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Meadows JRS, Kidd JM, Wang GD, Parker HG, Schall PZ, Bianchi M, Christmas MJ, Bougiouri K, Buckley RM, Hitte C, Nguyen AK, Wang C, Jagannathan V, Niskanen JE, Frantz LAF, Arumilli M, Hundi S, Lindblad-Toh K, Ginja C, Agustina KK, André C, Boyko AR, Davis BW, Drögemüller M, Feng XY, Gkagkavouzis K, Iliopoulos G, Harris AC, Hytönen MK, Kalthoff DC, Liu YH, Lymberakis P, Poulakakis N, Pires AE, Racimo F, Ramos-Almodovar F, Savolainen P, Venetsani S, Tammen I, Triantafyllidis A, vonHoldt B, Wayne RK, Larson G, Nicholas FW, Lohi H, Leeb T, Zhang YP, Ostrander EA. Genome sequencing of 2000 canids by the Dog10K consortium advances the understanding of demography, genome function and architecture. Genome Biol 2023; 24:187. [PMID: 37582787 PMCID: PMC10426128 DOI: 10.1186/s13059-023-03023-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Accepted: 07/25/2023] [Indexed: 08/17/2023] Open
Abstract
BACKGROUND The international Dog10K project aims to sequence and analyze several thousand canine genomes. Incorporating 20 × data from 1987 individuals, including 1611 dogs (321 breeds), 309 village dogs, 63 wolves, and four coyotes, we identify genomic variation across the canid family, setting the stage for detailed studies of domestication, behavior, morphology, disease susceptibility, and genome architecture and function. RESULTS We report the analysis of > 48 M single-nucleotide, indel, and structural variants spanning the autosomes, X chromosome, and mitochondria. We discover more than 75% of variation for 239 sampled breeds. Allele sharing analysis indicates that 94.9% of breeds form monophyletic clusters and 25 major clades. German Shepherd Dogs and related breeds show the highest allele sharing with independent breeds from multiple clades. On average, each breed dog differs from the UU_Cfam_GSD_1.0 reference at 26,960 deletions and 14,034 insertions greater than 50 bp, with wolves having 14% more variants. Discovered variants include retrogene insertions from 926 parent genes. To aid functional prioritization, single-nucleotide variants were annotated with SnpEff and Zoonomia phyloP constraint scores. Constrained positions were negatively correlated with allele frequency. Finally, the utility of the Dog10K data as an imputation reference panel is assessed, generating high-confidence calls across varied genotyping platform densities including for breeds not included in the Dog10K collection. CONCLUSIONS We have developed a dense dataset of 1987 sequenced canids that reveals patterns of allele sharing, identifies likely functional variants, informs breed structure, and enables accurate imputation. Dog10K data are publicly available.
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Affiliation(s)
- Jennifer R S Meadows
- Science for Life Laboratory, Department of Medical Biochemistry and Microbiology, Uppsala University, 75132, Uppsala, Sweden.
| | - Jeffrey M Kidd
- Department of Human Genetics, University of Michigan, Ann Arbor, MI, 48107, USA.
| | - Guo-Dong Wang
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, 650223, China
| | - Heidi G Parker
- National Human Genome Research Institute, National Institutes of Health, 50 South Drive, Building 50 Room 5351, Bethesda, MD, 20892, USA
| | - Peter Z Schall
- Department of Human Genetics, University of Michigan, Ann Arbor, MI, 48107, USA
| | - Matteo Bianchi
- Science for Life Laboratory, Department of Medical Biochemistry and Microbiology, Uppsala University, 75132, Uppsala, Sweden
| | - Matthew J Christmas
- Science for Life Laboratory, Department of Medical Biochemistry and Microbiology, Uppsala University, 75132, Uppsala, Sweden
| | - Katia Bougiouri
- Section for Molecular Ecology and Evolution, Globe Institute, University of Copenhagen, Øster Voldgade 5-7, 1350, Copenhagen, Denmark
| | - Reuben M Buckley
- National Human Genome Research Institute, National Institutes of Health, 50 South Drive, Building 50 Room 5351, Bethesda, MD, 20892, USA
| | - Christophe Hitte
- University of Rennes, CNRS, Institute Genetics and Development Rennes - UMR6290, 35000, Rennes, France
| | - Anthony K Nguyen
- Department of Human Genetics, University of Michigan, Ann Arbor, MI, 48107, USA
| | - Chao Wang
- Science for Life Laboratory, Department of Medical Biochemistry and Microbiology, Uppsala University, 75132, Uppsala, Sweden
| | - Vidhya Jagannathan
- Institute of Genetics, Vetsuisse Faculty, University of Bern, 3001, Bern, Switzerland
| | - Julia E Niskanen
- Department of Medical and Clinical Genetics, Department of Veterinary Biosciences, University of Helsinki and Folkhälsan Research Center, 02900, Helsinki, Finland
| | - Laurent A F Frantz
- School of Biological and Behavioural Sciences, Queen Mary University of London, London E14NS, UK and Palaeogenomics Group, Department of Veterinary Sciences, Ludwig Maximilian University, D-80539, Munich, Germany
| | - Meharji Arumilli
- Department of Medical and Clinical Genetics, Department of Veterinary Biosciences, University of Helsinki and Folkhälsan Research Center, 02900, Helsinki, Finland
