Relaxed selection during a recent human expansion
Ontology highlight
ABSTRACT:
PROVIDER: EGAS00001001957 | EGA |
REPOSITORIES: EGA
Similar Datasets
Project description:How and when the Americas were populated remains contentious. Using ancient and modern genome-wide data, we find that the ancestors of all present-day Native Americans, including Athabascans and Amerindians, entered the Americas as a single migration wave from Siberia no earlier than 23 thousand years ago (KYA), and after no more than 8,000-year isolation period in Beringia. Native Americans diversified into two basal genetic branches around 13 KYA, one in North and South America and the other restricted to North America. Subsequent gene flow resulted in some Native Americans sharing ancestry with present-day East Asians and Australo-Melanesians, the latter possibly through the ancestors of Aleutian Islanders. Putative relict populations in South America, including the historical Pericúes and Fuego-Patagonians, are not directly related to modern Australo-Melanesians.
2015-07-20 | GSE70987 | GEO
Project description:Over the past few years, studies of DNA isolated from human fossils and archaeological remains have generated considerable novel insight into the history of our species. Several landmark papers have described the genomes of ancient human ancestors and have demonstrated that contemporary humans harbour genetic material from ancient close relatives, the Neanderthals and Denisovans, and that ancient human individuals are often genetically distinct from nearby extant populations whilst also showing affinities with populations from further afield. Across West Eurasia, there is growing genetic evidence of large-scale, dynamic population movements over the period between 10,000 to 2,000 years ago, such that the ancestry across present-day populations is likely to be a mixture of several ancient groups. Whilst these efforts are bringing the details of West Eurasian prehistory into increasing focus, studies aimed at understanding the processes behind the generation of the current West Eurasian genetic landscape have been limited by the number of populations sampled, or have been either too regional or global in their outlook. Here, using recently described haplotype-based techniques, we present the results of a systematic survey of recent admixture history across Western Eurasia and show that admixture is a universal property across almost all groups. Admixture in all regions except North Western Europe involved the influx of genetic material from outside of West Eurasia, which we date to specific time periods. Within Northern, Western, and Central Europe, admixture tended to occur between local groups during the period 300 to 1200CE. Comparisons of the genetic profiles of West Eurasians before and after admixture show that population movements within the last 1500 years are likely to have maintained differentiation amongst groups. Our analysis provides a timeline of the gene flow events that have generated the contemporary genetic landscape of West Eurasia. 20 individuals from Croatia included as part of an analysis of admixture in West Eurasia
2015-09-17 | E-GEOD-71603 | biostudies-arrayexpress
Project description:In this dataset, we include expression data from 36 KRAS-mutant lung adenocarcinomas from Stage 1 of the BATTLE-2 trial, reflecting patients whose disease has relapsed or progresses following at least one front-line metastatic chemotherapy regimen. Tumor biopsy was performed following informed consent and prior to randomisation to one of the four possible treatment arms.
2015-10-01 | GSE61913 | GEO
Project description:Cytosolic and mitochondrial fragments that arise from the cleavage of tRNAs and mt-tRNAs, respectively, have been identified as potential novel regulators of cellular functions. In this study we identified hundreds of fragments in the pancreatic islets of healthy human individuals. We were able to annotate 3593 tRFs (16-55 base pairs) present in the islets of healthy human individuals (we considered a minimum of 5 cpm values in each of the 3 samples). Interestingly, the vast majority of the tRFs whose levels are altered in pancreatic islets of prediabetic NOD mice and in extracellular vesicles released by activated CD4+ T lymphocytes, are conserved in humans and were detected in human pancreatic islets. This suggests a possible conservation of the findings of this study in a human context.
2024-05-14 | GSE256343 | GEO
Project description:This project aimed to investigate the effects of glyphosate-based herbicide Roundup LB Plus on bacteria. For this, ten environmental strains of Salmonella enterica were exposed to the increasing concentrations of Roundup over several passages to obtain Roundup-resistant mutants. Four stable re-sequenced resistant mutants and their respective ancestors were characterized by global proteomics in the presence and absence of sub-inhibitory (1/4xMIC) concentrations of the herbicide. By comparing the proteomes of the Roundup-challenged ancestors with constitutive non-challenged ancestors, it became possible to deepen the understanding of how Roundup stress affects naïve bacteria. Similarly, comparing Mutants versus Ancestors in the absence of Roundup allowed to understand how Roundup resistance constitutively affects bacterial physiology, while the comparison of Roundup-challenged mutants versus constitutive mutants helped improve the understanding of the inducible responses in the resistant background.
