Detection of copy number variations and their effects in Chinese bulls
- Liangzhi Zhang†1,
- Shangang Jia†1, 4,
- Mingjuan Yang1,
- Yao Xu1,
- Congjun Li2,
- Jiajie Sun1,
- Yongzhen Huang1,
- Xianyong Lan1,
- Chuzhao Lei1,
- Yang Zhou1,
- Chunlei Zhang3,
- Xin Zhao1 and
- Hong Chen1Email author
© Zhang et al.; licensee BioMed Central Ltd. 2014
Received: 8 December 2013
Accepted: 10 June 2014
Published: 17 June 2014
Copy number variations (CNVs) are a main source of genomic structural variations underlying animal evolution and production traits. Here, with one pure-blooded Angus bull as reference, we describe a genome-wide analysis of CNVs based on comparative genomic hybridization arrays in 29 Chinese domesticated bulls and examined their effects on gene expression and cattle growth traits.
We identified 486 copy number variable regions (CNVRs), covering 2.45% of the bovine genome, in 24 taurine (Bos taurus), together with 161 ones in 2 yaks (Bos grunniens) and 163 ones in 3 buffaloes (Bubalus bubalis). Totally, we discovered 605 integrated CNVRs, with more “loss” events than both “gain” and “both” ones, and clearly clustered them into three cattle groups. Interestingly, we confirmed their uneven distributions across chromosomes, and the differences of mitochondrion DNA copy number (gain: taurine, loss: yak & buffalo). Furthermore, we confirmed approximately 41.8% (253/605) and 70.6% (427/605) CNVRs span cattle genes and quantitative trait loci (QTLs), respectively. Finally, we confirmed 6 CNVRs in 9 chosen ones by using quantitative PCR, and further demonstrated that CNVR22 had significantly negative effects on expression of PLA2G2D gene, and both CNVR22 and CNVR310 were associated with body measurements in Chinese cattle, suggesting their key effects on gene expression and cattle traits.
The results advanced our understanding of CNV as an important genomic structural variation in taurine, yak and buffalo. This study provides a highly valuable resource for Chinese cattle’s evolution and breeding researches.
KeywordsCopy number variations Bos taurus Bos grunniens Bubalus bubalis Gene expression
Copy number variation (CNV), as a form of widespread genomic structural variations, has been reported in many model organisms, such as primates and rodents [1–5]. Compared with single nucleotide polymorphisms (SNPs), CNVs seem to have a stronger impact on phenotype and are shown to have effects on changes in gene expression levels , which can be explained by disruption of gene dosage, unmasking of recessive alleles, and loss of regulatory elements or regulatory polymorphisms [7, 8]. Several recent publications have reviewed the effects of CNVs on gene expression and human diseases [9–11]. In addition, CNV provides materials and mechanisms for creating new genes .
Given the importance of CNVs and their high rates of mutation, interest in CNV detection has extended to domesticated animals, including dogs , pigs , goats , horse , and sheep . Similarly, CNV and copy number variable regions (CNVRs) have been a hot-spot in cattle genomic variation researches, which may be associated with, or affect, cattle’s health and production traits under recent selection. Previous studies have produced several CNV datasets on cattle [18–26]. Some are focused on one single breed by using SNP array: such as, Bos taurus coreanae (855 CNVs and 368 CNVRs in 265 individuals ) and Chinese Holstein cattle (367 CNVRs in 96 individuals  and 99 CNVRs in 2,047 individuals ). Other CNV evidences for multiple breeds are also shown on SNP array. For example, Matukumalli et al. identified 79 candidate deletions by using an earlier version of BovineSNP50 assay , and Hou et al. found 682 candidate CNVRs in 21 modern cattle breeds and 6 out-groups . At the same time, more studies are conducted on microarray-based comparative genomic hybridization (array CGH): 177 high-confidence CNVRs in 17 breeds , and 304 CNVRs in 4 breeds . Most recently, the next-generation sequencing was also used to detect CNVR with more power [22, 25, 26]. And in these studies, the researchers focus more on the detection of CNV in different breeds.
Up to this date, few studies have confirmed the genome-wide presence of CNVs in Chinese native cattle breeds. Compared to the previous CNV investigations mostly focusing on CNV detection, here we selected 15 breeds in three main bovine groups in China (twelve B. taurus, one Bos grunniens, and two Bubalus bubalis ones) to conduct a genome-wide CNV analysis and further examined their effects on gene expression and growth traits of cattle. Overall, we got started with genome-wide CNV screening of three cattle groups, and further associated them with cattle gene expression and body measurements, which provides novel insights into understanding the role of CNV in genomic variation studies.
For CGH analysis, we collected blood samples all over China in 15 bovine breeds or populations: twelve B. taurus breeds (taurine): Anxi, Bohaihei, Chinese Holstein, Jiaxian, Jinnan, Leiqiong, Luxi, Mongolia, Nanyang, Qinchuan, Wannan and Zaosheng; one B. grunniens (yak): Tianzhu White yak; and two B. bubalis ones (buffalo): Swamp buffalo and River buffalo (Additional file 1: Table S1).
