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1.
Nature ; 624(7990): 122-129, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37993721

RESUMO

Before the colonial period, California harboured more language variation than all of Europe, and linguistic and archaeological analyses have led to many hypotheses to explain this diversity1. We report genome-wide data from 79 ancient individuals from California and 40 ancient individuals from Northern Mexico dating to 7,400-200 years before present (BP). Our analyses document long-term genetic continuity between people living on the Northern Channel Islands of California and the adjacent Santa Barbara mainland coast from 7,400 years BP to modern Chumash groups represented by individuals who lived around 200 years BP. The distinctive genetic lineages that characterize present-day and ancient people from Northwest Mexico increased in frequency in Southern and Central California by 5,200 years BP, providing evidence for northward migrations that are candidates for spreading Uto-Aztecan languages before the dispersal of maize agriculture from Mexico2-4. Individuals from Baja California share more alleles with the earliest individual from Central California in the dataset than with later individuals from Central California, potentially reflecting an earlier linguistic substrate, whose impact on local ancestry was diluted by later migrations from inland regions1,5. After 1,600 years BP, ancient individuals from the Channel Islands lived in communities with effective sizes similar to those in pre-agricultural Caribbean and Patagonia, and smaller than those on the California mainland and in sampled regions of Mexico.


Assuntos
Variação Genética , Povos Indígenas , Humanos , Agricultura/história , California/etnologia , Região do Caribe/etnologia , Etnicidade/genética , Etnicidade/história , Europa (Continente)/etnologia , Variação Genética/genética , História do Século XV , História do Século XVI , História do Século XVII , História do Século XVIII , História do Século XIX , História Antiga , História Medieval , Migração Humana/história , Povos Indígenas/genética , Povos Indígenas/história , Ilhas , Idioma/história , México/etnologia , Zea mays , Genoma Humano/genética , Genômica , Alelos
2.
Nat Rev Genet ; 21(6): 377-384, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32251390

RESUMO

Addressing Indigenous rights and interests in genetic resources has become increasingly challenging in an open science environment that promotes unrestricted access to genomic data. Although Indigenous experiences with genetic research have been shaped by a series of negative interactions, there is increasing recognition that equitable benefits can only be realized through greater participation of Indigenous communities. Issues of trust, accountability and equity underpin Indigenous critiques of genetic research and the sharing of genomic data. This Perspectives article highlights identified issues for Indigenous communities around the sharing of genomic data and suggests principles and actions that genomic researchers can adopt to recognize community rights and interests in data.


Assuntos
Privacidade Genética/ética , Genômica/ética , Povos Indígenas/genética , Disseminação de Informação/ética , Acesso à Informação , Pesquisa em Genética/ética , Genoma Humano/genética , Direitos Humanos , Humanos
3.
Proc Natl Acad Sci U S A ; 119(4)2022 01 25.
Artigo em Inglês | MEDLINE | ID: mdl-35042810

RESUMO

The field of genomics has benefited greatly from its "openness" approach to data sharing. However, with the increasing volume of sequence information being created and stored and the growing number of international genomics efforts, the equity of openness is under question. The United Nations Convention of Biodiversity aims to develop and adopt a standard policy on access and benefit-sharing for sequence information across signatory parties. This standardization will have profound implications on genomics research, requiring a new definition of open data sharing. The redefinition of openness is not unwarranted, as its limitations have unintentionally introduced barriers of engagement to some, including Indigenous Peoples. This commentary provides an insight into the key challenges of openness faced by the researchers who aspire to protect and conserve global biodiversity, including Indigenous flora and fauna, and presents immediate, practical solutions that, if implemented, will equip the genomics community with both the diversity and inclusivity required to respectfully protect global biodiversity.


