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1.
Cell ; 184(18): 4612-4625.e14, 2021 09 02.
Artículo en Inglés | MEDLINE | ID: mdl-34352227

RESUMEN

The Middle East region is important to understand human evolution and migrations but is underrepresented in genomic studies. Here, we generated 137 high-coverage physically phased genome sequences from eight Middle Eastern populations using linked-read sequencing. We found no genetic traces of early expansions out-of-Africa in present-day populations but found Arabians have elevated Basal Eurasian ancestry that dilutes their Neanderthal ancestry. Population sizes within the region started diverging 15-20 kya, when Levantines expanded while Arabians maintained smaller populations that derived ancestry from local hunter-gatherers. Arabians suffered a population bottleneck around the aridification of Arabia 6 kya, while Levantines had a distinct bottleneck overlapping the 4.2 kya aridification event. We found an association between movement and admixture of populations in the region and the spread of Semitic languages. Finally, we identify variants that show evidence of selection, including polygenic selection. Our results provide detailed insights into the genomic and selective histories of the Middle East.


Asunto(s)
Genética de Población/historia , Genoma Humano , Animales , Cromosomas Humanos Y/genética , Bases de Datos Genéticas , Pool de Genes , Introgresión Genética , Geografía , Historia Antigua , Migración Humana , Humanos , Medio Oriente , Modelos Genéticos , Hombre de Neandertal/genética , Filogenia , Densidad de Población , Selección Genética , Análisis de Secuencia de ADN
2.
Cell ; 182(1): 189-199.e15, 2020 07 09.
Artículo en Inglés | MEDLINE | ID: mdl-32531199

RESUMEN

Structural variants contribute substantially to genetic diversity and are important evolutionarily and medically, but they are still understudied. Here we present a comprehensive analysis of structural variation in the Human Genome Diversity panel, a high-coverage dataset of 911 samples from 54 diverse worldwide populations. We identify, in total, 126,018 variants, 78% of which were not identified in previous global sequencing projects. Some reach high frequency and are private to continental groups or even individual populations, including regionally restricted runaway duplications and putatively introgressed variants from archaic hominins. By de novo assembly of 25 genomes using linked-read sequencing, we discover 1,643 breakpoint-resolved unique insertions, in aggregate accounting for 1.9 Mb of sequence absent from the GRCh38 reference. Our results illustrate the limitation of a single human reference and the need for high-quality genomes from diverse populations to fully discover and understand human genetic variation.


Asunto(s)
Genética de Población , Variación Estructural del Genoma , Alelos , Bases de Datos Genéticas , Dosificación de Gen , Duplicación de Gen , Frecuencia de los Genes/genética , Variación Genética , Genoma Humano , Humanos
3.
Cell ; 179(4): 984-1002.e36, 2019 10 31.
Artículo en Inglés | MEDLINE | ID: mdl-31675503

RESUMEN

Genomic studies in African populations provide unique opportunities to understand disease etiology, human diversity, and population history. In the largest study of its kind, comprising genome-wide data from 6,400 individuals and whole-genome sequences from 1,978 individuals from rural Uganda, we find evidence of geographically correlated fine-scale population substructure. Historically, the ancestry of modern Ugandans was best represented by a mixture of ancient East African pastoralists. We demonstrate the value of the largest sequence panel from Africa to date as an imputation resource. Examining 34 cardiometabolic traits, we show systematic differences in trait heritability between European and African populations, probably reflecting the differential impact of genes and environment. In a multi-trait pan-African GWAS of up to 14,126 individuals, we identify novel loci associated with anthropometric, hematological, lipid, and glycemic traits. We find that several functionally important signals are driven by Africa-specific variants, highlighting the value of studying diverse populations across the region.


Asunto(s)
Población Negra/genética , Predisposición Genética a la Enfermedad , Genoma Humano/genética , Genómica , Femenino , Frecuencia de los Genes/genética , Estudio de Asociación del Genoma Completo , Humanos , Masculino , Polimorfismo de Nucleótido Simple/genética , Uganda/epidemiología , Secuenciación Completa del Genoma
4.
Cell ; 149(4): 737-9, 2012 May 11.
Artículo en Inglés | MEDLINE | ID: mdl-22579279

RESUMEN

Geneticists have long sought to identify the genetic changes that made us human, but pinpointing the functionally relevant changes has been challenging. Two papers in this issue suggest that partial duplication of SRGAP2, producing an incomplete protein that antagonizes the original, contributed to human brain evolution.