Diverse tissues of fetal, calf (including heart, liver, spleen, lung, kidney, and muscle) and adult (including heart, liver, spleen, lung, kidney, stomach, intestine, muscle, and adipose) in Qinchuan breed were collected in the slaughter house for gene expression analysis (Additional file 1: Table S1). Blood samples of Nanyang (NY, N = 43), Jiaxian (JX, N = 39) and Qinchuan (QC, N = 47) were collected with body measurements (older than 2 years old), including body height, body length, heart girth, hucklebone width, and body weight for association analysis. All our sample collection was carried out in strict accordance with the ethical guidelines approved by the Animal Care Commission of College of Animal Science and Technology, Northwest A & F University.
Genomic DNA was extracted and purified from whole blood following standard procedures  and quantified by spectrophotometry and agarose gel electrophoresis. Total RNA was isolated from flash-frozen tissues. First-strand cDNA was synthesized from 500 ng of total RNA with the Prime Script RT Reagent Kit (TaKaRa, Dalian, China) according to the manufacturer’s instructions.
Array CGH platform
We quantified copy number by hybridizing DNA to Nimblegen3x720K CGH array (http://www.nimblegen.com), which provided an evenly distributed coverage of ~720,000 oligonucleotide probes (mean probe spacing: 3,364 bp, array No. GPL17177). The probes of 50–75 bp in length were designed with similar melting temperatures based on Btau_4.0 genome assembly .
We chose one pure-blooded Angus bull as the reference. DNA labelling, hybridization, washing, array scanning, and array imaging were carried out according to the previously described . Briefly, pairs of genomic DNA (1 μg) were labeled with fluorescent dyes Cy3 (test sample) or Cy5 (reference), and were co-hybridized on hybridization platform. The arrays were scanned and fluorescent intensity raw data was extracted. The initial data analysis (normalization and segmentation) was performed on NimbleScan v2.4 software with segMNT algorithm (Capital Bio Corporation, Beijing, China). We used an updated version of the previously described method to do CNV calling, ie., determining copy number gains and losses by changes in log2 signal intensity . The segment, with mean log2 ratio ≥ |0.5| and at least 5 consecutive probes covered, was defined as a CNV. CNVRs in one group were determined by aggregating overlapped CNVs of all samples .
Cattle gene annotations were downloaded from the UCSC genome browser (http://hgdownload.cse.ucsc.edu/downloads.html#cow), and cattle quantitative trait loci (QTLs)  were from the Animal QTL database (http://www.animalgenome.org/cgi-bin/QTLdb/BT/index). The genome positions were converted among genome assemblies of Btau_4.0, Btau_4.6, and Btau_4.6.1 by using the UCSC binary software LiftOver. We wrote Perl scripts to search for gene content and quantitative trait loci (QTLs) inside CNVRs, and determined a positive gene/QTL by > 50% overlap. Gene ontology (GO) identifiers were retrieved with Refgene IDs in R package biomaRt and plotted by the web histogram tool WEGO (http://wego.genomics.org.cn/cgi-bin/wego/index.pl) . CNVR chromosome plotting, clustering analysis, nonmetric multidimensional scaling (NMDS), GO identifier retrieving, and indicator species analysis (ISA) were performed by using R packages of ggbio, pvclust, vegan, biomaRt, and indicspecies, repectively. Principal component analysis (PCA) was performed in STAMP v2.02 .
Raw array CGH data in this study has been deposited in NCBI GEO database under accession number of GSE47086.
Quantitative PCR (qPCR)
We performed a qPCR analysis to validate copy number changes detected by array CGH based on the relative comparative cycle threshold (CT) method. Primers (Additional file 1: Table S2) were designed by using Beacon Designer™ (PREMIER Biosoft, USA). PCR reaction was done in a volume of 20 μL containing 20 ng of genomic DNA, 0.4 μM of each primer, and SYBR Premix Ex Taq™ II reagents (TaKaRa Biotechnology, Dalian, China). Analysis of resultant crossing thresholds (Ct) was performed based on the ΔΔCt method , and ΔΔCt values were determined by comparing test samples and Angus reference (two-copy states) with BTF3 gene as internal control. Finally, the relative copy number for each sample was calculated as 2-ΔΔCt.
We selected two qPCR-confirmed CNVR22 and CNVR310 for further analysis. First, we used the primers (Additional file 1: Table S2) to determine CNVR types (gain, loss or normal) in 30 individuals against the Angus reference. Then we selected checked individuals (20 samples for CNVR22, 3 of gain, 2 of loss and 15 of normal; 15 samples for CNVR310, 4 of loss and 11 of normal) for gene expression analysis of PLA2G2D in CNVR22 and MYH3 in CNVR310 on the CFX-96 Real-Time PCR Detection System (Bio-Rad, Hercules, CA, USA).