Assuntos
Povos Indígenas/genética , Disseminação de Informação/ética , Biodiversidade , Genômica/métodos , Humanos , Povos Indígenas/psicologia , Povos Indígenas/estatística & dados numéricos , Disseminação de Informação/métodos , Grupos Populacionais/genética
4.
Genet Med ; 26(7): 101158, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38699966

RESUMO

PURPOSE: Against a historical backdrop of researchers who violated trust through lack of benefit sharing, transparency, and engagement, efforts are underway to develop better approaches for genetic and genomic research with Indigenous communities. To increase engagement, there is a need to understand factors that affect researcher and community collaborations. This study aimed to understand the barriers, challenges, and facilitators of Indigenous Peoples in the United States participating in genetic research. METHODS: We conducted 42 semistructured interviews with Tribal leaders, clinicians, researchers, policy makers, and Tribal research review board members across the United States to explore perceived risks, benefits, barriers, and facilitators of genetic research participation. RESULTS: Participants, identifying as Indigenous (88%) or non-Indigenous allies (12%), described their concerns, hesitancy, and fears about genetic research, as well as the roles of trust, transparency, and respect for culture in facilitating partnerships. Previous harms-such as sample and data misuse, stigmatization, or misrepresentation by researchers-revealed strategies for building trust to create more equitable and reciprocal research partnerships. CONCLUSION: Participants in this study offered strategies for increasing genetic research engagement. The pathway forward should foster transparent research policies and practices to facilitate informed research that supports the needs and priorities of participants, communities, and researchers.


Assuntos
Pesquisa em Genética , Humanos , Pesquisa em Genética/ética , Estados Unidos , Feminino , Masculino , Povos Indígenas/genética , Povos Indígenas/psicologia , Confiança , Adulto , Pessoa de Meia-Idade , Pesquisadores/psicologia
5.
Proc Natl Acad Sci U S A ; 118(14)2021 04 06.
Artigo em Inglês | MEDLINE | ID: mdl-33782134

RESUMO

Different models have been proposed to elucidate the origins of the founding populations of America, along with the number of migratory waves and routes used by these first explorers. Settlements, both along the Pacific coast and on land, have been evidenced in genetic and archeological studies. However, the number of migratory waves and the origin of immigrants are still controversial topics. Here, we show the Australasian genetic signal is present in the Pacific coast region, indicating a more widespread signal distribution within South America and implicating an ancient contact between Pacific and Amazonian dwellers. We demonstrate that the Australasian population contribution was introduced in South America through the Pacific coastal route before the formation of the Amazonian branch, likely in the ancient coastal Pacific/Amazonian population. In addition, we detected a significant amount of interpopulation and intrapopulation variation in this genetic signal in South America. This study elucidates the genetic relationships of different ancestral components in the initial settlement of South America and proposes that the migratory route used by migrants who carried the Australasian ancestry led to the absence of this signal in the populations of Central and North America.


Assuntos
Evolução Molecular , Povos Indígenas/genética , Migração Humana , Humanos , América do Sul , Indígena Americano ou Nativo do Alasca
6.
Mol Biol Evol ; 39(2)2022 02 03.
Artigo em Inglês | MEDLINE | ID: mdl-34940850

RESUMO

Tropical indigenous peoples in Asia (TIA) attract much attention for their unique appearance, whereas their genetic history and adaptive evolution remain mysteries. We conducted a comprehensive study to characterize the genetic distinction and connection of broad geographical TIAs. Despite the diverse genetic makeup and large interarea genetic differentiation between the TIA groups, we identified a basal Asian ancestry (bASN) specifically shared by these populations. The bASN ancestry was relatively enriched in ancient Asian human genomes dated as early as ∼50,000 years before the present and diminished in more recent history. Notably, the bASN ancestry is unlikely to be derived from archaic hominins. Instead, we suggest it may be better modeled as a survived lineage of the initial peopling of Asia. Shared adaptations inherited from the ancient Asian ancestry were detected among the TIA groups (e.g., LIMS1 for hair morphology, and COL24A1 for bone formation), and they are enriched in neurological functions either at an identical locus (e.g., NKAIN3), or different loci in an identical gene (e.g., TENM4). The bASN ancestry could also have formed the substrate of the genetic architecture of the dark pigmentation observed in the TIA peoples. We hypothesize that phenotypic convergence of the dark pigmentation in TIAs could have resulted from parallel (e.g., DDB1/DAK) or genetic convergence driven by admixture (e.g., MTHFD1 and RAD18), new mutations (e.g., STK11), or notably purifying selection (e.g., MC1R). Our results provide new insights into the initial peopling of Asia and an advanced understanding of the phenotypic convergence of the TIA peoples.


