首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
Published data on two cases of linkage disequilibrium in Yakuts are analyzed. These are the disequilibria between loci HLA-A and HLA-Band between the mutation of gene SCA1 responsible for type 1 spinocerebellar ataxia and its flanking microsatellites D6S274 andD6S89. Both cases are regarded as consequences of the founder effect. The genetic archeological approach has been used to calculate the historical period when the mutant SCA1 gene and the HLA-A1\B17 haplotype spread in the population. It has been found that this was approximately 60–70 generations (1500–1750 years) ago in both cases. The time of the segregation of haplotype HLA-A1\B17 has also been calculated for some other populations. Caucasoids have proved to be the oldest carriers of this gene, which agrees with the well-known notion that HLA-A1 originated in Indo-Europeans. The general distribution of HLA genes in Yakuts is similar to that in east-central Asian Mongoloids; therefore, it is concluded that that Yakuts are east-central Asian Mongoloids by origin, except for the founder that had haplotype A1\B17. Historically, the time of the appearance of this haplotype coincided with the period when Saks conquered east-central Asia; therefore, it is hypothesized that the aforementioned founder was a Sak.  相似文献   

2.
The gene pool structure was studied for the indigenous population of the Sakha Republic (Yakutia). The composition and frequencies of Y-chromosome haplotypes in Yakuts were characterized. Six haplogroups were observed: C3×M77, C3c, N*, N2, N3a, and R1a1, N3a being the most common (89%). The gene diversity computed from the haplogroup frequencies was low in all samples examined. Gene differentiation was analyzed by AMOVA with two marker systems (haplogroup frequencies and Y-chromosomal microsatellite haplotypes) and was estimated at 0.24 and 2.85%, respectively. The frequencies and molecular phylogeny of the YSTR haplotypes were studied for the N3a haplogroup. In total, 40 haplotypes were found in Yakuts. Evenks and Yakuts displayed highly specific overlapping N3a haplotype spectra, atypical for other Siberian ethnic groups. Cluster analysis with N3a YSTR haplotypes showed that Yakuts are isolated from other Turkic-speaking populations of Southern Siberia. The genetic diversity generation time was estimated at 4450 ± 1960 years for the Yakut haplotype spectrum. In contrast to mtDNA data, the results suggest a significant contribution of the local Paleolithic component to the Y-chromosome gene pool of Yakuts. Ethnogenetic reconstructions were inferred from the diversity and phylogeography of the N3a haplogroup in Siberia.  相似文献   

3.
Gene pool structure of Sakha Republic (Yakutia) native population has been studied: we defined composition and frequencies of Y-chromosome haplogroups for Yakuts. Six haplogroups: C3 x M77, C3c, N*, N2, N3a and R1a1 have been revealed in Yakut gene pool. A greater part of Y-chromosome in Yakut population belongs to N3a haplogroup (89%). All investigated Yakut population samples have low values of gene diversity, calculated based on haplogroup frequencies. Gene differentiation of the investigated samples estimated using the analysis of molecular variance (AMOVA) by two marker systems (haplogroup frequencies and microsatellite haplotypes of Y-chromosome) revealed a portion of interpopulation differences amounting to 0.24 and 2.85%, respectively. Frequencies and molecular phylogeny of YSTR-haplotypes were revealed for N3a haplogroup of Y-chromosome. Altogether forty haplotypes were found in Yakuts. Evenks and Yakuts are characterized by overlapping and very specific spectrum of N3a haplotypes, which is not typical for other Siberian ethnic groups. Cluster analysis of populations by N3a YSTR-haplotypes shows Yakut isolation from Turkic-speaking populations in the South Siberia. Genetic diversity generation time for a specific spectrum of Yakut haplotypes was estimated as 4.45 +/- 1.96 thousand years. As opposed to the data on mtDNA, the obtained results give an evidence for significant contribution of a local palaeolithic component into Y-chromosomal Yakut gene pool. Ethnogenetic reconstruction of the present picture of genetic diversity in N3a haplogroup in the territory of Siberia is under consideration.  相似文献   