5.
Am J Hum Genet ; 108(4): 608-619, 2021 04 01.
Artículo en Inglés | MEDLINE | ID: mdl-33740458

RESUMEN

The number and distribution of recessive alleles in the population for various diseases are not known at genome-wide-scale. Based on 6,447 exome sequences of healthy, genetically unrelated Europeans of two distinct ancestries, we estimate that every individual is a carrier of at least 2 pathogenic variants in currently known autosomal-recessive (AR) genes and that 0.8%-1% of European couples are at risk of having a child affected with a severe AR genetic disorder. This risk is 16.5-fold higher for first cousins but is significantly more increased for skeletal disorders and intellectual disabilities due to their distinct genetic architecture.


Asunto(s)
Consanguinidad , Composición Familiar , Genes Recesivos/genética , Variación Genética/genética , Fenotipo , Población Blanca/genética , Estudios de Cohortes , Europa (Continente)/etnología , Exoma/genética , Femenino , Pruebas Genéticas , Salud , Heterocigoto , Humanos , Discapacidad Intelectual/genética , Masculino
6.
Am J Hum Genet ; 107(1): 149-157, 2020 07 02.
Artículo en Inglés | MEDLINE | ID: mdl-32470374

RESUMEN

The Iron and Classical Ages in the Near East were marked by population expansions carrying cultural transformations that shaped human history, but the genetic impact of these events on the people who lived through them is little-known. Here, we sequenced the whole genomes of 19 individuals who each lived during one of four time periods between 800 BCE and 200 CE in Beirut on the Eastern Mediterranean coast at the center of the ancient world's great civilizations. We combined these data with published data to traverse eight archaeological periods and observed any genetic changes as they arose. During the Iron Age (∼1000 BCE), people with Anatolian and South-East European ancestry admixed with people in the Near East. The region was then conquered by the Persians (539 BCE), who facilitated movement exemplified in Beirut by an ancient family with Egyptian-Lebanese admixed members. But the genetic impact at a population level does not appear until the time of Alexander the Great (beginning 330 BCE), when a fusion of Asian and Near Easterner ancestry can be seen, paralleling the cultural fusion that appears in the archaeological records from this period. The Romans then conquered the region (31 BCE) but had little genetic impact over their 600 years of rule. Finally, during the Ottoman rule (beginning 1516 CE), Caucasus-related ancestry penetrated the Near East. Thus, in the past 4,000 years, three limited admixture events detectably impacted the population, complementing the historical records of this culturally complex region dominated by the elite with genetic insights from the general population.


Asunto(s)
ADN/genética , Genética de Población/historia , Egipto , Etnicidad/genética , Etnicidad/historia , Genoma Humano/genética , Haplotipos/genética , Historia Antigua , Migración Humana/historia , Humanos , Medio Oriente
7.
Analyst ; 148(18): 4456-4462, 2023 Sep 11.
Artículo en Inglés | MEDLINE | ID: mdl-37560929

RESUMEN

Herein, a multifunctional electrochemiluminescence (ECL) and photoelectrochemical (PEC) biosensor based on exchange of Ag+ with CdTe QDs was developed for dual-mode detection of thrombin. First, CdTe QDs assembled on an electrode displayed superior ECL and PEC signals. At the same time, C-rich hairpin (HP) DNA linked to silicon spheres loaded a large amount of Ag+, and the specific binding of thrombin to an aptamer led to the release of DNA P; then, DNA P interacted with HP DNA to produce numerous Ag+ ions by an enzyme-digestion amplification reaction. Ag+ underwent ion exchange with CdTe QDs to generate AgTe/CdTe QDs, resulting in much reversed PEC and changed ECL signals for dual-mode detection of thrombin. This work takes advantage of outstanding multi-signals of QDs coupled with convenient ion exchange to achieve multi-mode detection of the target, avoiding false positive or false negative signals generated in the traditional detection process, and thus can be used for the rapid detection of various biomolecules in actual samples.


