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Fabbri MC, Lozada-Soto E, Tiezzi F, Čandek-Potokar M, Bovo S, Schiavo G, Fontanesi L, Muñoz M, Ovilo C, Bozzi R. Persistence of autozygosity in crossbreds between autochthonous and cosmopolitan breeds of swine: a simulation study. Animal 2024; 18:101070. [PMID: 38401921 DOI: 10.1016/j.animal.2023.101070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Revised: 12/18/2023] [Accepted: 12/21/2023] [Indexed: 02/26/2024] Open
Abstract
Crossbreeding might be a valid strategy to valorize local pig breeds. Crossbreeding should reduce homozygosity and, as a consequence, yield hybrid vigor for fitness and production traits. This study aimed to quantify the persistence of autozygosity in terminal crossbred pigs compared with purebreds and, in turn, identify genomic regions where autozygosity's persistence would not be found. The study was based on genotyping data from 20 European local pig breeds and three cosmopolitan pig breeds used to simulate crossbred offspring. This study consisted of two steps. First, one hundred matings were simulated for each pairwise combination of the 23 considered breeds (for a total of 276 combinations), ignoring the sex of the parent individuals in order to generate purebred and crossbred matings leveraging all the germplasm available. Second, a few preselected terminal-maternal breed pairs were used to mimic a realistic terminal crossbreeding system: (i) Mora Romagnola (boars) or Cinta Senese (boars) crossed with Large White (sows) or Landrace (sows); (ii) Duroc (boars) crossed with Mora Romagnola (sows) or Cinta Senese (sows). Runs of homozygosity was used to estimate genome-wide autozygosity (FROH). Observed FROH was higher in purebreds than in crossbreds, although some crossbred combinations showed higher FROH than other purebred combinations. Among the purebreds, the highest FROH values were observed in Mora Romagnola and Turopolje (0.50 and 0.46, respectively). FROH ranged from 0.04 to 0.16 in the crossbreds Alentejana × Large White and Alentejana × Iberian, respectively. Persistence of autozygosity was found in several genomic segments harboring regions where quantitative trait loci (QTLs) were found in the literature. The regions were enriched in QTLs involved in fatty acid metabolism and associated with performance traits. This simulation shows that autozygosity persists in most breed combinations of terminal crosses. Results suggest that a strategy for crossbreeding is implemented when leveraging autochthonous and cosmopolitan breeds to obtain most of the hybrid vigor.
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Affiliation(s)
- Maria Chiara Fabbri
- Dipartimento di Scienze e Tecnologie Agrarie, Alimentari, Ambientali e Forestali, Università di Firenze, Firenze, Italy.
| | - Emmanuel Lozada-Soto
- Department of Animal Science, North Carolina State University, Raleigh, NC 27695, United States
| | - Francesco Tiezzi
- Dipartimento di Scienze e Tecnologie Agrarie, Alimentari, Ambientali e Forestali, Università di Firenze, Firenze, Italy
| | | | - Samuele Bovo
- Department of Agricultural and Food Sciences, Division of Animal Sciences, University of Bologna, Viale G. Fanin 46, 40127 Bologna, Italy
| | - Giuseppina Schiavo
- Department of Agricultural and Food Sciences, Division of Animal Sciences, University of Bologna, Viale G. Fanin 46, 40127 Bologna, Italy
| | - Luca Fontanesi
- Department of Agricultural and Food Sciences, Division of Animal Sciences, University of Bologna, Viale G. Fanin 46, 40127 Bologna, Italy
| | - Maria Muñoz
- Departamento Mejora Genética Animal, INIA-CSIC, Crta. de la Coruña, km. 7,5, 28040 Madrid, Spain
| | - Cristina Ovilo
- Departamento Mejora Genética Animal, INIA-CSIC, Crta. de la Coruña, km. 7,5, 28040 Madrid, Spain
| | - Riccardo Bozzi
- Dipartimento di Scienze e Tecnologie Agrarie, Alimentari, Ambientali e Forestali, Università di Firenze, Firenze, Italy
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Wang Z, Zhong Z, Xie X, Wang F, Pan D, Wang Q, Pan Y, Xiao Q, Tan Z. Detection of Runs of Homozygosity and Identification of Candidate Genes in the Whole Genome of Tunchang Pigs. Animals (Basel) 2024; 14:201. [PMID: 38254370 PMCID: PMC10812771 DOI: 10.3390/ani14020201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2023] [Revised: 12/23/2023] [Accepted: 01/03/2024] [Indexed: 01/24/2024] Open