| | - Sruthi Hundi
- Department of Medical and Clinical Genetics, Department of Veterinary Biosciences, University of Helsinki and Folkhälsan Research Center, 02900, Helsinki, Finland
| | - Kerstin Lindblad-Toh
- Science for Life Laboratory, Department of Medical Biochemistry and Microbiology, Uppsala University, 75132, Uppsala, Sweden
- Broad Institute of MIT and Harvard, Cambridge, MA, 02142, USA
| | - Catarina Ginja
- BIOPOLIS-CIBIO-InBIO-Centro de Investigação Em Biodiversidade E Recursos Genéticos - ArchGen Group, Universidade Do Porto, 4485-661, Vairão, Portugal
| | | | - Catherine André
- University of Rennes, CNRS, Institute Genetics and Development Rennes - UMR6290, 35000, Rennes, France
| | - Adam R Boyko
- Department of Biomedical Sciences, Cornell University, 930 Campus Road, Ithaca, NY, 14853, USA
| | - Brian W Davis
- Department of Veterinary Integrative Biosciences, School of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, 77843, USA
| | - Michaela Drögemüller
- Institute of Genetics, Vetsuisse Faculty, University of Bern, 3001, Bern, Switzerland
| | - Xin-Yao Feng
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, 650223, China
| | - Konstantinos Gkagkavouzis
- Department of Genetics, School of Biology, ), Aristotle University of Thessaloniki, Thessaloniki, Macedonia 54124, Greece and Genomics and Epigenomics Translational Research (GENeTres), Center for Interdisciplinary Research and Innovation (CIRI-AUTH, Balkan Center, Thessaloniki, Greece
| | - Giorgos Iliopoulos
- NGO "Callisto", Wildlife and Nature Conservation Society, 54621, Thessaloniki, Greece
| | - Alexander C Harris
- National Human Genome Research Institute, National Institutes of Health, 50 South Drive, Building 50 Room 5351, Bethesda, MD, 20892, USA
| | - Marjo K Hytönen
- Department of Medical and Clinical Genetics, Department of Veterinary Biosciences, University of Helsinki and Folkhälsan Research Center, 02900, Helsinki, Finland
| | - Daniela C Kalthoff
- NGO "Callisto", Wildlife and Nature Conservation Society, 54621, Thessaloniki, Greece
| | - Yan-Hu Liu
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, 650223, China
| | - Petros Lymberakis
- Natural History Museum of Crete & Department of Biology, University of Crete, 71202, Irakleio, Greece
- Biology Department, School of Sciences and Engineering, University of Crete, Heraklion, Greece
- Palaeogenomics and Evolutionary Genetics Lab, Institute of Molecular Biology and Biotechnology (IMBB), Foundation for Research and Technology - Hellas (FORTH), Heraklion, Greece
| | - Nikolaos Poulakakis
- Natural History Museum of Crete & Department of Biology, University of Crete, 71202, Irakleio, Greece
- Biology Department, School of Sciences and Engineering, University of Crete, Heraklion, Greece
- Palaeogenomics and Evolutionary Genetics Lab, Institute of Molecular Biology and Biotechnology (IMBB), Foundation for Research and Technology - Hellas (FORTH), Heraklion, Greece
| | - Ana Elisabete Pires
- BIOPOLIS-CIBIO-InBIO-Centro de Investigação Em Biodiversidade E Recursos Genéticos - ArchGen Group, Universidade Do Porto, 4485-661, Vairão, Portugal
| | - Fernando Racimo
- Section for Molecular Ecology and Evolution, Globe Institute, University of Copenhagen, Øster Voldgade 5-7, 1350, Copenhagen, Denmark
| | | | - Peter Savolainen
- Department of Gene Technology, Science for Life Laboratory, KTH - Royal Institute of Technology, 17121, Solna, Sweden
| | - Semina Venetsani
- Department of Genetics, School of Biology, Aristotle University of Thessaloniki, 54124, Thessaloniki, Macedonia, Greece
| | - Imke Tammen
- Sydney School of Veterinary Science, The University of Sydney, Sydney, NSW, 2570, Australia
| | - Alexandros Triantafyllidis
- Department of Genetics, School of Biology, ), Aristotle University of Thessaloniki, Thessaloniki, Macedonia 54124, Greece and Genomics and Epigenomics Translational Research (GENeTres), Center for Interdisciplinary Research and Innovation (CIRI-AUTH, Balkan Center, Thessaloniki, Greece
| | - Bridgett vonHoldt
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ, 08544, USA
| | - Robert K Wayne
- Department of Ecology and Evolutionary Biology, Ecology and Evolutionary Biology, University of California, Los Angeles, CA, 90095-7246, USA
| | - Greger Larson
- Palaeogenomics and Bio-Archaeology Research Network, School of Archaeology, University of Oxford, Oxford, OX1 3TG, UK
| | - Frank W Nicholas
- Sydney School of Veterinary Science, The University of Sydney, Sydney, NSW, 2570, Australia
| | - Hannes Lohi
- Department of Medical and Clinical Genetics, Department of Veterinary Biosciences, University of Helsinki and Folkhälsan Research Center, 02900, Helsinki, Finland
| | - Tosso Leeb
- Institute of Genetics, Vetsuisse Faculty, University of Bern, 3001, Bern, Switzerland
| | - Ya-Ping Zhang
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, 650223, China
| | - Elaine A Ostrander
- National Human Genome Research Institute, National Institutes of Health, 50 South Drive, Building 50 Room 5351, Bethesda, MD, 20892, USA.