Asunto(s)
Técnicas Biosensibles , Compuestos de Cadmio , Puntos Cuánticos , Puntos Cuánticos/química , Trombina , Compuestos de Cadmio/química , Intercambio Iónico , Telurio/química , ADN/química , Mediciones Luminiscentes/métodos , Técnicas Biosensibles/métodos , Técnicas Electroquímicas/métodos , Límite de Detección
8.
Mol Biol Evol ; 38(12): 5655-5663, 2021 12 09.
Artículo en Inglés | MEDLINE | ID: mdl-34464968

RESUMEN

A nonsense allele at rs1343879 in human MAGEE2 on chromosome X has previously been reported as a strong candidate for positive selection in East Asia. This premature stop codon causing ∼80% protein truncation is characterized by a striking geographical pattern of high population differentiation: common in Asia and the Americas (up to 84% in the 1000 Genomes Project East Asians) but rare elsewhere. Here, we generated a Magee2 mouse knockout mimicking the human loss-of-function mutation to study its functional consequences. The Magee2 null mice did not exhibit gross abnormalities apart from enlarged brain structures (13% increased total brain area, P = 0.0022) in hemizygous males. The area of the granular retrosplenial cortex responsible for memory, navigation, and spatial information processing was the most severely affected, exhibiting an enlargement of 34% (P = 3.4×10-6). The brain size in homozygous females showed the opposite trend of reduced brain size, although this did not reach statistical significance. With these insights, we performed human association analyses between brain size measurements and rs1343879 genotypes in 141 Chinese volunteers with brain MRI scans, replicating the sexual dimorphism seen in the knockout mouse model. The derived stop gain allele was significantly associated with a larger volume of gray matter in males (P = 0.00094), and smaller volumes of gray (P = 0.00021) and white (P = 0.0015) matter in females. It is unclear whether or not the observed neuroanatomical phenotypes affect behavior or cognition, but it might have been the driving force underlying the positive selection in humans.


Asunto(s)
Antígenos de Neoplasias/metabolismo , Encéfalo , Proteínas/metabolismo , Caracteres Sexuales , Alelos , Animales , Encéfalo/diagnóstico por imagen , Femenino , Humanos , Masculino , Ratones , Ratones Noqueados , Tamaño de los Órganos , Fenotipo
9.
Am J Hum Genet ; 104(5): 977-984, 2019 05 02.
Artículo en Inglés | MEDLINE | ID: mdl-31006515

RESUMEN

During the medieval period, hundreds of thousands of Europeans migrated to the Near East to take part in the Crusades, and many of them settled in the newly established Christian states along the Eastern Mediterranean coast. Here, we present a genetic snapshot of these events and their aftermath by sequencing the whole genomes of 13 individuals who lived in what is today known as Lebanon between the 3rd and 13th centuries CE. These include nine individuals from the "Crusaders' pit" in Sidon, a mass burial in South Lebanon identified from the archaeology as the grave of Crusaders killed during a battle in the 13th century CE. We show that all of the Crusaders' pit individuals were males; some were Western Europeans from diverse origins, some were locals (genetically indistinguishable from present-day Lebanese), and two individuals were a mixture of European and Near Eastern ancestries, providing direct evidence that the Crusaders admixed with the local population. However, these mixtures appear to have had limited genetic consequences since signals of admixture with Europeans are not significant in any Lebanese group today-in particular, Lebanese Christians are today genetically similar to local people who lived during the Roman period which preceded the Crusades by more than four centuries.


Asunto(s)
Etnicidad/genética , Etnicidad/historia , Flujo Génico , Genética de Población , Genoma Humano , Población Blanca/genética , Cromosomas Humanos Y/genética , ADN Mitocondrial/análisis , ADN Mitocondrial/genética , Femenino , Historia Antigua , Humanos , Líbano/etnología , Masculino
10.
Small ; 18(2): e2105594, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34859583