Two primer pairs were used for expression detection of PLA2G2D and MYH3: PLA2-F, 5′-GACATACTGGACCTGAAC-3′; PLA2-R, 5′- AGCCATAGTGTGAATAGAAG-3′; MYH3-F, 5′-AGTCGTCAGTTGGAGGAA-3′; MYH3-R, 5′-GCTCTTCTATTTGCTGGGTAA-3′. GAPDH gene was used for normalization. The reaction was performed in a volume of 25 μL, containing 12.5 μL SYBR Premix Ex Taq II, 1 μL of each primer (10 μM), 2 μL cDNA (2.5 ng/μL), and 9.5 μL H2O. The relative fold change was calculated using 2-ΔΔCt . Mean expression levels and standard deviations were obtained by repeating three independent experiments.
Association analysis between CNVR types and growth traits
where Y ijk is trait measurement, μ is overall population mean, F i is farm, G j is genotype effect, B k is breed, and E ijk is random error.
We used the least-squares means (LSM) to estimate the association between CNVR types and body measurements in SPSS software .
Results and discussion
CNVRs in cattle groups
CNVR summary for Chinese bulls
CNVRs shared by this study and other studies on cattle CNV
Bickhart et al. 
Zhan et al. 
Stothard et al. 
Liu et al. 
Fadista et al. 
Hou et al. 
Bae et al. 
Jiang et al. 
Jiang et al. 
We performed an integrated hybridization on the three bovines in one CGH platform, and gained an advantage of parallel comparison, regardless of how different their genomes are. Our array probes were designed based on genome assembly Btau_4.0 (a Hereford cow) . Yak genome had been released after our CGH experiment was done, and shown very similar to that of cow [41, 42]. Up to date, the complete genome of buffalo is not placed well in NCBI, and only unplaced sequences are ready to download. All our CNVRs in yak and buffalo are from the orthologous regions of cow genome, and our 46 shared CNVRs are supposed to be from the common orthologs of the three bovine genomes. However, their genome positions in yak and buffalo may be different and should be considered cautiously. And the yak- and buffalo-specific regions are not covered by our probes, and out of our scope. It is noted that the bovine CGH array had also been used to scan CNV of goat and sheep [15, 17].
In addition, we designed five probes covering the mitochondrial region. Although there is only one CNVR in ChrM in three groups, we found a difference between taurine (gain) and yak (loss) & buffalo (loss) (Additional file 1: Table S5). The mitochondrion DNA copy number varies referring to energetic metabolism among cell types  and fertility between oocytes and sperm . Multiple copies of mtDNA in the same mitochondrion are directly associated with the amount of ATP synthesized [45, 46]. Our finding on mtDNA copy number difference suggests possible low energetic metabolism in yak and buffalo’s blood, and more studies are necessary to understand the role of mitochondrial copy number in cattle’s traits and performances.
We had discovered CNVRs’ distribution preferences across chromosomes. Just like the previous results [18, 21], cattle CNVs are distributed in a non-random way in this study, and their contents vary across chromosomes. The proportion of any known chromosome susceptible to CNVRs ranges from 0.3 to 4.07% (Figure 1), although ChrUnAll shows the strongest enrichment of CNVRs (8.21%), probably due to highly repetitive sequences in these unplaced contigs. Except for ChrM, we got strong CNV-enriched chromosomes of 27, 18, 15, 29, 5, × and 23 (>2.13% on average), which might have been shaped by local Chinese bulls, compared with other results [18, 21].
Clustered cattle CNVRs
Selection has also been shown to shape the architecture of segmental duplications during human genome evolution , and studying CNVs’ evolution may help us reveal the genomic alteration and environmental driving impact. The cluster analysis of CNVR in cattle and pig had evidenced that CNVR loci are consistent with the breed divergence and history [14, 18]. So we performed a clustering analysis of CNVRs on all individuals, which revealed remarkable profiles among groups. First, the three groups of taurine, yak, and buffalo are clearly divided (Additional file 2: Figure S1). Second, individuals in one single breed are easily clustered closely. The clustering results simply showed a phylogeny, while the principal component analysis (PCA) results showed their detailed relations. The PCA plotted samples into three groups (Additional file 2: Figure S2A). Similarly, we investigated the impact of groups on CNVRs structure by using nonmetric multidimensional scaling (NMDS), which is to visualize the interrelationships among a complex dataset and level of similarity of individuals, and generally grouped samples into taurine, yak, and buffalo (Additional file 2: Figure S2B). The results supported the hypothesis that genome structure variations, especially CNVs, may be raised by isolated evolutions and shaped by breed formation and adaptation .
To highlight potential evolutionary contributions of CNVs to Chinese major cattle breeds’ formation and adaptation, we identified 130 CNVRs which are abundant statistically in three groups (Additional file 1: Table S3) by using indicator species analysis (ISA) . Compared to 46 shared CNVRs from the orthologs, the biased ones reflect their unique genomic backgrounds, which suggest a potential variance of the three bovine genomes. Our parallel comparisons based on one single CGH platform are reliable, which overcome the shortcoming that it is difficult to compare the datasets by different technologies and methods.