Assuntos
Evolução Molecular , Genética Populacional , Hominidae , Povos Indígenas , Adaptação Fisiológica , Animais , Ásia , Genoma Humano , Humanos , Povos Indígenas/genética
7.
Hum Mol Genet ; 30(R1): R17-R23, 2021 04 26.
Artigo em Inglês | MEDLINE | ID: mdl-33284971

RESUMO

Compared with the rest of the African continent, North Africa has provided limited genomic data. Nonetheless, the genetic data available show a complex demographic scenario characterized by extensive admixture and drift. Despite the continuous gene flow from the Middle East, Europe and sub-Saharan Africa, an autochthonous genetic component that dates back to pre-Holocene times is still present in North African groups. The comparison of ancient and modern genomes has evidenced a genetic continuity in the region since Epipaleolithic times. Later population movements, especially the gene flow from the Middle East associated with the Neolithic, have diluted the genetic autochthonous component, creating an east to west gradient. Recent historical movements, such as the Arabization, have also contributed to the genetic landscape observed currently in North Africa and have culturally transformed the region. Genome analyses have not shown evidence of a clear correlation between cultural and genetic diversity in North Africa, as there is no genetic pattern of differentiation between Tamazight (i.e. Berber) and Arab speakers as a whole. Besides the gene flow received from neighboring areas, the analysis of North African genomes has shown that the region has also acted as a source of gene flow since ancient times. As a result of the genetic uniqueness of North African groups and the lack of available data, there is an urgent need for the study of genetic variation in the region and its implications in health and disease.


Assuntos
Árabes/genética , DNA/história , Genética Populacional/métodos , Povos Indígenas/genética , África do Norte/etnologia , Fluxo Gênico , História Antiga , Humanos , Oriente Médio , Filogeografia
8.
Hum Genet ; 142(9): 1407-1416, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37479894

RESUMO

Genomics research related to Indigenous people has been at worst exploitative and at best, retrospectively on a journey to improve effective engagement of Indigenous individuals and communities. Genomics can positively impact all stages of clinical management, and to improve genomic effectiveness researchers aggregate genomic data from diverse global sub-populations, such as shared ancestry groupings, as people within these groupings will have a greater proportion of shared DNA traits. While genomics is already being used worldwide to improve lives, its utility and effectiveness has not been maximized for individuals with Indigenous ancestry. Several large datasets of human genetic variation have been made publicly available, of which the most widely used is the Genome Aggregation Database (gnomAD), but none of these databases currently contain any population-specific data for Indigenous populations. There are many reasons why Indigenous people have been largely left out of genomics research and, because of this, miss out on the benefits offered. It is also clear that if research is to be effective, it needs to be done 'with' and not 'on' Indigenous communities. This systematic review of the literature regarding Indigenous peoples (in high income countries) and genomics aims to review the existing literature and identify areas of strength and weakness in study design and conduct, focusing on the effectiveness of Indigenous community engagement.


Assuntos
Genômica , Povos Indígenas , Humanos , Países Desenvolvidos , Estudos Retrospectivos , Povos Indígenas/genética , Bases de Dados Factuais
9.
J Hum Genet ; 68(10): 705-712, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37316650

RESUMO

Due to the geographical proximity of the northern coast of the Sea of Okhotsk and Kamchatka Peninsula to the Beringia, the indigenous populations of these territories are of great interest for elucidating the human settlement history of northern Asia and America. Meanwhile, there is a clear shortage of genetic studies of the indigenous populations of the northern coast of the Sea of Okhotsk. Here, in order to examine their fine-scale matrilineal genetic structure, ancestry and relationships with neighboring populations, we analyzed 203 complete mitogenomes (174 of which are new) from population samples of the Koryaks and Evens of the northern coast of the Sea of Okhotsk and the Chukchi of the extreme northeast Asia. The patterns observed underscore the reduced level of genetic diversity found in the Koryak, Even, and Chukchi populations, which, along with the high degree of interpopulation differentiation, may be the result of genetic drift. Our phylogeographic analysis reveals common Paleo-Asiatic ancestry for 51.1% of the Koryaks and 17.8% of the Evens. About third of the mitogenomes found in the Koryaks and Evens might be considered as ethno-specific, as these are virtually absent elsewhere in North, Central and East Asia. Coalescence ages of most of these lineages coincide well with the emergence and development of the Tokarev and Old Koryak archaeological cultures associated with the formation of the Koryaks, as well as with the period of separation and split of the North Tungusic groups migrated northwards from the Lake Baikal or the Amur River area.