RESUMEN

Aluminum-air batteries (AABs) are deemed as a potential clean energy storage device. However, exploiting high-efficiency and stable oxygen reduction reaction (ORR) electrocatalysts in AABs is still a challenge. Iron phthalocyanine (FePc) shows a great prospect in ORR but still far from Pt-based catalysts. Here, the hybrid electrocatalysts of monolayer FePc and hollow N,S-doped carbon spheres (HNSCs) are innovatively constructed through π-π stacking to achieve high dispersion. The resulting FePc@HNSC catalyst exhibits an outstanding ORR activity, outperforming that of pristine FePc and even most Fe-based catalysts reported to date. Moreover, the AAB using FePc@HNSC catalyst not only demonstrates a superior power density than the battery with Pt/C, but also displays stable discharge voltages and excellent durability. Furthermore, the theoretical calculations confirm that the charge distribution and d-band center of the Fe atom in FePc are efficiently optimized by hybrid configuration via the introduction of N,S-doped carbon substrate. The design leads to an enriched electron density around Fe active sites and significant reduction of energy barrier for OH* formation, which are favorable for the improvement of electrocatalytic ORR performance. This work provides a chance to expand the application of metallic macrocyclic compound electrocatalysts in various energy technologies.

11.
Inorg Chem ; 61(12): 5148-5156, 2022 Mar 28.
Artículo en Inglés | MEDLINE | ID: mdl-35289604

RESUMEN

Pt electrocatalysts with high activity and durability have still crucial issues for the oxygen reduction reaction (ORR) in proton exchange membrane fuel cells (PEMFCs). In this study, a novel catalyst consisting of Pt nanoparticles (NPs) on TiOx/C composites (TiOx-Vo-H/C) with abundant oxygen vacancies (Vo) is proposed, which is abbreviated as PTO-Vo-H/C. The introduction of Vo helps anchor highly dispersed Pt NPs with low loading and strengthen the strong metal-support interaction (SMSI), which benefits to the enhanced ORR catalytic activity. Moreover, the accelerated durability test (ADT) demonstrates the higher retention of ORR activity for PTO-Vo-H/C. Experimental and theoretical analyses reveal that electronic interactions between Pt NPs and TiOx/C composite support give rise to an electron-rich Pt NPs and strong SMSI effect, which is favorable for the electron transfer and stabilization of Pt NPs. More importantly, the assembled PEMFC with PTO-Vo-H/C shows only 6.9% of decay on maximum power density after 3000 ADT cycles while the performance of Pt/C sharply decreased. This work provides a new insight into the unique vacancy regulation of dispersive Pt on metal oxides for superior ORR performance.

12.
Nature ; 538(7624): 238-242, 2016 Oct 13.
Artículo en Inglés | MEDLINE | ID: mdl-27654910

RESUMEN

High-coverage whole-genome sequence studies have so far focused on a limited number of geographically restricted populations, or been targeted at specific diseases, such as cancer. Nevertheless, the availability of high-resolution genomic data has led to the development of new methodologies for inferring population history and refuelled the debate on the mutation rate in humans. Here we present the Estonian Biocentre Human Genome Diversity Panel (EGDP), a dataset of 483 high-coverage human genomes from 148 populations worldwide, including 379 new genomes from 125 populations, which we group into diversity and selection sets. We analyse this dataset to refine estimates of continent-wide patterns of heterozygosity, long- and short-distance gene flow, archaic admixture, and changes in effective population size through time as well as for signals of positive or balancing selection. We find a genetic signature in present-day Papuans that suggests that at least 2% of their genome originates from an early and largely extinct expansion of anatomically modern humans (AMHs) out of Africa. Together with evidence from the western Asian fossil record, and admixture between AMHs and Neanderthals predating the main Eurasian expansion, our results contribute to the mounting evidence for the presence of AMHs out of Africa earlier than 75,000 years ago.


Asunto(s)
Genoma Humano/genética , Genómica , Migración Humana/historia , Grupos Raciales/genética , África/etnología , Animales , Asia , Conjuntos de Datos como Asunto , Estonia , Europa (Continente) , Fósiles , Flujo Génico , Genética de Población , Heterocigoto , Historia Antigua , Humanos , Nativos de Hawái y Otras Islas del Pacífico/genética , Hombre de Neandertal/genética , Nueva Guinea , Dinámica Poblacional
13.
Nature ; 538(7624): 201-206, 2016 Oct 13.
Artículo en Inglés | MEDLINE | ID: mdl-27654912

RESUMEN

Here we report the Simons Genome Diversity Project data set: high quality genomes from 300 individuals from 142 diverse populations. These genomes include at least 5.8 million base pairs that are not present in the human reference genome. Our analysis reveals key features of the landscape of human genome variation, including that the rate of accumulation of mutations has accelerated by about 5% in non-Africans compared to Africans since divergence. We show that the ancestors of some pairs of present-day human populations were substantially separated by 100,000 years ago, well before the archaeologically attested onset of behavioural modernity. We also demonstrate that indigenous Australians, New Guineans and Andamanese do not derive substantial ancestry from an early dispersal of modern humans; instead, their modern human ancestry is consistent with coming from the same source as that of other non-Africans.


