresponds with the paternal genetic structure of the steppe population.

The medieval Mongolian roots of Y-chromosomal lineages from South Kazakhstan.

BACKGROUND: The majority of the Kazakhs from South Kazakhstan belongs to the 12 clans of the Senior Zhuz. According to traditional genealogy, nine of these clans have a common ancestor and constitute the Uissun tribe. There are three main hypotheses of the clans' origin, namely, origin from early Wusuns, from Niru'un Mongols, or from Darligin Mongols. We genotyped 490 samples of South Kazakhs by 35 Y-chromosomal SNPs (single nucleotide polymorphism) and 17 STRs (short tandem repeat). Additionally, 133 samples from citizen science projects were included into the study. RESULTS: We found that three Uissun clans have unique Y-chromosomal profiles, but the remaining six Uissun clans and one non-Uissun clan share a common paternal gene pool. They share a high frequency (> 40%) of the C2*-ST haplogroup (marked by the SNP F3796), which is associated with the early Niru'un Mongols. Phylogenetic analysis of this haplogroup carried out on 743 individuals from 25 populations of Eurasia has revealed a set of haplotype clusters, three of which contain the Uissun haplotypes. The demographic expansion of these clusters dates back to the 13-fourteenth century, coinciding with the time of the Uissun's ancestor Maiky-biy known from historical sources. In addition, it coincides with the expansion period of the Mongol Empire in the Late Middle Ages. A comparison of the results with published aDNA (ancient deoxyribonucleic acid) data and modern Y haplogroups frequencies suggest an origin of Uissuns from Niru'un Mongols rather than from Wusuns or Darligin Mongols. CONCLUSIONS: The Y-chromosomal variation in South Kazakh clans indicates their common origin in 13th-14th centuries AD, in agreement with the traditional genealogy. Though genetically there were at least three ancestral lineages instead of the traditional single ancestor. The majority of the Y-chromosomal lineages of South Kazakhstan was brought by the migration of the population related to the medieval Niru'un Mongols.

Optimizing the genetic prediction of the eye and hair color for North Eurasian populations.

BACKGROUND: Predicting the eye and hair color from genotype became an established and widely used tool in forensic genetics, as well as in studies of ancient human populations. However, the accuracy of this tool has been verified on the West and Central Europeans only, while populations from border regions between Europe and Asia (like Caucasus and Ural) also carry the light pigmentation phenotypes. RESULTS: We phenotyped 286 samples collected across North Eurasia, genotyped them by the standard HIrisPlex-S markers and found that predictive power in Caucasus/Ural/West Siberian populations is reasonable but lower than that in West Europeans. As these populations have genetic ancestries different from that of West Europeans, we hypothesized they may carry a somewhat different allele spectrum. Thus, for all samples we performed the exome sequencing additionally enriched with the 53 genes and intergenic regions known to be associated with the eye/hair color. Our association analysis replicated the importance of the key previously known SNPs but also identified five new markers whose eye color prediction power for the studied populations is compatible with the two major previously well-known SNPs. Four out of these five SNPs lie within the HERС2 gene and the fifth in the intergenic region. These SNPs are found at high frequencies in most studied populations. The released dataset of exomes from Russian populations can be further used for population genetic and medical genetic studies. CONCLUSIONS: This study demonstrated that precision of the established systems for eye/hair color prediction from a genotype is slightly lower for the populations from the border regions between Europe and Asia that for the West Europeans. However, this precision can be improved if some newly revealed predictive SNPs are added into the panel. We discuss that the replication of these pigmentation-associated SNPs on the independent North Eurasian sample is needed in the future studies.

Phylogenetic analysis of the Y-chromosome haplogroup C2b-F1067, a dominant paternal lineage in Eastern Eurasia.