Gene content and quantitative trait loci (QTLs) in CNVRs
Totally 253 CNVRs encompass 716 genes, which are shown with refGene ID and gene name (Additional file 1: Table S3). In order to determine biological functions of copy number variable genes, a gene ontology (GO) analysis annotated 647 out of 716 genes in three main GO categories: cellular component, molecular function and biological process (Additional file 2: Figure S3). As shown in the GO map, genes in all categories were mainly involved in eight ones, including cell/cell part (mainly intracellular), organelle (mainly intracellular organelle part), binding (mainly protein binding), catalytic activity (mainly hydrolase activity and transferase activity), metabolic process (mainly, primary, macromolecule, cellular, and nitrogen compound metabolic process), cellular process (mainly cellular metabolic process), pigmentation (mainly regulation of cellular process), and biological regulation (mainly regulation of biological process). This set of copy number variable genes possesses a wide spectrum of molecular functions, and provides a rich resource for hypotheses on their genetic basis of phenotypic variation within and among breeds. Many cattle specific genes were also found in our CNVRs, such as C-type lysozymes, BSP30A, interferon tau subfamilies, WC1, and ITLN1 . Moreover, EDA gene, which has been reported a deletion and responsible for hypotrichosis and dental defects in cattle , and SLC4A2 gene, which is a copy number variable gene and association with osteopetrosis, are both confirmed in our study .
We also downloaded 8035 cattle QTLs from Animal QTLs database, and searched for potential QTLs which reside inside 477 CNVRs on placed chromosomes (Additional file 1: Table S3). There are 89.5% (427/477 on placed chromosomes) of CNVRs overlapped with 1186 QTLs. The QTLs in multiple CNVRs are associated with exterior (20 QTLs), health (107 QTLs), meat and carcass (275 QTLs), milk (254 QTLs), production (302 QTLs) and reproduction (228 QTLs). The results are in accordance with Chinese breeding history.
CNVR confirmation and effects on gene expression
To evaluate the accuracy of copy number assignments, quantitative real time-PCR was used as described previously . We selected nine detected CNVR, including loss, gain, and both types, whose frequencies range from 4.17% to 37.50%. The selected CNVRs were all overlapped with genes and QTLs of meat, carcass and production (Additional file 1: Table S2). Totally 14 pairs of primers were used, one or two pairs to cover one selected CNVR. The results showed that out of 14 qPCR assays, 10 ones (71%) confirm the predictions by array CGH. False-positive identification is common in CNV detection, and there is always to some extent < 1 of confirming rate [18, 19, 21]. In fact, CNVRs were of complex structure, and qPCR can only target a small portion, which does not reflect their complete characteristics. And the boundaries of CNVR by arrays are indistinct. Notably the average size of 9 confirmed CNVRs is 63.40 kb, much smaller than those of three unconfirmed ones (72.18 kb). Certain number of samples are chosen randomly as negative control for the reliability of results .
CNVs’ association with growth traits of cattle
CNVs may affect phenotype by altering transcriptional level of genes within or adjacent to CNVR and subsequently alter translation levels [60, 61]. The association between the CNVs and production traits of economic interest had been reported. In swine, several copy number variable genes were identified as candidate genes for phenotypes related to carcass length, backfat thickness, abdominal fat weight, length of scapular, intermuscle fat content of logissimus muscle, body weight at 240 day, and fatness . In cattle, the direct evidence of close associations of CNVR#456 with index of total merit and genetic evaluations for protein production, fat production, and herd life in Holstein had been identified . We had demonstrated that the genes inside CNVRs might be expressed differently, and many CNVRs also overlapped with QTLs which are associated with cattle performance. So we believed that CNVRs should be potentially associated with cattle body measurements.
Association analysis of CNVR22 with body measurements
126.7 ± 5.3
133.9 ± 9.5b
169.9 ± 10.6b
23.2 ± 2.3
354.7 ± 48.0
125.5 ± 6.0
145.2 ± 7.8a
176.0 ± 12.0a
20.4 ± 6.1
385.1 ± 62.9
126.9 ± 6.2
139.9 ± 10.1a
174.5 ± 10.0a
21.3 ± 4.6
368.5 ± 59.7
126.7 ± 6.0
139.2 ± 10.2
173.7 ± 10.5
21.7 ± 4.4
367.3 ± 57.9
On the other hand, we also found that CNVR310 is significantly associated with heart girth (P < 0.05), probably due to the fact that CNVR310 was overlapped with the QTLs for production (QTLs 11079 and 5297) and meat and carcass (QTLs 10021, 12174, 1395, and 22873) in beef cattle (Additional file 1: Tables S3 and S7). Regardless of one single gene’s contributions, we had a direct look at the effects of selected CNVRs on cattle body performances, which might be caused by a group of genes. It took gene population effects into consideration, rather than focusing on only one single trait-related gene. The association between CNVs and traits is inspiring, but larger population may be needed to validate it.