Asunto(s)
Variación Genética/genética , Genoma Humano/genética , Genómica , Tasa de Mutación , Filogenia , Grupos Raciales/genética , Animales , Australia , Población Negra/genética , Conjuntos de Datos como Asunto , Genética de Población , Historia Antigua , Migración Humana/historia , Humanos , Nativos de Hawái y Otras Islas del Pacífico/genética , Hombre de Neandertal/genética , Nueva Guinea , Análisis de Secuencia de ADN , Especificidad de la Especie , Factores de Tiempo
14.
Nature ; 538(7624): 207-214, 2016 Oct 13.
Artículo en Inglés | MEDLINE | ID: mdl-27654914

RESUMEN

The population history of Aboriginal Australians remains largely uncharacterized. Here we generate high-coverage genomes for 83 Aboriginal Australians (speakers of Pama-Nyungan languages) and 25 Papuans from the New Guinea Highlands. We find that Papuan and Aboriginal Australian ancestors diversified 25-40 thousand years ago (kya), suggesting pre-Holocene population structure in the ancient continent of Sahul (Australia, New Guinea and Tasmania). However, all of the studied Aboriginal Australians descend from a single founding population that differentiated ~10-32 kya. We infer a population expansion in northeast Australia during the Holocene epoch (past 10,000 years) associated with limited gene flow from this region to the rest of Australia, consistent with the spread of the Pama-Nyungan languages. We estimate that Aboriginal Australians and Papuans diverged from Eurasians 51-72 kya, following a single out-of-Africa dispersal, and subsequently admixed with archaic populations. Finally, we report evidence of selection in Aboriginal Australians potentially associated with living in the desert.


Asunto(s)
Genoma Humano/genética , Genómica , Nativos de Hawái y Otras Islas del Pacífico/genética , Filogenia , Grupos Raciales/genética , África/etnología , Australia , Conjuntos de Datos como Asunto , Clima Desértico , Flujo Génico , Genética de Población , Historia Antigua , Migración Humana/historia , Humanos , Lenguaje , Nueva Guinea , Dinámica Poblacional , Tasmania
15.
Hum Mol Genet ; 28(16): 2785-2798, 2019 08 15.
Artículo en Inglés | MEDLINE | ID: mdl-31108506

RESUMEN

Human RBMY1 genes are located in four variable-sized clusters on the Y chromosome, expressed in male germ cells and possibly associated with sperm motility. We have re-investigated the mutational background and evolutionary history of the RBMY1 copy number distribution in worldwide samples and its relevance to sperm parameters in an Estonian cohort of idiopathic male factor infertility subjects. We estimated approximate RBMY1 copy numbers in 1218 1000 Genomes Project phase 3 males from sequencing read-depth, then chose 14 for valid ation by multicolour fibre-FISH. These fibre-FISH samples provided accurate calibration standards for the entire panel and led to detailed insights into population variation and mutational mechanisms. RBMY1 copy number worldwide ranged from 3 to 13 with a mode of 8. The two larger proximal clusters were the most variable, and additional duplications, deletions and inversions were detected. Placing the copy number estimates onto the published Y-SNP-based phylogeny of the same samples suggested a minimum of 562 mutational changes, translating to a mutation rate of 2.20 × 10-3 (95% CI 1.94 × 10-3 to 2.48 × 10-3) per father-to-son Y-transmission, higher than many short tandem repeat (Y-STRs), and showed no evidence for selection for increased or decreased copy number, but possible copy number stabilizing selection. An analysis of RBMY1 copy numbers among 376 infertility subjects failed to replicate a previously reported association with sperm motility and showed no significant effect on sperm count and concentration, serum follicle stimulating hormone (FSH), luteinizing hormone (LH) and testosterone levels or testicular and semen volume. These results provide the first in-depth insights into the structural rearrangements underlying RBMY1 copy number variation across diverse human lineages.


