Project description:Copy number variations (CNVs) constitute the largest portion of the human genome variation. We determined a genome-wide high resolution SNP/CNV haplotype structure of Asians, by analyzing a collection of complete hydatidiform moles (CHMs) of Japanese, using high-density DNA arrays. CHMs are tissues carrying duplicated haploid genomes derived from single sperms, and are suitable material for the detection of CNVs, because they are expected to reveal greater signal to noise ratio in hybridization experiments. Also, the absence of heterozygosity ensures straightforward CNV interpretation without being bothered by overlapping CNV segments. We genotyped 100 CHM genomes using Affymetrix SNP 6.0 and Illumina 1M-duo, created a definitive haplotype map including 1.7 million SNPs and 2339 CNV region (CNVR) that is presented as D-HaploDB Phase 4.1.
Project description:Copy number variations (CNVs) constitute the largest portion of the human genome variation. We determined a genome-wide high resolution SNP/CNV haplotype structure of Asians, by analyzing a collection of complete hydatidiform moles (CHMs) of Japanese, using high-density DNA arrays. CHMs are tissues carrying duplicated haploid genomes derived from single sperms, and are suitable material for the detection of CNVs, because they are expected to reveal greater signal to noise ratio in hybridization experiments. Also, the absence of heterozygosity ensures straightforward CNV interpretation without being bothered by overlapping CNV segments. We genotyped 100 CHM genomes using Affymetrix SNP 6.0 and Illumina 1M-duo, created a definitive haplotype map including 1.7 million SNPs and 2339 CNV region (CNVR) that is presented as D-HaploDB Phase 4.1. Illumina Human1M-Duov3 BeadChip analyses were performed according to the manufacturer's directions on DNA extracted from 97 complete hydatidiform moles (CHMs) tissues collected throughout Japan.
Project description:The haplotype map constructed by the International HapMap Project is a valuable source for the studies of disease genes, population structure, and evolution. In the Project, haplotypes have been inferred from experimentally determined genotypes, and are fairly accurate for Caucasians and Africans since the inference was based on the genotypes of trios. However, the inference for the Asians populations was less accurate, because of the lack of familial information. Here we assessed how the error in the inference can affect downstream studies, especially the analysis of recent positive selections, by comparing the results of the analyses using the data of HapMap JPT and of definitive haplotypes (DHaplo-DB) determined by us from a collection of Japanese complete hydatidiform moles (CHM), each of which carries a genome derived from a single sperm. We found that the error in JPT was not uniform throughout the genome, and the statistics for recent positive selection was significantly affected. Keywords: Definitive haplotype determination using CHMs, which carry haploid genomes. 100 CHM samples collected throughout Japan were analyzed by Affymetrix Genechip Mapping 500K Set array.
Project description:The haplotype map constructed by the International HapMap Project is a valuable source for the studies of disease genes, population structure, and evolution. In the Project, haplotypes have been inferred from experimentally determined genotypes, and are fairly accurate for Caucasians and Africans since the inference was based on the genotypes of trios. However, the inference for the Asians populations was less accurate, because of the lack of familial information. Here we assessed how the error in the inference can affect downstream studies, especially the analysis of recent positive selections, by comparing the results of the analyses using the data of HapMap JPT and of definitive haplotypes (DHaplo-DB) determined by us from a collection of Japanese complete hydatidiform moles (CHM), each of which carries a genome derived from a single sperm. We found that the error in JPT was not uniform throughout the genome, and the statistics for recent positive selection was significantly affected. Keywords: Definitive haplotype determination using CHMs, which carry haploid genomes.
Project description:Genotyping data on 192 schizophrenia cases and 181 healthy controls was generated using Psych Array V 1.3 Aim: To identify CNVs and SNPs associated with increased risk of schizophrenia
Project description:Copy number variations (CNVs) are abundant, possibly variable among populations, and can confer various phenotypic variations such as risk to complex disease. We determined a genome-wide high resolution SNP/CNV haplotype structure of Asians, by analyzing a collection of complete hydatidiform moles (CHMs) of Japanese, using high-density DNA arrays. CHMs are tissues carrying duplicated haploid genomes that originated from single sperm, and have advantages as materials over conventional diploid cells in detecting CNVs by hybridization, because greater S/N ratios are expected, and overlapping CNV segments are independently detected without being bothered by possible heterozygous situations. Overall occupancy of CNV segments per haploid found here was at a level similar to previous reports. Approximately a half of our polymorphic CNV regions have not been described in the previous report for Asians, but the frequencies of most of these new CNV regions were low. The limited number of examined samples is likely to be the reason that they have escaped detection in the previous report. Many common CNV regions are resolvable to clusters of CNV segmets (that is, CNV events) on the basis of mutual overlap of the segments. The similarity of haplotype backgrounds surrounding different CNV events within the same CNV regions suggests that ancestral recurrences of CNV events were predominantly haplotype preferential.
