1
|
Sigurðardóttir H, Ablondi M, Kristjansson T, Lindgren G, Eriksson S. Genetic diversity and signatures of selection in Icelandic horses and Exmoor ponies. BMC Genomics 2024; 25:772. [PMID: 39118059 PMCID: PMC11308356 DOI: 10.1186/s12864-024-10682-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2024] [Accepted: 08/01/2024] [Indexed: 08/10/2024] Open
Abstract
BACKGROUND The Icelandic horse and Exmoor pony are ancient, native breeds, adapted to harsh environmental conditions and they have both undergone severe historic bottlenecks. However, in modern days, the selection pressures on these breeds differ substantially. The aim of this study was to assess genetic diversity in both breeds through expected (HE) and observed heterozygosity (HO) and effective population size (Ne). Furthermore, we aimed to identify runs of homozygosity (ROH) to estimate and compare genomic inbreeding and signatures of selection in the breeds. RESULTS HO was estimated at 0.34 and 0.33 in the Icelandic horse and Exmoor pony, respectively, aligning closely with HE of 0.34 for both breeds. Based on genomic data, the Ne for the last generation was calculated to be 125 individuals for Icelandic horses and 42 for Exmoor ponies. Genomic inbreeding coefficient (FROH) ranged from 0.08 to 0.20 for the Icelandic horse and 0.12 to 0.27 for the Exmoor pony, with the majority of inbreeding attributed to short ROHs in both breeds. Several ROH islands associated with performance were identified in the Icelandic horse, featuring target genes such as DMRT3, DOCK8, EDNRB, SLAIN1, and NEURL1. Shared ROH islands between both breeds were linked to metabolic processes (FOXO1), body size, and the immune system (CYRIB), while private ROH islands in Exmoor ponies were associated with coat colours (ASIP, TBX3, OCA2), immune system (LYG1, LYG2), and fertility (TEX14, SPO11, ADAM20). CONCLUSIONS Evaluations of genetic diversity and inbreeding reveal insights into the evolutionary trajectories of both breeds, highlighting the consequences of population bottlenecks. While the genetic diversity in the Icelandic horse is acceptable, a critically low genetic diversity was estimated for the Exmoor pony, which requires further validation. Identified signatures of selection highlight the differences in the use of the two breeds as well as their adaptive trait similarities. The results provide insight into genomic regions under selection pressure in a gaited performance horse breed and various adaptive traits in small-sized native horse breeds. This understanding contributes to preserving genetic diversity and population health in these equine populations.
Collapse
Affiliation(s)
- Heiðrún Sigurðardóttir
- Department of Animal Biosciences, Swedish University of Agricultural Sciences, P.O. Box 7023, Uppsala, 75007, Sweden.
- Faculty of Agricultural Sciences, Agricultural University of Iceland, Hvanneyri, Borgarbyggð, 311, Iceland.
| | - Michela Ablondi
- Department of Veterinary Science, University of Parma, Parma, 43126, Italy
| | - Thorvaldur Kristjansson
- Faculty of Agricultural Sciences, Agricultural University of Iceland, Hvanneyri, Borgarbyggð, 311, Iceland
| | - Gabriella Lindgren
- Department of Animal Biosciences, Swedish University of Agricultural Sciences, P.O. Box 7023, Uppsala, 75007, Sweden
- Center for Animal Breeding and Genetics, Department of Biosystems, KU Leuven, Leuven, 3001, Belgium
| | - Susanne Eriksson
- Department of Animal Biosciences, Swedish University of Agricultural Sciences, P.O. Box 7023, Uppsala, 75007, Sweden
| |
Collapse
|
2
|
Liu X, Chen W, Huang B, Wang X, Peng Y, Zhang X, Chai W, Khan MZ, Wang C. Advancements in copy number variation screening in herbivorous livestock genomes and their association with phenotypic traits. Front Vet Sci 2024; 10:1334434. [PMID: 38274664 PMCID: PMC10808162 DOI: 10.3389/fvets.2023.1334434] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Accepted: 12/27/2023] [Indexed: 01/27/2024] Open
Abstract
Copy number variations (CNVs) have garnered increasing attention within the realm of genetics due to their prevalence in human, animal, and plant genomes. These structural genetic variations have demonstrated associations with a broad spectrum of phenotypic diversity, economic traits, environmental adaptations, epidemics, and other essential aspects of both plants and animals. Furthermore, CNVs exhibit extensive sequence variability and encompass a wide array of genomes. The advancement and maturity of microarray and sequencing technologies have catalyzed a surge in research endeavors pertaining to CNVs. This is particularly prominent in the context of livestock breeding, where molecular markers have gained prominence as a valuable tool in comparison to traditional breeding methods. In light of these developments, a contemporary and comprehensive review of existing studies on CNVs becomes imperative. This review serves the purpose of providing a brief elucidation of the fundamental concepts underlying CNVs, their mutational mechanisms, and the diverse array of detection methods employed to identify these structural variations within genomes. Furthermore, it seeks to systematically analyze the recent advancements and findings within the field of CNV research, specifically within the genomes of herbivorous livestock species, including cattle, sheep, horses, and donkeys. The review also highlighted the role of CNVs in shaping various phenotypic traits including growth traits, reproductive traits, pigmentation and disease resistance etc., in herbivorous livestock. The main goal of this review is to furnish readers with an up-to-date compilation of knowledge regarding CNVs in herbivorous livestock genomes. By integrating the latest research findings and insights, it is anticipated that this review will not only offer pertinent information but also stimulate future investigations into the realm of CNVs in livestock. In doing so, it endeavors to contribute to the enhancement of breeding strategies, genomic selection, and the overall improvement of herbivorous livestock production and resistance to diseases.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | - Muhammad Zahoor Khan
- Liaocheng Research Institute of Donkey High-Efficiency Breeding, Liaocheng University, Liaocheng, China
| | - Changfa Wang
- Liaocheng Research Institute of Donkey High-Efficiency Breeding, Liaocheng University, Liaocheng, China
| |
Collapse
|
3
|
Choudhury MP, Wang Z, Zhu M, Teng S, Yan J, Cao S, Yi G, Liu Y, Liao Y, Tang Z. Genome-Wide Detection of Copy Number Variations Associated with Miniature Features in Horses. Genes (Basel) 2023; 14:1934. [PMID: 37895283 PMCID: PMC10606273 DOI: 10.3390/genes14101934] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Revised: 10/10/2023] [Accepted: 10/10/2023] [Indexed: 10/29/2023] Open
Abstract
Copy number variations (CNVs) are crucial structural genomic variants affecting complex traits in humans and livestock animals. The current study was designed to conduct a comprehensive comparative copy number variation analysis among three breeds, Debao (DB), Baise (BS), and Warmblood (WB), with a specific focus on identifying genomic regions associated with miniature features in horses. Using whole-genome next-generation resequencing data, we identified 18,974 CNVs across 31 autosomes. Among the breeds, we found 4279 breed-specific CNV regions (CNVRs). Baise, Debao, and Warmblood displayed 2978, 986, and 895 distinct CNVRs, respectively, with 202 CNVRs shared across all three breeds. After removing duplicates, we obtained 1545 CNVRs from 26 horse genomes. Functional annotation reveals enrichment in biological functions, including antigen processing, cell metabolism, olfactory conduction, and nervous system development. Debao horses have 970 genes overlapping with CNVRs, possibly causing their small size and mountainous adaptations. We also found that the genes GHR, SOX9, and SOX11 may be responsible for the miniature features of the Debao horse by analyzing their overlapping CNVRs. Overall, this study offers valuable insights into the widespread presence of CNVs in the horse genome. The findings contribute to mapping horse CNVs and advance research on unique miniature traits observed in the Debao horse.
Collapse
Affiliation(s)
- Md. Panir Choudhury
- Kunpeng Institute of Modern Agriculture at Foshan, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Foshan 518124, China; (M.P.C.); (G.Y.); (Y.L.)
- Shenzhen Branch, Guangdong Laboratory of Lingnan Modern Agriculture, Key Laboratory of Livestock and Poultry Multi-omics of MARA, Kunpeng Institute of Modern Agriculture at Foshan, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen 518124, China
- Bangladesh Livestock Research Institute, Ministry of Fisheries and Livestock, Savar, Dhaka 1341, Bangladesh
| | - Zihao Wang
- Animal Husbandry Research Institute, Guangxi Vocational University of Agriculture, Nanning 530002,China; (Z.W.); (M.Z.); (S.T.); (J.Y.); (S.C.)
| | - Min Zhu
- Animal Husbandry Research Institute, Guangxi Vocational University of Agriculture, Nanning 530002,China; (Z.W.); (M.Z.); (S.T.); (J.Y.); (S.C.)
| | - Shaohua Teng
- Animal Husbandry Research Institute, Guangxi Vocational University of Agriculture, Nanning 530002,China; (Z.W.); (M.Z.); (S.T.); (J.Y.); (S.C.)
| | - Jing Yan
- Animal Husbandry Research Institute, Guangxi Vocational University of Agriculture, Nanning 530002,China; (Z.W.); (M.Z.); (S.T.); (J.Y.); (S.C.)
| | - Shuwei Cao
- Animal Husbandry Research Institute, Guangxi Vocational University of Agriculture, Nanning 530002,China; (Z.W.); (M.Z.); (S.T.); (J.Y.); (S.C.)
| | - Guoqiang Yi
- Kunpeng Institute of Modern Agriculture at Foshan, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Foshan 518124, China; (M.P.C.); (G.Y.); (Y.L.)
- Shenzhen Branch, Guangdong Laboratory of Lingnan Modern Agriculture, Key Laboratory of Livestock and Poultry Multi-omics of MARA, Kunpeng Institute of Modern Agriculture at Foshan, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen 518124, China
| | - Yuwen Liu
- Kunpeng Institute of Modern Agriculture at Foshan, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Foshan 518124, China; (M.P.C.); (G.Y.); (Y.L.)
- Shenzhen Branch, Guangdong Laboratory of Lingnan Modern Agriculture, Key Laboratory of Livestock and Poultry Multi-omics of MARA, Kunpeng Institute of Modern Agriculture at Foshan, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen 518124, China
| | - Yuying Liao
- Guangxi Veterinary Research Institute, Nanning 530001, China
| | - Zhonglin Tang
- Kunpeng Institute of Modern Agriculture at Foshan, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Foshan 518124, China; (M.P.C.); (G.Y.); (Y.L.)
- Shenzhen Branch, Guangdong Laboratory of Lingnan Modern Agriculture, Key Laboratory of Livestock and Poultry Multi-omics of MARA, Kunpeng Institute of Modern Agriculture at Foshan, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen 518124, China
| |
Collapse
|
4
|
Salehian-Dehkordi H, Huang JH, Pirany N, Mehrban H, Lv XY, Sun W, Esmailizadeh A, Lv FH. Genomic Landscape of Copy Number Variations and Their Associations with Climatic Variables in the World's Sheep. Genes (Basel) 2023; 14:1256. [PMID: 37372436 PMCID: PMC10298528 DOI: 10.3390/genes14061256] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2023] [Revised: 06/06/2023] [Accepted: 06/08/2023] [Indexed: 06/29/2023] Open
Abstract
Sheep show characteristics of phenotypic diversity and adaptation to diverse climatic regions. Previous studies indicated associations between copy number variations (CNVs) and climate-driven adaptive evolution in humans and other domestic animals. Here, we constructed a genomic landscape of CNVs (n = 39,145) in 47 old autochthonous populations genotyped at a set of high-density (600 K) SNPs to detect environment-driven signatures of CNVs using a multivariate regression model. We found 136 deletions and 52 duplications that were significantly (Padj. < 0.05) associated with climatic variables. These climate-mediated selective CNVs are involved in functional candidate genes for heat stress and cold climate adaptation (e.g., B3GNTL1, UBE2L3, and TRAF2), coat and wool-related traits (e.g., TMEM9, STRA6, RASGRP2, and PLA2G3), repairing damaged DNA (e.g., HTT), GTPase activity (e.g., COPG), fast metabolism (e.g., LMF2 and LPIN3), fertility and reproduction (e.g., SLC19A1 and CCDC155), growth-related traits (e.g., ADRM1 and IGFALS), and immune response (e.g., BEGAIN and RNF121) in sheep. In particular, we identified significant (Padj. < 0.05) associations between probes in deleted/duplicated CNVs and solar radiation. Enrichment analysis of the gene sets among all the CNVs revealed significant (Padj. < 0.05) enriched gene ontology terms and pathways related to functions such as nucleotide, protein complex, and GTPase activity. Additionally, we observed overlapping between the CNVs and 140 known sheep QTLs. Our findings imply that CNVs can serve as genomic markers for the selection of sheep adapted to specific climatic conditions.