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Evaluation of Genetic Diversity in Dog Breeds Using Pedigree and Molecular Analysis: A Review. DIVERSITY 2022. [DOI: 10.3390/d14121054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/05/2022]
Abstract
Domestic dogs are important for many economic and social reasons, and they have become a well-known model species for human disease. According to research, dog breeds exhibit significant levels of inbreeding and genetic diversity loss, decreasing the population’s ability to adapt in certain conditions, and indicating the need of conservation strategies. Before the development of molecular markers, pedigree information was used for genetic diversity management. In recent years, genomic tools are frequently applied for accurate estimation of genetic diversity and improved genetic conservation due to incomplete pedigrees and pedigree errors. The most frequently used molecular markers include PCR-based microsatellite markers (STRs) and DNA sequencing-based single-nucleotide polymorphism markers (SNP). The aim of this review was to highlight genetic diversity studies on dog breeds conducted using pedigree and molecular markers, as well as the importance of genetic diversity conservation in increasing the adaptability and survival of dog breed populations.
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Genetic Rescue of the Highly Inbred Norwegian Lundehund. Genes (Basel) 2022; 13:genes13010163. [PMID: 35052503 PMCID: PMC8775414 DOI: 10.3390/genes13010163] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Revised: 01/10/2022] [Accepted: 01/14/2022] [Indexed: 01/21/2023] Open
Abstract
Augmenting the genetic diversity of small, inbred populations by the introduction of new individuals is often termed “genetic rescue”. An example is the Norwegian Lundehund, a small spitz dog with inbreeding-related health problems that is being crossed with three Nordic breeds, including the Norwegian Buhund. Conservation breeding decisions for the (typically) small number of outcrossed individuals are vital for managing the rescue process, and we genotyped the Lundehund (n = 12), the Buhund (n = 12), their crosses (F1, n = 7) and first-generation backcrosses to the Lundehund (F2, n = 12) with >170,000 single nucleotide polymorphism loci to compare their levels of genetic diversity. We predicted that genome-wide diversity in F2 dogs would be higher than in the Lundehund but lower than in the F1 and the Buhund, and the heterozygosity values showed the expected patterns. We also found that runs of homozygosity, extended chromosomal regions of homozygous genotypes inherited from a common ancestor, were reduced in F2 individuals compared with Lundehund individuals. Our analyses demonstrate the benefits of outcrossing but indicate that some of the acquired genetic diversity is lost following immediate backcrossing. Additional breeding among F2 crosses could therefore merit from further consideration in genetic rescue management.
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Goleman M, Balicki I, Radko A, Rozempolska-Rucińska I, Zięba G. Pedigree and Molecular Analyses in the Assessment of Genetic Variability of the Polish Greyhound. Animals (Basel) 2021; 11:ani11020353. [PMID: 33572519 PMCID: PMC7911804 DOI: 10.3390/ani11020353] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Revised: 01/24/2021] [Accepted: 01/26/2021] [Indexed: 01/01/2023] Open
Abstract
Simple Summary The Polish Greyhound is an old Polish breed. The first descriptions of hunting with greyhounds can be found in the hunting literature of the 16th century, and the first detailed description of a greyhound comes from 1600. The Polish Greyhound probably originates from the Saluki-type Asian greyhounds. The population of this breed is very small and limited mainly to the territory of its country of origin (Poland). Pedigree books were opened for this breed in 1981. The narrow gene pool necessitated mating relatives, resulting in the appearance of various genetic diseases in the breed. The analysis of Polish Greyhound pedigrees registered in the pedigree books from the time of the registration of the breed and molecular tests facilitated calculation of the degree of relatedness in the breed and to design future breeding plans, taking into account that a 2.56% increase in inbreeding per complete generation will be observed if the current breeding program and similar matings are maintained. Abstract The aim of the study was to assess the genetic variability of the Polish Greyhound population based on pedigree analysis and molecular DNA testing and to determine the degree of relatedness among individuals in the population. Pedigree data of 912 Polish Greyhounds recorded in pedigree books since they were opened for this breed were analyzed. For molecular testing, DNA was obtained from cheek swabs taken from 235 dogs of the tested breed. A panel of 21 markers (Short Tandem Repeat—STR) was used. The mean inbreeding determined for the Polish Greyhound population based on pedigree analyses was low and amounted to 11.8%, but as many as 872 individuals of the 912 dogs in the studied population were inbred. A total of 83 founders (at least one unknown parent) were identified, among which 27 founders had both unknown parents. Full-sibling groups consisted of 130 individuals, with a minimum and maximum litter size of 2 and 16, respectively. The average litter size was 5.969. Gene diversity calculated based on the mean kinship matrix was 0.862 and the population mean kinship was 0.138. The founder genome equivalent based on the mean kinship matrix was 3.61; the founder genome surviving level was 12.34; the mean Ne was estimated at 21.76; and the Ne/N ratio was 0.135. The FIS inbreeding coefficient for 21 STR was negative, and the mean FIS value for all loci had a low negative value (−0.018). These values suggest a low level of inbreeding in the examined breed as well as the avoidance of mating related animals.