4.
To study the mitochondrial gene pool structure in Yakuts, polymorphism of mtDNA hypervariable segment I (16,024–16,390) was analyzed in 191 people sampled from the indigenous population of the Sakha Republic. In total, 67 haplotypes of 14 haplogroups were detected. Most (91.6%) haplotypes belonged to haplogroups A, B, C, D, F, G, M*, and Y, which are specific for East Eurasian ethnic groups; 8.4% haplotypes represented Caucasian haplogroups H, HV1, J, T, U, and W. A high frequency of mtDNA types belonging to Asian supercluster M was peculiar for Yakuts: mtDNA types belonging to haplogroup C, D, or G and undifferentiated mtDNA types of haplogroup M (M*) accounted for 81% of all haplotypes. The highest diversity was observed for haplogroups C and D, which comprised respectively 22 (44%) and 18 (30%) haplotypes. Yakuts showed the lowest genetic diversity (H = 0.964) among all Turkic ethnic groups. Phylogenetic analysis testified to common genetic substrate of Yakuts, Mongols, and Central Asian (Kazakh, Kyrgyz, Uighur) populations. Yakuts proved to share 21 (55.5%) mtDNA haplotypes with the Central Asian ethnic groups and Mongols. Comparisons with modern Paleoasian populations (Chukcha, Itelmen, Koryaks) revealed three (8.9%) haplotypes common for Yakuts and Koryaks. The results of mtDNA analysis disagree with the hypothesis of an appreciable Paleoasian contribution to the modern Yakut gene pool.  相似文献   

5.
Cholera epidemic has not been reported in Haiti for at least 100?years, although cholera has been present in Latin America since 1991. Surprisingly, the recent cholera epidemic in Haiti (October 2010) recorded more than 250,000 cases and 4000 deaths in the first 6?months and became one of the most explosive and deadly cholera outbreak in recent history. In the present study, we conducted genomic analyses of pathogenicity islands of three Haitian Vibrio cholerae strains and compared them with nine different V. cholerae O1 El Tor genomes. Although CIRS101 is evolutionarily most similar to the Haitian strains, our study also provides some important differences in the genetic organization of pathogenicity islands of Haitian strains with CIRS101. Evolutionary analysis suggests that unusual functional constraints have been imposed on the Haitian strains and we hypothesize that amino acid substitution is more deleterious in Haitian strains than in nonHaitian strains.  相似文献   

6.
Cholera epidemic has not been reported in Haiti for at least 100 years, although cholera has been present in Latin America since 1991. Surprisingly, the recent cholera epidemic in Haiti (October 2010) recorded more than 250,000 cases and 4000 deaths in the first 6 months and became one of the most explosive and deadly cholera outbreak in recent history. In the present study, we conducted genomic analyses of pathogenicity islands of three Haitian Vibrio cholerae strains and compared them with nine different V. cholerae O1 El Tor genomes. Although CIRS101 is evolutionarily most similar to the Haitian strains, our study also provides some important differences in the genetic organization of pathogenicity islands of Haitian strains with CIRS101. Evolutionary analysis suggests that unusual functional constraints have been imposed on the Haitian strains and we hypothesize that amino acid substitution is more deleterious in Haitian strains than in nonHaitian strains.  相似文献   

7.
Genetic clues to the origin of the apple   总被引:7,自引:0,他引:7  
Molecular genetic markers complement archaeological, breeding and geographical investigations of the origins, history and domestication of plants. With increasing access to wild apples from Central Asia, along with the use of molecular genetic markers capable of distinguishing between species, and explicit methods of phylogeny reconstruction, it is now possible to test hypotheses about the origin of the domesticated apple. Analyses of nuclear rDNA and chloroplast DNA (cpDNA) sequences indicate that the domesticated apple is most closely related to series Malus species. Moreover, the occurrence of a shared 18-bp duplication in the cpDNAs of wild and cultivated apple supports the close relationship between them. Hypotheses about the hybridization and the origin of the domesticated apple cannot be rejected completely until more variable, phylogenetically informative markers are found.  相似文献   