Collapse
Affiliation(s)
- Hosein Salehian-Dehkordi
- College of Animal Science and Technology, China Agricultural University, Beijing 100193, China; (H.S.-D.); (J.-H.H.)
- Department of Animal Science, Faculty of Agriculture, Shahrekord University, Shahrekord 88186-34141, Iran; (N.P.); (H.M.)
| | - Jia-Hui Huang
- College of Animal Science and Technology, China Agricultural University, Beijing 100193, China; (H.S.-D.); (J.-H.H.)
| | - Nasrollah Pirany
- Department of Animal Science, Faculty of Agriculture, Shahrekord University, Shahrekord 88186-34141, Iran; (N.P.); (H.M.)
| | - Hossein Mehrban
- Department of Animal Science, Faculty of Agriculture, Shahrekord University, Shahrekord 88186-34141, Iran; (N.P.); (H.M.)
| | - Xiao-Yang Lv
- Joint International Research Laboratory of Agriculture and Agri-Product Safety of Ministry of Education of China, Yangzhou University, Yangzhou 225009, China; (X.-Y.L.); (W.S.)
- International Joint Research Laboratory in Universities of Jiangsu Province of China for Domestic Animal Germplasm Resources and Genetic Improvement, Yangzhou University, Yangzhou 225009, China
| | - Wei Sun
- Joint International Research Laboratory of Agriculture and Agri-Product Safety of Ministry of Education of China, Yangzhou University, Yangzhou 225009, China; (X.-Y.L.); (W.S.)
- International Joint Research Laboratory in Universities of Jiangsu Province of China for Domestic Animal Germplasm Resources and Genetic Improvement, Yangzhou University, Yangzhou 225009, China
| | - Ali Esmailizadeh
- Department of Animal Science, Faculty of Agriculture, Shahid Bahonar University of Kerman, Kerman 76169-14111, Iran
| | - Feng-Hua Lv
- College of Animal Science and Technology, China Agricultural University, Beijing 100193, China; (H.S.-D.); (J.-H.H.)
| |
Collapse
|
5
|
Identification of Copy Number Variations in Four Horse Breed Populations in South Korea. Animals (Basel) 2022; 12:ani12243501. [PMID: 36552421 PMCID: PMC9774267 DOI: 10.3390/ani12243501] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2022] [Revised: 11/21/2022] [Accepted: 12/08/2022] [Indexed: 12/14/2022] Open
Abstract
In this study, genome-wide CNVs were identified using a total of 469 horses from four horse populations (Jeju horses, Thoroughbreds, Jeju riding horses, and Hanla horses). We detected a total of 843 CNVRs throughout all autosomes: 281, 30, 301, and 310 CNVRs for Jeju horses, Thoroughbreds, Jeju riding horses, and Hanla horses, respectively. Of the total CNVRs, copy number losses were found to be the most abundant (48.99%), while gains and mixed CNVRs accounted for 41.04% and 9.96% of the total CNVRs, respectively. The length of the CNVRs ranged from 0.39 kb to 2.8 Mb, while approximately 7.2% of the reference horse genome assembly was covered by the total CNVRs. By comparing the CNVRs among the populations, we found a significant portion of the CNVRs (30.13%) overlapped; the highest number of shared CNVRs was between Hanla horses and Jeju riding horses. When compared with the horse CNVRs of previous studies, 26.8% of CNVRs were found to be uniquely detected in this study. The CNVRs were not randomly distributed throughout the genome; in particular, the Equus caballus autosome (ECA) 7 comprised the largest proportion of its genome (16.3%), while ECA 24 comprised the smallest (0.7%). Furthermore, functional analysis was applied to CNVRs that overlapped with genes (genic-CNVRs); these overlapping areas may be potentially associated with the olfactory pathway and nervous system. A racing performance QTL was detected in a CNVR of Thoroughbreds, Jeju riding horses, and Hanla horses, and the CNVR value was mixed for three breeds.
Collapse
|
6
|
Copy Number Variation (CNV): A New Genomic Insight in Horses. Animals (Basel) 2022; 12:ani12111435. [PMID: 35681904 PMCID: PMC9179425 DOI: 10.3390/ani12111435] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Revised: 05/25/2022] [Accepted: 05/30/2022] [Indexed: 12/04/2022] Open
Abstract
Simple Summary This study aimed to contribute to our knowledge of CNVs, a type of genomic marker in equines, by producing, for the first time, a fine-scale characterization of the CNV regions (CNVRs) in the Pura Raza Española horse breed. We found not only the existence of a unique pattern of genomic regions enriched in CNVs in the PRE in comparison with the data available from other breeds but also the incidence of CNVs across the entire genome. Since these regions could affect the structure and dose of the genes involved, we also performed a gene ontology analysis which revealed that most of the genes overlapping in CNVRs were related to the olfactory pathways and immune response. Abstract Copy number variations (CNVs) are a new-fangled source of genetic variation that can explain changes in the phenotypes in complex traits and diseases. In recent years, their study has increased in many livestock populations. However, the study and characterization of CNVs in equines is still very limited. Our study aimed to investigate the distribution pattern of CNVs, characterize CNV regions (CNVRs), and identify the biological pathways affected by CNVRs in the Pura Raza Española (PRE) breed. To achieve this, we analyzed high-density SNP genotyping data (670,804 markers) from a large cohort of 654 PRE horses. In total, we identified 19,902 CNV segments and 1007 CNV regions in the whole population. The length of the CNVs ranged from 1.024 kb to 4.55 Mb, while the percentage of the genome covered by CNVs was 4.4%. Interestingly, duplications were more abundant than deletions and mixed CNVRs. In addition, the distribution of CNVs across the chromosomes was not uniform, with ECA12 being the chromosome with the largest percentage of its genome covered (19.2%), while the highest numbers of CNVs were found in ECA20, ECA12, and ECA1. Our results showed that 71.4% of CNVRs contained genes involved in olfactory transduction, olfactory receptor activity, and immune response. Finally, 39.1% of the CNVs detected in our study were unique when compared with CNVRs identified in previous studies. To the best of our knowledge, this is the first attempt to reveal and characterize the CNV landscape in PRE horses, and it contributes to our knowledge of CNVs in equines, thus facilitating the understanding of genetic and phenotypic variations in the species. However, further research is still needed to confirm if the CNVs observed in the PRE are also linked to variations in the specific phenotypical differences in the breed.
Collapse
|
7
|
Gömer A, Puff C, Reinecke B, Bracht S, Conze M, Baumgärtner W, Steinmann J, Feige K, Cavalleri JMV, Steinmann E, Todt D. Experimental cross-species infection of donkeys with equine hepacivirus and analysis of host immune signatures. ONE HEALTH OUTLOOK 2022; 4:9. [PMID: 35527255 PMCID: PMC9082851 DOI: 10.1186/s42522-022-00065-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Accepted: 04/06/2022] [Indexed: 06/14/2023]
Abstract
BACKGROUND The Equine Hepacivirus (EqHV) is an equine-specific and liver-tropic virus belonging to the diverse genus of Hepaciviruses. It was recently found in a large donkey (Equus asinus) cohort with a similar seroprevalence (30%), but lower rate of RNA-positive animals (0.3%) compared to horses. These rare infection events indicate either a lack of adaptation to the new host or a predominantly acute course of infection. METHODS In order to analyze the susceptibility and the course of EqHV infection in donkeys, we inoculated two adult female donkeys and one control horse intravenously with purified EqHV from a naturally infected horse. Liver biopsies were taken before and after inoculation to study changes in the transcriptome. RESULTS Infection kinetics were similar between the equids. All animals were EqHV PCR-positive from day three. EqHV RNA-levels declined when the animals seroconverted and both donkeys cleared the virus from the blood by week 12. Infection did not have an impact on the clinical findings and no significant histopathological differences were seen. Blood biochemistry revealed a mild increase in GLDH at the time of seroconversion in horses, which was less pronounced in donkeys. Transcriptomic analysis revealed a distinct set of differentially expressed genes, including viral host factors and immune genes. CONCLUSION To summarize, our findings indicate that donkeys are a natural host of EqHV, due to the almost identical infection kinetics. The different immune responses do however suggest different mechanisms in reacting to hepaciviral infections.
Collapse
Affiliation(s)
- André Gömer
- Department of Molecular and Medical Virology, Ruhr University Bochum, Bochum, Germany
- Institute of Virology, University of Veterinary Medicine Hannover, Foundation, Hannover, Germany
| | - Christina Puff
- Department of Pathology, University of Veterinary Medicine Hannover, Foundation, Hannover, Germany
| | - Birthe Reinecke
- Institute of Experimental Virology, TWINCORE Center for Experimental and Clinical Infection Research, Hannover, Germany
| | - Stephanie Bracht
- Institute of Experimental Virology, TWINCORE Center for Experimental and Clinical Infection Research, Hannover, Germany
| | - Maria Conze
- Clinic for Horses, University of Veterinary Medicine Hannover, Foundation, Hannover, Germany
| | - Wolfgang Baumgärtner
- Department of Pathology, University of Veterinary Medicine Hannover, Foundation, Hannover, Germany
| | - Jörg Steinmann
- Institute of Medical Microbiology, University of Hospital Essen, University of Duisburg-Essen, Essen, Germany
- Institute of Clinical Hygiene, Medical Microbiology and Infectiology, General Hospital Nürnberg, Paracelsus Medical University, Nürnberg, Germany
| | - Karsten Feige
- Clinic for Horses, University of Veterinary Medicine Hannover, Foundation, Hannover, Germany
| | - Jessika M V Cavalleri
- Clinical Unit of Equine Internal Medicine, Department for Companion Animals and Horses, University of Veterinary Medicine Vienna (Vetmeduni), Vienna, Austria
| | - Eike Steinmann
- Department of Molecular and Medical Virology, Ruhr University Bochum, Bochum, Germany
| | - Daniel Todt
- Department of Molecular and Medical Virology, Ruhr University Bochum, Bochum, Germany.