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Affiliation(s)
- Małgorzata Goleman
- Department of Ethology and Wildlife Management, University of Life Sciences, Akademicka 13, 20-950 Lublin, Poland
- Correspondence:
| | - Ireneusz Balicki
- Department and Clinic of Animal Surgery, University of Life Sciences, Głęboka 30, 20-612 Lublin, Poland;
| | - Anna Radko
- Department of Animal Molecular Biology, National Research Institute of Animal Production, Krakowska 1, 32-083 Balice, Poland;
| | - Iwona Rozempolska-Rucińska
- Institute of Biological Basis of Animal Production, University of Life Sciences, Akademicka 13, 20-950 Lublin, Poland; (I.R.-R.); (G.Z.)
| | - Grzegorz Zięba
- Institute of Biological Basis of Animal Production, University of Life Sciences, Akademicka 13, 20-950 Lublin, Poland; (I.R.-R.); (G.Z.)
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Sams AJ, Ford B, Gardner A, Boyko AR. Examination of the efficacy of small genetic panels in genomic conservation of companion animal populations. Evol Appl 2020; 13:2555-2565. [PMID: 33294008 PMCID: PMC7691451 DOI: 10.1111/eva.13038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Revised: 04/26/2020] [Accepted: 04/29/2020] [Indexed: 11/30/2022] Open
Abstract
In many ways, dogs are an ideal model for the study of genetic erosion and population recovery, problems of major concern in the field of conservation genetics. Genetic diversity in many dog breeds has been declining systematically since the beginning of the 1800s, when modern breeding practices came into fashion. As such, inbreeding in domestic dog breeds is substantial and widespread and has led to an increase in recessive deleterious mutations of high effect as well as general inbreeding depression. Pedigrees can in theory be used to guide breeding decisions, though are often incomplete and do not reflect the full history of inbreeding. Small microsatellite panels are also used in some cases to choose mating pairs to produce litters with low levels of inbreeding. However, the long-term impact of such practices has not been thoroughly evaluated. Here, we use forward simulation on a model of the dog genome to examine the impact of using limited marker panels to guide pairwise mating decisions on genome-wide population-level genetic diversity. Our results suggest that in unmanaged populations, where breeding decisions are made at the pairwise-rather than population-level, such panels can lead to accelerated loss of genetic diversity at genome regions unlinked to panel markers, compared to random mating. These results demonstrate the importance of genome-wide genetic panels for managing and conserving genetic diversity in dogs and other companion animals.
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Affiliation(s)
| | - Brett Ford
- Embark Veterinary, IncorporatedBostonMAUSA
| | | | - Adam R. Boyko
- Embark Veterinary, IncorporatedBostonMAUSA
- Department of Biomedical SciencesCollege of Veterinary MedicineCornell UniversityIthacaNYUSA
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Djurkin Kušec I, Bošković I, Zorc M, Gvozdanović K, Škorput D, Dovč P, Kušec G. Genomic Characterization of the Istrian Shorthaired Hound. Animals (Basel) 2020; 10:ani10112013. [PMID: 33139624 PMCID: PMC7693797 DOI: 10.3390/ani10112013] [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: 10/09/2020] [Revised: 10/28/2020] [Accepted: 10/29/2020] [Indexed: 02/07/2023] Open
Abstract
Istrian shorthaired hound is an old indigenous Croatian dog breed with historical traces of its origin, which date back to the 14th century. Due to its intelligence and great hunting abilities, it is considered an excellent hunting dog. Despite its ancient origin, there is no data on genetic diversity, population structure, and degree of inbreeding that could be used for advanced management and conservation of this breed. Our study aimed to provide a high-resolution population structure of the Istrian shorthaired hound using a 220K HD SNP array, to compare the obtained data with the genealogical records and to place the breed in a broader context of world dog populations. Relatively high population size and low inbreeding coefficient estimated from genealogical data indicate a preserved genetic diversity in this breed. The principle component analysis, the NeighborNet network, and TreeMix were used to determine the genetic relationship between the Istrian shorthaired hound and other breeds. The Istrian shorthaired hound was found to be genetically related to Italian hunting dogs sharing the same branch with the Segugio Italiano a Pelo Raso and Segugio Italiano a Pelo Forte. The ADMIXTURE analysis indicated that the Istrian shorthaired hound could be involved in the development of some other hunting dog breeds. The estimated effective population size (Ne) based on SNP data was similar to Ne calculated from genealogical data indicating the absence of bottlenecks and well-balanced use of breeding animals. The low genomic inbreeding coefficient, together with the higher number of short runs of homozygosity, observed in the Istrian shorthaired hound, confirms the ancient origin of the breed based on historical documents. The analysis of selective sweeps identified genomic regions with the strongest selection signals in the vicinity of the genes associated with cognitive performance and behavior. Genome analysis proved to be a useful tool for estimating population parameters and can be implemented in the conservation plan for this indigenous breed.
