Project description:Recents studies in mammalian genomes have uncovered the extent of copy number variation (CNV) that contributes to phenotypic diversity, including health and disease status. Here we report the first glimpse of CNVs in the pig genome covering part of the chromosomes 4, 7, 14 and 17 already sequenced and assembled. We used a custom tiling oligonucleotide array with a median probe spacing of 409 bp to screen 12 unrelated Duroc boar founders of a vast-family material. After a strict CNV calling pipeline it was identified 40 copy number variable regions covering all the four chromosomes, with some overlapping segmental duplications and pig unigenes. This CNV snapshot analysis lays the groundwork for a better understanding of porcine phenotypes and genotypes for the identification of important economic traits. Keywords: comparative genome hybridization, CNV, Sus Scrofa, Nimblegen tiling array
Project description:Copy number variations (CNVs), which represent a significant source of genetic diversity in mammals, are currently being associated with phenotypes of clinical relevance, mostly in humans and mice. Notwithstanding, little is known about the extent of CNV that contributes to genetic variation in farm animals, including pig. This Nimblegen experiment reports a genome-wide high resolution map of copy number variation in the porcine genome. After remapping the initial CNV sequences to the latest genome assembly (Sus scrofa v.9), 84 CNV regions (CNVRs) were identified among the genomes of 21 related porcine samples from Duroc breed. We used a set of NimbleGen CGH arrays that tile across the assayable portion of the pig genome with approximately 2.1 million probes, at a 502 bp average probe spacing (Sus scrofa pre assembly version 6). These CNVRs covered 2 Mb of the genome, and ranged in size from 4 to 352 kb (median size of 12 kb). Together, this analysis provides a useful resource to assist with the assessment of CNVs in the contexts of porcine variation, health and productive efficiency.
Project description:Copy number variations (CNVs) affect a wide range of phenotypic traits; however, CNVs in or near segmental duplication regions are often intractable. Using a read depth approach based on next-generation sequencing, we examined genome-wide copy number differences among five taurine (three Angus, one Holstein and one Hereford) and one indicine (Nelore) cattle. Within mapped chromosomal sequence, we identified 1,265 CNV regions comprising ~55.6 Mbp sequence-476 of which (~38%) have not previously been reported. We validated this sequence-based CNV call set with aCGH, qPCR and FISH, achieving a validation rate of 82% and a false positive rate of 8%. We further estimated absolute copy numbers for genomic segments and annotated genes in each individual. Surveys of the top 25 most variable genes revealed that the Nelore individual had the lowest copy numbers in 13 cases (~52%, chi squared test; p value <0.05). In contrast, genes related to pathogen- and parasite-resistance, such as CATHL4 and ULBP17, were highly duplicated in the Nelore individual relative to the taurine cattle, while genes involved in lipid transport and metabolism, including APOL3 and FABP2, were highly duplicated in the beef breeds. These CNV regions also harbor genes like BPIFA2A (BSP30A) and WC1, suggesting that some CNVs may be associated with breed-specific differences in adaptation, health, and production traits. By providing the first individualized cattle CNV and segmental duplication maps and genome-wide gene copy number estimates, we enable future CNV studies into highly duplicated regions in the cattle genome.
Project description:Recents studies in mammalian genomes have uncovered the extent of copy number variation (CNV) that contributes to phenotypic diversity, including health and disease status. Here we report the first glimpse of CNVs in the pig genome covering part of the chromosomes 4, 7, 14 and 17 already sequenced and assembled. We used a custom tiling oligonucleotide array with a median probe spacing of 409 bp to screen 12 unrelated Duroc boar founders of a vast-family material. After a strict CNV calling pipeline it was identified 40 copy number variable regions covering all the four chromosomes, with some overlapping segmental duplications and pig unigenes. This CNV snapshot analysis lays the groundwork for a better understanding of porcine phenotypes and genotypes for the identification of important economic traits. Keywords: comparative genome hybridization, CNV, Sus Scrofa, Nimblegen tiling array A custom 385k tiling-path array CGH was designed (Nimblegen Systems) to cover the preliminary Sus Scrofa assembly for chromosomes 4, 7, 14 and 17, from the August 2007 release (http://www.sanger.ac.uk/Projects/S_scrofa/), which was the newest version at the time of the experiment. From a pig family-material comprising 14 boar founders, 700 sows and about 12.000 offspring, 12 Duroc boar founders (A, B, C, D, E, G, H, J, K, L, M and N) were selected to function as test animals. An unrelated boar of the Hampshire breed was selected as the common reference. Each of the 12 boars were hybridized twice (technical replicates, 24 arrays) against the common reference.
