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1.
Cell Rep ; 42(11): 113346, 2023 11 28.
Artigo em Inglês | MEDLINE | ID: mdl-37917587

RESUMO

Borneo was a crossroad of ancient dispersals, with some of the earliest Southeast Asian human remains and rock art. The island is home to traditionally hunter-gatherer Punan communities, whose origins, whether of subsistence reversion or long-term foraging, are unclear. The connection between its past and present-day agriculturalist inhabitants, who currently speak Austronesian languages and have composite and complex genetic ancestry, is equally opaque. Here, we analyze the genetic ancestry of the northeastern Bornean Punan Batu (who still practice some mobile hunting and gathering), Tubu, and Aput. We find deep ancestry connections, with a shared Asian signal outgrouping modern and ancient Austronesian-ancestry proxies, suggesting a time depth of more than 7,500 years. They also largely lack the mainland Southeast Asian signals of agricultural Borneans, who are themselves genetically heterogeneous. Our results support long-term inhabitation of Borneo by some Punan ancestors and reveal unexpected complexity in the origins and dispersal of Austronesian-expansion-related ancestry.


Assuntos
Povo Asiático , Genética Populacional , Idioma , Humanos , Povo Asiático/genética , Bornéu
2.
PLoS Genet ; 18(12): e1010470, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36480515

RESUMO

Modern humans have admixed with multiple archaic hominins. Papuans, in particular, owe up to 5% of their genome to Denisovans, a sister group to Neanderthals whose remains have only been identified in Siberia and Tibet. Unfortunately, the biological and evolutionary significance of these introgression events remain poorly understood. Here we investigate the function of both Denisovan and Neanderthal alleles characterised within a set of 56 genomes from Papuan individuals. By comparing the distribution of archaic and non-archaic variants we assess the consequences of archaic admixture across a multitude of different cell types and functional elements. We observe an enrichment of archaic alleles within cis-regulatory elements and transcribed regions of the genome, with Denisovan variants strongly affecting elements active within immune-related cells. We identify 16,048 and 10,032 high-confidence Denisovan and Neanderthal variants that fall within annotated cis-regulatory elements and with the potential to alter the affinity of multiple transcription factors to their cognate DNA motifs, highlighting a likely mechanism by which introgressed DNA can impact phenotypes. Lastly, we experimentally validate these predictions by testing the regulatory potential of five Denisovan variants segregating within Papuan individuals, and find that two are associated with a significant reduction of transcriptional activity in plasmid reporter assays. Together, these data provide support for a widespread contribution of archaic DNA in shaping the present levels of modern human genetic diversity, with different archaic ancestries potentially affecting multiple phenotypic traits within non-Africans.


Assuntos
Evolução Molecular , Hominidae , Sistema Imunitário , Homem de Neandertal , Humanos , Hominidae/genética , Homem de Neandertal/genética , Papua Nova Guiné
3.
Evol Hum Sci ; 4: e9, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-37588920

RESUMO

Theories of early cooperation in human society often draw from a small sample of ethnographic studies of surviving populations of hunter-gatherers, most of which are now sedentary. Borneo hunter-gatherers (Punan, Penan) have seldom figured in comparative research because of a decades-old controversy about whether they are the descendants of farmers who adopted a hunting and gathering way of life. In 2018 we began an ethnographic study of a group of still-nomadic hunter-gatherers who call themselves Punan Batu (Cave Punan). Our genetic analysis clearly indicates that they are very unlikely to be the descendants of neighbouring agriculturalists. They also preserve a song language that is unrelated to other languages of Borneo. Dispersed travelling groups of Punan Batu with fluid membership use message sticks to stay in contact, co-operate and share resources as they journey between rock shelters and forest camps. Message sticks were once widespread among nomadic Punan in Borneo, but have largely disappeared in sedentary Punan villages. Thus the small community of Punan Batu offers a rare glimpse of a hunting and gathering way of life that was once widespread in the forests of Borneo, where prosocial behaviour extended beyond the face-to-face community, facilitating successful collective adaptation to the diverse resources of Borneo's forests.