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Affiliation(s)
- Ivona Djurkin Kušec
- Faculty of Agrobiotechnical Sciences Osijek, Josip Juraj Strossmayer University of Osijek, Vladimira Preloga 1, 31000 Osijek, Croatia; (I.D.K.); (I.B.); (K.G.); (G.K.)
| | - Ivica Bošković
- Faculty of Agrobiotechnical Sciences Osijek, Josip Juraj Strossmayer University of Osijek, Vladimira Preloga 1, 31000 Osijek, Croatia; (I.D.K.); (I.B.); (K.G.); (G.K.)
| | - Minja Zorc
- Department of Animal Science, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, 1000 Ljubljana, Slovenia;
- Correspondence:
| | - Kristina Gvozdanović
- Faculty of Agrobiotechnical Sciences Osijek, Josip Juraj Strossmayer University of Osijek, Vladimira Preloga 1, 31000 Osijek, Croatia; (I.D.K.); (I.B.); (K.G.); (G.K.)
| | - Dubravko Škorput
- Faculty of Agriculture, University of Zagreb, Svetošimunska cesta 25, 10000 Zagreb, Croatia;
| | - Peter Dovč
- Department of Animal Science, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, 1000 Ljubljana, Slovenia;
| | - Goran Kušec
- Faculty of Agrobiotechnical Sciences Osijek, Josip Juraj Strossmayer University of Osijek, Vladimira Preloga 1, 31000 Osijek, Croatia; (I.D.K.); (I.B.); (K.G.); (G.K.)
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Letko A, Minor KM, Jagannathan V, Seefried FR, Mickelson JR, Oliehoek P, Drögemüller C. Genomic diversity and population structure of the Leonberger dog breed. Genet Sel Evol 2020; 52:61. [PMID: 33054768 PMCID: PMC7557023 DOI: 10.1186/s12711-020-00581-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Accepted: 10/02/2020] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Leonberger is a giant dog breed formed in the 1850s in Germany. Its post-World War II popularity has resulted in a current global population of ~ 30,000 dogs. The breed has predispositions to neurodegenerative disorders and cancer, which is likely due in large part to limited genetic diversity. However, to date there is no scientific literature on the overall demography and genomic architecture of this breed. RESULTS We assessed extensive pedigree records, SNP array genotype data, and whole-genome sequences (WGS) on 142,072, 1203 and 39 Leonberger dogs, respectively. Pedigree analyses identified 22 founder animals and revealed an apparent popular sire effect. The average pedigree-based inbreeding coefficient of 0.29 and average kinship of 0.31 show a dramatic loss of genetic diversity. The observed average life span decreased over time from 9.4 years in 1989 to 7.7 years in 2004. A global health survey confirmed a high prevalence of cancer and neurological disorders. Analysis of SNP-based runs of homozygosity (ROH) identified 125,653 ROH with an average length of 5.88 Mb, and confirmed an average inbreeding coefficient of 0.28. Genome-wide filtering of the WGS data revealed 28 non-protein-changing variants that were present in all Leonberger individuals and a list of 22 potentially pathogenic variants for neurological disorders of which 50% occurred only in Leonbergers and 50% occurred rarely in other breeds. Furthermore, one of the two mtDNA haplogroups detected was present in one dog only. CONCLUSIONS The increasing size of the Leonberger population has been accompanied by a considerable loss of genetic diversity after the bottleneck that occurred in the 1940s due to the intensive use of popular sires resulting in high levels of inbreeding. This might explain the high prevalence of certain disorders; however, genomic data provide no evidence for fixed coding variants that explain these predispositions. The list of candidate causative variants for polyneuropathy needs to be further evaluated. Preserving the current genetic diversity is possible by increasing the number of individuals for breeding while restricting the number of litters per sire/dam. In addition, outcrossing would help optimize long-term genetic diversity and contribute to the sustainability and health of the population.
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Affiliation(s)
- Anna Letko
- Institute of Genetics, Vetsuisse Faculty, University of Bern, 3012 Bern, Switzerland
| | - Katie M. Minor
- Department of Veterinary and Biomedical Sciences, College of Veterinary Medicine, University of Minnesota, St. Paul, Minnesota 55108 USA
| | - Vidhya Jagannathan
- Institute of Genetics, Vetsuisse Faculty, University of Bern, 3012 Bern, Switzerland
| | | | - James R. Mickelson
- Department of Veterinary and Biomedical Sciences, College of Veterinary Medicine, University of Minnesota, St. Paul, Minnesota 55108 USA
| | | | - Cord Drögemüller
- Institute of Genetics, Vetsuisse Faculty, University of Bern, 3012 Bern, Switzerland
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Analysis of Genetic Diversity in the Czech Spotted Dog. Animals (Basel) 2020; 10:ani10081416. [PMID: 32823819 PMCID: PMC7459660 DOI: 10.3390/ani10081416] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Revised: 08/08/2020] [Accepted: 08/10/2020] [Indexed: 11/16/2022] Open
Abstract
Loss off genetic diversity negatively affects most of the modern dog breeds. However, no breed created strictly for laboratory purposes has been analyzed so far. In this paper, we sought to explore by pedigree analysis exactly such a breed-the Czech Spotted Dog (CSD). The pedigree contained a total of 2010 individuals registered since the second half of the 20th century. Parameters such as the mean average relatedness, coefficient of inbreeding, effective population size, effective number of founders, ancestors and founder genomes and loss of genetic diversity-which was calculated based on the reference population and pedigree completeness-were used to assess genetic variability. Compared to the founding population, the reference population lost 38.2% of its genetic diversity, of which 26% is due to random genetic drift and 12.2% is due to the uneven contribution of the founders. The reference population is highly inbred and related. The average inbreeding coefficient is 36.45%, and the mean average relatedness is 74.83%. The effective population size calculated based on the increase of inbreeding coefficient is 10.28. Thus, the Czech Spotted Dog suffered significant losses of genetic diversity that threaten its future existence.
