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
2008-02-05 | GSE10331 | GEO
Project description:Genetic Diversity and Population Structure of eddoe Taro in China Using Genome-wide SNP Markers
Project description:Eucalyptus urophylla is a commercially important wood crop plantation species due to its rapid growth, biomass yield, and use as bioenergy feedstock. We characterized the genetic diversity and population structure of 332 E. urophylla individuals from 19 geographically defined E. urophylla populations with a reliability of 14,468 single nucleotide polymorphisms (SNPs). We compared the patterns of genetic variation among these 19 populations. High levels of genetic diversity were observed throughout the 19 E. urophylla populations based on genome-wide SNP data (HE=0.2677 to 0.3487). Analysis with STRUCTURE software, Principal component analysis (PCA) and a neighbor-joining (NJ) tree indicated that E. urophylla populations could be divided into three groups, and moderate and weak population structure was observed with pairwise genetic differentiation (FST) values ranging from −0.09 to 0.074. The low genetic diversity and shallow genetic differentiation found within the 19 populations may be a consequence of their pollination system and seed dispersal mechanism. In addition, 55 core germplasms of E. urophylla were constructed according to the genetic marker data. The genome-wide SNPs we identified will provide a valuable resource for further genetic improvement and effective use of the germplasm resources.
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.
Project description:Schizophrenia is a severe psychiatric disease with complex etiology, affecting approximately one percent of the general population. Most genetic studies so far focused on disease association with common genetic variation such as single nucleotide polymorphisms, but recently it has become apparent that large-scale genomic copy number variants (CNVs) are involved in disease development as well. To assess the role of rare CNVs in schizophrenia, we screened 54 patients with deficit schizophrenia using Affymetrixâ GeneChip 250K SNP arrays. Keywords: genomic hybridisation We hybridized genomic DNA of 54 patients with deficit schizophrenia to Affymetrix' GeneChip 250K SNP (Nsp) arrays, and identified genome-wide CNV using the Copy Number Analyzer for Affymetrix GeneChip (CNAG v2.0) software, which uses a Hidden Markov Model (HMM) algorithm to calculate copy numbers.