Asunto(s)
Cromosomas Humanos Y , Variaciones en el Número de Copia de ADN , Evolución Molecular , Proteínas Nucleares/genética , Proteínas de Unión al ARN/genética , Hibridación Genómica Comparativa , Genoma Humano , Genómica/métodos , Humanos , Hibridación Fluorescente in Situ , Masculino , Familia de Multigenes , Mutación , Filogenia , Espermatozoides/metabolismo
16.
Hum Genet ; 140(2): 299-307, 2021 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-32666166

RESUMEN

The genomes of present-day humans outside Africa originated almost entirely from a single out-migration ~ 50,000-70,000 years ago, followed by mixture with Neanderthals contributing ~ 2% to all non-Africans. However, the details of this initial migration remain poorly understood because no ancient DNA analyses are available from this key time period, and interpretation of present-day autosomal data is complicated due to subsequent population movements/reshaping. One locus, however, does retain male-specific information from this early period: the Y chromosome, where a detailed calibrated phylogeny has been constructed. Three present-day Y lineages were carried by the initial migration: the rare haplogroup D, the moderately rare C, and the very common FT lineage which now dominates most non-African populations. Here, we show that phylogenetic analyses of haplogroup C, D and FT sequences, including very rare deep-rooting lineages, together with phylogeographic analyses of ancient and present-day non-African Y chromosomes, all point to East/Southeast Asia as the origin 50,000-55,000 years ago of all known surviving non-African male lineages (apart from recent migrants). This observation contrasts with the expectation of a West Eurasian origin predicted by a simple model of expansion from a source near Africa, and can be interpreted as resulting from extensive genetic drift in the initial population or replacement of early western Y lineages from the east, thus informing and constraining models of the initial expansion.


Asunto(s)
Pueblo Asiatico/genética , Cromosomas Humanos Y/genética , África , ADN/genética , Emigración e Inmigración , Genética de Población/métodos , Genoma Humano/genética , Haplotipos/genética , Humanos , Masculino , Filogenia , Filogeografía/métodos
17.
Inorg Chem ; 60(23): 17942-17951, 2021 Dec 06.
Artículo en Inglés | MEDLINE | ID: mdl-34762802

RESUMEN

Within Mn-activated phosphors, the oxidation state of Mn dopant strongly depends on the structural features of the host lattice. This paper reported a new polymorph of CsMg(PO3)3 (CMP) with a complicated three-dimensional (3D) framework of [Mg(PO3)3]∞ that is constructed by MgO6 octahedra and 1D infinite [PO3]∞ chains. Then we prepared a series of red phosphors CsMg1-x(PO3)3:xMn2+ (CMP:xMn2+) by high temperature solid state reactions in the open air. Powder X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and photoluminescence (PL) studies revealed the single Mn2+-oxidation. Under 404 nm light exciting, CMP:0.2Mn2+ can emit single-band emission at around 630 nm with full-width at half-maximum (fwhm) of 70 nm. Besides, CMP:0.2Mn2+ possesses excellent thermostability up to 450 K. These features indicate that CMP:0.2Mn2+ is suitable to be used for LED backlight display. Moreover, this work suggests that a host lattice with suitable structure feature can form single Mn2+-oxidation and is rigid enough to protect Mn2+ from being oxidized by O2 at high temperature.

18.
Nature ; 517(7534): 327-32, 2015 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-25470054

RESUMEN

Given the importance of Africa to studies of human origins and disease susceptibility, detailed characterization of African genetic diversity is needed. The African Genome Variation Project provides a resource with which to design, implement and interpret genomic studies in sub-Saharan Africa and worldwide. The African Genome Variation Project represents dense genotypes from 1,481 individuals and whole-genome sequences from 320 individuals across sub-Saharan Africa. Using this resource, we find novel evidence of complex, regionally distinct hunter-gatherer and Eurasian admixture across sub-Saharan Africa. We identify new loci under selection, including loci related to malaria susceptibility and hypertension. We show that modern imputation panels (sets of reference genotypes from which unobserved or missing genotypes in study sets can be inferred) can identify association signals at highly differentiated loci across populations in sub-Saharan Africa. Using whole-genome sequencing, we demonstrate further improvements in imputation accuracy, strengthening the case for large-scale sequencing efforts of diverse African haplotypes. Finally, we present an efficient genotype array design capturing common genetic variation in Africa.


