Project description:Copy Number Variations (CNVs) were identified performing Comparative Genomic Hybridization (CGH) on 225 patients after whole-genome amplification, using Agilent SurePrint G3 4x180K microarrays. CNVs were further integrated with gene expression (Affymetrix U133+2 arrays) and mutations (targeted DNA resequencing). Complete description of the methods, array quality checks and called segments are available as supplemental material in the corresponding publication.
Project description:BackgroundCopy number variations (CNVs) are deletions, insertions, duplications, and more complex variations ranging from 1 kb to sub-microscopic sizes. Recent advances in array technologies have enabled researchers to identify a number of CNVs from normal individuals. However, the identification of new CNVs has not yet reached saturation, and more CNVs from diverse populations remain to be discovered.ResultsWe identified 65 copy number variation regions (CNVRs) in 116 normal Korean individuals by analyzing Affymetrix 250 K Nsp whole-genome SNP data. Ten of these CNVRs were novel and not present in the Database of Genomic Variants (DGV). To increase the specificity of CNV detection, three algorithms, CNAG, dChip and GEMCA, were applied to the data set, and only those regions recognized at least by two algorithms were identified as CNVs. Most CNVRs identified in the Korean population were rare (<1%), occurring just once among the 116 individuals. When CNVs from the Korean population were compared with CNVs from the three HapMap ethnic groups, African, European, and Asian; our Korean population showed the highest degree of overlap with the Asian population, as expected. However, the overlap was less than 40%, implying that more CNVs remain to be discovered from the Asian population as well as from other populations. Genes in the novel CNVRs from the Korean population were enriched for genes involved in regulation and development processes.ConclusionCNVs are recently-recognized structural variations among individuals, and more CNVs need to be identified from diverse populations. Until now, CNVs from Asian populations have been studied less than those from European or American populations. In this regard, our study of CNVs from the Korean population will contribute to the full cataloguing of structural variation among diverse human populations.
Project description:Segmental copy number variations (CNVs) in the human genome are associated with developmental disorders and susceptibility to human diseases. More importantly, these variations may represent a major genetic component of our phenotypic diversity. In this study, using a whole genome array CGH assay, we identified 3,654 autosomal segmental CNVs, of which 800 appeared at a frequency of at least 3%. 77% of these frequent CNVs are novel. In the 95 individuals analyzed, the most diverse genomes differed by at least 9 Mb in size or varied by at least 266 loci in content. Approximately 68% of the 800 polymorphic regions overlap with genes, reflecting human diversity in senses (smell, hearing, taste, and sight), Rhesus phenotype, metabolism, and disease susceptibility. Intriguingly, 14 polymorphic regions harbor 21 of the known human microRNAs, raising the possibility of microRNAs’ contribution to phenotypic diversity in humans. This in depth survey of CNVs across the human genome provides a valuable baseline for studies involving human genetics. Keywords: array CGH, segmental copy number variations (CNVs)
Project description:It has been shown that the human genome contains extensive copy number variations (CNVs). Investigating the medical and evolutionary impacts of CNVs requires the knowledge of locations, sizes and frequency distribution of CNVs within and between populations. However, CNV study of Chinese populations has been underrepresented considering the same efforts in other populations. Here we constructed a Chinese CNV map by using Affymetrix SNP 6 array. We did population analysis with other HapMap populations and identified population specific CNVs as well as candidate CNV regions under selection. Our results serve as a useful resource in further evolutionary and medical studies.
Project description:Here we describe a genome-wide analysis of copy number variations (CNVs) in Chinese domestic cattle by using array comparative genomic hybridization (array CGH) and quantitative PCR (qPCR). We conducted array CGH analysis on 30 male cattle individuals, animals from consisting of 12 breeds of Bos taurus/Bos indicus, 1 Bos grunniens and and two ones of Bubalus bubalis breeds for with beef, and/or dairy or dual purpose. We identified over 470 candidate CNV regions (CNVRs) in Bos B. taurus/B. indicus; 118 candidate CNV regions (CNVRs) in B. grunniens, 139 CNVRs in B. bubalis. Furthermore, based on the Y haplotypes of B. taurus/ B. indicus, Wwe also identified 69, 337, and 251 candidate CNV regions (CNVRs) in the sub-groups of Y1, Y2 and Y3 haplotypes.
Project description:Gene copy number variations (CNVs) involved in phenotypic variations have already been shown in plants, but genome-wide testing of CNVs for adaptive variation was not doable until recent technological developments. Thus, reports of the genomic architecture of adaptation involving CNVs remain scarce to date. Here, we investigated F1 progenies of an intra-provenance cross (north-north cross, 58th parallel) and an inter-provenances cross (north-south cross, 58th/49th parallels) for CNVs using comparative genomic hybridization on arrays of probes targeting gene sequences in balsam poplar (Populus balsamifera L.), a wide-spread North American forest tree. Results: A total of 1,721 genes were found in varying copy numbers over the set of 19,823 tested genes. These gene CNVs presented an estimated average size of 8.3 kb and were distributed over poplar’s 19 chromosomes including 22 hotspot regions. Gene CNVs number was higher for the inter-provenance progeny in accordance with an expected higher genetic diversity related to the composite origin of this family. Regression analyses between gene CNVs and seven adaptive trait variations resulted in 23 significant links; among these adaptive gene CNVs, 30% were located in hotspots. One-to-five gene CNVs were found related to each of the measured adaptive traits and annotated for both biotic and abiotic stress responses. These annotations can be related to the occurrence of a higher pathogenic pressure in the southern parts of balsam poplar’s distribution, and higher photosynthetic assimilation rates and water-use efficiency at high-latitudes. Overall, our findings suggest that gene CNVs typically having higher mutation rates than SNPs, may in fact represent efficient adaptive variations against fast-evolving pathogens.
Project description:De novo copy number variations in cloned dogs from the same nuclear donor In this study, we aimed to identify de novo post-cloning CNV events and estimated the rate of CNV mosaicism in cloned dogs with the identical genetic background.