- European Virus Bioinformatics Center (EVBC), Jena, Germany.
| |
Collapse
|
8
|
Wang M, Liu Y, Bi X, Ma H, Zeng G, Guo J, Guo M, Ling Y, Zhao C. Genome-Wide Detection of Copy Number Variants in Chinese Indigenous Horse Breeds and Verification of CNV-Overlapped Genes Related to Heat Adaptation of the Jinjiang Horse. Genes (Basel) 2022; 13:genes13040603. [PMID: 35456409 PMCID: PMC9033042 DOI: 10.3390/genes13040603] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2022] [Revised: 03/23/2022] [Accepted: 03/25/2022] [Indexed: 02/05/2023] Open
Abstract
In the present study, genome-wide CNVs were detected in a total of 301 samples from 10 Chinese indigenous horse breeds using the Illumina Equine SNP70 Bead Array, and the candidate genes related to adaptability to high temperature and humidity in Jinjiang horses were identified and validated. We determined a total of 577 CNVs ranging in size from 1.06 Kb to 2023.07 Kb on the 31 pairs of autosomes. By aggregating the overlapping CNVs for each breed, a total of 495 CNVRs were detected in the 10 Chinese horse breeds. As many as 211 breed-specific CNVRs were determined, of which 64 were found in the Jinjiang horse population. By removing repetitive CNV regions between breeds, a total of 239 CNVRs were identified in the Chinese indigenous horse breeds including 102 losses, 133 gains and 4 of both events (losses and gains in the same region), in which 131 CNVRs were novel and only detected in the present study compared with previous studies. The total detected CNVR length was 41.74 Mb, accounting for 1.83% of the total length of equine autosomal chromosomes. The coverage of CNVRs on each chromosome varied from 0.47% to 15.68%, with the highest coverage on ECA 12, but the highest number of CNVRs was detected on ECA1 and ECA24. A total of 229 genes overlapping with CNVRs were detected in the Jinjiang horse population, which is an indigenous horse breed unique to the southeastern coast of China exhibiting adaptability to high temperature and humidity. The functional annotation of these genes showed significant relation to cellular heat acclimation and immunity. The expression levels of the candidate genes were validated by heat shock treatment of various durations on fibroblasts of horses. The results show that the expression levels of HSPA1A were significantly increased among the different heat shock durations. The expression level of NFKBIA and SOCS4 declined from the beginning of heat shock to 2 h after heat shock and then showed a gradual increase until it reached the highest value at 6 h and 10 h of heat shock, respectively. Breed-specific CNVRs of Chinese indigenous horse breeds were revealed in the present study, and the results facilitate mapping CNVs on the whole genome and also provide valuable insights into the molecular mechanisms of adaptation to high temperature and humidity in the Jinjiang horse.
Collapse
Affiliation(s)
- Min Wang
- College of Animal Science and Technology, China Agricultural University, Beijing 100193, China; (M.W.); (Y.L.); (X.B.); (Y.L.)
- Equine Center, China Agricultural University, Beijing 100193, China
- Key Laboratory of Animal Genetics, Breeding and Reproduction, Ministry of Agriculture, Beijing 100193, China
- National Engineering Laboratory for Animal Breeding, Beijing 100193, China
- Beijing Key Laboratory for Genetic Improvement of Livestock and Poultry, Beijing 100193, China
| | - Yu Liu
- College of Animal Science and Technology, China Agricultural University, Beijing 100193, China; (M.W.); (Y.L.); (X.B.); (Y.L.)
- Equine Center, China Agricultural University, Beijing 100193, China
- Key Laboratory of Animal Genetics, Breeding and Reproduction, Ministry of Agriculture, Beijing 100193, China
- National Engineering Laboratory for Animal Breeding, Beijing 100193, China
- Beijing Key Laboratory for Genetic Improvement of Livestock and Poultry, Beijing 100193, China
| | - Xiaokun Bi
- College of Animal Science and Technology, China Agricultural University, Beijing 100193, China; (M.W.); (Y.L.); (X.B.); (Y.L.)
- Equine Center, China Agricultural University, Beijing 100193, China
- Key Laboratory of Animal Genetics, Breeding and Reproduction, Ministry of Agriculture, Beijing 100193, China
- National Engineering Laboratory for Animal Breeding, Beijing 100193, China
- Beijing Key Laboratory for Genetic Improvement of Livestock and Poultry, Beijing 100193, China
| | - Hongying Ma
- Shaanxi Key Laboratory for Animal Conservation, Shaanxi Institute of Zoology, Xi’an 710032, China;
| | - Guorong Zeng
- Jinjiang Animal Husbandry and Veterinary Station, Quanzhou 362200, China; (G.Z.); (J.G.); (M.G.)
| | - Jintu Guo
- Jinjiang Animal Husbandry and Veterinary Station, Quanzhou 362200, China; (G.Z.); (J.G.); (M.G.)
| | - Minghao Guo
- Jinjiang Animal Husbandry and Veterinary Station, Quanzhou 362200, China; (G.Z.); (J.G.); (M.G.)
| | - Yao Ling
- College of Animal Science and Technology, China Agricultural University, Beijing 100193, China; (M.W.); (Y.L.); (X.B.); (Y.L.)
| | - Chunjiang Zhao
- College of Animal Science and Technology, China Agricultural University, Beijing 100193, China; (M.W.); (Y.L.); (X.B.); (Y.L.)
- Equine Center, China Agricultural University, Beijing 100193, China
- Key Laboratory of Animal Genetics, Breeding and Reproduction, Ministry of Agriculture, Beijing 100193, China
- National Engineering Laboratory for Animal Breeding, Beijing 100193, China
- Beijing Key Laboratory for Genetic Improvement of Livestock and Poultry, Beijing 100193, China
- Correspondence:
| |
Collapse
|
9
|
Genome-wide exploration of oil biosynthesis genes in cultivated olive tree varieties (Olea europaea): insights into regulation of oil biosynthesis. Funct Integr Genomics 2022; 22:171-178. [PMID: 34997394 DOI: 10.1007/s10142-021-00824-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Revised: 11/11/2021] [Accepted: 11/30/2021] [Indexed: 11/27/2022]
Abstract
Genome-wide oil biosynthesis was explored by de novo sequencing two cultivated olive tree (Olea europaea) varieties (cv. Ayvalik and Picual). This is the first report of the former variety sequencing. As outgroups, raw reads of cv. Leccino and scaffold-level assembly of cv. Farga were also retrieved. Each of these four cultivars was chromosome-scale assembled into 23 pseudochromosomes, with 1.31 Gbp (Farga), 0.93 Gbp (Ayvalik), 0.7 Gbp (Picual), and 0.54 Gbp (Leccino) in size. Ab initio gene finding was performed on these assemblies, using wild olive tree (oleaster)-trained parameters. High numbers of gene models were predicted and anchored to the pseudochromosomes: 69,028 (Ayvalik), 55,073 (Picual), 63,785 (Farga), and 40,449 (Leccino). Using previously reported oil biosynthesis genes from wild olive tree genome project, the following homologous sequences were identified: 1,355 (Ayvalik), 1,269 (Farga), 812 (Leccino), and 774 (Picual). Of these, 358 sequences were commonly shared by all cultivars. Besides, some sequences were cultivar unique: Ayvalik (126), Farga (118), Leccino (46), and Picual (52). These putative sequences were assigned to various GO terms, ranging from lipid metabolism to stress tolerance, from signal transactions to development, and to many others, implicating that oil biosynthesis is synergistically regulated with involvement of various other pathways.
Collapse
|
10
|
Prunier J, Carrier A, Gilbert I, Poisson W, Albert V, Taillon J, Bourret V, Côté SD, Droit A, Robert C. CNVs with adaptive potential in Rangifer tarandus: genome architecture and new annotated assembly. Life Sci Alliance 2021; 5:5/3/e202101207. [PMID: 34911809 PMCID: PMC8711850 DOI: 10.26508/lsa.202101207] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Revised: 11/29/2021] [Accepted: 11/29/2021] [Indexed: 01/13/2023] Open
Abstract
Rangifer tarandus has experienced recent drastic population size reductions throughout its circumpolar distribution and preserving the species implies genetic diversity conservation. To facilitate genomic studies of the species populations, we improved the genome assembly by combining long read and linked read and obtained a new highly accurate and contiguous genome assembly made of 13,994 scaffolds (L90 = 131 scaffolds). Using de novo transcriptome assembly of RNA-sequencing reads and similarity with annotated human gene sequences, 17,394 robust gene models were identified. As copy number variations (CNVs) likely play a role in adaptation, we additionally investigated these variations among 20 genomes representing three caribou ecotypes (migratory, boreal and mountain). A total of 1,698 large CNVs (length > 1 kb) showing a genome distribution including hotspots were identified. 43 large CNVs were particularly distinctive of the migratory and sedentary ecotypes and included genes annotated for functions likely related to the expected adaptations. This work includes the first publicly available annotation of the caribou genome and the first assembly allowing genome architecture analyses, including the likely adaptive CNVs reported here.
Collapse
Affiliation(s)
- Julien Prunier
- Département de Médecine Moléculaire, Faculté de Médecine, Université Laval, Quebec City, Canada
| | - Alexandra Carrier
- Département des sciences animales, Faculté des Sciences de l'Agriculture et de l'Alimentation, Université Laval, Quebec City, Canada
| | - Isabelle Gilbert
- Département des sciences animales, Faculté des Sciences de l'Agriculture et de l'Alimentation, Université Laval, Quebec City, Canada
| | - William Poisson
- Département des sciences animales, Faculté des Sciences de l'Agriculture et de l'Alimentation, Université Laval, Quebec City, Canada
| | - Vicky Albert
- Ministère des Forêts, de la Faune et des Parcs du Québec, Quebec City, Canada
| | - Joëlle Taillon
- Ministère des Forêts, de la Faune et des Parcs du Québec, Quebec City, Canada
| | - Vincent Bourret
- Ministère des Forêts, de la Faune et des Parcs du Québec, Quebec City, Canada
| | - Steeve D Côté
- Caribou Ungava, département de biologie, Faculté des Sciences et de Génie, Université Laval, Quebec City, Canada
| | - Arnaud Droit
- Département de Médecine Moléculaire, Faculté de Médecine, Université Laval, Quebec City, Canada
| | - Claude Robert
- Département des sciences animales, Faculté des Sciences de l'Agriculture et de l'Alimentation, Université Laval, Quebec City, Canada
| |
Collapse
|
11
|
Lim KY, Lee K, Shim Y, Park JW, Kim H, Kang J, Won JK, Kim SK, Phi JH, Park CK, Chung CK, Yun H, Park SH. Molecular subtyping of ependymoma and prognostic impact of Ki-67. Brain Tumor Pathol 2021; 39:1-13. [PMID: 34812989 PMCID: PMC8752536 DOI: 10.1007/s10014-021-00417-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Accepted: 10/26/2021] [Indexed: 10/25/2022]
Abstract
Although ependymomas (EPNs) have similar histopathology, they are heterogeneous tumors with diverse immunophenotypes, genetics, epigenetics, and different clinical behavior according to anatomical locations. We reclassified 141 primary EPNs from a single institute with immunohistochemistry (IHC) and next-generation sequencing (NGS). Supratentorial (ST), posterior fossa (PF), and spinal (SP) EPNs comprised 12%, 41%, and 47% of our cohort, respectively. Fusion genes were found only in ST-EPNs except for one SP-EPN with ZFTA-YAP1 fusion, NF2 gene alterations were found in SP-EPNs, but no driver gene was present in PF-EPNs. Surrogate IHC markers revealed high concordance rates between L1CAM and ZFTA-fusion and H3K27me3 loss or EZHIP overexpression was used for PFA-EPNs. The 7% cut-off of Ki-67 was sufficient to classify EPNs into two-tiered grades at all anatomical locations. Multivariate analysis also delineated that a Ki-67 index was the only independent prognostic factor in both overall and progression-free survivals. The gain of chromosome 1q and CDKN2A/2B deletion were associated with poor outcomes, such as multiple recurrences or extracranial metastases. In this study, we propose a cost-effective schematic diagnostic flow of EPNs by the anatomical location, three biomarkers (L1CAM, H3K27me3, and EZHIP), and a cut-off of a 7% Ki-67 labeling index.