We have performed a comprehensive genomic analysis of CNVs based on CGH arrays in Chinese cattle, and a detailed functional investigation for CNVRs’ effects on both gene expression and cattle body measurements. We identified 486 CNVRs in B. taurus, which covered 2.45% of the bovine genome, together with 161 and 163 CNVRs in B. grunnies and B. bubalis. Furthermore, we confirmed that CNVR22 had significantly negative effects on both PLA2G2D gene expression and cattle body measurements, while CNVR310 showed a significant negative association with heart girth. Our results generated a valuable genome-wide variation resource for Chinese cattle genomic researches, and provided a novel insight into understanding the association between animal complex traits and CNVRs during their adapting to local geographical environment and domesticated needs from human society.
Copy number variations
Copy number variable region
Comparative genomic hybridization
Myosin-3, B. taurus myosin, heavy chain 3
Indicator species analysis
B. taurus calcium-dependent phospholipase A2
Nonmetric multidimensional scaling
Principal component analysis
Quantitative real time PCR
Quantitative trait loci
Single nucleotide polymorphism.
This study was supported by the National Natural Science Foundation of China (Grant No.30972080, No.31272408), Program of National Beef Cattle Industrial Technology System (CARS-38), and National 863 Program of China (Grant No. 2013AA102505).
- Conrad DF, Pinto D, Redon R, Feuk L, Gokcumen O, Zhang Y, Aerts J, Andrews TD, Barnes C, Campbell P: Origins and functional impact of copy number variation in the human genome. Nature. 2009, 464: 704-712.PubMed CentralPubMedView ArticleGoogle Scholar
- Perry GH, Tchinda J, McGrath SD, Zhang J, Picker SR, Cáceres AM, Iafrate AJ, Tyler-Smith C, Scherer SW, Eichler EE: Hotspots for copy number variation in chimpanzees and humans. Proc Natl Acad Sci U S A. 2006, 103 (21): 8006-8011.PubMed CentralPubMedView ArticleGoogle Scholar
- Cutler G, Marshall LA, Chin N, Baribault H, Kassner PD: Significant gene content variation characterizes the genomes of inbred mouse strains. Genome Res. 2007, 17 (12): 1743-1754.PubMed CentralPubMedView ArticleGoogle Scholar
- Graubert TA, Cahan P, Edwin D, Selzer RR, Richmond TA, Eis PS, Shannon WD, Li X, McLeod HL, Cheverud JM: A high-resolution map of segmental DNA copy number variation in the mouse genome. PLoS Genet. 2007, 3 (1): e3-PubMed CentralPubMedView ArticleGoogle Scholar
- She X, Cheng Z, Zöllner S, Church DM, Eichler EE: Mouse segmental duplication and copy number variation. Nat Genet. 2008, 40 (7): 909-914.PubMed CentralPubMedView ArticleGoogle Scholar
- Henrichsen CN, Vinckenbosch N, Zöllner S, Chaignat E, Pradervand S, Schütz F, Ruedi M, Kaessmann H, Reymond A: Segmental copy number variation shapes tissue transcriptomes. Nat Genet. 2009, 41 (4): 424-429.PubMedView ArticleGoogle Scholar
- Weischenfeldt J, Symmons O, Spitz F, Korbel JO: Phenotypic impact of genomic structural variation: insights from and for human disease. Nat Rev Genet. 2013, 14 (2): 125-138.PubMedView ArticleGoogle Scholar
- Reymond A, Henrichsen CN, Harewood L, Merla G: Side effects of genome structural changes. Curr Opin Genet Dev. 2007, 17 (5): 381-386.PubMedView ArticleGoogle Scholar
- Aitman TJ, Dong R, Vyse TJ, Norsworthy PJ, Johnson MD, Smith J, Mangion J, Roberton-Lowe C, Marshall AJ, Petretto E: Copy number polymorphism in Fcgr3 predisposes to glomerulonephritis in rats and humans. Nature. 2006, 439 (7078): 851-855.PubMedView ArticleGoogle Scholar
- Glessner JT, Wang K, Cai G, Korvatska O, Kim CE, Wood S, Zhang H, Estes A, Brune CW, Bradfield JP: Autism genome-wide copy number variation reveals ubiquitin and neuronal genes. Nature. 2009, 459 (7246): 569-573.PubMed CentralPubMedView ArticleGoogle Scholar
- McCarroll SA, Altshuler DM: Copy-number variation and association studies of human disease. Nat Genet. 2007, 39: S37-S42.PubMedView ArticleGoogle Scholar
- Emerson JJ, Cardoso-Moreira M, Borevitz JO, Long M: Natural selection shapes genome-wide patterns of copy-number polymorphism in Drosophila melanogaster. Science. 2008, 320 (5883): 1629-1631.PubMedView ArticleGoogle Scholar