Abstract
Tunchang pigs are an indigenous pig population in China known for their high tolerance to roughage, delicious meat, and fecundity. However, the number of Tunchang pigs has been declining due to the influence of commercial breeds and African swine fever, which could potentially lead to inbreeding. To assess the inbreeding level and the genetic basis of important traits in Tunchang pigs, our research investigated the patterns in "runs of homozygosity" (ROHs) using whole genome resequencing data from 32 Tunchang pigs. The study aimed to determine the length, number, coverage, and distribution model of ROHs in Tunchang pigs, as well as genomic regions with high ROH frequencies. The results of the study revealed that a total of 20,499,374 single-nucleotide polymorphisms (SNPs) and 1953 ROH fragments were recognized in 32 individuals. The ROH fragments in Tunchang pigs were predominantly short, ranging from 0.5 to 1 megabases (Mb) in length. Furthermore, the coverage of ROHs varied across chromosomes, with chromosome 3 having the highest coverage and chromosome 11 having the lowest coverage. The genetic diversity of Tunchang pigs was found to be relatively high based on the values of HE (expected heterozygosity), HO (observed heterozygosity), pi (nucleotide diversity), Ne (effective population size), and MAF (minor allele frequency). The average inbreeding coefficients of Tunchang pigs, as determined by three different methods (FHOM, FGRM, and FROH), were 0.019, 0.0138, and 0.0304, respectively. These values indicate that the level of inbreeding in Tunchang pigs is currently low. Additionally, the study identified a total of 13 ROH islands on all chromosomes, which in total contained 38,913 SNPs and 120 genes. These ROH islands included genes associated with economically important traits, including meat quality (GYS1, PHLPP1, SLC27A5, and CRTC1), growth and development (ANKS1A, TAF11, SPDEF, LHB, and PACSIN1), and environmental adaptation (SLC26A7). The findings of this research offer valuable perspectives on the present status of Tunchang pig resources and offer a reference for breeding conservation plans and the efficient utilization of Tunchang pigs in the future. By understanding the inbreeding level and genetic basis of important traits in Tunchang pigs, conservation efforts can be targeted towards maintaining genetic diversity and promoting the sustainable development of this indigenous pig population.
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Affiliation(s)
- Ziyi Wang
- Hainan Key Laboratory of Tropical Animal Reproduction & Breeding and Epidemic Disease Research, School of Tropical Agriculture and Forestry, Hainan University, Haikou 570228, China; (Z.W.)
| | - Ziqi Zhong
- Hainan Key Laboratory of Tropical Animal Reproduction & Breeding and Epidemic Disease Research, School of Tropical Agriculture and Forestry, Hainan University, Haikou 570228, China; (Z.W.)
| | - Xinfeng Xie
- Hainan Key Laboratory of Tropical Animal Reproduction & Breeding and Epidemic Disease Research, School of Tropical Agriculture and Forestry, Hainan University, Haikou 570228, China; (Z.W.)
| | - Feifan Wang
- Hainan Key Laboratory of Tropical Animal Reproduction & Breeding and Epidemic Disease Research, School of Tropical Agriculture and Forestry, Hainan University, Haikou 570228, China; (Z.W.)
| | - Deyou Pan
- Hainan Key Laboratory of Tropical Animal Reproduction & Breeding and Epidemic Disease Research, School of Tropical Agriculture and Forestry, Hainan University, Haikou 570228, China; (Z.W.)
| | - Qishan Wang
- Hainan Yazhou Bay Seed Laboratory, Yongyou Industrial Park, Yazhou Bay Sci-Tech City, Sanya 572025, China
- Department of Animal Science, College of Animal Science, Zhejiang University, Hangzhou 310058, China
| | - Yuchun Pan
- Hainan Yazhou Bay Seed Laboratory, Yongyou Industrial Park, Yazhou Bay Sci-Tech City, Sanya 572025, China
- Department of Animal Science, College of Animal Science, Zhejiang University, Hangzhou 310058, China
| | - Qian Xiao
- Hainan Key Laboratory of Tropical Animal Reproduction & Breeding and Epidemic Disease Research, School of Tropical Agriculture and Forestry, Hainan University, Haikou 570228, China; (Z.W.)