4.
Am J Hum Genet ; 109(1): 50-65, 2022 01 06.
Artigo em Inglês | MEDLINE | ID: mdl-34919805

RESUMO

Lack of diversity in human genomics limits our understanding of the genetic underpinnings of complex traits, hinders precision medicine, and contributes to health disparities. To map genetic effects on gene regulation in the underrepresented Indonesian population, we have integrated genotype, gene expression, and CpG methylation data from 115 participants across three island populations that capture the major sources of genomic diversity in the region. In a comparison with European datasets, we identify eQTLs shared between Indonesia and Europe as well as population-specific eQTLs that exhibit differences in allele frequencies and/or overall expression levels between populations. By combining local ancestry and archaic introgression inference with eQTLs and methylQTLs, we identify regulatory loci driven by modern Papuan ancestry as well as introgressed Denisovan and Neanderthal variation. GWAS colocalization connects QTLs detected here to hematological traits, and further comparison with European datasets reflects the poor overall transferability of GWAS statistics across diverse populations. Our findings illustrate how population-specific genetic architecture, local ancestry, and archaic introgression drive variation in gene regulation across genetically distinct and in admixed populations and highlight the need for performing association studies on non-European populations.


Assuntos
Regulação da Expressão Gênica , Genética Populacional , Genoma Humano , Locos de Características Quantitativas , Biologia Computacional/métodos , Metilação de DNA , Bases de Dados Genéticas , Estudo de Associação Genômica Ampla , Genômica/métodos , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Indonésia , Masculino , Modelos Genéticos , Anotação de Sequência Molecular , Herança Multifatorial , Característica Quantitativa Herdável , Seleção Genética , Sequenciamento Completo do Genoma
5.
Nat Ecol Evol ; 5(5): 616-624, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33753899

RESUMO

The hominin fossil record of Island Southeast Asia (ISEA) indicates that at least two endemic 'super-archaic' species-Homo luzonensis and H. floresiensis-were present around the time anatomically modern humans arrived in the region >50,000 years ago. Intriguingly, contemporary human populations across ISEA carry distinct genomic traces of ancient interbreeding events with Denisovans-a separate hominin lineage that currently lacks a fossil record in ISEA. To query this apparent disparity between fossil and genetic evidence, we performed a comprehensive search for super-archaic introgression in >400 modern human genomes, including >200 from ISEA. Our results corroborate widespread Denisovan ancestry in ISEA populations, but fail to detect any substantial super-archaic admixture signals compatible with the endemic fossil record of ISEA. We discuss the implications of our findings for the understanding of hominin history in ISEA, including future research directions that might help to unlock more details about the prehistory of the enigmatic Denisovans.


Assuntos
Hominidae , Homem de Neandertal , Animais , Sudeste Asiático , Fósseis , Hominidae/genética , Humanos , Ilhas
6.
Eur J Hum Genet ; 28(12): 1694-1702, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32499598

RESUMO

Ectodysplasin A1 receptor (EDAR) is a TNF receptor family member with roles in the development and growth of hair, teeth and glands. A derived allele of EDAR, single-nucleotide variant rs3827760, encodes EDAR:p.(Val370Ala), a receptor with more potent signalling effects than the ancestral EDAR370Val. This allele of rs3827760 is at very high frequency in modern East Asian and Native American populations as a result of ancient positive selection and has been associated with straighter, thicker hair fibres, alteration of tooth and ear shape, reduced chin protrusion and increased fingertip sweat gland density. Here we report the characterisation of another SNV in EDAR, rs146567337, encoding EDAR:p.(Ser380Arg). The derived allele of this SNV is at its highest global frequency, of up to 5%, in populations of southern China, Vietnam, the Philippines, Malaysia and Indonesia. Using haplotype analyses, we find that the rs3827760 and rs146567337 SNVs arose on distinct haplotypes and that rs146567337 does not show the same signs of positive selection as rs3827760. From functional studies in cultured cells, we find that EDAR:p.(Ser380Arg) displays increased EDAR signalling output, at a similar level to that of EDAR:p.(Val370Ala). The existence of a second SNV with partly overlapping geographic distribution, the same in vitro functional effect and similar evolutionary age as the derived allele of rs3827760, but of independent origin and not exhibiting the same signs of strong selection, suggests a northern focus of positive selection on EDAR function in East Asia.


