Physiological and genetic adaptations to diving in Sea Nomads
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ABSTRACT:
PROVIDER: EGAS00001002823 | EGA |
REPOSITORIES: EGA
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Project description:The shift from a hunter-gatherer (HG) to an agricultural (AG) mode of subsistence is believed to have been associated with profound changes in the burden and diversity of pathogens across human populations. Yet, the extent to which the advent of agriculture impacted the evolution of the human immune system remains unknown. Here we present a comparative study of variation in the transcriptional responses of peripheral blood mononuclear cells (PBMCs) to bacterial and viral stimuli between the Batwa, a rainforest hunter-gatherer, and the Bakiga, an agriculturalist population from Central Africa. We observed increased divergence between hunter-gatherers and farmers in the transcriptional response to viruses compared to that for bacterial stimuli. We demonstrate that a significant fraction of these transcriptional differences are under genetic control, and we show that positive natural selection has helped to shape population differences in immune regulation. Unexpectedly, we found stronger signatures of recent natural selection in the rainforest hunter-gatherers, which argues against the popularized notion that shifts in pathogen exposure due to the advent of agriculture imposed radically heightened selective pressures in agriculturalist populations.
2018-09-27 | GSE120502 | GEO
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2022-10-31 | E-MTAB-12243 | biostudies-arrayexpress
Project description:During tumour growth cancer cells are subject to and selected by microenvironmental stress. The selection of such cells allows for continued growth and survival, during hypoxia, acidosis, nutritional deprivation, drug treatment and radiation. However, there is great microenvironmental heterogeneity in every tumour. Must studies of gene regulation in vitro investigate whole cell populations, often by western blotting or mRNA expression. Thus, the individual variability of gene induction that could lead to selection, and basal cell molecular variability on which the selection operates, basic Darwinian principles, are not defined. We previously showed that two distinct populations can often be induced in epithelial tumour cell lines under hypoxia, identified by induction of Carbonic Anhydrase 9 [CA9].Here, we investigated the heterogeneity of breast cancer cells, and the relationship to the CA9 positive population in hypoxia, by using single cell sequencing analysis.
2021-09-09 | GSE134038 | GEO
Project description:The interplay between phenotypic plasticity and adaptive evolution has long been an important topic of evolutionary biology. This process is critical to our understanding of a species evolutionary potential in light of rapid climate changes. Despite recent theoretical work, empirical studies of natural populations, especially in marine invertebrates, are scarce. In this study, we investigated the relationship between adaptive divergence and plasticity by integrating genetic and phenotypic variation in Pacific oysters from its natural range in China. Genome resequencing of 371 oysters revealed unexpected fine-scale genetic structure that is largely consistent with phenotypic divergence in growth, physiology, thermal tolerance and gene expression across environmental gradient. These findings suggest that selection and local adaptation are pervasive and together with limited gene flow shape adaptive divergence. Plasticity in gene expression is positively correlated with evolved divergence, indicating that plasticity is adaptive and likely favored by selection in organisms facing dynamic environments such as oysters. Divergence in heat response and tolerance implies that the evolutionary potential to a warming climate differs among oyster populations. We suggest that trade-offs in energy allocation are important to adaptive divergence with acetylation playing a role in energy depression under thermal stress.