| | - Zhen Tan
- Hainan Key Laboratory of Tropical Animal Reproduction & Breeding and Epidemic Disease Research, School of Tropical Agriculture and Forestry, Hainan University, Haikou 570228, China; (Z.W.)
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Wu X, Zhou R, Wang Y, Zhang W, Zheng X, Zhao G, Zhang X, Yin Z, Ding Y. Genome‐wide scan for runs of homozygosity in Asian wild boars and Anqing six‐end‐white pigs. Anim Genet 2022; 53:867-871. [DOI: 10.1111/age.13250] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Revised: 04/26/2022] [Accepted: 08/02/2022] [Indexed: 01/28/2023]
Affiliation(s)
- Xudong Wu
- Anhui Provincial Laboratory of Local Animal Genetic Resource Conservation and Bio‐Breeding, College of Animal Science and Technology Anhui Agricultural University Hefei Anhui China
- Anhui Provincial Key Laboratory of Livestock and Poultry Product Safety Engineering, Institute of Animal Husbandry and Veterinary Medicine Institute of Animal Husbandry and Veterinary Medicine, Anhui Academy of Agricultural Sciences Hefei China
| | - Ren Zhou
- Anhui Provincial Laboratory of Local Animal Genetic Resource Conservation and Bio‐Breeding, College of Animal Science and Technology Anhui Agricultural University Hefei Anhui China
| | - Yuanlang Wang
- Anhui Provincial Key Laboratory of Livestock and Poultry Product Safety Engineering, Institute of Animal Husbandry and Veterinary Medicine Institute of Animal Husbandry and Veterinary Medicine, Anhui Academy of Agricultural Sciences Hefei China
| | - Wei Zhang
- Anhui Provincial Key Laboratory of Livestock and Poultry Product Safety Engineering, Institute of Animal Husbandry and Veterinary Medicine Institute of Animal Husbandry and Veterinary Medicine, Anhui Academy of Agricultural Sciences Hefei China
| | - Xianrui Zheng
- Anhui Provincial Laboratory of Local Animal Genetic Resource Conservation and Bio‐Breeding, College of Animal Science and Technology Anhui Agricultural University Hefei Anhui China
| | - Guiying Zhao
- College of Animal Science and Technology Yunnan Agricultural University Kunming China
| | - Xiaodong Zhang
- Anhui Provincial Laboratory of Local Animal Genetic Resource Conservation and Bio‐Breeding, College of Animal Science and Technology Anhui Agricultural University Hefei Anhui China
| | - Zongjun Yin
- Anhui Provincial Laboratory of Local Animal Genetic Resource Conservation and Bio‐Breeding, College of Animal Science and Technology Anhui Agricultural University Hefei Anhui China
| | - Yueyun Ding
- Anhui Provincial Laboratory of Local Animal Genetic Resource Conservation and Bio‐Breeding, College of Animal Science and Technology Anhui Agricultural University Hefei Anhui China
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Kim YM, Seong HS, Kim YS, Hong JK, Sa SJ, Lee J, Lee JH, Cho KH, Chung WH, Choi JW, Cho ES. Genome-Wide Assessment of a Korean Composite Pig Breed, Woori-Heukdon. Front Genet 2022; 13:779152. [PMID: 35186025 PMCID: PMC8847790 DOI: 10.3389/fgene.2022.779152] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2021] [Accepted: 01/07/2022] [Indexed: 02/03/2023] Open
Abstract
A Korean synthetic pig breed, Woori-Heukdon (WRH; F3), was developed by crossing parental breeds (Korean native pig [KNP] and Korean Duroc [DUC]) with their crossbred populations (F1 and F2). This study in genome-wide assessed a total of 2,074 pigs which include the crossbred and the parental populations using the Illumina PorcineSNP60 BeadChip. After quality control of the initial datasets, we performed population structure, genetic diversity, and runs of homozygosity (ROH) analyses. Population structure analyses showed that crossbred populations were genetically influenced by the parental breeds according to their generation stage in the crossbreeding scheme. Moreover, principal component analysis showed the dispersed cluster of WRH, which might reflect introducing a new breeding group into the previous one. Expected heterozygosity values, which were used to assess genetic diversity, were .365, .349, .336, .330, and .211 for WRH, F2, F1, DUC, and KNP, respectively. The inbreeding coefficient based on ROH was the highest in KNP (.409), followed by WRH (.186), DUC (.178), F2 (.107), and F1 (.035). Moreover, the frequency of short ROH decreased according to the crossing stage (from F1 to WRH). Alternatively, the frequency of medium and long ROH increased, which indicated recent inbreeding in F2 and WRH. Furthermore, gene annotation of the ROH islands in WRH that might be inherited from their parental breeds revealed several interesting candidate genes that may be associated with adaptation, meat quality, production, and reproduction traits in pigs.