Assuntos
DNA Mitocondrial , Genômica , População da Ásia Setentrional , Humanos , DNA Mitocondrial/genética , Variação Genética/genética , População da Ásia Setentrional/etnologia , População da Ásia Setentrional/genética , Filogeografia , Povos Indígenas/genética
10.
Mol Biol (Mosk) ; 57(2): 350-359, 2023.
Artigo em Russo | MEDLINE | ID: mdl-37000662

RESUMO

The study of immune response and inflammation gene polymorphisms in a genogeographic context is relevant in the study of human populations. Here, in the indigenous populations of Siberia the frequencies of polymorphic variants -174G/C (rs1800795) and -572C/G (rs1800796) of the IL6 gene encoding the proinflammatory cytokine IL-6 were determined. For the first time, it was shown that the frequencies of the -174G and -572C alleles, which determine increased inflammatory response and are also associated with several diseases were statistically significantly higher in ethnic groups of Buryats, Teleuts, Yakuts, Dolgans and Tuvinians than in Russians living in Siberia. These values were in the intermediate position between those in the European and East-Asian groups. We hypothesize an adaptive role of these IL6 genetic variants in human settlement from Africa to the Eurasian continent. However, due to the departure from the traditional way of life and the increasing anthropogenic environmental pollution, the risk of diseases whose pathogenesis is based on inflammation in indigenous Siberian populations is likely increased.


Assuntos
Povos Indígenas , Interleucina-6 , Humanos , Alelos , Frequência do Gene , Povos Indígenas/genética , Inflamação , Interleucina-6/genética , Polimorfismo de Nucleotídeo Único , Sibéria
12.
BMC Biol ; 19(1): 61, 2021 03 29.
Artigo em Inglês | MEDLINE | ID: mdl-33781248

RESUMO

BACKGROUND: The demographic history of South and Southeast Asia (S&SEA) is complex and contentious, with multiple waves of human migration. Some of the earliest footfalls were of the ancestors of modern Austroasiatic (AA) language speakers. Understanding the history of the AA language family, comprising of over 150 languages and their speakers distributed across broad geographical region in isolated small populations of various sizes, can help shed light on the peopling of S&SEA. Here we investigated the genetic relatedness of two AA groups, their relationship with other ethno-linguistically distinct populations, and the relationship of these groups with ancient genomes of individuals living in S&SEA at different time periods, to infer about the demographic history of this region. RESULTS: We analyzed 1451 extant genomes, 189 AAs from India and Malaysia, and 43 ancient genomes from S&SEA. Population structure analysis reveals neither language nor geography appropriately correlates with genetic diversity. The inconsistency between "language and genetics" or "geography and genetics" can largely be attributed to ancient admixture with East Asian populations. We estimated a pre-Neolithic origin of AA language speakers, with shared ancestry between Indian and Malaysian populations until about 470 generations ago, contesting the existing model of Neolithic expansion of the AA culture. We observed a spatio-temporal transition in the genetic ancestry of SEA with genetic contribution from East Asia significantly increasing in the post-Neolithic period. CONCLUSION: Our study shows that contrary to assumptions in many previous studies and despite having linguistic commonality, Indian AAs have a distinct genomic structure compared to Malaysian AAs. This linguistic-genetic discordance is reflective of the complex history of population migration and admixture shaping the genomic landscape of S&SEA. We postulate that pre-Neolithic ancestors of today's AAs were widespread in S&SEA, and the fragmentation and dissipation of the population have largely been a resultant of multiple migrations of East Asian farmers during the Neolithic period. It also highlights the resilience of AAs in continuing to speak their language in spite of checkered population distribution and possible dominance from other linguistic groups.