8.
On the origin of mitochondria: a genomics perspective   总被引:10,自引:0,他引:10  
The availability of complete genome sequence data from both bacteria and eukaryotes provides information about the contribution of bacterial genes to the origin and evolution of mitochondria. Phylogenetic analyses based on genes located in the mitochondrial genome indicate that these genes originated from within the alpha-proteobacteria. A number of ancestral bacterial genes have also been transferred from the mitochondrial to the nuclear genome, as evidenced by the presence of orthologous genes in the mitochondrial genome in some species and in the nuclear genome of other species. However, a multitude of mitochondrial proteins encoded in the nucleus display no homology to bacterial proteins, indicating that these originated within the eukaryotic cell subsequent to the acquisition of the endosymbiont. An analysis of the expression patterns of yeast nuclear genes coding for mitochondrial proteins has shown that genes predicted to be of eukaryotic origin are mainly translated on polysomes that are free in the cytosol whereas those of putative bacterial origin are translated on polysomes attached to the mitochondrion. The strong relationship with alpha-proteobacterial genes observed for some mitochondrial genes, combined with the lack of such a relationship for others, indicates that the modern mitochondrial proteome is the product of both reductive and expansive processes.  相似文献   

9.
10.
The area of what is now the Ukraine has been the arena of large‐scale demographic processes that may have left their traces in the contemporary gene pool of Ukrainians. In this study, we present new mitochondrial DNA data for 607 Ukrainians (hypervariable segment I sequences and coding region polymorphisms). To study the maternal affinities of Ukrainians at the level of separate mitochondrial haplotypes, we apply an original technique, the haplotype co‐occurrence analysis. About 20% of the Ukrainian maternal gene pool is represented by lineages highly specific to Ukrainians, but is scarcely found in other populations. About 9% of Ukrainian mtDNA lineages are typical for peoples of the Volga region. We also identified minor gene pool strata (1.6–3.3%), each of which is common in Lithuanians, Estonians, Saami, Nenets, Cornish, and the populations of the North Caucasus. Am J Phys Anthropol 152:543–550, 2013. © 2013 Wiley Periodicals, Inc.  相似文献   

11.
Integrated with both a historical perspective and an evolutionary angle, this opinion article presents a brief and personal view of the emergence of cellular microbiology research. From the very first observations of phagocytosis by Goeze in 1777 to the exhaustive analysis of the cellular defence mechanisms performed in modern laboratories, the studies by cell biologists and microbiologists have converged into an integrative research field distinct from, but fully coupled to immunity: cellular microbiology. In addition, this brief article is thought as a humble patchwork of the motivations that have guided the research in my group over a quarter century.  相似文献   

12.
Gene duplication is considered to be the most important evolutionary process for generating novel genes. However, the mechanisms involved in the evolution of such genetic innovations remain unclear. There is compelling evidence to suggest that changing the subcellular location of a protein can also alter its function, and that diversity in subcellular targeting within gene families is common. Here, we introduce the idea that protein subcellular relocalization might be an important evolutionary mechanism for the origins of new genes.  相似文献   

13.
Over the course of the last two decades, the understanding of the early evolution of feathers in nonavian dinosaurs has been revolutionized. It is now recognized that early feathers had a simple form comparable in general structure to the hairs of mammals. Insight into the prevalence of simple feathers throughout the dinosaur family tree has gradually arisen in tandem with the growing evidence for endothermic dinosaur metabolisms. This has led to the generally accepted opinion that the early feather coats of dinosaurs functioned as thermo insulation. However, thermo insulation is often erroneously stated to be a likely functional explanation for the origin of feathers. The problem with this explanation is that, like mammalian hair, simple feathers could serve as insulation only when present in sufficiently high concentrations. The theory therefore necessitates the origination of feathers en masse. We advocate for a novel origin theory of feathers as bristles. Bristles are facial feathers common among modern birds that function like mammalian tactile whiskers, and are frequently simple and hair‐like in form. Bristles serve their role in low concentrations, and therefore offer a feasible first stage in feather evolution.  相似文献   