Human Y-chromosome haplogroup C2b-F1067 is one of the dominant paternal lineages of populations in Eastern Eurasia. In order to explore the origin, diversification, and expansion of this haplogroup, we generated 206 new Y-chromosome sequences from C2b-F1067 males and coanalyzed 220 Y-chromosome sequences of this haplogroup. BEAST software was used to reconstruct a revised phylogenetic tree of haplogroup C2b-F1067 with age estimates. The revised phylogeny of C2b-F1067 included 155 sublineages, 1986 non-private variants, and >6000 private variants. The age estimation suggested that the initial splitting of C2b-F1067 happened at about 32.8 thousand years ago (kya) and the major sublineages of this haplgroup experienced continuous expansion in the most recent 10,000 years. We identified numerous sublineages that were nearly specific for Korean, Mongolian, Chinese, and other ethnic minorities in China. In particular, we evaluated the candidate-specific lineage for the Dayan Khan family and the Confucius family, the descendants of the ruling family of the Chinese Shang dynasty. These findings suggest that ancient populations with varied C2b-F1067 sublineages played an important role during the formation of most modern populations in Eastern Eurasia, and thus eventually became the founding paternal lineages of these populations.

Y-chromosome evidence confirmed the Kerei-Abakh origin of Aksay Kazakhs.

Aksay Kazakhs are the easternmost branch of Kazakhs, residing in Jiuquan city, the forefront of the ancient Silk Road. However, the genetic diversity of Aksay Kazakhs and its relationships with other Kazakhs still lack attention. To clarify this issue, we analyzed the non-recombining portion of the Y-chromosome from 93 Aksay Kazakhs samples, using a high-resolution analysis of 106 biallelic markers and 17 STRs. The lowest haplogroup diversity (0.38) was observed in Aksay Kazakhs among all studied Kazakh populations. The social and cultural traditions of the Kazakhs shaped their current pattern of genetic variation. Aksay Kazakhs tended to migrate with clans and had limited paternal admixture with neighboring populations. Aksay Kazakhs had the highest frequency (80%) of haplogroup C2b1a3a1-F3796 (previous C3*-Star Cluster) among the investigated Eurasian steppe populations, which was now seen as the genetic marker of Kerei clan. Furthermore, NETWORK analysis indicated that Aksay Kazakhs originated from sub-clan Kerei-Abakh in Kazakhstan with DYS448 = 23. TMRCA estimates of three recent descent clusters detected in C2*-M217 (xM48) network, one of which incorporate nearly all of the C2b1a3a1-F3796 Aksay Kazakhs samples, gave the age range of 976-1405 YA for DC1, 1059-1314 YA for DC2, and 1139-1317 YA for DC3, respectively; this is coherent with the 7th to the 11th centuries Altaic-speaking pastoral nomadic population expansion.

Molecular genealogy of Tusi Lu's family reveals their paternal relationship with Jochi, Genghis Khan's eldest son.

Genghis Khan's lineage has attracted both academic and general interest because of its mystery and large influence. However, the truth behind the mystery is complicated and continues to confound the scientific study. In this study, we surveyed the molecular genealogy of Northwestern China's Lu clan who claim to be the descendants of the sixth son of Genghis Khan, Toghan. We also investigated living members of the Huo and Tuo clans, who, according to oral tradition, were close male relatives of Lu clan. Using network analysis, we found that the Y-chromosomal haplotypes of Lu clan mainly belong to haplogroup C2b1a1b1-F1756, widely prevalent in Altaic-speaking populations, and are closely related to the Tore clan from Kazakhstan, who claim to be the descendants of the first son of Genghis Khan, Jochi. The most recent common ancestor of the special haplotype cluster that includes the Lu clan and Tore clan lived about 1000 years ago (YA), while the Huo and Tuo clans do not share any Y lineages with the Lu clan. In addition to the reported lineages, such as C3*-Star Cluster, R1b-M343, and Q, our results indicate that haplogroup C2b1a1b1-F1756 might be another candidate of the true Y lineage of Genghis Khan.

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-harbour 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 additional damage-reduced genome-wide data of two previously published individuals from the Eneolithic Botai culture in Kazakhstan (~5,400 BP). We find that present-day inner Eurasian populations are structured into three distinct admixture clines stretching between various western and eastern Eurasian ancestries, mirroring geography. The Botai and more recent ancient genomes from Siberia show a decrease in contributions from so-called 'ancient North Eurasian' ancestry over time, which is detectable only in the northern-most 'forest-tundra' cline. The intermediate 'steppe-forest' cline descends from the Late Bronze Age steppe ancestries, while the 'southern steppe' cline further to the south shows a strong West/South Asian influence. Ancient genomes suggest a northward spread of the southern steppe cline in Central Asia during the first millennium BC. 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.

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.