Assuntos
Demografia , Genoma Humano , Povos Indígenas/genética , Idioma , Humanos , Índia , Malásia
13.
Mol Biol Evol ; 37(10): 2944-2954, 2020 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-32697301

RESUMO

The southern African indigenous Khoe-San populations harbor the most divergent lineages of all living peoples. Exploring their genomes is key to understanding deep human history. We sequenced 25 full genomes from five Khoe-San populations, revealing many novel variants, that 25% of variants are unique to the Khoe-San, and that the Khoe-San group harbors the greatest level of diversity across the globe. In line with previous studies, we found several gene regions with extreme values in genome-wide scans for selection, potentially caused by natural selection in the lineage leading to Homo sapiens and more recent in time. These gene regions included immunity-, sperm-, brain-, diet-, and muscle-related genes. When accounting for recent admixture, all Khoe-San groups display genetic diversity approaching the levels in other African groups and a reduction in effective population size starting around 100,000 years ago. Hence, all human groups show a reduction in effective population size commencing around the time of the Out-of-Africa migrations, which coincides with changes in the paleoclimate records, changes that potentially impacted all humans at the time.


Assuntos
Evolução Biológica , Genoma Humano , Migração Humana , Povos Indígenas/genética , Densidade Demográfica , África Subsaariana , Humanos , Filogeografia
14.
Mol Biol Evol ; 37(3): 611-626, 2020 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-31710665

RESUMO

Indigenous peoples have occupied the island of Puerto Rico since at least 3000 BC. Due to the demographic shifts that occurred after European contact, the origin(s) of these ancient populations, and their genetic relationship to present-day islanders, are unclear. We use ancient DNA to characterize the population history and genetic legacies of precontact Indigenous communities from Puerto Rico. Bone, tooth, and dental calculus samples were collected from 124 individuals from three precontact archaeological sites: Tibes, Punta Candelero, and Paso del Indio. Despite poor DNA preservation, we used target enrichment and high-throughput sequencing to obtain complete mitochondrial genomes (mtDNA) from 45 individuals and autosomal genotypes from two individuals. We found a high proportion of Native American mtDNA haplogroups A2 and C1 in the precontact Puerto Rico sample (40% and 44%, respectively). This distribution, as well as the haplotypes represented, supports a primarily Amazonian South American origin for these populations and mirrors the Native American mtDNA diversity patterns found in present-day islanders. Three mtDNA haplotypes from precontact Puerto Rico persist among Puerto Ricans and other Caribbean islanders, indicating that present-day populations are reservoirs of precontact mtDNA diversity. Lastly, we find similarity in autosomal ancestry patterns between precontact individuals from Puerto Rico and the Bahamas, suggesting a shared component of Indigenous Caribbean ancestry with close affinity to South American populations. Our findings contribute to a more complete reconstruction of precontact Caribbean population history and explore the role of Indigenous peoples in shaping the biocultural diversity of present-day Puerto Ricans and other Caribbean islanders.


Assuntos
Cromossomos Humanos/genética , DNA Antigo/análise , DNA Mitocondrial/genética , Cálculos Dentários/genética , Povos Indígenas/genética , Osso e Ossos , Fósseis , Genética Populacional , Haplótipos , Sequenciamento de Nucleotídeos em Larga Escala , Migração Humana , Humanos , Porto Rico/etnologia , Dente
15.
Int J Legal Med ; 135(5): 1773-1776, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33742257

RESUMO

In the present work, an extensive analysis of the X-chromosomal pool of Native American and Mestizo groups of Central America (Guatemala, El Salvador, Nicaragua, and Panama) has been carried out. Allele and haplotype frequency databases, as well as other forensic parameters for these populations, are presented. The admixture analysis supports the tri-hybrid composition in terms of ancestry in the Mestizo populations, with a predominant Native American contribution (54-69%), followed by European (19-28%) and African contributions (12-19%). Pairwise FST genetic distances highlight the genetic proximity between the northernmost Central American populations, especially among admixed populations. The unique and complex nature of this area, where populations from different origins intercrossed, as well as the informativity of X-STR data, highpoint the great interest of this genetic study. Furthermore, the X-chromosome databases for Central American populations here provided will be not only useful for forensic and population purposes not only in the target countries but also in the host countries.


