Genetic markers on the distribution of ancient marine hunters in Priokhotye

This is a review of studies on the genetic polymorphism of modern and ancient populations of the north of Asia and America, with the aim of reconstructing the history of migrations of ancient marine hunters in the Okhotsk Sea region. The data on mitochondrial DNA polymorphism and the “Arctic” mutation distribution – the rs80356779-A variant of the CPT1A gene – were analyzed. It is known that the “Arctic” variant of the CPT1A gene is widely distributed in modern populations of the Eskimos, Chukchis, Koryaks, and other peoples of the Okhotsk Sea region, whose economic structure is associated with marine hunting. According to paleogenomic data, the earliest cases of the “Arctic” variant of the CPT1A gene were found in the Greenland and Canadian Paleoeskimos (4 thousand years ago), among representatives of the Tokarev culture of the Northern Priokhotye (3 thousand years ago), and among the bearers of the culture of the late Jomon of Hokkaido (3.5–3.8 thousand years ago). The results of the analysis revealed several migration events associated with the spread of marine hunters in the Okhotsk Sea region. The latest migration, which left traces on bearers of the Epi-Jomon culture (2.0–2.5 thousand years ago), introduced the mitochondrial haplogroup G1b and the “Arctic” variant of the CPT1A gene from the north of Priokhotye to Hokkaido and neighboring territories of the Amur Region. Traces of earlier migration, which also brought the “Arctic” mutation, were recorded in the Hokkaido population of the late Jomon period (3.5–3.8 thousand years ago). A phylogenetic analysis of mitochondrial genomes belonging to the rare haplogroup C1a, found in populations of the Far East and Japan, but phylogenetically related to the C1-haplogroups of the Amerindians, was carried out. The results of the analysis showed that the divergence of mitochondrial lineages within the C1a haplogroup occurred in the range from 7.9 to 6.6 thousand years ago, and the age of the Japanese branch of the C1a haplogroup is approximately 5.2 thousand years. It is not yet known whether this migration is associated with the spread of the “Arctic” variant of the CPT1A gene or the presence of C1a haplotypes in the population of the Japanese islands marks another, earlier, episode of the migration history linking the populations of Northwest Pacific and North America

The role of Beringia in human adaptation to Arctic conditions based on results of genomic studies of modern and ancient populations

The results of studies in Quaternary geology, archeology, paleoanthropology and human genetics demonstrate that the ancestors of Native Americans arrived in mid-latitude North America mainly along the Pacific Northwest Coast, but had previously inhabited the Arctic and during the last glacial maximum were in a refugium in Beringia, a land bridge connecting Eurasia and North America. The gene pool of Native Americans is represented by unique haplogroups of mitochondrial DNA and the Y chromosome, the evolutionary age of which ranges from 13 to 22 thousand years. The results of a paleogenomic analysis also show that during the last glacial maximum Beringia was populated by human groups that had arisen as a result of interaction between the most ancient Upper Paleolithic populations of Northern Eurasia and newcomer groups from East Asia. Approximately 20 thousand years ago the Beringian populations began to form, and the duration of their existence in relative isolation is estimated at about 5 thousand years. Thus, the adaptation of the Beringians to the Arctic conditions could have taken several millennia. The adaptation of Amerindian ancestors to high latitudes and cold climates is supported by genomic data showing that adaptive genetic variants in Native Americans are associated with various metabolic pathways: melanin production processes in the skin, hair and eyes, the functioning of the cardiovascular system, energy metabolism and immune response characteristics. Meanwhile, the analysis of the existing hypotheses about the selection of some genetic variants in the Beringian ancestors of the Amerindians in connection with adaptation to the Arctic conditions (for example, in the FADS, ACTN3, EDAR genes) shows the ambiguity of the testing results, which may be due to the loss of some traces of the “Beringian” adaptation in the gene pools of modern Native Americans. The most optimal strategy for further research seems to be the search for adaptive variants using the analysis of paleogenomic data from the territory of Beringia, but such genetic data are still very scarce

Sources of the mitochondrial gene pool of Russians by the results of analysis of modern and paleogenomic data