Assuntos
Receptor Edar/genética , Mutação com Ganho de Função , Frequência do Gene , Sudeste Asiático , Receptor Edar/química , Receptor Edar/metabolismo , Evolução Molecular , Células HEK293 , Células HaCaT , Haplótipos , Humanos , Simulação de Dinâmica Molecular , Polimorfismo de Nucleotídeo Único , Seleção Genética
7.
PLoS Genet ; 16(5): e1008749, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32453742

RESUMO

Indonesia is the world's fourth most populous country, host to striking levels of human diversity, regional patterns of admixture, and varying degrees of introgression from both Neanderthals and Denisovans. However, it has been largely excluded from the human genomics sequencing boom of the last decade. To serve as a benchmark dataset of molecular phenotypes across the region, we generated genome-wide CpG methylation and gene expression measurements in over 100 individuals from three locations that capture the major genomic and geographical axes of diversity across the Indonesian archipelago. Investigating between- and within-island differences, we find up to 10.55% of tested genes are differentially expressed between the islands of Sumba and New Guinea. Variation in gene expression is closely associated with DNA methylation, with expression levels of 9.80% of genes correlating with nearby promoter CpG methylation, and many of these genes being differentially expressed between islands. Genes identified in our differential expression and methylation analyses are enriched in pathways involved in immunity, highlighting Indonesia's tropical role as a source of infectious disease diversity and the strong selective pressures these diseases have exerted on humans. Finally, we identify robust within-island variation in DNA methylation and gene expression, likely driven by fine-scale environmental differences across sampling sites. Together, these results strongly suggest complex relationships between DNA methylation, transcription, archaic hominin introgression and immunity, all jointly shaped by the environment. This has implications for the application of genomic medicine, both in critically understudied Indonesia and globally, and will allow a better understanding of the interacting roles of genomic and environmental factors shaping molecular and complex phenotypes.


Assuntos
Metilação de DNA , Etnicidade/genética , Interação Gene-Ambiente , Transcriptoma , Ilhas de CpG , Meio Ambiente , Epigênese Genética/fisiologia , Etnicidade/estatística & dados numéricos , Perfilação da Expressão Gênica/estatística & dados numéricos , Genética Populacional , Estudo de Associação Genômica Ampla/estatística & dados numéricos , Genômica/métodos , Humanos , Indonésia/epidemiologia , Ilhas/epidemiologia , Ilhas do Pacífico/epidemiologia , Linhagem , Fenótipo , Polimorfismo de Nucleotídeo Único , RNA-Seq
8.
Sci Rep ; 10(1): 4618, 2020 03 12.
Artigo em Inglês | MEDLINE | ID: mdl-32165662

RESUMO

The Indian cheetah was hunted to extinction by the mid-20th century. While analysis of 139 bp of mitochondrial DNA (mtDNA) has confirmed that the Indian cheetah was part of the Asiatic subspecies (Acinonyx jubatus venaticus), the detailed relationships between cheetah populations remains unclear due to limited genetic data. We clarify these relationships by studying larger fragments of cheetah mtDNA, both from an Indian cheetah museum specimen and two African cheetah, one modern and one historic, imported into India at different times. Our results suggest that the most recent common ancestor of cheetah mtDNA is approximately twice as ancient as currently recognised. The Indian and Southeast African (Acinonyx jubatus jubatus) cheetah mtDNA diverged approximately 72 kya, while the Southeast and Northeast African (Acinonyx jubatus soemmeringii) cheetah mtDNA diverged around 139 kya. Additionally, the historic African cheetah sampled from India proved to have an A. j. jubatus haplotype, suggesting a hitherto unrecognised South African route of cheetah importation into India in the 19th century. Together, our results provide a deeper understanding of the relationships between cheetah subspecies, and have important implications for the conservation of A. j. venaticus and potential reintroduction of cheetahs into India.


Assuntos
Acinonyx/classificação , Acinonyx/genética , DNA Mitocondrial , Extinção Biológica , Variação Genética , Genética Populacional , África , Animais , Índia , Filogenia , Filogeografia
9.
R Soc Open Sci ; 6(8): 190733, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31598251

RESUMO

Population genetics has been successful at identifying the relationships between human groups and their interconnected histories. However, the link between genetic demography inferred at large scales and the individual human behaviours that ultimately generate that demography is not always clear. While anthropological and historical context are routinely presented as adjuncts in population genetic studies to help describe the past, determining how underlying patterns of human sociocultural behaviour impact genetics still remains challenging. Here, we analyse patterns of genetic variation in village-scale samples from two islands in eastern Indonesia, patrilocal Sumba and a matrilocal region of Timor. Adopting a 'process modelling' approach, we iteratively explore combinations of structurally different models as a thinking tool. We find interconnected socio-genetic interactions involving sex-biased migration, lineage-focused founder effects, and on Sumba, heritable social dominance. Strikingly, founder ideology, a cultural model derived from anthropological and archaeological studies at larger regional scales, has both its origins and impact at the scale of villages. Process modelling lets us explore these complex interactions, first by circumventing the complexity of formal inference when studying large datasets with many interacting parts, and then by explicitly testing complex anthropological hypotheses about sociocultural behaviour from a more familiar population genetic standpoint.