Collapse
Affiliation(s)
- Ka Young Lim
- Department of Pathology, Seoul National University College of Medicine, 101 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea
| | - Kwanghoon Lee
- Department of Pathology, Seoul National University College of Medicine, 101 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea
| | - Yumi Shim
- Department of Pathology, Seoul National University College of Medicine, 101 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea
| | - Jin Woo Park
- Department of Pathology, Seoul National University College of Medicine, 101 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea
| | - Hyunhee Kim
- Department of Pathology, Seoul National University College of Medicine, 101 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea
| | - Jeongwan Kang
- Department of Pathology, Seoul National University College of Medicine, 101 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea
| | - Jae Kyung Won
- Department of Pathology, Seoul National University College of Medicine, 101 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea
| | - Seung-Ki Kim
- Department of Neurosurgery, Seoul National University College of Medicine, 101 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea
| | - Ji Hoon Phi
- Department of Neurosurgery, Seoul National University College of Medicine, 101 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea
| | - Chul-Kee Park
- Department of Neurosurgery, Seoul National University College of Medicine, 101 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea
| | - Chun-Kee Chung
- Department of Neurosurgery, Seoul National University College of Medicine, 101 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea
| | - Hongseok Yun
- Department of Precision Medicine, Seoul National University College of Medicine, 101 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea
| | - Sung-Hye Park
- Department of Pathology, Seoul National University College of Medicine, 101 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea. .,Institute of Neuroscience, Seoul National University College of Medicine, 101 Daehak-ro, Jongo-gu, Seoul, 03080, Republic of Korea.
| |
Collapse
|
12
|
Klumplerova M, Splichalova P, Oppelt J, Futas J, Kohutova A, Musilova P, Kubickova S, Vodicka R, Orlando L, Horin P. Genetic diversity, evolution and selection in the major histocompatibility complex DRB and DQB loci in the family Equidae. BMC Genomics 2020; 21:677. [PMID: 32998693 PMCID: PMC7525986 DOI: 10.1186/s12864-020-07089-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Accepted: 09/21/2020] [Indexed: 02/08/2023] Open
Abstract
Background The mammalian Major Histocompatibility Complex (MHC) is a genetic region containing highly polymorphic genes with immunological functions. MHC class I and class II genes encode antigen-presenting molecules expressed on the cell surface. The MHC class II sub-region contains genes expressed in antigen presenting cells. The antigen binding site is encoded by the second exon of genes encoding antigen presenting molecules. The exon 2 sequences of these MHC genes have evolved under the selective pressure of pathogens. Interspecific differences can be observed in the class II sub-region. The family Equidae includes a variety of domesticated, and free-ranging species inhabiting a range of habitats exposed to different pathogens and represents a model for studying this important part of the immunogenome. While equine MHC class II DRA and DQA loci have received attention, the genetic diversity and effects of selection on DRB and DQB loci have been largely overlooked. This study aimed to provide the first in-depth analysis of the MHC class II DRB and DQB loci in the Equidae family. Results Three DRB and two DQB genes were identified in the genomes of all equids. The genes DRB2, DRB3 and DQB3 showed high sequence conservation, while polymorphisms were more frequent at DRB1 and DQB1 across all species analyzed. DQB2 was not found in the genome of the Asiatic asses Equus hemionus kulan and E. h. onager. The bioinformatic analysis of non-zero-coverage-bases of DRB and DQB genes in 14 equine individual genomes revealed differences among individual genes. Evidence for recombination was found for DRB1, DRB2, DQB1 and DQB2 genes. Trans-species allele sharing was identified in all genes except DRB1. Site-specific selection analysis predicted genes evolving under positive selection both at DRB and DQB loci. No selected amino acid sites were identified in DQB3. Conclusions The organization of the MHC class II sub-region of equids is similar across all species of the family. Genomic sequences, along with phylogenetic trees suggesting effects of selection as well as trans-species polymorphism support the contention that pathogen-driven positive selection has shaped the MHC class II DRB/DQB sub-regions in the Equidae.
Collapse
Affiliation(s)
- Marie Klumplerova
- Department of Animal Genetics, Veterinary and Pharmaceutical University, Brno, Czech Republic.,Ceitec VFU, RG Animal Immunogenomics, Brno, Czech Republic
| | - Petra Splichalova
- Department of Animal Genetics, Veterinary and Pharmaceutical University, Brno, Czech Republic.,Ceitec VFU, RG Animal Immunogenomics, Brno, Czech Republic
| | - Jan Oppelt
- Ceitec VFU, RG Animal Immunogenomics, Brno, Czech Republic.,Ceitec MU, Masaryk University, Kamenice 753/5, 625 00, Brno, Czech Republic.,National Centre for Biomolecular research, Faculty of Science, Masaryk University, Kamenice 753/5, 625 00, Brno, Czech Republic
| | - Jan Futas
- Department of Animal Genetics, Veterinary and Pharmaceutical University, Brno, Czech Republic.,Ceitec VFU, RG Animal Immunogenomics, Brno, Czech Republic
| | - Aneta Kohutova
- Department of Animal Genetics, Veterinary and Pharmaceutical University, Brno, Czech Republic.,Department of Biology, Faculty of Medicine, Masaryk University, Kamenice 753/5, 625 00, Brno, Czech Republic
| | - Petra Musilova
- Department of Genetics and Reproductive Biotechnologies, Veterinary Research Institute, Brno, Czech Republic.,Ceitec VRI, RG Animal Cytogenomics, Brno, Czech Republic
| | - Svatava Kubickova
- Department of Genetics and Reproductive Biotechnologies, Veterinary Research Institute, Brno, Czech Republic.,Ceitec VRI, RG Animal Cytogenomics, Brno, Czech Republic
| | - Roman Vodicka
- Zoo Prague, U Trojského zámku 120/3, 171 00, Praha 7, Czech Republic
| | - Ludovic Orlando
- Laboratoire d'Anthropobiologie Moléculaire et d'Imagerie de Synthèse, CNRS UMR 5288, Université de Toulouse, Université Paul Sabatier, 31000, Toulouse, France.,Centre for GeoGenetics, Natural History Museum of Denmark, Øster Voldgade 5-7, 1350K, Copenhagen, Denmark
| | - Petr Horin
- Department of Animal Genetics, Veterinary and Pharmaceutical University, Brno, Czech Republic. .,Ceitec VFU, RG Animal Immunogenomics, Brno, Czech Republic.
| |
Collapse
|
13
|
Whole genome detection of sequence and structural polymorphism in six diverse horses. PLoS One 2020; 15:e0230899. [PMID: 32271776 PMCID: PMC7144971 DOI: 10.1371/journal.pone.0230899] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Accepted: 03/12/2020] [Indexed: 12/30/2022] Open
Abstract
The domesticated horse has played a unique role in human history, serving not just as a source of animal protein, but also as a catalyst for long-distance migration and military conquest. As a result, the horse developed unique physiological adaptations to meet the demands of both their climatic environment and their relationship with man. Completed in 2009, the first domesticated horse reference genome assembly (EquCab 2.0) produced most of the publicly available genetic variations annotations in this species. Yet, there are around 400 geographically and physiologically diverse breeds of horse. To enrich the current collection of genetic variants in the horse, we sequenced whole genomes from six horses of six different breeds: an American Miniature, a Percheron, an Arabian, a Mangalarga Marchador, a Native Mongolian Chakouyi, and a Tennessee Walking Horse, and mapped them to EquCab3.0 genome. Aside from extreme contrasts in body size, these breeds originate from diverse global locations and each possess unique adaptive physiology. A total of 1.3 billion reads were generated for the six horses with coverage between 15x to 24x per horse. After applying rigorous filtration, we identified and functionally annotated 17,514,723 Single Nucleotide Polymorphisms (SNPs), and 1,923,693 Insertions/Deletions (INDELs), as well as an average of 1,540 Copy Number Variations (CNVs) and 3,321 Structural Variations (SVs) per horse. Our results revealed putative functional variants including genes associated with size variation like LCORL gene (found in all horses), ZFAT in the Arabian, American Miniature and Percheron horses and ANKRD1 in the Native Mongolian Chakouyi horse. We detected a copy number variation in the Latherin gene that may be the result of evolutionary selection impacting thermoregulation by sweating, an important component of athleticism and heat tolerance. The newly discovered variants were formatted into user-friendly browser tracks and will provide a foundational database for future studies of the genetic underpinnings of diverse phenotypes within the horse. The domesticated horse played a unique role in human history, serving not just as a source of dietary animal protein, but also as a catalyst for long-distance migration and military conquest. As a result, the horse developed unique physiological adaptations to meet the demands of both their climatic environment and their relationship with man. Although the completion of the horse reference genome allowed for the discovery of many genetic variants, the remarkable diversity across breeds of horse calls for additional effort to quantify the complete span of genetic polymorphism within this unique species. In this work, we present genome re-sequencing and variant detection analysis for six horses belonging to six different breeds representing different morphology, origins and vary in their physiological demands and response. We identified and annotated not just single nucleotide polymorphisms (SNPs), but also insertions and deletions (INDELs), copy number variations (CNVs) and structural variations (SVs). Our results illustrate novel sources of polymorphism and highlight potentially impactful variations for phenotypes of body size and conformation. We also detected a copy number loss in the Latherin gene that could be the result of an evolutionary selection affecting thermoregulation through sweating. Our newly discovered variants were formatted into easy-to-use tracks that can be easily accessed by researchers around the globe.
Collapse
|
14
|
Ablondi M, Eriksson S, Tetu S, Sabbioni A, Viklund Å, Mikko S. Genomic Divergence in Swedish Warmblood Horses Selected for Equestrian Disciplines. Genes (Basel) 2019; 10:E976. [PMID: 31783652 PMCID: PMC6947233 DOI: 10.3390/genes10120976] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Revised: 11/20/2019] [Accepted: 11/23/2019] [Indexed: 01/12/2023] Open
Abstract
The equestrian sport horse Swedish Warmblood (SWB) originates from versatile cavalry horses. Most modern SWB breeders have specialized their breeding either towards show jumping or dressage disciplines. The aim of this study was to explore the genomic structure of SWB horses to evaluate the presence of genomic subpopulations, and to search for signatures of selection in subgroups of SWB with high or low breeding values (EBVs) for show jumping. We analyzed high density genotype information from 380 SWB horses born in the period 2010-2011, and used Principal Coordinates Analysis and Discriminant Analysis of Principal Components to detect population stratification. Fixation index and Cross Population Extended Haplotype Homozygosity scores were used to scan the genome for potential signatures of selection. In accordance with current breeding practice, this study highlights the development of two separate breed subpopulations with putative signatures of selection in eleven chromosomes. These regions involve genes with known function in, e.g., mentality, endogenous reward system, development of connective tissues and muscles, motor control, body growth and development. This study shows genetic divergence, due to specialization towards different disciplines in SWB horses. This latter evidence can be of interest for SWB and other horse studbooks encountering specialized breeding.