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Affiliation(s)
- Yong-Min Kim
- Swine Science Division, National Institute of Animal Science, Rural Development Administration, Cheonan, South Korea.,Department of Animal Science, College of Animal Life Sciences, Kangwon National University, Chuncheon, South Korea
| | - Ha-Seung Seong
- Swine Science Division, National Institute of Animal Science, Rural Development Administration, Cheonan, South Korea.,Department of Animal Science, College of Animal Life Sciences, Kangwon National University, Chuncheon, South Korea
| | - Young-Sin Kim
- Swine Science Division, National Institute of Animal Science, Rural Development Administration, Cheonan, South Korea
| | - Joon-Ki Hong
- Swine Science Division, National Institute of Animal Science, Rural Development Administration, Cheonan, South Korea
| | - Soo-Jin Sa
- Swine Science Division, National Institute of Animal Science, Rural Development Administration, Cheonan, South Korea
| | - Jungjae Lee
- Department of Animal Science and Technology, College of Biotechnology and Natural Resources, Chung-Ang University, Anseong, South Korea
| | - Jun-Hee Lee
- Institute of Agriculture and Life Science, College of Agriculture and Life Sciences, Gyeongsang National University, Jinju, South Korea
| | - Kyu-Ho Cho
- Swine Science Division, National Institute of Animal Science, Rural Development Administration, Cheonan, South Korea
| | - Won-Hyong Chung
- Research Group of Healthcare, Korea Food Research Institute, Wanju, South Korea
| | - Jung-Woo Choi
- Department of Animal Science, College of Animal Life Sciences, Kangwon National University, Chuncheon, South Korea
| | - Eun-Seok Cho
- Swine Science Division, National Institute of Animal Science, Rural Development Administration, Cheonan, South Korea
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Wu X, Zhou R, Zhang W, Cao B, Xia J, Caiyun W, Zhang X, Chu M, Yin Z, Ding Y. Genome-wide scan for runs of homozygosity identifies candidate genes in Wannan Black pigs. Anim Biosci 2021; 34:1895-1902. [PMID: 33705632 PMCID: PMC8563231 DOI: 10.5713/ab.20.0679] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Accepted: 02/07/2021] [Indexed: 11/27/2022] Open
Abstract
Objective Runs of homozygosity (ROH) are contiguous lengths of homozygous genotypes that can reveal inbreeding levels, selection pressure, and mating schemes. In this study, ROHs were evaluated in Wannan Black pigs to assess the inbreeding levels and the genome regions with high ROH frequency. Methods In a previous study, we obtained 501.52 GB of raw data from resequencing (10×) of the genome and identified 21,316,754 single-nucleotide variants in 20 Wannan Black pig samples. We investigated the number, length, and frequency of ROH using resequencing data to characterize the homozygosity in Wannan Black pigs and identified genomic regions with high ROH frequencies. Results In this work, 1,813 ROHs (837 ROHs in 100 to 500 kb, 449 ROHs in 500 to 1,000 kb, 527 ROHs in >1,000 kb) were identified in all samples, and the average genomic inbreeding coefficient (FROH) in Wannan Black pigs was 0.5234. Sixty-one regions on chromosomes 2, 3, 7, 8, 13, 15, and 16 harbored ROH islands. In total, 105 genes were identified in 42 ROH islands, among which some genes were related to production traits. Conclusion This is the first study to identify ROH across the genome of Wannan Black pigs, the Chinese native breed of the Anhui province. Overall, Wannan Black pigs have high levels of inbreeding due to the influence of ancient and recent inbreeding due to the genome. These findings are a reliable resource for future studies and contribute to save and use the germplasm resources of Wannan Black pigs.