10.
Cell ; 177(4): 1010-1021.e32, 2019 05 02.
Artigo em Inglês | MEDLINE | ID: mdl-30981557

RESUMO

Genome sequences are known for two archaic hominins-Neanderthals and Denisovans-which interbred with anatomically modern humans as they dispersed out of Africa. We identified high-confidence archaic haplotypes in 161 new genomes spanning 14 island groups in Island Southeast Asia and New Guinea and found large stretches of DNA that are inconsistent with a single introgressing Denisovan origin. Instead, modern Papuans carry hundreds of gene variants from two deeply divergent Denisovan lineages that separated over 350 thousand years ago. Spatial and temporal structure among these lineages suggest that introgression from one of these Denisovan groups predominantly took place east of the Wallace line and continued until near the end of the Pleistocene. A third Denisovan lineage occurs in modern East Asians. This regional mosaic suggests considerable complexity in archaic contact, with modern humans interbreeding with multiple Denisovan groups that were geographically isolated from each other over deep evolutionary time.


Assuntos
Introgressão Genética/genética , Haplótipos/genética , Hominidae/genética , Animais , Povo Asiático/genética , Evolução Biológica , Fluxo Gênico , Variação Genética/genética , Genoma Humano/genética , Humanos , Indonésia , Homem de Neandertal/genética , Oceania
11.
Cardiovasc Ther ; 36(6): e12467, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30239134

RESUMO

BACKGROUND: Both cardiac resynchronization therapy (CRT) and Multidisciplinary Cardiac Rehabilitation (CR) beneficially influence symptomatic status, exercise capacity, quality of life, and heart failure readmission rates. However, the interaction between both therapies remain incompletely addressed. METHODS: Consecutive CRT patients implanted in a single tertiary care center were retrospectively analyzed. Patients were dived according to the participation in a structured CR-program following CRT-implant. The effect on functional status (New York Heart Association; NYHA-class), reverse remodeling (change in left ventricular ejection fraction; LVEF), and the combined endpoint of heart failure readmission and all-cause mortality was assessed after multivariate correction. RESULTS: A total of 655 patients were analyzed of whom 223(34%) did and 432(66%) did not participate in a structured multidisciplinary CR-program following implant. No adverse events relating to exercise training occurred during the CR-program. Patients who participated in the CR-program had a more pronounced improvement in NYHA-class at 6-months (P = 0.006), even after multivariate correction (ß = -0.144; 95% CI = [-0.270; -0.018]; P = 0.025). Maximal workload and VO2max on CPET at 6 months improved significantly even after adjustment (P < 0.001, respectively P = 0.017). At 6-months, CR associated with more improvement in LVEF (+11.9 ± 13 vs +14.5 ± 11; P = 0.008), however, this relationship was lost after multivariate correction (P = 0.136). During 36 ± 22 months follow-up, patients in the CR group had a higher event-free survival for the combined endpoint (P = 0.001), even after multivariate correction (adjusted HR = 0.547; CI = 0.366-0.818; P = 0.003). CONCLUSIONS: Following CRT-implant, the participation in a structured CR-program is safe and beneficially influences symptomatic response and clinical outcome. The beneficial effects of exercise training are potentially independent and additive to the beneficial reverse remodeling effect induced by CRT itself.


Assuntos
Reabilitação Cardíaca/métodos , Dispositivos de Terapia de Ressincronização Cardíaca , Terapia de Ressincronização Cardíaca , Terapia por Exercício , Insuficiência Cardíaca/reabilitação , Idoso , Idoso de 80 Anos ou mais , Bélgica , Reabilitação Cardíaca/efeitos adversos , Reabilitação Cardíaca/mortalidade , Terapia de Ressincronização Cardíaca/efeitos adversos , Terapia de Ressincronização Cardíaca/mortalidade , Terapia Combinada , Terapia por Exercício/efeitos adversos , Terapia por Exercício/mortalidade , Tolerância ao Exercício , Feminino , Nível de Saúde , Insuficiência Cardíaca/diagnóstico , Insuficiência Cardíaca/mortalidade , Insuficiência Cardíaca/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Readmissão do Paciente , Qualidade de Vida , Recuperação de Função Fisiológica , Estudos Retrospectivos , Fatores de Risco , Volume Sistólico , Fatores de Tempo , Resultado do Tratamento , Função Ventricular Esquerda , Remodelação Ventricular
12.
Am J Hum Biol ; 30(5): e23170, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-30099804