Collapse
Affiliation(s)
- Michela Ablondi
- Department of Veterinary Science, University of Parma, 43126 Parma, Italy; (M.A.); (A.S.)
| | - Susanne Eriksson
- Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, PO Box 7023, S-75007 Uppsala, Sweden; (S.E.); (S.T.); (Å.V.)
| | - Sasha Tetu
- Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, PO Box 7023, S-75007 Uppsala, Sweden; (S.E.); (S.T.); (Å.V.)
| | - Alberto Sabbioni
- Department of Veterinary Science, University of Parma, 43126 Parma, Italy; (M.A.); (A.S.)
| | - Åsa Viklund
- Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, PO Box 7023, S-75007 Uppsala, Sweden; (S.E.); (S.T.); (Å.V.)
| | - Sofia Mikko
- Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, PO Box 7023, S-75007 Uppsala, Sweden; (S.E.); (S.T.); (Å.V.)
| |
Collapse
|
15
|
Solé M, Ablondi M, Binzer-Panchal A, Velie BD, Hollfelder N, Buys N, Ducro BJ, François L, Janssens S, Schurink A, Viklund Å, Eriksson S, Isaksson A, Kultima H, Mikko S, Lindgren G. Inter- and intra-breed genome-wide copy number diversity in a large cohort of European equine breeds. BMC Genomics 2019; 20:759. [PMID: 31640551 PMCID: PMC6805398 DOI: 10.1186/s12864-019-6141-z] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Accepted: 09/25/2019] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Copy Number Variation (CNV) is a common form of genetic variation underlying animal evolution and phenotypic diversity across a wide range of species. In the mammalian genome, high frequency of CNV differentiation between breeds may be candidates for population-specific selection. However, CNV differentiation, selection and its population genetics have been poorly explored in horses. RESULTS We investigated the patterns, population variation and gene annotation of CNV using the Axiom® Equine Genotyping Array (670,796 SNPs) from a large cohort of individuals (N = 1755) belonging to eight European horse breeds, varying from draught horses to several warmblood populations. After quality control, 152,640 SNP CNVs (individual markers), 18,800 segment CNVs (consecutive SNP CNVs of same gain/loss state or both) and 939 CNV regions (CNVRs; overlapping segment CNVs by at least 1 bp) compared to the average signal of the reference (Belgian draught horse) were identified. Our analyses showed that Equus caballus chromosome 12 (ECA12) was the most enriched in segment CNV gains and losses (~ 3% average proportion of the genome covered), but the highest number of segment CNVs were detected on ECA1 and ECA20 (regardless of size). The Friesian horses showed private SNP CNV gains (> 20% of the samples) on ECA1 and Exmoor ponies displayed private SNP CNV losses on ECA25 (> 20% of the samples). The Warmblood cluster showed private SNP CNV gains located in ECA9 and Draught cluster showed private SNP CNV losses located in ECA7. The length of the CNVRs ranged from 1 kb to 21.3 Mb. A total of 10,612 genes were annotated within the CNVRs. The PANTHER annotation of these genes showed significantly under- and overrepresented gene ontology biological terms related to cellular processes and immunity (Bonferroni P-value < 0.05). We identified 80 CNVRs overlapping with known QTL for fertility, coat colour, conformation and temperament. We also report 67 novel CNVRs. CONCLUSIONS This work revealed that CNV patterns, in the genome of some European horse breeds, occurred in specific genomic regions. The results provide support to the hypothesis that high frequency private CNVs residing in genes may potentially be responsible for the diverse phenotypes seen between horse breeds.
Collapse
Affiliation(s)
- Marina Solé
- Department of Animal Breeding & Genetics, Swedish University of Agricultural Sciences, Uppsala, Sweden.
| | - Michela Ablondi
- Department of Veterinary Science, Università di Parma, Parma, Italy
| | - Amrei Binzer-Panchal
- Department of Medical Sciences, Array and Analysis Facility, Uppsala University, Uppsala, Sweden
| | - Brandon D Velie
- Faculty of Life and Environmental Science, University of Sydney, Sydney, NSW, Australia
| | - Nina Hollfelder
- Department of Medical Sciences, Array and Analysis Facility, Uppsala University, Uppsala, Sweden
| | - Nadine Buys
- Livestock Genetics, Department of Biosystems, KU Leuven, 3001, Leuven, Belgium
| | - Bart J Ducro
- Animal Breeding and Genomics, Wageningen University & Research, P.O. Box 338, 6700 AH, Wageningen, the Netherlands
| | - Liesbeth François
- Livestock Genetics, Department of Biosystems, KU Leuven, 3001, Leuven, Belgium
| | - Steven Janssens
- Livestock Genetics, Department of Biosystems, KU Leuven, 3001, Leuven, Belgium
| | - Anouk Schurink
- Animal Breeding and Genomics, Wageningen University & Research, P.O. Box 338, 6700 AH, Wageningen, the Netherlands.,Centre for Genetic Resources, the Netherlands (CGN), Wageningen University & Research, P.O. Box 338, 6700 AH, Wageningen, the Netherlands
| | - Åsa Viklund
- Department of Animal Breeding & Genetics, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Susanne Eriksson
- Department of Animal Breeding & Genetics, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Anders Isaksson
- Department of Medical Sciences, Array and Analysis Facility, Uppsala University, Uppsala, Sweden
| | - Hanna Kultima
- Department of Medical Sciences, Array and Analysis Facility, Uppsala University, Uppsala, Sweden
| | - Sofia Mikko
- Department of Animal Breeding & Genetics, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Gabriella Lindgren
- Department of Animal Breeding & Genetics, Swedish University of Agricultural Sciences, Uppsala, Sweden.,Livestock Genetics, Department of Biosystems, KU Leuven, 3001, Leuven, Belgium
| |
Collapse
|
16
|
Raudsepp T, Finno CJ, Bellone RR, Petersen JL. Ten years of the horse reference genome: insights into equine biology, domestication and population dynamics in the post-genome era. Anim Genet 2019; 50:569-597. [PMID: 31568563 PMCID: PMC6825885 DOI: 10.1111/age.12857] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/09/2019] [Indexed: 12/14/2022]
Abstract
The horse reference genome from the Thoroughbred mare Twilight has been available for a decade and, together with advances in genomics technologies, has led to unparalleled developments in equine genomics. At the core of this progress is the continuing improvement of the quality, contiguity and completeness of the reference genome, and its functional annotation. Recent achievements include the release of the next version of the reference genome (EquCab3.0) and generation of a reference sequence for the Y chromosome. Horse satellite‐free centromeres provide unique models for mammalian centromere research. Despite extremely low genetic diversity of the Y chromosome, it has been possible to trace patrilines of breeds and pedigrees and show that Y variation was lost in the past approximately 2300 years owing to selective breeding. The high‐quality reference genome has led to the development of three different SNP arrays and WGSs of almost 2000 modern individual horses. The collection of WGS of hundreds of ancient horses is unique and not available for any other domestic species. These tools and resources have led to global population studies dissecting the natural history of the species and genetic makeup and ancestry of modern breeds. Most importantly, the available tools and resources, together with the discovery of functional elements, are dissecting molecular causes of a growing number of Mendelian and complex traits. The improved understanding of molecular underpinnings of various traits continues to benefit the health and performance of the horse whereas also serving as a model for complex disease across species.
Collapse
Affiliation(s)
- T Raudsepp
- Department of Veterinary Integrative Biosciences, College of Veterinary Medicine and Biomedical Research, Texas A&M University, College Station, TX, 77843, USA
| | - C J Finno
- Department of Population Health and Reproduction, School of Veterinary Medicine, University of California-Davis, Davis, CA, 95616, USA
| | - R R Bellone
- Department of Population Health and Reproduction, School of Veterinary Medicine, University of California-Davis, Davis, CA, 95616, USA.,School of Veterinary Medicine, Veterinary Genetics Laboratory, University of California-Davis, Davis, CA, 95616, USA
| | - J L Petersen
- Department of Animal Science, University of Nebraska, Lincoln, NE, 68583-0908, USA
| |
Collapse
|
17
|
Gabur I, Chawla HS, Snowdon RJ, Parkin IAP. Connecting genome structural variation with complex traits in crop plants. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2019; 132:733-750. [PMID: 30448864 DOI: 10.1007/s00122-018-3233-0] [Citation(s) in RCA: 64] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Accepted: 11/07/2018] [Indexed: 05/05/2023]
Abstract
Structural genome variation is a major determinant of useful trait diversity. We describe how genome analysis methods are enabling discovery of trait-associated structural variants and their potential impact on breeding. As our understanding of complex crop genomes continues to grow, there is growing evidence that structural genome variation plays a major role in determining traits important for breeding and agriculture. Identifying the extent and impact of structural variants in crop genomes is becoming increasingly feasible with ongoing advances in the sophistication of genome sequencing technologies, particularly as it becomes easier to generate accurate long sequence reads on a genome-wide scale. In this article, we discuss the origins of structural genome variation in crops from ancient and recent genome duplication and polyploidization events and review high-throughput methods to assay such variants in crop populations in order to find associations with phenotypic traits. There is increasing evidence from such studies that gene presence-absence and copy number variation resulting from segmental chromosome exchanges may be at the heart of adaptive variation of crops to counter abiotic and biotic stress factors. We present examples from major crops that demonstrate the potential of pangenomic diversity as a key resource for future plant breeding for resilience and sustainability.
Collapse
Affiliation(s)
- Iulian Gabur
- Department of Plant Breeding, Justus Liebig University, Heinrich-Buff-Ring 26-32, 35392, Giessen, Germany
| | - Harmeet Singh Chawla
- Department of Plant Breeding, Justus Liebig University, Heinrich-Buff-Ring 26-32, 35392, Giessen, Germany
| | - Rod J Snowdon
- Department of Plant Breeding, Justus Liebig University, Heinrich-Buff-Ring 26-32, 35392, Giessen, Germany.
| | - Isobel A P Parkin
- Agriculture and Agri-Food Canada, 107 Science Place, Saskatoon, SK, S7N OX2, Canada
| |
Collapse
|
18
|
Schurink A, da Silva VH, Velie BD, Dibbits BW, Crooijmans RPMA, Franҫois L, Janssens S, Stinckens A, Blott S, Buys N, Lindgren G, Ducro BJ. Copy number variations in Friesian horses and genetic risk factors for insect bite hypersensitivity. BMC Genet 2018; 19:49. [PMID: 30060732 PMCID: PMC6065148 DOI: 10.1186/s12863-018-0657-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Accepted: 07/19/2018] [Indexed: 12/04/2022] Open
Abstract
Background Many common and relevant diseases affecting equine welfare have yet to be tested regarding structural variants such as copy number variations (CNVs). CNVs make up a substantial proportion of total genetic variability in populations of many species, resulting in more sequence differences between individuals than SNPs. Associations between CNVs and disease phenotypes have been established in several species, but equine CNV studies have been limited. Aim of this study was to identify CNVs and to perform a genome-wide association (GWA) study in Friesian horses to identify genomic loci associated with insect bite hypersensitivity (IBH), a common seasonal allergic dermatitis observed in many horse breeds worldwide. Results Genotypes were obtained using the Axiom® Equine Genotyping Array containing 670,796 SNPs. After quality control of genotypes, 15,041 CNVs and 5350 CNV regions (CNVRs) were identified in 222 Friesian horses. Coverage of the total genome by CNVRs was 11.2% with 49.2% of CNVRs containing genes. 58.0% of CNVRs were novel (i.e. so far only identified in Friesian horses). A SNP- and CNV-based GWA analysis was performed, where about half of the horses were affected by IBH. The SNP-based analysis showed a highly significant association between the MHC region on ECA20 and IBH in Friesian horses. Associations between the MHC region on ECA20 and IBH were also detected based on the CNV-based analysis. However, CNVs associated with IBH in Friesian horses were not often in close proximity to SNPs identified to be associated with IBH. Conclusions CNVs were identified in a large sample of the Friesian horse population, thereby contributing to our knowledge on CNVs in horses and facilitating our understanding of the equine genome and its phenotypic expression. A clear association was identified between the MHC region on ECA20 and IBH in Friesian horses based on both SNP- and CNV-based GWA studies. These results imply that MHC contributes to IBH sensitivity in Friesian horses. Although subsequent analyses are needed for verification, nucleotide differences, as well as more complex structural variations like CNVs, seem to contribute to IBH sensitivity. IBH should be considered as a common disease with a complex genomic architecture. Electronic supplementary material The online version of this article (10.1186/s12863-018-0657-0) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Anouk Schurink
- Animal Breeding and Genomics, Wageningen University & Research, P.O. Box 338, 6700, AH, Wageningen, the Netherlands.