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Lampi S, Donner J, Anderson H, Pohjoismäki J. Variation in breeding practices and geographic isolation drive subpopulation differentiation, contributing to the loss of genetic diversity within dog breed lineages. Canine Med Genet 2020; 7:5. [PMID: 32835230 PMCID: PMC7386235 DOI: 10.1186/s40575-020-00085-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Accepted: 05/26/2020] [Indexed: 02/07/2023] Open
Abstract
Background Discrete breed ideals are not restricted to delimiting dog breeds from another, but also are key drivers of subpopulation differentiation. As genetic differentiation due to population fragmentation results in increased rates of inbreeding and loss of genetic diversity, detecting and alleviating the reasons of population fragmentation can provide effective tools for the maintenance of healthy dog breeds. Results Using a genome-wide SNP array, we detected genetic differentiation to subpopulations in six breeds, Belgian Shepherd, English Greyhound, Finnish Lapphund, Italian Greyhound, Labrador Retriever and Shetland Sheepdog, either due to geographical isolation or as a result of differential breeding strategies. The subpopulation differentiation was strongest in show dog lineages. Conclusions Besides geographical differentiation caused by founder effect and lack of gene flow, selection on champion looks or restricted pedigrees is a strong driver of population fragmentation. Artificial barriers for gene flow between the different subpopulations should be recognized, their necessity evaluated critically and perhaps abolished in order to maintain genetic diversity within a breed. Subpopulation differentiation might also result in false positive signals in genome-wide association studies of different traits. Lay summary Purebred dogs are, by definition, reproductively isolated from other breeds. However, similar isolation can also occur within a breed due to conflicting breeder ideals and geographic distances between the dog populations. We show here that both of these examples can contribute to breed division, with subsequent loss of genetic variation in the resulting breed lineages. Breeders should avoid creating unnecessary boundaries between breed lineages and facilitate the exchange of dogs between countries.
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Affiliation(s)
- Sara Lampi
- Department of Environmental and Biological Sciences, University of Eastern Finland, P.O. Box 111, 80101 Joensuu, Finland
| | - Jonas Donner
- Wisdom Health, P.O. Box 1040, 00251 Helsinki, Finland
| | | | - Jaakko Pohjoismäki
- Department of Environmental and Biological Sciences, University of Eastern Finland, P.O. Box 111, 80101 Joensuu, Finland
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10
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Boccardo A, Marelli SP, Pravettoni D, Bagnato A, Busca GA, Strillacci MG. The German Shorthair Pointer Dog Breed ( Canis lupus familiaris): Genomic Inbreeding and Variability. Animals (Basel) 2020; 10:ani10030498. [PMID: 32192001 PMCID: PMC7143860 DOI: 10.3390/ani10030498] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 03/11/2020] [Accepted: 03/13/2020] [Indexed: 12/22/2022] Open
Abstract
The German Shorthaired Pointer (GSHP) is a breed worldwide known for its hunting versatility. Dogs of this breed are appreciated as valuable companions, effective trackers, field trailers and obedience athletes. The aim of the present work is to describe the genomic architecture of the GSHP breed and to analyze inbreeding levels under a genomic and a genealogic perspective. A total of 34 samples were collected (24 Italian, 10 USA), and the genomic and pedigree coefficients of inbreeding have been calculated. A total of 3183 runs of homozygosity (ROH) across all 34 dogs have been identified. The minimum and maximum number of Single Nucleotide Polymorphisms (SNPs) defining all ROH are 40 and 3060. The mean number of ROH for the sample was 93.6. ROH were found on all chromosomes. A total of 854 SNPs (TOP_SNPs) defined 11 ROH island regions (TOP_ROH), in which some gene already associated with behavioral and morphological canine traits was annotated. The proportion of averaged observed homozygotes estimated on total number of SNPs was 0.70. The genomic inbreeding coefficient based on ROH was 0.17. The mean inbreeding based on genealogical information resulted 0.023. The results describe a low inbred population with quite a good level of genetic variability.
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Affiliation(s)
- Antonio Boccardo
- Department of Veterinary Medicine, Università degli Studi di Milano, Via dell’Università 6, 26900 Lodi, Italy (S.P.M.); (D.P.)
| | - Stefano Paolo Marelli
- Department of Veterinary Medicine, Università degli Studi di Milano, Via dell’Università 6, 26900 Lodi, Italy (S.P.M.); (D.P.)
| | - Davide Pravettoni
- Department of Veterinary Medicine, Università degli Studi di Milano, Via dell’Università 6, 26900 Lodi, Italy (S.P.M.); (D.P.)
| | - Alessandro Bagnato
- Department of Veterinary Medicine, Università degli Studi di Milano, Via dell’Università 6, 26900 Lodi, Italy (S.P.M.); (D.P.)
| | - Giuseppe Achille Busca
- Centro Clinico-Veterinario e Zootecnico-Sperimentale, Università degli Studi di Milano, Via dell’Università 6, 26900 Lodi, Italy;
| | - Maria Giuseppina Strillacci
- Department of Veterinary Medicine, Università degli Studi di Milano, Via dell’Università 6, 26900 Lodi, Italy (S.P.M.); (D.P.)