- Nicholas TJ, Cheng Z, Ventura M, Mealey K, Eichler EE, Akey JM: The genomic architecture of segmental duplications and associated copy number variants in dogs. Genome Res. 2009, 19 (3): 491-499.PubMed CentralPubMedView ArticleGoogle Scholar
- Li Y, Mei S, Zhang X, Peng X, Liu G, Tao H, Wu H, Jiang S, Xiong Y, Li F: Identification of genome-wide copy number variations among diverse pig breeds by array CGH. BMC Genomics. 2012, 13 (1): 725-PubMed CentralPubMedView ArticleGoogle Scholar
- Fontanesi L, Beretti F, Riggio V, Dall’Olio S, Davoli R, Russo V, Portolano B: Copy number variation and missense mutations of the agouti signaling protein (ASIP) gene in goat breeds with different coat colors. Cytogenet Genome Res. 2009, 126 (4): 333-347.PubMedView ArticleGoogle Scholar
- Metzger J, Philipp U, Lopes MS, da Camara Machado A, Felicetti M, Silvestrelli M, Distl O: Analysis of copy number variants by three detection algorithms and their association with body size in horses. BMC Genomics. 2013, 14 (1): 487-PubMed CentralPubMedView ArticleGoogle Scholar
- Fontanesi L, Beretti F, Martelli P, Colombo M, Dall’Olio S, Occidente M, Portolano B, Casadio R, Matassino D, Russo V: A first comparative map of copy number variations in the sheep genome. Genomics. 2011, 97 (3): 158-165.PubMedView ArticleGoogle Scholar
- Liu GE, Hou Y, Zhu B, Cardone MF, Jiang L, Cellamare A, Mitra A, Alexander LJ, Coutinho LL, Dell’Aquila ME, Gasbarre LC, Lacalandra G, Li RW, Matukumalli LK, Nonneman D, Regitano LCA, Smith TPL, Song J, Sonstegard TS, Tassell CPV, Ventura M, Eichler EE, McDaneld TG, Keele JW: Analysis of copy number variations among diverse cattle breeds. Genome Res. 2010, 20 (5): 693-703.PubMed CentralPubMedView ArticleGoogle Scholar
- Fadista J, Thomsen B, Holm LE, Bendixen C: Copy number variation in the bovine genome. BMC Genomics. 2010, 11 (1): 284-PubMed CentralPubMedView ArticleGoogle Scholar
- Bae J, Cheong H, Kim L, NamGung S, Park T, Chun JY, Kim J, Pasaje C, Lee J, Shin H: Identification of copy number variations and common deletion polymorphisms in cattle. BMC Genomics. 2010, 11 (1): 232-PubMed CentralPubMedView ArticleGoogle Scholar
- Hou Y, Liu GE, Bickhart DM, Cardone MF, Wang K, Kim E, Matukumalli LK, Ventura M, Song J, VanRaden PM: Genomic characteristics of cattle copy number variations. BMC Genomics. 2011, 12 (1): 127-PubMed CentralPubMedView ArticleGoogle Scholar
- Bickhart DM, Hou Y, Schroeder SG, Alkan C, Cardone MF, Matukumalli LK, Song J, Schnabel RD, Ventura M, Taylor JF: Copy number variation of individual cattle genomes using next-generation sequencing. Genome Res. 2012, 22 (4): 778-790.PubMed CentralPubMedView ArticleGoogle Scholar
- Jiang L, Jiang J, Yang J, Liu X, Wang J, Wang H, Ding X, Liu J, Zhang Q: Genome-wide detection of copy number variations using high-density SNP genotyping platforms in Holsteins. BMC Genomics. 2013, 14 (1): 131-PubMed CentralPubMedView ArticleGoogle Scholar
- Jiang L, Jiang J, Wang J, Ding X, Liu J, Zhang Q: Genome-wide identification of copy number variations in Chinese Holstein. PLoS ONE. 2012, 7 (11): e48732-PubMed CentralPubMedView ArticleGoogle Scholar
- Stothard P, Choi JW, Basu U, Sumner-Thomson JM, Meng Y, Liao X, Moore SS: Whole genome resequencing of black Angus and Holstein cattle for SNP and CNV discovery. BMC Genomics. 2011, 12 (1): 559-PubMed CentralPubMedView ArticleGoogle Scholar
- Zhan B, Fadista J, Thomsen B, Hedegaard J, Panitz F, Bendixen C: Global assessment of genomic variation in cattle by genome resequencing and high-throughput genotyping. BMC Genomics. 2011, 12 (1): 557-PubMed CentralPubMedView ArticleGoogle Scholar
- Matukumalli LK, Lawley CT, Schnabel RD, Taylor JF, Allan MF, Heaton MP, O’Connell J, Moore SS, Smith TP, Sonstegard TS: Development and characterization of a high density SNP genotyping assay for cattle. PLoS ONE. 2009, 4 (4): e5350-PubMed CentralPubMedView ArticleGoogle Scholar
- Sambrook J, Russell D: Molecular cloning: a laboratory manual. 2001, Beijing, China: Sicence PressGoogle Scholar