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Affiliation(s)
- Xudong Wu
- College of Animal Science and Technology, Anhui Agricultural University, Hefei, Anhui 230036, P. R. China.,Anhui province key laboratory of local livestock and poultry genetic resource conservation and bio-breeding, Anhui Agricultural University, Hefei, 230036, P.R. China
| | - Ren Zhou
- College of Animal Science and Technology, Anhui Agricultural University, Hefei, Anhui 230036, P. R. China.,Anhui province key laboratory of local livestock and poultry genetic resource conservation and bio-breeding, Anhui Agricultural University, Hefei, 230036, P.R. China
| | - Wei Zhang
- College of Animal Science and Technology, Anhui Agricultural University, Hefei, Anhui 230036, P. R. China.,Key Laboratory of Pig Molecular Quantitative Genetics of Anhui Academy of Agricultural Sciences, Anhui Provincial Key Laboratory of Livestock and Poultry Product Safety Engineering, Institute of Animal Husbandry and Veterinary Medicine, Anhui Academy of Agricultural Sciences, Hefei, Anhui 230031, P.R. China
| | - Bangji Cao
- College of Animal Science and Technology, Anhui Agricultural University, Hefei, Anhui 230036, P. R. China.,Anhui province key laboratory of local livestock and poultry genetic resource conservation and bio-breeding, Anhui Agricultural University, Hefei, 230036, P.R. China
| | - Jing Xia
- College of Animal Science and Technology, Anhui Agricultural University, Hefei, Anhui 230036, P. R. China.,Anhui province key laboratory of local livestock and poultry genetic resource conservation and bio-breeding, Anhui Agricultural University, Hefei, 230036, P.R. China
| | - Wang Caiyun
- College of Animal Science and Technology, Anhui Agricultural University, Hefei, Anhui 230036, P. R. China.,Anhui province key laboratory of local livestock and poultry genetic resource conservation and bio-breeding, Anhui Agricultural University, Hefei, 230036, P.R. China
| | - Xiaodong Zhang
- College of Animal Science and Technology, Anhui Agricultural University, Hefei, Anhui 230036, P. R. China.,Anhui province key laboratory of local livestock and poultry genetic resource conservation and bio-breeding, Anhui Agricultural University, Hefei, 230036, P.R. China
| | - Mingxing Chu
- Key Laboratory of Animal (Poultry) Genetics Breeding and Reproduction, Ministry of Agriculture and Rural Affairs, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing,100193, P. R. China
| | - Zongjun Yin
- College of Animal Science and Technology, Anhui Agricultural University, Hefei, Anhui 230036, P. R. China.,Anhui province key laboratory of local livestock and poultry genetic resource conservation and bio-breeding, Anhui Agricultural University, Hefei, 230036, P.R. China
| | - Yueyun Ding
- College of Animal Science and Technology, Anhui Agricultural University, Hefei, Anhui 230036, P. R. China.,Anhui province key laboratory of local livestock and poultry genetic resource conservation and bio-breeding, Anhui Agricultural University, Hefei, 230036, P.R. China
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Ganteil A, Rodriguez-Ramilo ST, Ligonesche B, Larzul C. Characterization of Autozygosity in Pigs in Three-Way Crossbreeding. Front Genet 2021; 11:584556. [PMID: 33584790 PMCID: PMC7876413 DOI: 10.3389/fgene.2020.584556] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Accepted: 12/21/2020] [Indexed: 11/16/2022] Open
Abstract
Crossbreeding in livestock can be used to increase genetic diversity. The resulting increase in variability is related to the heterozygosity of the crossbred animal. The evolution of diversity during crossbreeding can be assessed using genomic data. The objective of this study was to describe patterns of runs of homozygosity (ROH) in animals resulting from three-way crossbreeding, from parental pure lines, and in their crossbred offspring. The crossbreeding scheme consisted of a first crossbreeding Pietrain boars and Large White sows, after which the offspring of the Pietrain × Large White were crossed with Duroc boars. The offspring of the second crossbreeding are called G0, the offspring of G0 boars and G0 sows are called G1. All the animals were genotyped using the Illumina SNP60 porcine chip. After filtering, analyses were performed with 2,336 animals and 48,579 autosomal single nucleotide polymorphism (SNP). The mean ROH-based inbreeding