Paleogenomic studies of recent years have shown that the Bronze Age migrations of populations of the PontoCaspian steppes from the east to the west of Europe had a great influence on the formation of the genetic makeup of modern Europeans. The results of studies of the variability of mitochondrial genomes in the modern Russian populations of Eastern Europe also made it possible to identify an increase in the effective population size during the Bronze Age, which, apparently, could be related to the migration processes of this time. This paper presents the results of analysis of data on the variability of entire mitochondrial genomes in the modern Russian populations in comparison with the distribution of mtDNA haplogroups in the ancient populations of Europe and the Caucasus of the Neolithic and Bronze Age. It was shown that the formation of the modern appearance of the Russian mitochondrial gene pool began approximately 4 thousand years B.C. due to the influx of mtDNA haplotypes characteristic of the population of Central and Western Europe to the east of Europe. It is assumed that the migrations of the ancient populations of the Ponto-Caspian steppes in the western direction led to the formation of mixed populations in Central Europe, bearing mitochondrial haplogroups H, J, T, K, W characteristic of Western and Central Europeans. Further expansion of these populations to the east of Europe and further to Asia explains the emergence of new features of the mitochondrial gene pool in Eastern Europeans. The results of a phylogeographic analysis are also presented, showing that the features of the geographical distribution of the subgroups of the mitochondrial haplogroup R1a in Europe are a reflection of the “Caucasian” component that appeared in the gene pools of various groups of Europeans during the migration of the Bronze Age. The results of phylogeographic analysis of mitochondrial haplogroups U2e2a1d, U4d2, N1a1a1a1, H2b, and H8b1 testify to the migrations of ancient Eastern Europeans to Asia – the south of Siberia and the Indian subcontinent

Accompanies activity of teachers by saving and formation of health of pupils

The authors describe the various functions of scientific director by support of activity of teachers in the field of saving and formation of health of pupilsОписаны разнообразные функции научного руководителя по сопровождению деятельности педагогов в сфере сбережения и формирования здоровья обучающихс

Functions of scientific director, who accompanies activity of teachers by saving and formation of health of pupils

The authors describe the various functions of scientific director by support of activity of teachers in the field of saving and formation of health of pupilsОписаны разнообразные функции научного руководителя по сопровождению деятельности педагогов в сфере сбережения и формирования здоровья обучающихс

Polymorphism of the cold receptor gene TRPM8 in native populations of Siberia: putative selective role of rs11563208 polymorphism in Northeast Asia

The TRPM8 gene encodes the cold-activated receptor TRPM8, which has an important role in cold adaptation as well as in metabolic and immune responses. Previously, it has been found that polymorphic variants of the TRPM8 gene, which are present in human populations, are associated with different cold sensitivity. In the present study we have investigated variability of all exons and adjacent intronic sequences of this gene in samples of native populations of Siberia, including regional groups from Northeastern, Central, Southern and Western parts of Siberia. In 9 out of 21 variable loci revealed, the frequency of the derived alleles accounts for more than 10 % (loci rs28901637, rs11562975, rs10929319, rs28901644, rs7593557, rs12185590, rs10171428, rs11563208, and rs11563071). Different variants of these polymorphic loci, which are most frequent in native Siberians, generate 26 haplotypes. In addition to 7 haplotypes shared by all regional groups and present there at frequencies of 2–28 %, unique haplotypes were found in all regional samples. One of them characterized by derived allele T at rs11563208 locus is very interesting because it is spread at the frequency of 14 % only in Northeast Asia (in Koryaks and Chukchi). A synonymous substitution at rs11563208 locus may have a functional role because the amino acid residue (isoleucine at position 1016 of TRPM8 protein) corresponding to this locus is located in functionally important TRP-domain and, hence, it can influence thermoreception processes. It is assumed that the appearance of the haplotype carrying the rs11563208-T allele may be due to the necessity to counteract the inhibition of TRPM8 receptors by polyunsaturated fatty acids, which are typical of the traditional diet of native people of Northeast Asia (Siberian Eskimo, Chukchi and Koryaks)

Evaluating the role of selection in the evolution of mitochondrial genomes of aboriginal peoples of Siberia

Studies of the nature of mitochondrial DNA (mtDNA) variability in human populations have shown that protein­coding genes are under negative (purifying) selection, since their mutation spectra are characterized by a pro­ nounced predominance of synonymous substitutions over non­synonymous ones (Ka/Ks < 1). Meanwhile, a number of studies have shown that the adaptation of populations to various environmental conditions may be accompanied by a relaxation of negative selection in some mtDNA genes. For example, it was previously found that in Arctic populations, negative selection is relaxed in the mitochondrial ATP6 gene, which encodes one of the subunits of ATP synthase. In this work, we performed a Ka/Ks analysis of mitochondrial genes in large samples of three regional population groups in Eurasia: Siberia (N = 803), Western Asia/Transcaucasia (N = 753), and Eastern Europe (N = 707). The main goal of this work is to search for traces of adaptive evolution in the mtDNA genes of aboriginal peoples of Siberia represented by populations of the north (Koryaks, Evens) and the south of Siberia and the adjacent territory of Northeast China (Bu­ryats, Barghuts, Khamnigans). Using standard Ka/Ks analysis, it was found that all mtDNA genes in all studied regional population groups are subject to negative selection. The highest Ka/Ks values in different regional samples were found in almost the same set of genes encoding subunits of ATP synthase (ATP6, ATP8), NADH dehydrogenase complex (ND1, ND2, ND3), and cytochrome bc1 complex (CYB). The highest Ka/Ks value, indicating a relaxation of negative selection, was found in the ATP6 gene in the Siberian group. The results of the analysis performed using the FUBAR method (HyPhy software package) and aimed at searching for mtDNA codons under the influence of selection also showed the predominance of negative selection over positive selection in all population groups. In Siberian populations, nucleotide sites that are under positive selection and associated with mtDNA haplogroups were registered not in the north (which is expected under the assumption of adaptive evolution of mtDNA), but in the south of Siberia