- Liu Y, Qin X, Song XZH, Jiang H, Shen Y, Durbin KJ, Lien S, Kent MP, Sodeland M, Ren Y: Bos taurus genome assembly. BMC Genomics. 2009, 10 (1): 180-PubMed CentralPubMedView ArticleGoogle Scholar
- Selzer RR, Richmond TA, Pofahl NJ, Green RD, Eis PS, Nair P, Brothman AR, Stallings RL: Analysis of chromosome breakpoints in neuroblastoma at sub-kilobase resolution using fine-tiling oligonucleotide array CGH. Genes Chromosom Cancer. 2005, 44 (3): 305-319.PubMedView ArticleGoogle Scholar
- Olshen AB, Venkatraman ES, Lucito R, Wigler M: Circular binary segmentation for the analysis of array-based DNA copy number data. Biostatistics. 2004, 5 (4): 557-572.PubMedView ArticleGoogle Scholar
- Redon R, Ishikawa S, Fitch KR, Feuk L, Perry GH, Andrews TD, Fiegler H, Shapero MH, Carson AR, Chen W: Global variation in copy number in the human genome. Nature. 2006, 444 (7118): 444-454.PubMed CentralPubMedView ArticleGoogle Scholar
- Hu ZL, Park CA, Wu XL, Reecy JM: Animal QTLdb: an improved database tool for livestock animal QTL/association data dissemination in the post-genome era. Nucl Acids Res. 2013, 41 (D1): D871-D879.PubMed CentralPubMedView ArticleGoogle Scholar
- Ye J, Fang L, Zheng H, Zhang Y, Chen J, Zhang Z, Wang J, Li S, Li R, Bolund L: WEGO: a web tool for plotting GO annotations. Nucleic Acids Res. 2006, 34 (suppl 2): W293-W297.PubMed CentralPubMedView ArticleGoogle Scholar
- Parks DH, Beiko RG: Identifying biologically relevant differences between metagenomic communities. Bioinformatics. 2010, 26 (6): 715-721.PubMedView ArticleGoogle Scholar
- Schmittgen TD, Livak KJ: Analyzing real-time PCR data by the comparative CT method. Nat Protoc. 2008, 3 (6): 1101-1108.PubMedView ArticleGoogle Scholar
- Huang Y, He H, Wang J, Li Z, Lan X, Lei C, Zhang E, Zhang C, Wang J, Shen Q: Sequence variants in the bovine nucleophosmin 1 gene, their linkage and their associations with body weight in native cattle breeds in China. Anim Genet. 2011, 42 (5): 556-559.PubMedView ArticleGoogle Scholar
- Force A, Lynch M, Pickett FB, Amores A, Yan Y, Postlethwait J: Preservation of duplicate genes by complementary, degenerative mutations. Genetics. 1999, 151 (4): 1531-1545.PubMed CentralPubMedGoogle Scholar
- Wyman MJ, Cutter AD, Rowe L: Gene duplication in the evolution of sexual dimorphism. Evolution. 2012, 66 (5): 1556-1566.PubMedView ArticleGoogle Scholar
- Elsik CG, Tellam RL, Worley KC: The genome sequence of taurine cattle: a window to ruminant biology and evolution. Science. 2009, 324 (5926): 522-528.PubMed CentralPubMedView ArticleGoogle Scholar
- Hu Q, Ma T, Wang K, Xu T, Liu J, Qiu Q: The Yak genome database: an integrative database for studying yak biology and high-altitude adaption. BMC Genomics. 2012, 13 (1): 600-PubMed CentralPubMedView ArticleGoogle Scholar
- Qiu Q, Zhang G, Ma T, Qian W, Wang J, Ye Z, Cao C, Hu Q, Kim J, Larkin DM: The yak genome and adaptation to life at high altitude. Nat Genet. 2012, 44 (8): 946-949.PubMedView ArticleGoogle Scholar
- Robin ED, Wong R: Mitochondrial DNA molecules and virtual number of mitochondria per cell in mammalian cells. J Cell Physiol. 1988, 136 (3): 507-513.PubMedView ArticleGoogle Scholar
- Wai T, Ao A, Zhang X, Cyr D, Dufort D, Shoubridge EA: The role of mitochondrial DNA copy number in mammalian fertility. Biol Reprod. 2010, 83 (1): 52-62.PubMed CentralPubMedView ArticleGoogle Scholar
- May-Panloup P, Chretien MF, Malthiery Y, Reynier P: Mitochondrial DNA in the oocyte and the developing embryo. Curr Top Dev Biol. 2007, 77: 51-83.PubMedView ArticleGoogle Scholar
- Dumollard R, Duchen M, Carroll J: The role of mitochondrial function in the oocyte and embryo. Curr Top Dev Biol. 2007, 77: 21-49.PubMedView ArticleGoogle Scholar
- Jiang Z, Tang H, Ventura M, Cardone MF, Marques-Bonet T, She X, Pevzner PA, Eichler EE: Ancestral reconstruction of segmental duplications reveals punctuated cores of human genome evolution. Nat Genet. 2007, 39 (11): 1361-1368.PubMedView ArticleGoogle Scholar
- De Cáceres M, Legendre P, Wiser SK, Brotons L: Using species combinations in indicator value analyses. Methods Ecol Evol. 2012, 3 (6): 973-982.View ArticleGoogle Scholar