Assuntos
Cromossomos Humanos Y , Etnicidade/genética , Povos Indígenas/genética , Repetições de Microssatélites , América Central/etnologia , Feminino , Variação Genética , Humanos , Masculino
16.
Int J Legal Med ; 135(4): 1191-1199, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33586030

RESUMO

Population and geographic assignment are frequently undertaken using DNA sequences on the mitochondrial genome. Assignment to broad continental populations is common, although finer resolution to subpopulations can be less accurate due to shared genetic ancestry at a local level and members of different ancestral subpopulations cohabiting the same geographic area. This study reports on the accuracy of population and subpopulation assignment by using the sequence data obtained from the 3070 mitochondrial genomes and applying the K-nearest neighbors (KNN) algorithm. These data also included training samples used for continental and population assignment comprised of 1105 Europeans (including Austria, France, Germany, Spain, and England and Caucasian countries), 374 Africans (including North and East Africa and non-specific area (Pan-Africa)), and 1591 Asians (including Japan, Philippines, and Taiwan). Subpopulations included in this study were 1153 mitochondrial DNA (mtDNA) control region sequences from 12 subpopulations in Taiwan (including Han, Hakka, Ami, Atayal, Bunun, Paiwan, Puyuma, Rukai, Saisiyat, Tsou, Tao, and Pingpu). Additionally, control region sequence data from a further 50 samples, obtained from the Sigma Company, were included after they were amplified and sequenced. These additional 50 samples acted as the "testing samples" to verify the accuracy of the population. In this study, based on genetic distances as genetic metric, we used the KNN algorithm and the K-weighted-nearest neighbors (KWNN) algorithm weighted by genetic distance to classify individuals into continental populations, and subpopulations within the same continent. Accuracy results of ethnic inferences at the level of continental populations and of subpopulations among KNN and KWNN algorithms were obtained. The training sample set achieved an overall accuracy of 99 to 82% for assignment to their continental populations with K values from 1 to 101. Population assignment for subpopulations with K assignments from 1 to 5 reached an accuracy of 77 to 54%. Four out of 12 Taiwanese populations returned an accuracy of assignment of over 60%, Ami (66%), Atayal (67%), Saisiyat (66%), and Tao (80%). For the testing sample set, results of ethnic prediction for continental populations with recommended K values as 5, 10, and 35, based on results of the training sample set, achieved overall an accuracy of 100 to 94%. This study provided an accurate method in population assignment for not only continental populations but also subpopulations, which can be useful in forensic and anthropological studies.


Assuntos
Algoritmos , DNA Mitocondrial/genética , Genética Populacional/métodos , Região de Controle de Locus Gênico , Filogenia , Grupos Raciais/genética , Humanos , Povos Indígenas/genética , Taiwan/etnologia
18.
Int J Mol Sci ; 22(9)2021 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-33925025

RESUMO

Leptin plays an important role in thermoregulation and is possibly associated with the microevolutionary processes of human adaptation to a cold climate. In this study, based on the Yakut population (n = 281 individuals) living in the coldest region of Siberia (t°minimum -71.2 °C), we analyze the serum leptin levels and data of 14 single nucleotide polymorphisms (SNPs) of 10 genes (UCP1, UCP2, UCP3, FNDC5, PPARGC1A, CIDEA, PTGS2, TRPV1, LEPR, BDNF) that are possibly involved in nonshivering thermogenesis processes. Our results demonstrate that from 14 studied SNPs of 10 genes, 2 SNPs (the TT rs3811787 genotype of the UCP1 gene and the GG rs6265 genotype of the BDNF gene) were associated with the elevated leptin levels in Yakut females (p < 0.05). Furthermore, of these two SNPs, the rs3811787 of the UCP1 gene demonstrated more indications of natural selection for cold climate adaptation. The prevalence gradient of the T-allele (rs3811787) of UCP1 increased from the south to the north across Eurasia, along the shore of the Arctic Ocean. Thereby, our study suggests the potential involvement of the UCP1 gene in the leptin-mediated thermoregulation mechanism, while the distribution of its allelic variants is probably related to human adaptation to a cold climate.


Assuntos
Aclimatação/genética , Aclimatação/fisiologia , Clima Frio , Leptina/sangue , Termogênese/genética , Termogênese/fisiologia , Proteína Desacopladora 1/genética , Adolescente , Índice de Massa Corporal , Fator Neurotrófico Derivado do Encéfalo/genética , Evolução Molecular , Feminino , Genótipo , Humanos , Povos Indígenas/genética , Masculino , Polimorfismo de Nucleotídeo Único , Seleção Genética , Sibéria , Adulto Jovem
19.
Mol Biol Evol ; 36(9): 1849-1861, 2019 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-31288264