Polymorphism of the trehalase gene (TREH) in native populations of Siberia

Deficiency of some carbohydrates in the traditional diet of native populations of the Far North contributed to a high population prevalence of inactive variants of genes encoding, for example, amylase (AMY2A gene) and sucrase­isomaltase (SI gene). Trehalose, which is found in algae, higher fungi, lichens and some higher plants, is another of the disaccharides, poorly digested by native people of the Far North. Here, in native populations of Siberia, we studied the polymorphism of the TREH gene, which encodes trehalase, an enzyme that cleaves trehalose. The analysis of exome polymorphism showed the presence of seven haplotypes of the TREH gene in the population. Three of them are determined by the variant rs2276064­A, which is associated with the lowest activity of trehalase. The maximum frequency of this group of haplotypes is observed in the samples of native populations of Northeast Asia (about 60 %), in the remaining samples of the Siberian populations, its frequency is 30–40 %. Thus, the high frequency of variant rs2276064­A, associated with a low­activity trehalase, explains why Northern aboriginal peoples avoid food containing trehalose. It is assumed that the increase in the frequency of this variant in the populations of Northeast Asia can have been facilitated by gene drift acting in populations of a small effective size. However, it is possible that artificially induced trehalose deficiency in the traditional diet of the indigenous peoples of the Far North (due to the tradition of rejecting fungi) could also cause an increase in the frequency of low­activity trehalase, provided that this tradition has been existing among Northern aboriginal peoples for many generations

Uniparental Genetic Heritage of Belarusians: Encounter of Rare Middle Eastern Matrilineages with a Central European Mitochondrial DNA Pool

Ethnic Belarusians make up more than 80% of the nine and half million people inhabiting the Republic of Belarus. Belarusians together with Ukrainians and Russians represent the East Slavic linguistic group, largest both in numbers and territory, inhabiting East Europe alongside Baltic-, Finno-Permic- and Turkic-speaking people. Till date, only a limited number of low resolution genetic studies have been performed on this population. Therefore, with the phylogeographic analysis of 565 Y-chromosomes and 267 mitochondrial DNAs from six well covered geographic sub-regions of Belarus we strove to complement the existing genetic profile of eastern Europeans. Our results reveal that around 80% of the paternal Belarusian gene pool is composed of R1a, I2a and N1c Y-chromosome haplogroups – a profile which is very similar to the two other eastern European populations – Ukrainians and Russians. The maternal Belarusian gene pool encompasses a full range of West Eurasian haplogroups and agrees well with the genetic structure of central-east European populations. Our data attest that latitudinal gradients characterize the variation of the uniparentally transmitted gene pools of modern Belarusians. In particular, the Y-chromosome reflects movements of people in central-east Europe, starting probably as early as the beginning of the Holocene. Furthermore, the matrilineal legacy of Belarusians retains two rare mitochondrial DNA haplogroups, N1a3 and N3, whose phylogeographies were explored in detail after de novo sequencing of 20 and 13 complete mitogenomes, respectively, from all over Eurasia. Our phylogeographic analyses reveal that two mitochondrial DNA lineages, N3 and N1a3, both of Middle Eastern origin, might mark distinct events of matrilineal gene flow to Europe: during the mid-Holocene period and around the Pleistocene-Holocene transition, respectively

Origin and Post-Glacial Dispersal of Mitochondrial DNA Haplogroups C and D in Northern Asia

More than a half of the northern Asian pool of human mitochondrial DNA (mtDNA) is fragmented into a number of subclades of haplogroups C and D, two of the most frequent haplogroups throughout northern, eastern, central Asia and America. While there has been considerable recent progress in studying mitochondrial variation in eastern Asia and America at the complete genome resolution, little comparable data is available for regions such as southern Siberia – the area where most of northern Asian haplogroups, including C and D, likely diversified. This gap in our knowledge causes a serious barrier for progress in understanding the demographic pre-history of northern Eurasia in general. Here we describe the phylogeography of haplogroups C and D in the populations of northern and eastern Asia. We have analyzed 770 samples from haplogroups C and D (174 and 596, respectively) at high resolution, including 182 novel complete mtDNA sequences representing haplogroups C and D (83 and 99, respectively). The present-day variation of haplogroups C and D suggests that these mtDNA clades expanded before the Last Glacial Maximum (LGM), with their oldest lineages being present in the eastern Asia. Unlike in eastern Asia, most of the northern Asian variants of haplogroups C and D began the expansion after the LGM, thus pointing to post-glacial re-colonization of northern Asia. Our results show that both haplogroups were involved in migrations, from eastern Asia and southern Siberia to eastern and northeastern Europe, likely during the middle Holocene