coefficients were shown to be 0.27 ± 0.05, 0.23 ± 0.04, and 0.26 ± 0.04 for Duroc, Large White, and Pietrain, respectively. ROH were detected in the Pietrain × Large White crossbred but the homozygous segments were fewer and smaller than in their parents. Similar results were obtained in the G0 crossbred. However, in the G1 crossbreds the number and the size of ROH were higher than in G0 parents. Similar ROH hotspots were detected on SSC1, SSC4, SSC7, SSC9, SSC13, SSC14, and SSC15 in both G0 and G1 animals. Long ROH (>16 Mb) were observed in G1 animals, suggesting regions with low recombination rates. The conservation of these homozygous segments in the three crossbred populations means that some haplotypes were shared between parental breeds. Gene annotation in ROH hotspots in G0 animals identified genes related to production traits including carcass composition and reproduction. These findings advance our understanding of how to manage genetic diversity in crossbred populations.
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Affiliation(s)
- Audrey Ganteil
- GenPhySE, Université de Toulouse, INRAE, ENVT, Castanet-Tolosan, France.,SAS NUCLEUS, Le Rheu, France
| | | | | | - Catherine Larzul
- GenPhySE, Université de Toulouse, INRAE, ENVT, Castanet-Tolosan, France
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Gomez-Raya L, Rauw WM, Dekkers JCM. Vector space algebra for scaling and centering relationship matrices under non-Hardy-Weinberg equilibrium conditions. Genet Sel Evol 2021; 53:7. [PMID: 33461489 PMCID: PMC7812663 DOI: 10.1186/s12711-020-00589-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Accepted: 11/03/2020] [Indexed: 11/13/2022] Open
Abstract
Background Scales are linear combinations of variables with coefficients that add up to zero and have a similar meaning to “contrast” in the analysis of variance. Scales are necessary in order to incorporate genomic information into relationship matrices for genomic selection. Statistical and biological parameterizations using scales under different assumptions have been proposed to construct alternative genomic relationship matrices. Except for the natural and orthogonal interactions approach (NOIA) method, current methods to construct relationship matrices assume Hardy–Weinberg equilibrium (HWE). The objective of this paper is to apply vector algebra to center and scale relationship matrices under non-HWE conditions, including orthogonalization by the Gram-Schmidt process. Theory and methods Vector space algebra provides an evaluation of current orthogonality between additive and dominance vectors of additive and dominance scales for each marker. Three alternative methods to center and scale additive and dominance relationship matrices based on the Gram-Schmidt process (GSP-A, GSP-D, and GSP-N) are proposed. GSP-A removes additive-dominance co-variation by first fitting the additive and then the dominance scales. GSP-D fits scales in the opposite order. We show that GSP-A is algebraically the same as the NOIA model. GSP-N orthonormalizes the additive and dominance scales that result from GSP-A. An example with genotype information on 32,645 single nucleotide polymorphisms from 903 Large-White × Landrace crossbred pigs is used to construct existing and newly proposed additive and dominance relationship matrices. Results An exact test for departures from HWE showed that a majority of loci were not in HWE in crossbred pigs. All methods, except the one that assumes HWE, performed well to attain an average of diagonal elements equal to one and an average of off diagonal elements equal to zero. Variance component estimation for a recorded quantitative phenotype showed that orthogonal methods (NOIA, GSP-A, GSP-N) can adjust for the additive-dominance co-variation when estimating the additive genetic variance, whereas GSP-D does it when estimating dominance components. However, different methods to orthogonalize relationship matrices resulted in different proportions of additive and dominance components of variance. Conclusions Vector space methodology can be applied to measure orthogonality between vectors of additive and dominance scales and to construct alternative orthogonal models such as GSP-A, GSP-D and an orthonormal model such as GSP-N. Under non-HWE conditions, GSP-A is algebraically the same as the previously developed NOIA model.