Project description:Copy number variations (CNVs) are abundant, possibly variable among populations, and can confer various phenotypic variations such as risk to complex disease. We determined a genome-wide high resolution SNP/CNV haplotype structure of Asians, by analyzing a collection of complete hydatidiform moles (CHMs) of Japanese, using high-density DNA arrays. CHMs are tissues carrying duplicated haploid genomes that originated from single sperm, and have advantages as materials over conventional diploid cells in detecting CNVs by hybridization, because greater S/N ratios are expected, and overlapping CNV segments are independently detected without being bothered by possible heterozygous situations. Overall occupancy of CNV segments per haploid found here was at a level similar to previous reports. Approximately a half of our polymorphic CNV regions have not been described in the previous report for Asians, but the frequencies of most of these new CNV regions were low. The limited number of examined samples is likely to be the reason that they have escaped detection in the previous report. Many common CNV regions are resolvable to clusters of CNV segmets (that is, CNV events) on the basis of mutual overlap of the segments. The similarity of haplotype backgrounds surrounding different CNV events within the same CNV regions suggests that ancestral recurrences of CNV events were predominantly haplotype preferential.
Project description:Copy number variations (CNVs) are abundant, possibly variable among populations, and can confer various phenotypic variations such as risk to complex disease. We determined a genome-wide high resolution SNP/CNV haplotype structure of Asians, by analyzing a collection of complete hydatidiform moles (CHMs) of Japanese, using high-density DNA arrays. CHMs are tissues carrying duplicated haploid genomes that originated from single sperm, and have advantages as materials over conventional diploid cells in detecting CNVs by hybridization, because greater S/N ratios are expected, and overlapping CNV segments are independently detected without being bothered by possible heterozygous situations. Overall occupancy of CNV segments per haploid found here was at a level similar to previous reports. Approximately a half of our polymorphic CNV regions have not been described in the previous report for Asians, but the frequencies of most of these new CNV regions were low. The limited number of examined samples is likely to be the reason that they have escaped detection in the previous report. Many common CNV regions are resolvable to clusters of CNV segmets (that is, CNV events) on the basis of mutual overlap of the segments. The similarity of haplotype backgrounds surrounding different CNV events within the same CNV regions suggests that ancestral recurrences of CNV events were predominantly haplotype preferential. Illumina Human1M-Duov3 BeadChip analyses were performed according to the manufacturer's directions on DNA extracted from 5 complete hydatidiform moles (CHMs) tissues collected throughout Japan.
Project description:The identification of multiple signals at individual loci could explain additional phenotypic variance ('missing heritability') of common traits, and help identify causal genes. We examined gene expression levels as a model trait because of the large number of strong genetic effects acting in cis. Using expression profiles from 613 individuals, we performed genome-wide single nucleotide polymorphism (SNP) analyses to identify cis-expression quantitative trait loci (eQTLs), and conditional analysis to identify second signals. We examined patterns of association when accounting for multiple SNPs at a locus and when including additional SNPs from the 1000 Genomes Project. We identified 1298 cis-eQTLs at an approximate false discovery rate 0.01, of which 118 (9%) showed evidence of a second independent signal. For this subset of 118 traits, accounting for two signals resulted in an average 31% increase in phenotypic variance explained (Wilcoxon P< 0.0001). The association of SNPs with cis gene expression could increase, stay similar or decrease in significance when accounting for linkage disequilibrium with second signals at the same locus. Pairs of SNPs increasing in significance tended to have gene expression increasing alleles on opposite haplotypes, whereas pairs of SNPs decreasing in significance tended to have gene expression increasing alleles on the same haplotypes. Adding data from the 1000 Genomes Project showed that apparently independent signals could be potentially explained by a single association signal. Our results show that accounting for multiple variants at a locus will increase the variance explained in a substantial fraction of loci, but that allelic heterogeneity will be difficult to define without resequencing loci and functional work. Gene expression data was determined of peripheral blood samples (n=705) from InChianti cohort.
Project description:Porcine 60K BeadChip genotyping arrays (Illumina) are increasingly being applied in pig genomics to validate SNPs identified by re-sequencing or assembly-versus-assembly method. Here we report that more than 98% SNPs identified from the porcine 60K BeadChip genotyping array (Illumina) were consistent with the SNPs identified from the assembly-based method. This result demonstrates that whole-genome de novo assembly is a reliable approach to deriving accurate maps of SNPs.