14.
Here we argue that, based on evolutionary, ecological and agronomic considerations, climate change could not have been a suitable background nor a probable cause of plant domestication in the Near East. This thesis is developed based on the year-to-year yield dynamics in traditional rainfed grain farming in semi-arid environments, on the genetic basis that underlies temporal yield dynamics in natural wild cereal populations as well as in traditional farming systems, and upon the recognition that prior to elaborate high capacity and long-range trade networks, yield stability was more important than yield maximization. We also briefly discuss the likely social and cultural responses to subtle and real climatic changes vs. responses to rapid directional environmental trends. Taking into account the agronomic, ecological and genetic aspects discussed, it is suggested that the Near Eastern founder crop assemblage was chosen to function within the normal east Mediterranean precipitation regime, in which good rainy years create the ‘normal surplus’ that sustains farming communities during drought years, and the different crop types provide the system with its compensating ability. A slow (but real) climatic change is unlikely to induce major (revolutionary) cultural changes. Nor would a prominent environmental change provide the proper background for the origins of agriculture because it would abolish the buffering capacity of the system. Therefore, farming cannot function as a sustainable ‘buffering mechanism’ to counterbalance climatic instability causing natural resource depletion.  相似文献   

15.
Parkinson disease (PD), once considered as a prototype of a sporadic disease, is now known to be considerably affected by various genetic factors, which interact with environmental factors and the normal process of aging, leading to PD. Large studies determined that the hereditary component of PD is at least 27%, and in some populations, single genetic factors are responsible for more than 33% of PD patients. Interestingly, many of these genetic factors, such as LRRK2, GBA, SMPD1, SNCA, PARK2, PINK1, PARK7, SCARB2, and others, are involved in the autophagy-lysosome pathway (ALP). Some of these genes encode lysosomal enzymes, whereas others correspond to proteins that are involved in transport to the lysosome, mitophagy, or other autophagic-related functions. Is it possible that all these factors converge into a single pathway that causes PD? In this review, we will discuss these genetic findings and the role of the ALP in the pathogenesis of PD and will try to answer this question. We will suggest a novel hypothesis for the pathogenic mechanism of PD that involves the lysosome and the different autophagy pathways.  相似文献   

16.
17.
The Kelantanese Malays who resided in the remote northeastern regions of the Malay Peninsula in the Kelantan state are believed to have a unique genetic signature. The objective of this review is to analyze the populational sub-structure of the Kelantanese Malays from historical, genetic and linguistic perspectives. Historical data suggest that the Semang were composed of the Jahai, Bateq and Kensiu sub-tribes, whereas the Senoi were composed of only the Temiar sub-tribe. The Mendriq sub-tribe is believed to be the first group of aborigines to land in Kelantan. Subsequently, genetic analysis showed that the Kelantanese Malays are an independent clade at the base of the phylogenetic tree and contain genetic material similar to that of the Semang, specifically the Jahai and the Kensiu sub-tribes. The genetic data are supported by the fact that the Aslian language, a branch of the Austroasiatic languages that is widely spoken by the Semang, was potentially transmitted through agricultural activities. However, the potential limitation of this mini-review is the lack of primary reliable sources covering the historical, linguistic and genetic features of the Kelantanese Malays.  相似文献   

18.
Biological invasions and climate change are two of the largest threats to biodiversity, and this is especially true for island ecosystems that have largely evolved in isolation. The house mouse is considered to have been introduced to sub-Antarctic Marion Island by sealers in the early 1800s. It is currently widespread across the island and has a large impact on the indigenous biota. To date, little information is available on genetic aspects of biological invasions in the sub-Antarctic. Ten specimens of the house mouse were collected from two geographically separated localities on Marion Island. Sequences of the mitochondrial DNA control region revealed only two haplotypes, separated by a single site change. More importantly, these haplotypes are shared between the eastern and western side of Marion Island. By comparing our sequences to data available on GenBank, we provide evidence that house mice on Marion Island is Mus musculus domesticus (Rutty 1772), and most closely related to haplotypes characterizing this species from Denmark, Sweden, Finland, and northern Germany.  相似文献   

19.
20.
Tarskaia LA  Melton P 《Genetika》2006,42(12):1703-1711
Mitochondrial DNA of Yakuts has been compared to those of other Asian populations that belong to the Turkic, Mongolic, and Manchu-Tungusic linguistic groups. Haplogroups C and D proved to be the most frequent ones in Yakuts. In contrast to other Asian populations, subcluster D5a is major in Yakuts. The results have demonstrated that Yakuts are close to Tuvinians and Altaians in maternal lineage.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号