RESUMO

OBJECTIVES: Skin color is a highly visible and variable trait across human populations. It is not yet clear how evolutionary forces interact to generate phenotypic diversity. Here, we sought to unravel through an integrative framework the role played by three factors-demography and migration, sexual selection, and natural selection-in driving skin color diversity in India. METHODS: Skin reflectance data were collected from 10 diverse socio-cultural populations along the latitudinal expanse of India, including both sexes. We first looked at how skin color varies within and between these populations. Second, we compared patterns of sexual dimorphism in skin color. Third, we studied the influence of ultraviolet radiation on skin color throughout India. Finally, we attempted to disentangle the interactions between these factors in the context of available genetic data. RESULTS: We found that the relative importance of these forces varied between populations. Social factors and population structure have played a stronger role than natural selection in shaping skin color diversity across India. Phenotypic overprinting resulted from additional genetic mutations overriding the skin lightening effect of variants such as the SLC24A5 rs1426654-A allele in some populations, in the context of the variable influence of sexual selection. Furthermore, specific genotypes are not associated reliably with specific skin color phenotypes. This result has relevance for DNA forensics and ancient DNA research. CONCLUSIONS: India is a crucible of macro- and micro-evolutionary forces, and the complex interactions of physical and social forces are visible in the patterns of skin color seen today in the country.


Assuntos
Evolução Biológica , Fenótipo , Seleção Genética , Pigmentação da Pele/fisiologia , Feminino , Humanos , Índia , Masculino , Fatores Sexuais , Pigmentação da Pele/genética , Pigmentação da Pele/efeitos da radiação , Raios Ultravioleta
13.
Proc Natl Acad Sci U S A ; 114(49): 12910-12915, 2017 12 05.
Artigo em Inglês | MEDLINE | ID: mdl-29158378

RESUMO

Languages are transmitted through channels created by kinship systems. Given sufficient time, these kinship channels can change the genetic and linguistic structure of populations. In traditional societies of eastern Indonesia, finely resolved cophylogenies of languages and genes reveal persistent movements between stable speech communities facilitated by kinship rules. When multiple languages are present in a region and postmarital residence rules encourage sustained directional movement between speech communities, then languages should be channeled along uniparental lines. We find strong evidence for this pattern in 982 individuals from 25 villages on two adjacent islands, where different kinship rules have been followed. Core groups of close relatives have stayed together for generations, while remaining in contact with, and marrying into, surrounding groups. Over time, these kinship systems shaped their gene and language phylogenies: Consistently following a postmarital residence rule turned social communities into speech communities.


Assuntos
Idioma , DNA Mitocondrial/genética , Família , Feminino , Variação Genética , Migração Humana , Humanos , Indonésia , Ilhas , Linguística , Masculino , Filogenia , Análise de Sequência de DNA
14.
Sci Rep ; 7(1): 13042, 2017 10 12.
Artigo em Inglês | MEDLINE | ID: mdl-29026132

RESUMO

The aim of this study is to identify genetic variants that harbour signatures of recent positive selection and may facilitate physiological adaptations to hypobaric hypoxia. To achieve this, we conducted whole genome sequencing and lung function tests in 19 Argentinean highlanders (>3500 m) comparing them to 16 Native American lowlanders. We developed a new statistical procedure using a combination of population branch statistics (PBS) and number of segregating sites by length (nSL) to detect beneficial alleles that arose since the settlement of the Andes and are currently present in 15-50% of the population. We identified two missense variants as significant targets of selection. One of these variants, located within the GPR126 gene, has been previously associated with the forced expiratory volume/forced vital capacity ratio. The other novel missense variant mapped to the EPAS1 gene encoding the hypoxia inducible factor 2α. EPAS1 is known to be the major selection candidate gene in Tibetans. The derived allele of GPR126 is associated with lung function in our sample of highlanders (p < 0.05). These variants may contribute to the physiological adaptations to hypobaric hypoxia, possibly by altering lung function. The new statistical approach might be a useful tool to detect selected variants in population studies.


