Project description:Genome-wide patterns of variation across individuals provide a powerful source of data for uncovering the history of migration, range expansion, and adaptation of the human species. However, high-resolution surveys of variation in genotype, haplotype and copy number have generally focused on a small number of population groups. Here we report the analysis and public release of high-quality genotypes at 525,910 single-nucleotide polymorphisms (SNPs) and 396 copy-number-variable loci in a worldwide sample of 29 populations. Analysis of SNP genotypes yields strongly supported fine-scale inferences about population structure. Increasing linkage disequilibrium is observed with geographic distance from Africa, as expected under a serial founder effect for an out-of-Africa spread of human populations. New approaches for haplotype analysis produce inferences about population structure that complement results based on unphased SNPs. Despite a difference from SNPs in the frequency spectrum of the copy-number variants (CNVs) detected—including a comparatively large number of CNVs in previously unexamined populations from Oceania and the Americas—the global distribution of CNVs largely accords with population structure analyses for SNP data sets of similar size. Our results produce new inferences about inter-population variation, support the utility of CNVs in human population-genetic research, and serve as a genomic resource for human-genetic studies in diverse worldwide populations. Keywords: High Density SNP array
Project description:Daghestan, with its exceptional combination of linguistic, geographic, and cultural diversity, presents an excellent natural laboratory for tracking the influence of demographic processes on patterns of genetic variation. This study was designed to investigate the co-evolution of genes and languages, comparing and contrasting patterns of linguistic, genetic and geographic variation among Daghestani populations.
Project description:We combined new data with previously published data to characterize the population structure of Corsican population in the context of their geographic neighbors across Eurasia and North Africa.
Project description:We genotyped 322 new samples from 38 Eurasian populations and combined it with previously published data to characterize the population structure of Turkic-speaking populations in the context of their geographic neighbors across Eurasia
Project description:We genotyped 45 new samples from 4 populations of Northwest India and combined it with previously published data to characterize the population structure of modern Northwest Indian populations in the context of their geographic neighbors across South Asia and West Eurasia.
Project description:Giardia duodenalis is a protozoan parasite of a wide range of vertebrates and one of the leading causes of gastroenteritis worldwide. G. duodenalis is a species complex of 8 assemblages with the zoonotic assemblage A as one of two discrete subtypes that is infective for humans. With increasing genomic and transcriptomic data now publicly available through the centralised giardiaDB.org, we have quantitatively analysed the proteomes of 8 G. duodenalis assemblage A strains (7 A1 and 1 A2) to provide a comprehensive proteomic baseline to complement these studies. Protein analysis identified a non-redundant total of 1220 proteins with an average of 764 proteins in each strain. At least 10% of all proteins identified were from the 4 protein families in the G. duodenalis variable genome, and substantial differences in number and abundance profiles in the Variable Surface Protein (VSP) family was observed. We also searched the 8 strains against both assemblage A genomes (subassemblage A1 and A2 genomes) and showed losses in protein identifications, especially for protein identifications associated with Giardia variable gene families which are sub-assemblage specific. We observed two expression profiles of VSPs within Giardia, which was independent to host origin, subassemblage, geographic origin and introduction to axenic culture and may indicate variation in surface antigen switching events and population heterogeneity. We hypothesise this variation may be related to karotype and chromosomal variation, which would indicate an assemblage-independent mechanism of variation in G. duodenalis.