Project description:The Caucasus, inhabited by modern humans since the Early Upper Paleolithic and known for its linguistic diversity, is considered to be important for understanding human dispersals and genetic diversity in Eurasia. We report a synthesis of autosomal, Y chromosome, and mitochondrial DNA (mtDNA) variation in populations from all major subregions and linguistic phyla of the area. Autosomal genome variation in the Caucasus reveals significant genetic uniformity among its ethnically and linguistically diverse populations and is consistent with predominantly Near/Middle Eastern origin of the Caucasians, with minor external impacts. In contrast to autosomal and mtDNA variation, signals of regional Y chromosome founder effects distinguish the eastern from western North Caucasians. Genetic discontinuity between the North Caucasus and the East European Plain contrasts with continuity through Anatolia and the Balkans, suggesting major routes of ancient gene flows and admixture. 204 samples were analysed with the Illumina platform Human610-Quad v 1.0 and are described herein.
Project description:The Caucasus, inhabited by modern humans since the Early Upper Paleolithic and known for its linguistic diversity, is considered to be important for understanding human dispersals and genetic diversity in Eurasia. We report a synthesis of autosomal, Y chromosome, and mitochondrial DNA (mtDNA) variation in populations from all major subregions and linguistic phyla of the area. Autosomal genome variation in the Caucasus reveals significant genetic uniformity among its ethnically and linguistically diverse populations and is consistent with predominantly Near/Middle Eastern origin of the Caucasians, with minor external impacts. In contrast to autosomal and mtDNA variation, signals of regional Y chromosome founder effects distinguish the eastern from western North Caucasians. Genetic discontinuity between the North Caucasus and the East European Plain contrasts with continuity through Anatolia and the Balkans, suggesting major routes of ancient gene flows and admixture.
Project description:Hispanic/Latino populations possess a complex genetic structure that reflects recent admixture among and potentially ancient substructure within Native American, European, and West African source populations. Here, we quantify genome-wide patterns of SNP and haplotype variation among 100 individuals with ancestry from Ecuador, Colombia, Puerto Rico, and the Dominican Republic genotyped using Illumina technology.
2010-04-08 | GSE21248 | GEO
Project description:Global patterns of cercozoan diversity in drylands
Project description:The inherent diversity of canines is closely intertwined with the unique color patterns of each dog population. These variations in color patterns are believed to have originated through mutations and selective breeding practices that occurred during and after the domestication of dogs from wolves. To address the significant gaps that persist in comprehending the evolutionary processes that underlie the development of these patterns, we generated and analyzed deep-sequenced genomes of 113 Korean indigenous Jindo dogs that represent five distinct color patterns to identify the associated mutations in CBD103, ASIP, and MC1R. The degree of linkage disequilibrium and estimated allelic ages consistently indicate that the black-and-tan dogs descend from the first major founding population on Jindo island, compatible with the documented literature. We additionally demonstrate that black-and-tan dogs, in contrast to other color variations within the breed, exhibit a closer genetic affinity to ancient wolves from western Eurasia than those from eastern Eurasia. Lastly, population-specific genetic variants with moderate effects were identified, particularly in loci associated with traits underlying body size and behavioral variations, potentially explaining the observed phenotypic diversity based on coat colors. Overall, comparisons of whole genome sequences of each coat color population diverged from the same breed provided an unprecedented glimpse into the properties of evolutionary processes maintaining variation in Korean Jindo dog populations that were previously inaccessible.
Project description:Alternative splicing is a critical determinant of genome complexity and by implication, is assumed to engender proteomic diversity. This notion has not been experimentally tested in a targeted, quantitative manner. Here, we have developed an integrative approach to ask whether dynamic perturbations in mRNA splicing patterns that follow depletion of the core spliceosome factor PRPF8 alter the composition of the proteome. We integrate RNA-sequencing (to comprehensively report intron retention, differential transcript usage and gene expression) with a newly developed data-independent acquisition (DIA) method, SWATH-MS (Sequential Window Acquisition of all THeoretical spectra – mass spectrometry), to capture an unbiased and quantitative snapshot of constitutive and alternative splicing events at the protein level. Whereas intron retention is accompanied by decreased protein abundance, dynamic alterations in differential transcript usage and gene expression alter protein abundance proportionally to transcript levels. Our findings exemplify how RNA splicing exerts a pervasive effect linking isoform expression in the human transcriptome with proteomic diversity, and provide a toolkit for studying its perturbation in human diseases.
Project description:DNA methylation is an epigenetic modification, influenced by both genetic and environmental variation, that plays a key role in transcriptional regulation and many organismal phenotypes. Although patterns of DNA methylation have been shown to differ between human populations, it remains to be determined how epigenetic diversity relates to the patterns of genetic and gene expression variation at a global scale. Here we measured DNA methylation at 485,000 CpG sites in five diverse human populations, and analyzed these data together with genome-wide genotype and gene expression data. We found that population-specific DNA methylation mirrors genetic variation, and has greater local genetic control than mRNA levels. We estimated the rate of epigenetic divergence between populations, which indicates far greater evolutionary stability of DNA methylation in humans than has been observed in plants. This study provides a deeper understanding of worldwide patterns of human epigenetic diversity, as well as initial estimates of the rate of epigenetic divergence in recent human evolution.
Project description:We report on a genome-wide scan for introgression in the house mouse (Mus musculus domesticus) involving the Algerian mouse (Mus spretus), using 20 samples from the ranges of sympatry and allopatry. Our analysis reveals significant variability in introgression signatures along the genomes, as well as across the samples. We find that fewer than half of the chromosomes in each genome harbor all detectable introgression. Further, a surprising result is that European mice carry more M. spretus alleles than the sympatric African ones. Using the length distribution and sharing patterns of introgressed genomic tracts across the samples, we propose three hypotheses. First, at least three distinct hybridization events involving M. spretus have occurred, one of which is ancient, and the other two are recent. Second, several of the inferred introgressed tracts contain genes that are likely to confer adaptive advantage. Third, introgressed tracts might contain driver genes that determine the evolutionary fate of those tracts. Further, our analysis revealed introgressed genes of functional importance, including the Vkorc1 gene, which is implicated in rodenticide resistance, and olfactory receptor genes. Our findings highlight the extent and role of introgression in nature, and call for careful analysis and interpretation of house mouse data in evolutionary and genetic studies. Six wild M. m. domesticus samples were genotyped using the Affymetrix Mouse Diversity Genotyping Array.