2020-09-22 | PXD019463 | Pride
Project description:Over the past few years, studies of DNA isolated from human fossils and archaeological remains have generated considerable novel insight into the history of our species. Several landmark papers have described the genomes of ancient human ancestors and have demonstrated that contemporary humans harbour genetic material from ancient close relatives, the Neanderthals and Denisovans, and that ancient human individuals are often genetically distinct from nearby extant populations whilst also showing affinities with populations from further afield. Across West Eurasia, there is growing genetic evidence of large-scale, dynamic population movements over the period between 10,000 to 2,000 years ago, such that the ancestry across present-day populations is likely to be a mixture of several ancient groups. Whilst these efforts are bringing the details of West Eurasian prehistory into increasing focus, studies aimed at understanding the processes behind the generation of the current West Eurasian genetic landscape have been limited by the number of populations sampled, or have been either too regional or global in their outlook. Here, using recently described haplotype-based techniques, we present the results of a systematic survey of recent admixture history across Western Eurasia and show that admixture is a universal property across almost all groups. Admixture in all regions except North Western Europe involved the influx of genetic material from outside of West Eurasia, which we date to specific time periods. Within Northern, Western, and Central Europe, admixture tended to occur between local groups during the period 300 to 1200CE. Comparisons of the genetic profiles of West Eurasians before and after admixture show that population movements within the last 1500 years are likely to have maintained differentiation amongst groups. Our analysis provides a timeline of the gene flow events that have generated the contemporary genetic landscape of West Eurasia.
2015-09-17 | GSE71603 | GEO
Project description:To determine the protein partners of ETV6, we expressed ETV6 and HA-tagged ETV6 in Reh pre-B leukemic cells. Anti-HA magnetic beads were used for affinity purification of ETV6-HA (and ETV6 control) from the nuclear and cytoplasmic fraction. Following purification on-beads digest and LC-MS/MS experiments were performed at the Proteomics platform of the CHU de Quebec Research Center, Quebec, Canada.
2022-01-26 | PXD031001 | Pride
Project description:Knowing when a person was infected with Mycobacterium tuberculosis (M.tb) is critical as recent infection is the strongest clinical risk factor for progression to TB disease in immunocompetent individuals. However, time since M.tb infection is very difficult to determine in routine clinical practice. We determined whether gene expression patterns in blood RNA correlate with time since M.tb infection or exposure to develop a biomarker for recent exposure. As proof of concept, we found an RNA signature that accurately discriminated early and late time periods after experimental infection in mice.
2020-10-20 | GSE124688 | GEO
Project description:Animal longevity widely differs across species, and even individuals from the same species may exhibit different rates of ageing. In different species, the rate at which individuals actually age is related to the level of their social interactions, but this was still not known in ants. In a given colony, ant individuals are close genetic relatives, exhibit very different behaviours and a contrasted lifespan according to the Caste. Such characteristics constitute main advantages to study relationships between sociality and ageing. Therefore, the aim of this study was to characterize differences in the proteome of Lasius niger queens versus that of domestic and foraging workers. Proteomic data were put in relation with the behaviour of individuals from the three Castes. Hence, it was found that sociality correlates with ant longevity, with i) social immunity enabling the queen to mainly invest in soma protection, and ii) marked exposition of workers to the environment and nutrients inducing metabolic pathways that reduce their lifespan.
2020-08-03 | PXD006779 | Pride
Project description:Naturally occurring FoxP3+CD4+CD25+high regulatory T cells (Tregs) play an important role in dominant tolerance, suppressing auto-reactive CD4+CD25- T cell activity. Although Tregs from T1D subjects are functionally deficient, there is little knowledge of the molecular mechanisms that orchestrate this loss of Treg function. We observed increased apoptosis (by a novel YOPRO-1/7AAD dual staining protocol) and decreased suppression in polyclonal Tregs in the periphery from high at-risk and T1D subjects. We hypothesize that prior to and during the onset of disease, Tregs lack pro-survival signals and are caught up in a relatively deficient cytokine milieu whose effects may be detectable in the periphery. Microarray analysis was performed on un-stimulated Tregs from 12 subjects with newly diagnosed T1D and 15 healthy controls. Keywords: disease-state analysis
2008-02-22 | GSE10586 | GEO