Assuntos
Altitude , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Receptores Acoplados a Proteínas G/genética , Seleção Genética , Alelos , Argentina , Frequência do Gene/genética , Humanos
15.
Sci Rep ; 6: 37198, 2016 11 17.
Artigo em Inglês | MEDLINE | ID: mdl-27853181

RESUMO

Humans have more copies of amylase genes than other primates. It is still poorly understood, however, when the copy number expansion occurred and whether its spread was enhanced by selection. Here we assess amylase copy numbers in a global sample of 480 high coverage genomes and find that regions flanking the amylase locus show notable depression of genetic diversity both in African and non-African populations. Analysis of genetic variation in these regions supports the model of an early selective sweep in the human lineage after the split of humans from Neanderthals which led to the fixation of multiple copies of AMY1 in place of a single copy. We find evidence of multiple secondary losses of copy number with the highest frequency (52%) of a deletion of AMY2A and associated low copy number of AMY1 in Northeast Siberian populations whose diet has been low in starch content.


Assuntos
Amilases/genética , Evolução Molecular , Dosagem de Genes , Variação Genética , Genoma Humano , Animais , Feminino , Humanos , Masculino , Homem de Neandertal
16.
Nature ; 538(7624): 238-242, 2016 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-27654910

RESUMO

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.


Assuntos
Genoma Humano/genética , Genômica , Migração Humana/história , Grupos Raciais/genética , África/etnologia , Animais , Ásia , Conjuntos de Dados como Assunto , Estônia , Europa (Continente) , Fósseis , Fluxo Gênico , Genética Populacional , Heterozigoto , História Antiga , Humanos , Havaiano Nativo ou Outro Ilhéu do Pacífico/genética , Homem de Neandertal/genética , Nova Guiné , Dinâmica Populacional
17.
Genetics ; 203(4): 1807-25, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27516617

RESUMO

During a selective sweep, characteristic patterns of linkage disequilibrium can arise in the genomic region surrounding a selected locus. These have been used to infer past selective sweeps. However, the recombination rate is known to vary substantially along the genome for many species. We here investigate the effectiveness of current (Kelly's [Formula: see text] and [Formula: see text]) and novel statistics at inferring hard selective sweeps based on linkage disequilibrium distortions under different conditions, including a human-realistic demographic model and recombination rate variation. When the recombination rate is constant, Kelly's [Formula: see text] offers high power, but is outperformed by a novel statistic that we test, which we call [Formula: see text] We also find this statistic to be effective at detecting sweeps from standing variation. When recombination rate fluctuations are included, there is a considerable reduction in power for all linkage disequilibrium-based statistics. However, this can largely be reversed by appropriately controlling for expected linkage disequilibrium using a genetic map. To further test these different methods, we perform selection scans on well-characterized HapMap data, finding that all three statistics-[Formula: see text] Kelly's [Formula: see text] and [Formula: see text]-are able to replicate signals at regions previously identified as selection candidates based on population differentiation or the site frequency spectrum. While [Formula: see text] replicates most candidates when recombination map data are not available, the [Formula: see text] and [Formula: see text] statistics are more successful when recombination rate variation is controlled for. Given both this and their higher power in simulations of selective sweeps, these statistics are preferred when information on local recombination rate variation is available.


Assuntos
Genômica , Desequilíbrio de Ligação , Recombinação Genética , Seleção Genética , Genética Populacional/estatística & dados numéricos , Projeto HapMap , Haplótipos/genética , Humanos , Modelos Teóricos
18.
Am J Hum Genet ; 95(5): 584-589, 2014 11 06.
Artigo em Inglês | MEDLINE | ID: mdl-25449608

RESUMO

Arctic populations live in an environment characterized by extreme cold and the absence of plant foods for much of the year and are likely to have undergone genetic adaptations to these environmental conditions in the time they have been living there. Genome-wide selection scans based on genotype data from native Siberians have previously highlighted a 3 Mb chromosome 11 region containing 79 protein-coding genes as the strongest candidates for positive selection in Northeast Siberians. However, it was not possible to determine which of the genes might be driving the selection signal. Here, using whole-genome high-coverage sequence data, we identified the most likely causative variant as a nonsynonymous G>A transition (rs80356779; c.1436C>T [p.Pro479Leu] on the reverse strand) in CPT1A, a key regulator of mitochondrial long-chain fatty-acid oxidation. Remarkably, the derived allele is associated with hypoketotic hypoglycemia and high infant mortality yet occurs at high frequency in Canadian and Greenland Inuits and was also found at 68% frequency in our Northeast Siberian sample. We provide evidence of one of the strongest selective sweeps reported in humans; this sweep has driven this variant to high frequency in circum-Arctic populations within the last 6-23 ka despite associated deleterious consequences, possibly as a result of the selective advantage it originally provided to either a high-fat diet or a cold environment.

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