| | - Vinicius H da Silva
- Animal Breeding and Genomics, Wageningen University & Research, P.O. Box 338, 6700, AH, Wageningen, the Netherlands.,Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, P.O. Box 7023, 75007, Uppsala, Sweden.,Department of Animal Ecology, Netherlands Institute of Ecology, NIOO-KNAW, 6708, PB, Wageningen, the Netherlands
| | - Brandon D Velie
- Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, P.O. Box 7023, 75007, Uppsala, Sweden
| | - Bert W Dibbits
- Animal Breeding and Genomics, Wageningen University & Research, P.O. Box 338, 6700, AH, Wageningen, the Netherlands
| | - Richard P M A Crooijmans
- Animal Breeding and Genomics, Wageningen University & Research, P.O. Box 338, 6700, AH, Wageningen, the Netherlands
| | - Liesbeth Franҫois
- KU Leuven, Department of Biosystems, Livestock Genetics, P.O. Box 2456, 3001, Heverlee, Belgium
| | - Steven Janssens
- KU Leuven, Department of Biosystems, Livestock Genetics, P.O. Box 2456, 3001, Heverlee, Belgium
| | - Anneleen Stinckens
- KU Leuven, Department of Biosystems, Livestock Genetics, P.O. Box 2456, 3001, Heverlee, Belgium
| | - Sarah Blott
- Reproductive Biology, Faculty of Medicine and Health Sciences, The University of Nottingham, Leicestershire, LE12 5RD, UK
| | - Nadine Buys
- KU Leuven, Department of Biosystems, Livestock Genetics, P.O. Box 2456, 3001, Heverlee, Belgium
| | - Gabriella Lindgren
- Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, P.O. Box 7023, 75007, Uppsala, Sweden
| | - Bart J Ducro
- Animal Breeding and Genomics, Wageningen University & Research, P.O. Box 338, 6700, AH, Wageningen, the Netherlands
| |
Collapse
|
19
|
Renaud G, Petersen B, Seguin-Orlando A, Bertelsen MF, Waller A, Newton R, Paillot R, Bryant N, Vaudin M, Librado P, Orlando L. Improved de novo genomic assembly for the domestic donkey. SCIENCE ADVANCES 2018; 4:eaaq0392. [PMID: 29740610 PMCID: PMC5938232 DOI: 10.1126/sciadv.aaq0392] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Accepted: 02/14/2018] [Indexed: 06/01/2023]
Abstract
Donkeys and horses share a common ancestor dating back to about 4 million years ago. Although a high-quality genome assembly at the chromosomal level is available for the horse, current assemblies available for the donkey are limited to moderately sized scaffolds. The absence of a better-quality assembly for the donkey has hampered studies involving the characterization of patterns of genetic variation at the genome-wide scale. These range from the application of genomic tools to selective breeding and conservation to the more fundamental characterization of the genomic loci underlying speciation and domestication. We present a new high-quality donkey genome assembly obtained using the Chicago HiRise assembly technology, providing scaffolds of subchromosomal size. We make use of this new assembly to obtain more accurate measures of heterozygosity for equine species other than the horse, both genome-wide and locally, and to detect runs of homozygosity potentially pertaining to positive selection in domestic donkeys. Finally, this new assembly allowed us to identify fine-scale chromosomal rearrangements between the horse and the donkey that likely played an active role in their divergence and, ultimately, speciation.
Collapse
Affiliation(s)
- Gabriel Renaud
- Centre for GeoGenetics, Natural History Museum of Denmark, Øster Voldgade 5-7, 1350K Copenhagen, Denmark
| | - Bent Petersen
- DTU Bioinformatics, Department of Bio and Health Informatics, Technical University of Denmark, Kongens Lyngby, Denmark
- Centre of Excellence for Omics-Driven Computational Biodiscovery, Faculty of Applied Sciences, Asian Institute of Medicine, Science and Technology, Kedah, Malaysia
| | - Andaine Seguin-Orlando
- Centre for GeoGenetics, Natural History Museum of Denmark, Øster Voldgade 5-7, 1350K Copenhagen, Denmark
- National High-Throughput DNA Sequencing Center, Copenhagen, Denmark
- Laboratoire d’Anthropobiologie Moléculaire et d’Imagerie de Synthése UMR 5288, Université de Toulouse, CNRS, Université Paul Sabatier, 31000 Toulouse, France
| | - Mads Frost Bertelsen
- Center for Zoo and Wild Animal Health, Copenhagen Zoo, 2000 Frederiksberg, Denmark
| | - Andrew Waller
- Animal Health Trust, Lanwades Park, Kentford, Newmarket, Suffolk CB8 7UU, UK
| | - Richard Newton
- Animal Health Trust, Lanwades Park, Kentford, Newmarket, Suffolk CB8 7UU, UK
| | - Romain Paillot
- Animal Health Trust, Lanwades Park, Kentford, Newmarket, Suffolk CB8 7UU, UK
| | - Neil Bryant
- Animal Health Trust, Lanwades Park, Kentford, Newmarket, Suffolk CB8 7UU, UK
| | - Mark Vaudin
- Animal Health Trust, Lanwades Park, Kentford, Newmarket, Suffolk CB8 7UU, UK
| | - Pablo Librado
- Centre for GeoGenetics, Natural History Museum of Denmark, Øster Voldgade 5-7, 1350K Copenhagen, Denmark
- Laboratoire d’Anthropobiologie Moléculaire et d’Imagerie de Synthése UMR 5288, Université de Toulouse, CNRS, Université Paul Sabatier, 31000 Toulouse, France
| | - Ludovic Orlando
- Centre for GeoGenetics, Natural History Museum of Denmark, Øster Voldgade 5-7, 1350K Copenhagen, Denmark
- Laboratoire d’Anthropobiologie Moléculaire et d’Imagerie de Synthése UMR 5288, Université de Toulouse, CNRS, Université Paul Sabatier, 31000 Toulouse, France
| |
Collapse
|
20
|
Pawlina-Tyszko K, Gurgul A, Szmatoła T, Ropka-Molik K, Semik-Gurgul E, Klukowska-Rötzler J, Koch C, Mählmann K, Bugno-Poniewierska M. Genomic landscape of copy number variation and copy neutral loss of heterozygosity events in equine sarcoids reveals increased instability of the sarcoid genome. Biochimie 2017; 140:122-132. [PMID: 28743673 DOI: 10.1016/j.biochi.2017.07.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Accepted: 07/20/2017] [Indexed: 12/20/2022]
Abstract
Although they are the most common neoplasms in equids, sarcoids are not fully characterized at the molecular level. Therefore, the objective of this study was to characterize the landscape of structural rearrangements, such as copy number variation (CNV) and copy neutral loss of heterozygosity (cnLOH), in the genomes of sarcoid tumor cells. This information will not only broaden our understanding of the characteristics of this genome but will also improve the general knowledge of this tumor and the mechanisms involved in its generation. To this end, Equine SNP64K Illumina microarrays were applied along with bioinformatics tools dedicated for signal intensity analysis. The analysis revealed increased instability of the genome of sarcoid cells compared with unaltered skin tissue samples, which was manifested by the prevalence of CNV and cnLOH events. Many of the identified CNVs overlapped with the other research results, but the simultaneously observed variability in the number and sizes of detected aberrations indicated a need for further studies and the development of more reliable bioinformatics algorithms. The functional analysis of genes co-localized with the identified aberrations revealed that these genes are engaged in vital cellular processes. In addition, a number of these genes directly contribute to neoplastic transformation. Furthermore, large numbers of cnLOH events identified in the sarcoids suggested that they may play no less significant roles than CNVs in the carcinogenesis of this tumor. Thus, our results indicate the importance of cnLOH and CNV in equine sarcoid oncogenesis and present a direction of future research.
Collapse
Affiliation(s)
- Klaudia Pawlina-Tyszko
- Laboratory of Genomics, Department of Animal Genomics and Molecular Biology, National Research Institute of Animal Production, Krakowska 1, 32-083, Balice, Poland.
| | - Artur Gurgul
- Laboratory of Genomics, Department of Animal Genomics and Molecular Biology, National Research Institute of Animal Production, Krakowska 1, 32-083, Balice, Poland.
| | - Tomasz Szmatoła
- Laboratory of Genomics, Department of Animal Genomics and Molecular Biology, National Research Institute of Animal Production, Krakowska 1, 32-083, Balice, Poland.
| | - Katarzyna Ropka-Molik
- Laboratory of Genomics, Department of Animal Genomics and Molecular Biology, National Research Institute of Animal Production, Krakowska 1, 32-083, Balice, Poland.
| | - Ewelina Semik-Gurgul
- Laboratory of Genomics, Department of Animal Genomics and Molecular Biology, National Research Institute of Animal Production, Krakowska 1, 32-083, Balice, Poland.
| | - Jolanta Klukowska-Rötzler
- Division of Pedriatric Hematology/Oncology, Department of Clinical Research, University of Bern, Murtenstrasse 35, 3008, Bern, Switzerland; Department of Emergency Medicine, University Hospital Bern, Inselspital, 3010, Bern, Switzerland.
| | - Christoph Koch
- Swiss Institute of Equine Medicine ISME, Faculty of Veterinary Medicine, University of Bern and Agroscope, Länggassstrasse 124c, Postfach 8466, CH-3001, Bern, Switzerland.
| | - Kathrin Mählmann
- Swiss Institute of Equine Medicine ISME, Faculty of Veterinary Medicine, University of Bern and Agroscope, Länggassstrasse 124c, Postfach 8466, CH-3001, Bern, Switzerland; Equine Clinic: Surgery and Radiology, Department of Veterinary Medicine, Free University of Berlin, Oertzenweg 19b, 14163, Berlin, Germany.
| | - Monika Bugno-Poniewierska
- Laboratory of Genomics, Department of Animal Genomics and Molecular Biology, National Research Institute of Animal Production, Krakowska 1, 32-083, Balice, Poland.
| |
Collapse
|
21
|
Shaw JA, Guttery DS, Hills A, Fernandez-Garcia D, Page K, Rosales BM, Goddard KS, Hastings RK, Luo J, Ogle O, Woodley L, Ali S, Stebbing J, Coombes RC. Mutation Analysis of Cell-Free DNA and Single Circulating Tumor Cells in Metastatic Breast Cancer Patients with High Circulating Tumor Cell Counts. Clin Cancer Res 2017; 23:88-96. [PMID: 27334837 PMCID: PMC6241844 DOI: 10.1158/1078-0432.ccr-16-0825] [Citation(s) in RCA: 155] [Impact Index Per Article: 22.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Revised: 05/13/2016] [Accepted: 06/12/2016] [Indexed: 12/21/2022]
Abstract
PURPOSE The purpose of this study was to directly compare mutation profiles in multiple single circulating tumor cells (CTC) and cell-free DNA (cfDNA) isolated from the same blood samples taken from patients with metastatic breast cancer (MBC). We aimed to determine whether cfDNA would reflect the heterogeneity observed in 40 single CTCs. EXPERIMENTAL DESIGN CTCs were enumerated by CELLSEARCH. CTC count was compared with the quantity of matched cfDNA and serum CA15-3 and alkaline phosphatase (ALP) in 112 patients with MBC. In 5 patients with ≥100 CTCs, multiple individual EpCAM-positive CTCs were isolated by DEPArray and compared with matched cfDNA and primary tumor tissue by targeted next-generation sequencing (NGS) of about 2,200 mutations in 50 cancer genes. RESULTS In the whole cohort, total cfDNA levels and cell counts (≥5 CTCs) were both significantly associated with overall survival, unlike CA15-3 and ALP. NGS analysis of 40 individual EpCAM-positive CTCs from 5 patients with MBC revealed mutational heterogeneity in PIK3CA, TP53, ESR1, and KRAS genes between individual CTCs. In all 5 patients, cfDNA profiles provided an accurate reflection of mutations seen in individual CTCs. ESR1 and KRAS gene mutations were absent from primary tumor tissue and therefore likely either reflect a minor subclonal mutation or were acquired with disease progression. CONCLUSIONS Our results demonstrate that cfDNA reflects persisting EpCAM-positive CTCs in patients with high CTC counts and therefore may enable monitoring of the metastatic burden for clinical decision-making. Clin Cancer Res; 23(1); 88-96. ©2016 AACR.