- Liu GE, Ventura M, Cellamare A, Chen L, Cheng Z, Zhu B, Li C, Song J, Eichler EE: Analysis of recent segmental duplications in the bovine genome. BMC Genomics. 2009, 10 (1): 571-PubMed CentralPubMedView ArticleGoogle Scholar
- Drögemüller C, Distl O, Leeb T: Partial deletion of the bovine ED1 gene causes anhidrotic ectodermal dysplasia in cattle. Genome Res. 2001, 11 (10): 1699-1705.PubMed CentralPubMedView ArticleGoogle Scholar
- Meyers SN, McDaneld TG, Swist SL, Marron BM, Steffen DJ, O’Toole D, O’Connell JR, Beever JE, Sonstegard TS, Smith TP: A deletion mutation in bovine SLC4A2 is associated with osteopetrosis in Red Angus cattle. BMC Genomics. 2010, 11 (1): 337-PubMed CentralPubMedView ArticleGoogle Scholar
- Guryev V, Saar K, Adamovic T, Verheul M, Van Heesch SA, Cook S, Pravenec M, Aitman T, Jacob H, Shull JD: Distribution and functional impact of DNA copy number variation in the rat. Nat Genet. 2008, 40 (5): 538-545.PubMedView ArticleGoogle Scholar
- Golik M, Cohen-Zinder M, Loor JJ, Drackley JK, Band MR, Lewin HA, Weller JI, Ron M, Seroussi E: Accelerated expansion of group IID-like phospholipase A2 genes in Bos taurus. Genomics. 2006, 87 (4): 527-533.PubMedView ArticleGoogle Scholar
- Seroussi E, Klompus S, Silanikove M, Krifucks O, Shapiro F, Gertler A, Leitner G: Nonbactericidal secreted phospholipase A2s are potential anti-inflammatory factors in the mammary gland. Immunogenetics. 2013, 65 (12): 861-871.PubMedView ArticleGoogle Scholar
- Rutland CS, Polo-Parada L, Ehler E, Alibhai A, Thorpe A, Suren S, Emes RD, Patel B, Loughna S: Knockdown of embryonic myosin heavy chain reveals an essential role in the morphology and function of the developing heart. Development. 2011, 138 (18): 3955-3966.PubMed CentralPubMedView ArticleGoogle Scholar
- Toydemir RM, Rutherford A, Whitby FG, Jorde LB, Carey JC, Bamshad MJ: Mutations in embryonic myosin heavy chain (MYH3) cause Freeman-Sheldon syndrome and Sheldon-Hall syndrome. Nat Genet. 2006, 38 (5): 561-565.PubMedView ArticleGoogle Scholar
- Niu F, Wang L, Liu X, Wang H, Yang J, Liu Y, Chen L: Genetic diversity of MYH 3 gene associated with growth and carcass traits in Chinese Qinchuan cattle. Mol Biol Rep. 2013, 40 (10): 5635-5643.PubMedView ArticleGoogle Scholar
- Kleinjan DA, Van Heyningen V: Long-range control of gene expression: emerging mechanisms and disruption in disease. Am J Hum Genet. 2005, 76 (1): 8-32.PubMed CentralPubMedView ArticleGoogle Scholar
- Henrichsen CN, Chaignat E, Reymond A: Copy number variants, diseases and gene expression. Hum Mol Genet. 2009, 18 (R1): R1-R8.PubMedView ArticleGoogle Scholar
- Aldred P, Hollox E, Armour J: Copy number polymorphism and expression level variation of the human α-defensin genes DEFA1 and DEFA3. Hum Mol Genet. 2005, 14 (14): 2045-2052.PubMedView ArticleGoogle Scholar
- Perry GH, Dominy NJ, Claw KG, Lee AS, Fiegler H, Redon R, Werner J, Villanea FA, Mountain JL, Misra R: Diet and the evolution of human amylase gene copy number variation. Nat Genet. 2007, 39: 1256-1260.PubMed CentralPubMedView ArticleGoogle Scholar
- Chen C, Qiao R, Wei R, Guo Y, Ai H, Ma J, Ren J, Huang L: A comprehensive survey of copy number variation in 18 diverse pig populations and identification of candidate copy number variable genes associated with complex traits. BMC Genomics. 2012, 13 (1): 733-PubMed CentralPubMedView ArticleGoogle Scholar
- Seroussi E, Glick G, Shirak A, Yakobson E, Weller JI, Ezra E, Zeron Y: Analysis of copy loss and gain variations in Holstein cattle autosomes using BeadChip SNPs. BMC Genomics. 2010, 11 (1): 673-PubMed CentralPubMedView ArticleGoogle Scholar
- Hu ZL, Reecy JM: Animal QTLdb: beyond a repository. Mamm Genome. 2007, 18: 1-4.PubMedView ArticleGoogle Scholar
- Sonstegard TS, Garrett WM, Ashwell MS, Bennett GL, Kappes SM, Van Tassell CP: Comparative map alignment of BTA27 and HSA4 and 8 to identify conserved segments of genome containing fat deposition QTL. Mamm Genome. 2000, 11 (8): 682-688.PubMedView ArticleGoogle Scholar
This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.