Origin and diffusion of mtDNA haplogroup X

A maximum parsimony tree of 21 complete mitochondrial DNA (mtDNA) sequences belonging to haplogroup X and the survey of the haplogroup-associated polymorphisms in 13,589 mtDNAs from Eurasia and Africa revealed that haplogroup X is subdivided into two major branches, here defined as “X1” and “X2.” The first is restricted to the populations of North and East Africa and the Near East, whereas X2 encompasses all X mtDNAs from Europe, western and Central Asia, Siberia, and the great majority of the Near East, as well as some North African samples. Subhaplogroup X1 diversity indicates an early coalescence time, whereas X2 has apparently undergone a more recent population expansion in Eurasia, most likely around or after the last glacial maximum. It is notable that X2 includes the two complete Native American X sequences that constitute the distinctive X2a clade, a clade that lacks close relatives in the entire Old World, including Siberia. The position of X2a in the phylogenetic tree suggests an early split from the other X2 clades, likely at the very beginning of their expansion and spread from the Near East.     

Mitochondrial DNA polymorphism in populations of aboriginal residents of the Far East

An analysis of mtDNA polymorphism in eight populations of aboriginal residents (N = 519) of the Far East has been performed. The majority of haplogroups revealed in the examined groups were of East Eurasian origin. Haplogroup D was revealed in seven populations and its frequency varied from 2.8% in Koryaks to 28.3% and 28.9% in Nanaians and Evenks, respectively. Chukchi and Koryak populations, which belong to the same language family, exhibited haplogroup G, which has the same motive and indicates the genetic kinship of both populations. The presence of East Eurasian haplogroups A and D with a strong predominance of haplogroup A in Chukchi indicates the closer relationship of this population both with Asian and Canadian Eskimos and northern Atapasks on the other side of Bering Strait. The high level of genetic variability was revealed in populations belonging to the Tungus-Manjur group. The high frequency of east Eurasian haplogroups in Nanaians could result from close historical associations with Siberian Evenks.     

Beringian standstill and spread of Native American founders

Native Americans derive from a small number of Asian founders who likely arrived to the Americas via Beringia. However, additional details about the initial colonization of the Americas remain unclear. To investigate the pioneering phase in the Americas we analyzed a total of 623 complete mtDNAs from the Americas and Asia, including 20 new complete mtDNAs from the Americas and seven from Asia. This sequence data was used to direct high-resolution genotyping from 20 American and 26 Asian populations. Here we describe more genetic diversity within the founder population than was previously reported. The newly resolved phylogenetic structure suggests that ancestors of Native Americans paused when they reached Beringia, during which time New World founder lineages differentiated from their Asian sister-clades. This pause in movement was followed by a swift migration southward that distributed the founder types all the way to South America. The data also suggest more recent bi-directional gene flow between Siberia and the North American Arctic.     

长江中下游湿地大型水鸟种群动态和幼鸟比例研究

迁徙水鸟保护对生物多样性保护具有重要意义。开展水鸟种群数量和幼鸟比例监测,对科学评估其种群变化趋势、制定长期保护策略具有重要价值。长江中下游湿地是东亚-澳大利西亚迁徙路线上重要的水鸟越冬区之一。本研究采用野外同步调查等方法对该区域87个湿地的亟需保护和具有代表性的10种大型越冬水鸟,其中雁形目6种,分别是鸿雁Anser cygnoides、豆雁A.fabalis、灰雁A.grus、白额雁A.albifrons、小白额雁A.erythropus和小天鹅Cygnus columbianus;鹤形目4种,分别是白鹤Leucogeranus leucogeranus、白枕鹤Antigone vipio、灰鹤Grus grus和白头鹤G.monacha,进行了长期监测(2003—2019年冬季),并结合相关文献,评估其种群变化趋势、幼鸟比例和死亡率。研究结果如下：(1)2005—2019年3种水鸟(豆雁、灰雁和灰鹤)的种群数量呈上升趋势,7种水鸟(鸿雁、白额雁、小白额雁、小天鹅、白鹤、白枕鹤和白头鹤)种群数量呈下降趋势;(2)种群趋势下降组(N=7)和上升组(N=3)的幼鸟比例均值在2016—2...     