Collapse
Affiliation(s)
- Jacqueline A Shaw
- Department of Cancer Studies, University of Leicester, Robert Kilpatrick Clinical Sciences Building, Leicester Royal Infirmary, Leicester, United Kingdom.
| | - David S Guttery
- Department of Cancer Studies, University of Leicester, Robert Kilpatrick Clinical Sciences Building, Leicester Royal Infirmary, Leicester, United Kingdom
| | - Allison Hills
- Department of Surgery and Cancer, Imperial College London, Hammersmith, United Kingdom
| | - Daniel Fernandez-Garcia
- Department of Cancer Studies, University of Leicester, Robert Kilpatrick Clinical Sciences Building, Leicester Royal Infirmary, Leicester, United Kingdom
| | - Karen Page
- Department of Cancer Studies, University of Leicester, Robert Kilpatrick Clinical Sciences Building, Leicester Royal Infirmary, Leicester, United Kingdom
| | - Brenda M Rosales
- Department of Surgery and Cancer, Imperial College London, Hammersmith, United Kingdom
| | - Kate S Goddard
- Department of Surgery and Cancer, Imperial College London, Hammersmith, United Kingdom
| | - Robert K Hastings
- Cancer Research UK Leicester Centre, University of Leicester, Leicester, London, United Kingdom
| | - Jinli Luo
- Cancer Research UK Leicester Centre, University of Leicester, Leicester, London, United Kingdom
| | - Olivia Ogle
- Department of Surgery and Cancer, Imperial College London, Hammersmith, United Kingdom
| | - Laura Woodley
- Department of Surgery and Cancer, Imperial College London, Hammersmith, United Kingdom
| | - Simak Ali
- Department of Surgery and Cancer, Imperial College London, Hammersmith, United Kingdom
| | - Justin Stebbing
- Department of Surgery and Cancer, Imperial College London, Hammersmith, United Kingdom
| | - R Charles Coombes
- Department of Surgery and Cancer, Imperial College London, Hammersmith, United Kingdom.
| |
Collapse
|
22
|
Kader A, Liu X, Dong K, Song S, Pan J, Yang M, Chen X, He X, Jiang L, Ma Y. Identification of copy number variations in three Chinese horse breeds using 70K single nucleotide polymorphism BeadChip array. Anim Genet 2016; 47:560-9. [PMID: 27440410 DOI: 10.1111/age.12451] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/04/2016] [Indexed: 02/06/2023]
Abstract
Copy number variation (CNV), an essential form of genetic variation, has been increasingly recognized as one promising genetic marker in the analysis of animal genomes. Here, we used the Equine 70K single nucleotide polymorphism genotyping array for the genome-wide detection of CNVs in 96 horses from three diverse Chinese breeds: Debao pony (DB), Mongolian horse (MG) and Yili horse (YL). A total of 287 CNVs were determined and merged into 122 CNV regions (CNVRs) ranging from 199 bp to 2344 kb in size and distributed in a heterogeneous manner on chromosomes. These CNVRs were integrated with seven existing reports to generate a composite genome-wide dataset of 1558 equine CNVRs, revealing 69 (56.6%) novel CNVRs. The majority (69.7%) of the 122 CNVRs overlapped with 438 genes, whereas 30.3% were located in intergenic regions. Most of these genes were associated with common CNVRs, which were shared by divergent horse breeds. As many as 60, 42 and 91 genes overlapping with the breed-specific ss were identified in DB, MG and YL respectively. Among these genes, FGF11, SPEM1, PPARG, CIDEB, HIVEP1 and GALR may have potential relevance to breed-specific traits. These findings provide valuable information for understanding the equine genome and facilitating association studies of economically important traits with equine CNVRs in the future.
Collapse
Affiliation(s)
- Adiljan Kader
- The Key Laboratory for Farm Animal Genetic Resources and Utilization of Ministry of Agriculture of China, Institute of Animal Sciences (IAS), Chinese Academy of Agricultural Sciences (CAAS), No 2 Yuanmingyuan West Rd., Haidian, Beijing, 100193, China.,Xinjiang Academy of Animal Science, Urumqi, Xinjiang, 83000, China
| | - Xuexue Liu
- The Key Laboratory for Farm Animal Genetic Resources and Utilization of Ministry of Agriculture of China, Institute of Animal Sciences (IAS), Chinese Academy of Agricultural Sciences (CAAS), No 2 Yuanmingyuan West Rd., Haidian, Beijing, 100193, China
| | - Kunzhe Dong
- The Key Laboratory for Farm Animal Genetic Resources and Utilization of Ministry of Agriculture of China, Institute of Animal Sciences (IAS), Chinese Academy of Agricultural Sciences (CAAS), No 2 Yuanmingyuan West Rd., Haidian, Beijing, 100193, China.,United States Department of Agriculture, Agricultural Research Service, Avian Disease and Oncology Laboratory, East Lansing, MI, 48823, USA
| | - Shen Song
- The Key Laboratory for Farm Animal Genetic Resources and Utilization of Ministry of Agriculture of China, Institute of Animal Sciences (IAS), Chinese Academy of Agricultural Sciences (CAAS), No 2 Yuanmingyuan West Rd., Haidian, Beijing, 100193, China.,Department of Animal Genetics and Breeding, College of Animal Science and Technology, China Agricultural University, Beijing, 100094, China
| | - Jianfei Pan
- The Key Laboratory for Farm Animal Genetic Resources and Utilization of Ministry of Agriculture of China, Institute of Animal Sciences (IAS), Chinese Academy of Agricultural Sciences (CAAS), No 2 Yuanmingyuan West Rd., Haidian, Beijing, 100193, China
| | - Min Yang
- The Key Laboratory for Farm Animal Genetic Resources and Utilization of Ministry of Agriculture of China, Institute of Animal Sciences (IAS), Chinese Academy of Agricultural Sciences (CAAS), No 2 Yuanmingyuan West Rd., Haidian, Beijing, 100193, China
| | - Xiaofei Chen
- The Key Laboratory for Farm Animal Genetic Resources and Utilization of Ministry of Agriculture of China, Institute of Animal Sciences (IAS), Chinese Academy of Agricultural Sciences (CAAS), No 2 Yuanmingyuan West Rd., Haidian, Beijing, 100193, China
| | - Xiaohong He
- The Key Laboratory for Farm Animal Genetic Resources and Utilization of Ministry of Agriculture of China, Institute of Animal Sciences (IAS), Chinese Academy of Agricultural Sciences (CAAS), No 2 Yuanmingyuan West Rd., Haidian, Beijing, 100193, China
| | - Lin Jiang
- The Key Laboratory for Farm Animal Genetic Resources and Utilization of Ministry of Agriculture of China, Institute of Animal Sciences (IAS), Chinese Academy of Agricultural Sciences (CAAS), No 2 Yuanmingyuan West Rd., Haidian, Beijing, 100193, China.
| | - Yuehui Ma
- The Key Laboratory for Farm Animal Genetic Resources and Utilization of Ministry of Agriculture of China, Institute of Animal Sciences (IAS), Chinese Academy of Agricultural Sciences (CAAS), No 2 Yuanmingyuan West Rd., Haidian, Beijing, 100193, China.
| |
Collapse
|
23
|
Ghosh S, Das PJ, McQueen CM, Gerber V, Swiderski CE, Lavoie JP, Chowdhary BP, Raudsepp T. Analysis of genomic copy number variation in equine recurrent airway obstruction (heaves). Anim Genet 2016; 47:334-44. [PMID: 26932307 DOI: 10.1111/age.12426] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/10/2016] [Indexed: 12/18/2022]
Abstract
We explored the involvement of genomic copy number variants (CNVs) in susceptibility to recurrent airway obstruction (RAO), or heaves-an asthmalike inflammatory disease in horses. Analysis of 16 RAO-susceptible (cases) and six RAO-resistant (control) horses on a custom-made whole-genome 400K equine tiling array identified 245 CNV regions (CNVRs), 197 previously known and 48 new, distributed on all horse autosomes and the X chromosome. Among the new CNVRs, 30 were exclusively found in RAO cases and were further analyzed by quantitative PCR, including additional cases and controls. Suggestive association (P = 0.03; corrected P = 0.06) was found between RAO and a loss on chromosome 5 involving NME7, a gene necessary for ciliary functions in lungs and involved in primary ciliary dyskinesia in humans. The CNVR could be a potential marker for RAO susceptibility but needs further study in additional RAO cohorts. Other CNVRs were not associated with RAO, although several involved genes of interest, such as SPI2/SERPINA1 from the serpin gene family, which are associated with chronic obstructive pulmonary disease and asthma in humans. The SPI2/SERPINA1 CNVR showed striking variation among horses, but it was not significantly different between RAO cases and controls. The findings provide baseline information on the relationship between CNVs and RAO susceptibility. Discovery of new CNVs and the use of a larger population of RAO-affected and control horses are needed to shed more light on their significance in modulating this complex and heterogeneous disease.
Collapse
Affiliation(s)
- S Ghosh
- Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, TX, 77843, USA
| | - P J Das
- Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, TX, 77843, USA.,National Research Centre on Yak (ICAR), Dirang, Arunachal Pradesh, 790101, India
| | - C M McQueen
- Department of Large Animal Clinical Sciences, Texas A&M University, College Station, TX, 77843, USA
| | - V Gerber
- Department of Veterinary Medicine, University of Bern, Bern, Switzerland
| | - C E Swiderski
- Department of Clinical Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi State, MS, USA
| | - J-P Lavoie
- Department of Clinical Sciences, University of Montreal, Montreal, QC, J2S 7C6, Canada
| | - B P Chowdhary
- Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, TX, 77843, USA.,New Research Complex, Qatar University, Doha, 2713, Qatar
| | - T Raudsepp
- Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, TX, 77843, USA
| |
Collapse
|
24
|
Thudi M, Khan AW, Kumar V, Gaur PM, Katta K, Garg V, Roorkiwal M, Samineni S, Varshney RK. Whole genome re-sequencing reveals genome-wide variations among parental lines of 16 mapping populations in chickpea (Cicer arietinum L.). BMC PLANT BIOLOGY 2016; 16 Suppl 1:10. [PMID: 26822060 PMCID: PMC4895712 DOI: 10.1186/s12870-015-0690-3] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
BACKGROUND Chickpea (Cicer arietinum L.) is the second most important grain legume cultivated by resource poor farmers in South Asia and Sub-Saharan Africa. In order to harness the untapped genetic potential available for chickpea improvement, we re-sequenced 35 chickpea genotypes representing parental lines of 16 mapping populations segregating for abiotic (drought, heat, salinity), biotic stresses (Fusarium wilt, Ascochyta blight, Botrytis grey mould, Helicoverpa armigera) and nutritionally important (protein content) traits using whole genome re-sequencing approach. RESULTS A total of 192.19 Gb data, generated on 35 genotypes of chickpea, comprising 973.13 million reads, with an average sequencing depth of ~10 X for each line. On an average 92.18 % reads from each genotype were aligned to the chickpea reference genome with 82.17 % coverage. A total of 2,058,566 unique single nucleotide polymorphisms (SNPs) and 292,588 Indels were detected while comparing with the reference chickpea genome. Highest number of SNPs were identified on the Ca4 pseudomolecule. In addition, copy number variations (CNVs) such as gene deletions and duplications were identified across the chickpea parental genotypes, which were minimum in PI 489777 (1 gene deletion) and maximum in JG 74 (1,497). A total of 164,856 line specific variations (144,888 SNPs and 19,968 Indels) with the highest percentage were identified in coding regions in ICC 1496 (21 %) followed by ICCV 97105 (12 %). Of 539 miscellaneous variations, 339, 138 and 62 were inter-chromosomal variations (CTX), intra-chromosomal variations (ITX) and inversions (INV) respectively. CONCLUSION Genome-wide SNPs, Indels, CNVs, PAVs, and miscellaneous variations identified in different mapping populations are a valuable resource in genetic research and helpful in locating genes/genomic segments responsible for economically important traits. Further, the genome-wide variations identified in the present study can be used for developing high density SNP arrays for genetics and breeding applications.