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Affiliation(s)
- Luis Gomez-Raya
- Department of Animal Science, Iowa State University, Ames, IA, USA. .,Dept Mejora Genética Animal, INIA, Madrid, Spain.
| | - Wendy M Rauw
- Department of Animal Science, Iowa State University, Ames, IA, USA.,Dept Mejora Genética Animal, INIA, Madrid, Spain
| | - Jack C M Dekkers
- Department of Animal Science, Iowa State University, Ames, IA, USA
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Szmatoła T, Jasielczuk I, Semik-Gurgul E, Szyndler-Nędza M, Blicharski T, Szulc K, Skrzypczak E, Gurgul A. Detection of runs of homozygosity in conserved and commercial pig breeds in Poland. J Anim Breed Genet 2020; 137:571-580. [PMID: 32362048 DOI: 10.1111/jbg.12482] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Revised: 04/01/2020] [Accepted: 04/03/2020] [Indexed: 01/22/2023]
Abstract
Runs of homozygosity (ROH) are continuous segments of the genome that arose as a result of inbreeding, resulting in the inheritance of identical haplotypes from both parents who shared a common ancestor. In the present study, we performed a detailed characterization and comparison of ROH in four pig breeds, including intensively selected Polish Landrace as well as native unselected animals of Puławska and two Złotnicka breeds (White and Spotted). We used a medium-density PorcineSNP60 BeadChip assay (Illumina) and cgaTOH software to detect ROH covering a minimum of 30 adjacent SNPs and maintaining a size over 1 Mb. By analysing ROH distribution and frequency across the genome, we also identified genomic regions with high ROH frequency (so-called "ROH hotspots"). The obtained results showed that the analysed conserved breeds were characterized by a higher ROH span and higher ROH-based inbreeding coefficients (FROH ), which likely result from past population bottlenecks, increasing the overall inbreeding level within these populations. The analysis of ROH distribution across the genomes revealed the presence of both shared and breed-specific ROH hotspots. These hotspots, presumably representing genome regions under selection, overlapped with a variety of genes associated with processes connected with immune system functioning, reproduction, glucose homeostasis and metabolism. The genome regions with ROH hotspots overlapping in all analysed populations, located on SSC4 (51.9-55.9 Mb) and 13 (92.6-97.8 Mb), covered thirty-one different genes, including MMP16, SLC7A13, ATP6V0D2, CNGB3, WWiP1, RiMDN1 and CPNE3. These genes are primarily associated with biological regulation and metabolism, processes that could be responsible for the variety of the selected production and functional features.
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Affiliation(s)
- Tomasz Szmatoła
- Center for Experimental and Innovative Medicine, University of Agriculture in Krakow, Kraków, Poland.,Department of Animal Molecular Biology, National Research Institute of Animal Production, Balice, Poland
| | - Igor Jasielczuk
- Center for Experimental and Innovative Medicine, University of Agriculture in Krakow, Kraków, Poland.,Department of Animal Molecular Biology, National Research Institute of Animal Production, Balice, Poland
| | - Ewelina Semik-Gurgul
- Department of Animal Molecular Biology, National Research Institute of Animal Production, Balice, Poland
| | | | - Tadeusz Blicharski
- Department of Genomics and Biodiversity, Institute of Genetics and Animal Breeding, Jastrzębiec, Poland
| | - Karolina Szulc
- Faculty of Veterinary Medicine and Animal Science, Poznań University of Life Sciences, Poznań, Poland
| | - Ewa Skrzypczak
- Faculty of Veterinary Medicine and Animal Science, Poznań University of Life Sciences, Poznań, Poland
| | - Artur Gurgul
- Center for Experimental and Innovative Medicine, University of Agriculture in Krakow, Kraków, Poland.,Department of Animal Molecular Biology, National Research Institute of Animal Production, Balice, Poland
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