Polymorphism of mitochondrial DNA in old believers from Siberia

The polymorphism of mtDNA was examined in populations of Old Believers (n = 104) and Russians from Novosibirsk oblast (n = 270). Most of the haplogroups identified belonged to West Eurasian lineages. The frequencies of these haplogroups constituted 96.6% in Russians from Novosibirsk and 93.2% in Old Believers from Tyumen oblast. The populations examined were characterized by a high mtDNA diversity level (h = 0.98) compared to other population samples of Russians from Russia. Among the West Eurasian haplogroups, the most common (a frequency of more than 10%) were haplogroups H, U, J, and T, the proportion of which constituted 77.9% in Old Believers and 83.1% in Russians from Novosibirsk. The Mongoloid admixture in Russians (3.3%) and Old Believers (6.7%) was represented by haplogroups A, D, Z, and C, D, M*, respectively. Statistically significant differences (P < 0.05) were revealed between the Old Believers examined and Bosnians, Czechs, Slovenes, and Russians from the cities of Nizhny Novgorod and Tula. The data obtained confirm the earlier hypothesized influence of the Finno-Ugric component on the East Slavic populations.     

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.     

Haplotype diversity in mtDNA and Y-chromosome in populations of Altai-Sayan region

Polymorphism of mtDNA was examined in five ethnic populations that belong to the Turkic language group and inhabit the territory of the Altai-Sayan upland (N = 1007). Most of the haplogroups identified in the examined populations belonged to East Eurasian lineages. In all five populations, only three haplogroups, C, D, and F, were prevailing. The frequencies of the other six haplogroups (A, B, G, M, Y, and Z) varied in the range from 1.1 to 6.5%. Among West Eurasian haplogrous, the most common were haplogroups H, J, T, and U. An analysis of Y-chromosome haplogroups in 407 individuals showed that only two haplogroups, N* and R1a1, were present in all five populations examined. Moreover, in different ethnic groups, the highest frequencies were observed for C-M130, N-P43, and N-Tat haplogroups. The differences in the distribution patterns of ancient West Eurasian and East Eurasian haplotypes from Gorny Altai in the present-day populations from the northern part of Eurasia revealed can be explained in terms of the multistage expansion of humans across these territories. The ubiquity of haplotypes from haplogroup H and cluster U across the wide territory from the Yenisei River basin to the Atlantic Ocean can indicate directional human expansion, which most likely occurred out of Central Asia as early as in the Paleolithic era, and took place in several waves with the glacier retreat.     

The western and eastern roots of the Saami--the story of genetic "outliers" told by mitochondrial DNA and Y chromosomes

The Saami are regarded as extreme genetic outliers among European populations. In this study, a high-resolution phylogenetic analysis of Saami genetic heritage was undertaken in a comprehensive context, through use of maternally inherited mitochondrial DNA (mtDNA) and paternally inherited Y-chromosomal variation. DNA variants present in the Saami were compared with those found in Europe and Siberia, through use of both new and previously published data from 445 Saami and 17,096 western Eurasian and Siberian mtDNA samples, as well as 127 Saami and 2,840 western Eurasian and Siberian Y-chromosome samples. It was shown that the “Saami motif” variant of mtDNA haplogroup U5b is present in a large area outside Scandinavia. A detailed phylogeographic analysis of one of the predominant Saami mtDNA haplogroups, U5b1b, which also includes the lineages of the “Saami motif,” was undertaken in 31 populations. The results indicate that the origin of U5b1b, as for the other predominant Saami haplogroup, V, is most likely in western, rather than eastern, Europe. Furthermore, an additional haplogroup (H1) spread among the Saami was virtually absent in 781 Samoyed and Ob-Ugric Siberians but was present in western and central European populations. The Y-chromosomal variety in the Saami is also consistent with their European ancestry. It suggests that the large genetic separation of the Saami from other Europeans is best explained by assuming that the Saami are descendants of a narrow, distinctive subset of Europeans. In particular, no evidence of a significant directional gene flow from extant aboriginal Siberian populations into the haploid gene pools of the Saami was found.