2018-07-27 | PXD008057 | Pride
Project description:Hypoxia-induced cell injury has been related to multiple pathological conditions. In order to render hypoxia-sensitive cells and tissues resistant to low O2 environment, in this current study, we used Drosophila melanogaster as a model to dissect the mechanisms underlying hypoxia-tolerance. A D. melanogaster strain that lives perpetually in an extremely low-oxygen environment (4% O2, an oxygen level that is equivalent to that over about 4,000 m above Mt. Everest) was generated through laboratory selection pressure using a continuing reduction of O2 over many generations. This phenotype is genetically stable since selected flies, after several generations in room air, survive at this low O2 level. Gene expression profiling showed striking differences between tolerant and naïve flies, in larvae and adults, both quantitatively and qualitatively. Up-regulated genes in the tolerant flies included signal transduction pathways (e.g., Notch and Toll/Imd pathways), but metabolic genes were remarkably down-regulated in the larvae. Furthermore, a different allelic frequency and enzymatic activity of the triose phosphate isomerase (TPI) was present in the tolerant versus naïve flies. The transcriptional suppressor, hairy, was up-regulated in the microarrays and its binding elements were present in the regulatory region of the specifically down-regulated metabolic genes but not others, and mutations in hairy significantly reduced hypoxia tolerance. We conclude that, the hypoxia-selected flies: (a) altered their gene expression and genetic code, and (b) coordinated their metabolic suppression, especially during development, with hairy acting as a metabolic switch, thus playing a crucial role in hypoxia-tolerance. Keywords: genetic bases of hypoxia adaptation 27 isogenic D. melanogaster Lines were pooled and following long-term selection over generations with decreased oxygen level in the culture environment. The differences in gene expression were compared between adapted flies and generation matched naive controls by microarray. Pooled RNA samples from 3rd instar larvae of 27 parental lines were used as common reference.
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Project description:In Arabidopsis thaliana a high rate of spontaneous epigenetic variation can occur in the DNA methylome in the absence of genetic variation and selection. It has been of great interest, whether natural epigenetic variation is subject to selection and contributes to fitness and adaptation in selective environments. We compared the variation in selected phenotypic traits, genome-wide cytosine DNA methylation and gene expression in two Arabidopsis recombinant inbred lines, which had undergone five generations of selection in experimental landscapes relative to their genetically identical ancestors. Selected populations exerted significant differences in flowering time and the number of branches and fruits, differences that were maintained over two to three generations in the absence of selection. We identified 4,629 and 5,158 differentially methylated cytosines which were overrepresented in genes that regulate flowering time, epigenetic processes, development and morphogenesis. Differentially methylated genes were enriched in differentially expressed genes. Thus, epigenetic variation is subject to selection and may play an important role in the adaptive response of populations in rapidly changing natural environments.
2014-09-01 | GSE36844 | GEO
Project description:In Arabidopsis thaliana a high rate of spontaneous epigenetic variation can occur in the DNA methylome in the absence of genetic variation and selection. It has been of great interest, whether natural epigenetic variation is subject to selection and contributes to fitness and adaptation in selective environments. We compared the variation in selected phenotypic traits, genome-wide cytosine DNA methylation and gene expression in two Arabidopsis recombinant inbred lines, which had undergone five generations of selection in experimental landscapes relative to their genetically identical ancestors. Selected populations exerted significant differences in flowering time and the number of branches and fruits, differences that were maintained over two to three generations in the absence of selection. We identified 4,629 and 5,158 differentially methylated cytosines which were overrepresented in genes that regulate flowering time, epigenetic processes, development and morphogenesis. Differentially methylated genes were enriched in differentially expressed genes. Thus, epigenetic variation is subject to selection and may play an important role in the adaptive response of populations in rapidly changing natural environments.
2014-09-01 | GSE47490 | GEO
Project description:In Arabidopsis thaliana a high rate of spontaneous epigenetic variation can occur in the DNA methylome in the absence of genetic variation and selection. It has been of great interest, whether natural epigenetic variation is subject to selection and contributes to fitness and adaptation in selective environments. We compared the variation in selected phenotypic traits, genome-wide cytosine DNA methylation and gene expression in two Arabidopsis recombinant inbred lines, which had undergone five generations of selection in experimental landscapes relative to their genetically identical ancestors. Selected populations exerted significant differences in flowering time and the number of branches and fruits, differences that were maintained over two to three generations in the absence of selection. We identified 4,629 and 5,158 differentially methylated cytosines which were overrepresented in genes that regulate flowering time, epigenetic processes, development and morphogenesis. Differentially methylated genes were enriched in differentially expressed genes. Thus, epigenetic variation is subject to selection and may play an important role in the adaptive response of populations in rapidly changing natural environments.
2014-09-01 | GSE36845 | GEO
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