Asunto(s)
Variación Genética/genética , Genética Médica/tendencias , Genoma Humano/genética , Genómica/tendencias , África , África del Sur del Sahara , Asia/etnología , Europa (Continente)/etnología , Humanos , Factores de Riesgo , Selección Genética/genética
19.
Am J Hum Genet ; 101(2): 274-282, 2017 Aug 03.
Artículo en Inglés | MEDLINE | ID: mdl-28757201

RESUMEN

The Canaanites inhabited the Levant region during the Bronze Age and established a culture that became influential in the Near East and beyond. However, the Canaanites, unlike most other ancient Near Easterners of this period, left few surviving textual records and thus their origin and relationship to ancient and present-day populations remain unclear. In this study, we sequenced five whole genomes from ∼3,700-year-old individuals from the city of Sidon, a major Canaanite city-state on the Eastern Mediterranean coast. We also sequenced the genomes of 99 individuals from present-day Lebanon to catalog modern Levantine genetic diversity. We find that a Bronze Age Canaanite-related ancestry was widespread in the region, shared among urban populations inhabiting the coast (Sidon) and inland populations (Jordan) who likely lived in farming societies or were pastoral nomads. This Canaanite-related ancestry derived from mixture between local Neolithic populations and eastern migrants genetically related to Chalcolithic Iranians. We estimate, using linkage-disequilibrium decay patterns, that admixture occurred 6,600-3,550 years ago, coinciding with recorded massive population movements in Mesopotamia during the mid-Holocene. We show that present-day Lebanese derive most of their ancestry from a Canaanite-related population, which therefore implies substantial genetic continuity in the Levant since at least the Bronze Age. In addition, we find Eurasian ancestry in the Lebanese not present in Bronze Age or earlier Levantines. We estimate that this Eurasian ancestry arrived in the Levant around 3,750-2,170 years ago during a period of successive conquests by distant populations.


Asunto(s)
ADN Mitocondrial/genética , Etnicidad/genética , Genética de Población/métodos , Genoma Humano/genética , Variación Genética/genética , Historia Antigua , Humanos , Líbano , Desequilibrio de Ligamiento , Masculino , Población Blanca/genética
20.
BMC Genet ; 21(Suppl 1): 108, 2020 10 22.
Artículo en Inglés | MEDLINE | ID: mdl-33092534

RESUMEN

BACKGROUND: In the process of adaptation of humans to their environment, positive or adaptive selection has played a main role. Positive selection has, however, been under-studied in African populations, despite their diversity and importance for understanding human history. RESULTS: Here, we have used 119 available whole-genome sequences from five Ethiopian populations (Amhara, Oromo, Somali, Wolayta and Gumuz) to investigate the modes and targets of positive selection in this part of the world. The site frequency spectrum-based test SFselect was applied to idfentify a wide range of events of selection (old and recent), and the haplotype-based statistic integrated haplotype score to detect more recent events, in each case with evaluation of the significance of candidate signals by extensive simulations. Additional insights were provided by considering admixture proportions and functional categories of genes. We identified both individual loci that are likely targets of classic sweeps and groups of genes that may have experienced polygenic adaptation. We found population-specific as well as shared signals of selection, with folate metabolism and the related ultraviolet response and skin pigmentation standing out as a shared pathway, perhaps as a response to the high levels of ultraviolet irradiation, and in addition strong signals in genes such as IFNA, MRC1, immunoglobulins and T-cell receptors which contribute to defend against pathogens. CONCLUSIONS: Signals of positive selection were detected in Ethiopian populations revealing novel adaptations in East Africa, and abundant targets for functional follow-up.


Asunto(s)
Adaptación Biológica/genética , Genética de Población , Selección Genética , Población Negra/genética , Simulación por Computador , Etiopía , Ácido Fólico/metabolismo , Haplotipos , Humanos , Desequilibrio de Ligamiento , Aprendizaje Automático , Modelos Genéticos , Herencia Multifactorial , Pigmentación de la Piel/genética
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