Project description:Copy number variations (CNVs), which represent a significant source of genetic diversity in mammals, are currently being associated with phenotypes of clinical relevance, mostly in humans and mice. Notwithstanding, little is known about the extent of CNV that contributes to genetic variation in farm animals, including pig. This Nimblegen experiment reports a genome-wide high resolution map of copy number variation in the porcine genome. After remapping the initial CNV sequences to the latest genome assembly (Sus scrofa v.9), 84 CNV regions (CNVRs) were identified among the genomes of 21 related porcine samples from Duroc breed. We used a set of NimbleGen CGH arrays that tile across the assayable portion of the pig genome with approximately 2.1 million probes, at a 502 bp average probe spacing (Sus scrofa pre assembly version 6). These CNVRs covered 2 Mb of the genome, and ranged in size from 4 to 352 kb (median size of 12 kb). Together, this analysis provides a useful resource to assist with the assessment of CNVs in the contexts of porcine variation, health and productive efficiency. 21 samples were analyzed in a dye swap loop design. In order to cover the latest, at the time of the experiment, porcine genome assembly (Sus scrofa v.6) with high density, custom Nimblegen HD2 CGH arrays were planned to cover all the chromosomes available with 2.1M probes, which yielded 502 bp of average probe spacing.
Project description:Background: Copy number variation is an important component of genetic variation in higher eukaryotes. The extent of natural copy number variation in C. elegans is unknown outside of 2 highly divergent wild isolates and the canonical N2 Bristol strain. Results: We have used array comparative genomic hybridization (aCGH) to detect copy number variation in the genomes of 12 natural isolates of Caenorhabditis elegans. Deletions relative to the canonical N2 strain are more common in these isolates than duplications, and indels are enriched in multigene families on the autosome arms. Among the strains in our study, the Hawaiian and Madeiran strains (CB4856 and JU258) carry the largest number of deletions, followed by the Vancouver strain (KR314). Overall we detected 510 different deletions affecting 1136 genes, or over 5% of the genes in the canonical N2 genome. The indels we identified had a median length of 2.7 kb. Since many deletions are found in multiple isolates, deletion loci were used as markers to derive an unrooted tree to estimate genetic relatedness among the strains. Conclusion: Copy number variation is extensive in C. elegans, affecting over 5% of the genes in the genome. The deletions we have detected in natural isolates of C. elegans contribute significantly to the number of deletion alleles available to researchers. The relationships between strains are complex and different regions of the genome possess different genealogies due to recombination throughout the natural history of the species, which may not be apparent in studies utilizing smaller numbers of genetic markers.
Project description:Copy number variations (CNVs) affect a wide range of phenotypic traits; however, CNVs in or near segmental duplication regions are often intractable. Using a read depth approach based on next-generation sequencing, we examined genome-wide copy number differences among five taurine (three Angus, one Holstein and one Hereford) and one indicine (Nelore) cattle. Within mapped chromosomal sequence, we identified 1,265 CNV regions comprising ~55.6 Mbp sequence-476 of which (~38%) have not previously been reported. We validated this sequence-based CNV call set with aCGH, qPCR and FISH, achieving a validation rate of 82% and a false positive rate of 8%. We further estimated absolute copy numbers for genomic segments and annotated genes in each individual. Surveys of the top 25 most variable genes revealed that the Nelore individual had the lowest copy numbers in 13 cases (~52%, chi squared test; p value <0.05). In contrast, genes related to pathogen- and parasite-resistance, such as CATHL4 and ULBP17, were highly duplicated in the Nelore individual relative to the taurine cattle, while genes involved in lipid transport and metabolism, including APOL3 and FABP2, were highly duplicated in the beef breeds. These CNV regions also harbor genes like BPIFA2A (BSP30A) and WC1, suggesting that some CNVs may be associated with breed-specific differences in adaptation, health, and production traits. By providing the first individualized cattle CNV and segmental duplication maps and genome-wide gene copy number estimates, we enable future CNV studies into highly duplicated regions in the cattle genome. 5 NimbleGen Bos Taurus UMD3 custom 2.1M whole genome high density aCGH
Project description:Copy-number variants (CNVs) are large-scale amplifications or deletions of DNA that can drive rapid adaptive evolution and result in large-scale changes in gene expression. Whereas alterations in the copy number of one or more genes within a CNV can confer a selective advantage, other genes within a CNV can decrease fitness when their dosage is changed. Dosage compensation - in which the gene expression output from multiple gene copies is less than expected - is one means by which an organism can mitigate the fitness costs of deleterious gene amplification. Previous research has shown evidence for dosage compensation at both the transcriptional level and at the level of protein expression; however, the extent of compensation differs substantially between genes, strains, and studies. Here, we investigated sources of dosage compensation at multiple levels of gene expression regulation by defining the transcriptome, translatome and proteome of experimentally evolved yeast (Saccharomyces cerevisiae) strains containing adaptive CNVs.