- Correspondence: ; Tel.: +39-02-50334582
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11
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Thomas F, Giraudeau M, Dheilly NM, Gouzerh F, Boutry J, Beckmann C, Biro PA, Hamede R, Abadie J, Labrut S, Bieuville M, Misse D, Bramwell G, Schultz A, Le Loc'h G, Vincze O, Roche B, Renaud F, Russell T, Ujvari B. Rare and unique adaptations to cancer in domesticated species: An untapped resource? Evol Appl 2020. [DOI: 10.1111/eva.12920] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Affiliation(s)
- Frédéric Thomas
- CREECUMR IRD 224‐CNRS 5290‐Université de Montpellier Montpellier France
| | - Mathieu Giraudeau
- CREECUMR IRD 224‐CNRS 5290‐Université de Montpellier Montpellier France
| | - Nolwenn M. Dheilly
- School of Marine and Atmospheric Sciences Stony Brook University Stony Brook NY USA
| | - Flora Gouzerh
- CREECUMR IRD 224‐CNRS 5290‐Université de Montpellier Montpellier France
| | - Justine Boutry
- CREECUMR IRD 224‐CNRS 5290‐Université de Montpellier Montpellier France
| | - Christa Beckmann
- Centre for Integrative Ecology School of Life and Environmental Sciences Deakin University Waurn Ponds VIC Australia
- School of Science Western Sydney UniversityParramatta NSW Australia
| | - Peter A. Biro
- Centre for Integrative Ecology School of Life and Environmental Sciences Deakin University Waurn Ponds VIC Australia
| | - Rodrigo Hamede
- School of Natural Sciences University of Tasmania Hobart TAS Australia
| | | | | | - Margaux Bieuville
- CREECUMR IRD 224‐CNRS 5290‐Université de Montpellier Montpellier France
| | - Dorothée Misse
- CREECUMR IRD 224‐CNRS 5290‐Université de Montpellier Montpellier France
| | - Georgina Bramwell
- Centre for Integrative Ecology School of Life and Environmental Sciences Deakin University Waurn Ponds VIC Australia
| | - Aaron Schultz
- Centre for Integrative Ecology School of Life and Environmental Sciences Deakin University Waurn Ponds VIC Australia
| | - Guillaume Le Loc'h
- Clinique des NAC et de la Faune Sauvage, UMR IHAP École Nationale Vétérinaire de Toulouse Toulouse France
| | - Orsolya Vincze
- Hungarian Department of Biology and Ecology Evolutionary Ecology Group Babeş‐Bolyai University Cluj‐Napoca Romania
- Department of Tisza Research MTA Centre for Ecological Research‐DRI Debrecen Hungary
| | - Benjamin Roche
- CREECUMR IRD 224‐CNRS 5290‐Université de Montpellier Montpellier France
- Unité mixte Internationale de Modélisation Mathématique et Informatique des Systèmes Complexes UMI IRD/Sorbonne UniversitéUMMISCO Bondy France
| | - François Renaud
- CREECUMR IRD 224‐CNRS 5290‐Université de Montpellier Montpellier France
| | - Tracey Russell
- School of Life and Environmental Sciences The University of Sydney Sydney NSW Australia
| | - Beata Ujvari
- Centre for Integrative Ecology School of Life and Environmental Sciences Deakin University Waurn Ponds VIC Australia
- School of Natural Sciences University of Tasmania Hobart TAS Australia
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12
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Marelli SP, Beccaglia M, Bagnato A, Strillacci MG. Canine fertility: The consequences of selection for special traits. Reprod Domest Anim 2020; 55 Suppl 2:4-9. [PMID: 31913541 DOI: 10.1111/rda.13586] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Revised: 11/05/2019] [Accepted: 11/08/2019] [Indexed: 01/07/2023]
Abstract
Pedigree dogs and cats are bred aiming to conform breed standards with very poor consideration for breeding stock fertility. At the same time, the genetic asset underlining reproductive traits could be effectively analysed like in other species under selection. The definition of selection targets is very important in breeding protocols determination. The aim of the present work is to present an overview of the different correlations between reproduction and genetics, starting from selection procedure and inbreeding coefficient moving to genomic and the application of SNPs and GWAS on population study and identification of genes involved in phenotypical variation of reproductive traits in dogs. Particular relevance has been given to the concept of inbreeding which effects on canine reproduction have been presented. The use of genomic information in inbreeding coefficient calculation can be considered an improved effective procedure in the evaluation of the genetic variability loss in canine population and its negative effects on reproductive traits.