RESUMO

Southern African indigenous groups, traditionally hunter-gatherers (San) and herders (Khoekhoe), are commonly referred to as "Khoe-San" populations and have a long history in southern Africa. Their ancestors were largely isolated up until ∼2,000 years ago before the arrival of pastoralists and farmers in southern Africa. Assessing relationships among regional Khoe-San groups has been challenging due to admixture with immigrant populations that obscure past population affinities and gene flow among these autochthonous communities. We re-evaluate a combined genome-wide data set of previously published southern Africa Khoe-San populations in conjunction with novel data from Khoe-San individuals collected in Xade (Central Kalahari Game Reserve, Botswana) prior to their resettlement outside the reserve. After excluding regions in the genome that trace their ancestry to recent migrant groups, the genetic diversity of 20 Khoe-San groups fitted an isolation-by-distance model. Even though isolation-by-distance explained most genetic affinities between the different autochthonous groups, additional signals of contact between Khoe-San groups could be detected. For instance, we found stronger genetic affinities, than what would be explained by isolation-by-distance gene flow, between the two geographically separated Khoe-San groups, who speak branches of the Kx'a-language family (ǂHoan and Ju). We also scanned the genome-wide data for signals of adaptive gene flow from farmers/herders into Khoe-San groups and identified a number of genomic regions potentially introduced by the arrival of the new groups. This study provides a comprehensive picture of affinities among Khoe-San groups, prior to the arrival of recent migrants, and found that these affinities are primarily determined by the geographic landscape.


Assuntos
Povos Indígenas/genética , África Subsaariana , Fazendeiros , Fluxo Gênico , Genoma Humano , Humanos , Filogeografia
20.
J Pharmacol Exp Ther ; 374(2): 233-240, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32423989

RESUMO

CYP2C9 is a major form of human liver cytochrome P450 that is responsible for the oxidative metabolism of several widely used low-therapeutic index drugs, including (S)-warfarin and phenytoin. In a cohort of Alaska Native people, ultrarare or novel CYP2C9 protein variants, M1L (rs114071557), N218I (rs780801862), and P279T (rs182132442, CYP2C9*29), are expressed with higher frequencies than the well characterized CYP2C9*2 and CYP2C9*3 alleles. We report here on their relative expression in lentivirus-infected HepG2 cells and the functional characterization of purified reconstituted enzyme variants expressed in Escherichia coli toward (S)-warfarin, phenytoin, flurbiprofen, and (S)-naproxen. In the infected HepG2 cells, robust mRNA and protein expression were obtained for wild-type, N218I, and P279T variants, but as expected, the M1L variant protein was not translated in this liver-derived cell line. His-tagged wild-type protein and the N218I and P279T variants, but not M1L, expressed well in E. coli and were highly purified after affinity chromatography. Upon reconstitution with cytochrome P450 oxidoreductase and cytochrome b5, the N218I and P279T protein variants metabolized (S)-warfarin, phenytoin, flurbiprofen, and (S)-naproxen to the expected monohydroxylated or O-demethylated metabolites. Steady-state kinetic analyses revealed that the relative catalytic efficiency ratios of (S)-warfarin metabolism by the P279T and N218I variants were 87% and 24%, respectively, of wild-type CYP2C9 protein. A similar rank ordering was observed for metabolism of phenytoin, flurbiprofen, and (S)-naproxen. We conclude that carriers of the variant N218I and, especially, the M1L alleles would be at risk of exacerbated therapeutic effects from drugs that rely on CYP2C9 for their metabolic clearance. SIGNIFICANCE STATEMENT: Novel gene variants of CYP2C9-M1L, and N218I, along with P279T (CYP2C9*29)-are expressed in Alaska Native people at relatively high frequencies. In vitro characterization of their functional effects revealed that each variant confers reduced catalytic efficiency toward several substrates, including the low-therapeutic index drugs (S)-warfarin and phenytoin. These data provide the first functional information for new, common CYP2C9 variants in this understudied population. The data may help guide dose adjustments in allele carriers, thus mitigating potential healthcare disparities.


Assuntos
Citocromo P-450 CYP2C9/genética , Citocromo P-450 CYP2C9/metabolismo , Povos Indígenas/genética , Alaska/etnologia , Escherichia coli/genética , Expressão Gênica , Células HEK293 , Humanos , Proteólise , Tripsina/metabolismo
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