Collapse
Affiliation(s)
- Mahendar Thudi
- International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Hyderabad, India.
| | - Aamir W Khan
- International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Hyderabad, India
| | - Vinay Kumar
- International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Hyderabad, India
| | - Pooran M Gaur
- International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Hyderabad, India
| | - Krishnamohan Katta
- International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Hyderabad, India
| | - Vanika Garg
- International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Hyderabad, India
| | - Manish Roorkiwal
- International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Hyderabad, India
| | - Srinivasan Samineni
- International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Hyderabad, India
| | - Rajeev K Varshney
- International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Hyderabad, India.
- The University of Western Australia (UWA), Crawley, Western Australia, Australia.
| |
Collapse
|
25
|
McQueen CM, Dindot SV, Foster MJ, Cohen ND. Genetic Susceptibility to Rhodococcus equi. J Vet Intern Med 2015; 29:1648-59. [PMID: 26340305 PMCID: PMC4895676 DOI: 10.1111/jvim.13616] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2015] [Revised: 06/29/2015] [Accepted: 08/10/2015] [Indexed: 02/02/2023] Open
Abstract
Rhodococcus equi pneumonia is a major cause of morbidity and mortality in neonatal foals. Much effort has been made to identify preventative measures and new treatments for R. equi with limited success. With a growing focus in the medical community on understanding the genetic basis of disease susceptibility, investigators have begun to evaluate the interaction of the genetics of the foal with R. equi. This review describes past efforts to understand the genetic basis underlying R. equi susceptibility and tolerance. It also highlights the genetic technology available to study horses and describes the use of this technology in investigating R. equi. This review provides readers with a foundational understanding of candidate gene approaches, single nucleotide polymorphism‐based, and copy number variant‐based genome‐wide association studies, and next generation sequencing (both DNA and RNA).
Collapse
Affiliation(s)
- C M McQueen
- Department of Large Animal Clinical Sciences, Texas A&M University, College Station, TX
| | - S V Dindot
- Department of Veterinary Pathobiology, Texas A&M University, College Station, TX
| | - M J Foster
- Medical Sciences Library, Texas A&M University, College Station, TX
| | - N D Cohen
- Department of Large Animal Clinical Sciences, Texas A&M University, College Station, TX
| |
Collapse
|
26
|
Bertolini F, Scimone C, Geraci C, Schiavo G, Utzeri VJ, Chiofalo V, Fontanesi L. Next Generation Semiconductor Based Sequencing of the Donkey (Equus asinus) Genome Provided Comparative Sequence Data against the Horse Genome and a Few Millions of Single Nucleotide Polymorphisms. PLoS One 2015; 10:e0131925. [PMID: 26151450 PMCID: PMC4495037 DOI: 10.1371/journal.pone.0131925] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2015] [Accepted: 06/08/2015] [Indexed: 12/13/2022] Open
Abstract
Few studies investigated the donkey (Equus asinus) at the whole genome level so far. Here, we sequenced the genome of two male donkeys using a next generation semiconductor based sequencing platform (the Ion Proton sequencer) and compared obtained sequence information with the available donkey draft genome (and its Illumina reads from which it was originated) and with the EquCab2.0 assembly of the horse genome. Moreover, the Ion Torrent Personal Genome Analyzer was used to sequence reduced representation libraries (RRL) obtained from a DNA pool including donkeys of different breeds (Grigio Siciliano, Ragusano and Martina Franca). The number of next generation sequencing reads aligned with the EquCab2.0 horse genome was larger than those aligned with the draft donkey genome. This was due to the larger N50 for contigs and scaffolds of the horse genome. Nucleotide divergence between E. caballus and E. asinus was estimated to be ~ 0.52-0.57%. Regions with low nucleotide divergence were identified in several autosomal chromosomes and in the whole chromosome X. These regions might be evolutionally important in equids. Comparing Y-chromosome regions we identified variants that could be useful to track donkey paternal lineages. Moreover, about 4.8 million of single nucleotide polymorphisms (SNPs) in the donkey genome were identified and annotated combining sequencing data from Ion Proton (whole genome sequencing) and Ion Torrent (RRL) runs with Illumina reads. A higher density of SNPs was present in regions homologous to horse chromosome 12, in which several studies reported a high frequency of copy number variants. The SNPs we identified constitute a first resource useful to describe variability at the population genomic level in E. asinus and to establish monitoring systems for the conservation of donkey genetic resources.
Collapse
Affiliation(s)
- Francesca Bertolini
- Department of Agricultural and Food Sciences, Division of Animal Sciences, University of Bologna, Viale Fanin 46, Bologna, Italy
- Department of Veterinary Sciences, Animal Production Unit, University of Messina, Polo Universitario dell'Annunziata, Messina, Italy
| | - Concetta Scimone
- Department of Veterinary Sciences, Animal Production Unit, University of Messina, Polo Universitario dell'Annunziata, Messina, Italy
| | - Claudia Geraci
- Department of Agricultural and Food Sciences, Division of Animal Sciences, University of Bologna, Viale Fanin 46, Bologna, Italy
| | - Giuseppina Schiavo
- Department of Agricultural and Food Sciences, Division of Animal Sciences, University of Bologna, Viale Fanin 46, Bologna, Italy
| | - Valerio Joe Utzeri
- Department of Agricultural and Food Sciences, Division of Animal Sciences, University of Bologna, Viale Fanin 46, Bologna, Italy
| | - Vincenzo Chiofalo
- Department of Veterinary Sciences, Animal Production Unit, University of Messina, Polo Universitario dell'Annunziata, Messina, Italy
- Meat Research Consortium, Polo Universitario dell’Annunziata, Messina, Italy
| | - Luca Fontanesi
- Department of Agricultural and Food Sciences, Division of Animal Sciences, University of Bologna, Viale Fanin 46, Bologna, Italy
- * E-mail:
| |
Collapse
|
27
|
Escaramís G, Docampo E, Rabionet R. A decade of structural variants: description, history and methods to detect structural variation. Brief Funct Genomics 2015; 14:305-14. [PMID: 25877305 DOI: 10.1093/bfgp/elv014] [Citation(s) in RCA: 78] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
In the past decade, the view on genomic structural variation (SV) has been changed completely. SVs, previously considered rare events, are now recognized as the largest source of interindividual genetic variation affecting more bases than single nucleotide polymorphisms, variable number of tandem repeats and other small genetic variants. They have also been shown to play a role in phenotypic variation and in disease. In this review, the authors will provide an introduction to SV; a short historical perspective on the research of this source of genomic variation; a description of the types of structural variants, and on how they may have arisen; and an overview on methods of detecting structural variants, focusing on the analysis of high-throughput sequencing data.
Collapse
|
28
|
Dong K, Pu Y, Yao N, Shu G, Liu X, He X, Zhao Q, Guan W, Ma Y. Copy number variation detection using SNP genotyping arrays in three Chinese pig breeds. Anim Genet 2015; 46:101-9. [PMID: 25590996 DOI: 10.1111/age.12247] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/03/2014] [Indexed: 01/19/2023]
Abstract
We performed genome-wide CNV detection based on SNP genotyping data of 96 Chinese-native Tibetan, Dahe and Wuzhishan pigs. These pigs are particularly interesting because of their excellent adaptation to hypoxia or small body size, which facilitates the use of them as models of different human diseases in addition to valuable agricultural animals. A total of 105 CNV regions (CNVRs) were identified, encompassing 16.71 Mb of the pig genome. Seven of 10 (70%) CNVRs selected randomly were validated by quantitative real-time PCR. Comparison with previous studies revealed 25 (23.81%) novel CNVRs, indicating that CNV coverage of the pig genome is still incomplete and there exists large diversity between pig breeds. Functional analysis of genes located in these CNVRs confirmed the high representation of genes involved in sensory perception, neurological system processes and other basic metabolic processes. In addition, the majority of these CNVRs were detected to span reported pig QTL that affect various traits, which highlighted three biologically interesting genes with copy number changes (i.e., ANKRD34B, FAM110B and ABCG1). These genes may have economic importance in pig breeding and are worth being further investigated. We also obtained some CNVRs harboring genes that had human orthologs involved in human diseases such as cardiovascular disease and Alzheimer's disease. The findings of this study are a significant extension of the coverage of CNVRs in the pig genome and provide valuable resources for follow-up-associated studies of CNVs in pig complex traits as well as important implications of human diseases.
Collapse
Affiliation(s)
- K Dong
- Institute of Animal Science (IAS), Chinese Academy of Agricultural Science (CAAS), Beijing, 100193, China
| | | | | | | | | | | | | | | | | |
Collapse
|
29
|
Abstract
We constructed a 400K WG tiling oligoarray for the horse and applied it for the discovery of copy number variations (CNVs) in 38 normal horses of 16 diverse breeds, and the Przewalski horse. Probes on the array represented 18,763 autosomal and X-linked genes, and intergenic, sub-telomeric and chrY sequences. We identified 258 CNV regions (CNVRs) across all autosomes, chrX and chrUn, but not in chrY. CNVs comprised 1.3% of the horse genome with chr12 being most enriched. American Miniature horses had the highest and American Quarter Horses the lowest number of CNVs in relation to Thoroughbred reference. The Przewalski horse was similar to native ponies and draft breeds. The majority of CNVRs involved genes, while 20% were located in intergenic regions. Similar to previous studies in horses and other mammals, molecular functions of CNV-associated genes were predominantly in sensory perception, immunity and reproduction. The findings were integrated with previous studies to generate a composite genome-wide dataset of 1476 CNVRs. Of these, 301 CNVRs were shared between studies, while 1174 were novel and require further validation. Integrated data revealed that to date, 41 out of over 400 breeds of the domestic horse have been analyzed for CNVs, of which 11 new breeds were added in this study. Finally, the composite CNV dataset was applied in a pilot study for the discovery of CNVs in 6 horses with XY disorders of sexual development. A homozygous deletion involving AKR1C gene cluster in chr29 in two affected horses was considered possibly causative because of the known role of AKR1C genes in testicular androgen synthesis and sexual development. While the findings improve and integrate the knowledge of CNVs in horses, they also show that for effective discovery of variants of biomedical importance, more breeds and individuals need to be analyzed using comparable methodological approaches. Genomes of individuals in a species vary in many ways, one of which is DNA copy number variation (CNV). This includes deletions, duplications, and complex rearrangements typically larger than 50 base-pairs. CNVs are part of normal genetic variation contributing to phenotypic diversity but can also be pathogenic and associated with diseases and disorders. In order to distinguish between the two, detailed knowledge about CNVs in the species of interest is needed. Here we studied the genomes of 38 normal horses of 16 diverse breeds, and identified 258 CNV regions. We integrated our findings with previously published horse CNVs and generated a composite dataset of ∼1400 CNVRs. Despite this large number, our analysis shows that CNV research in horses needs further improvement because the current data are based on 10% of horse breeds and that most CNVRs are study-specific and require validation. Finally, we analyzed CNVs in horses with disorders of sexual development and found in two male pseudo-hermaphrodites a large deletion disrupting a group of genes involved in sex hormone metabolism and sexual differentiation. The findings underline the possible role of CNVs in complex disorders such as development and reproduction.
Collapse
|