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Affiliation(s)
- Stefano P Marelli
- Department of Veterinary Medicine - DIMEVET, University of Milan, Milano, Italy
| | | | - Alessandro Bagnato
- Department of Veterinary Medicine - DIMEVET, University of Milan, Milano, Italy
| | - Maria G Strillacci
- Department of Veterinary Medicine - DIMEVET, University of Milan, Milano, Italy
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13
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Dreger DL, Hooser BN, Hughes AM, Ganesan B, Donner J, Anderson H, Holtvoigt L, Ekenstedt KJ. True Colors: Commercially-acquired morphological genotypes reveal hidden allele variation among dog breeds, informing both trait ancestry and breed potential. PLoS One 2019; 14:e0223995. [PMID: 31658272 PMCID: PMC6816562 DOI: 10.1371/journal.pone.0223995] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Accepted: 10/02/2019] [Indexed: 01/15/2023] Open
Abstract
Direct-to-consumer canine genetic testing is becoming increasingly popular among dog owners. The data collected therein provides intriguing insight into the current status of morphological variation present within purebred populations. Mars WISDOM PANELTM data from 11,790 anonymized dogs, representing 212 breeds and 4 wild canine species, were evaluated at genes associated with 7 coat color traits and 5 physical characteristics. Frequencies for all tested alleles at these 12 genes were determined by breed and by phylogenetic grouping. A sub-set of the data, consisting of 30 breeds, was divided into separate same-breed populations based on country of collection, body size, coat variation, or lineages selected for working or conformation traits. Significantly different (p ≤ 0.00167) allele frequencies were observed between populations for at least one of the tested genes in 26 of the 30 breeds. Next, standard breed descriptions from major American and international registries were used to determine colors and tail lengths (e.g. genetic bobtail) accepted within each breed. Alleles capable of producing traits incongruous with breed descriptions were observed in 143 breeds, such that random mating within breeds has probabilities of between 4.9e-7 and 0.25 of creating undesirable phenotypes. Finally, the presence of rare alleles within breeds, such as those for the recessive black coloration and natural bobtail, was combined with previously published identity-by-decent haplotype sharing levels to propose pathways by which the alleles may have spread throughout dog breeds. Taken together, this work demonstrates that: 1) the occurrence of low frequency alleles within breeds can reveal the influence of regional or functional selection practices; 2) it is possible to visualize the potential historic connections between breeds that share rare alleles; and 3) the necessity of addressing conflicting ideals in breed descriptions relative to actual genetic potential is crucial.
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Affiliation(s)
- Dayna L. Dreger
- Department of Basic Medical Sciences, College of Veterinary Medicine, Purdue University, West Lafayette, IN, United States of America
| | - Blair N. Hooser
- Department of Basic Medical Sciences, College of Veterinary Medicine, Purdue University, West Lafayette, IN, United States of America
| | | | | | | | | | | | - Kari J. Ekenstedt
- Department of Basic Medical Sciences, College of Veterinary Medicine, Purdue University, West Lafayette, IN, United States of America
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14
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Wellmann R, Bennewitz J. Key Genetic Parameters for Population Management. Front Genet 2019; 10:667. [PMID: 31475027 PMCID: PMC6707806 DOI: 10.3389/fgene.2019.00667] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Accepted: 06/25/2019] [Indexed: 11/13/2022] Open
Abstract
Population management has the primary task of maximizing the long-term competitiveness of a breed. Breeds compete with each other for being able to supply consumer demands at low costs and also for funds from conservation programs. The competition for consumer preference is won by breeds with high genetic gain for total merit who maintained a sufficiently high genetic diversity, whereas the competition for funds is won by breeds with high conservation value. The conservation value of a breed could be improved by increasing its contribution to the gene pool of the species. This may include the recovery of its original genetic background and the maintenance of a high genetic diversity at native haplotype segments. The primary objective of a breeding program depends on the genetic state of the population and its intended usage. In this paper, we review the key genetic parameters that are relevant for population management, compare the methods for estimating them, derive the formulas for predicting their value at a future time, and clarify their usage in various types of breeding programs that differ in their main objectives. These key parameters are kinships, native kinships, breeding values, Mendelian sampling variances, native contributions, and mutational effects. Population management currently experiences a transition from using pedigree-based estimates to marker-based estimates, which improves the accuracies of these estimates and thereby increases response to selection. In addition, improved measures of the factors that determine the competitiveness of a breed and utilize auxiliary parameters, such as Mendelian sampling variances, mutational effects, and native kinships, enable to improve further upon historic recommendations for genetic population management.
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Affiliation(s)
- Robin Wellmann
- Animal Genetics and Breeding, Institute of Animal Science, University of Hohenheim, Stuttgart, Germany
| | - Jörn Bennewitz
- Animal Genetics and Breeding, Institute of Animal Science, University of Hohenheim, Stuttgart, Germany
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15
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Schäler J, Wellmann R, Bennewitz J, Thaller G, Hinrichs D. Genetic diversity and historic introgression in German Angler and Red Dual Purpose cattle and possibilities to reverse introgression. ACTA AGR SCAND A-AN 2019. [DOI: 10.1080/09064702.2019.1600011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Affiliation(s)
- J. Schäler
- Institute of Animal Breeding and Husbandry, Christian-Albrechts-University, Kiel, Germany
- Department of Animal Breeding, University of Kassel, Witzenhausen, Germany
| | - R. Wellmann
- Department of Animal Breeding and Genetics, University of Hohenheim, Stuttgart, Germany
| | - J. Bennewitz
- Department of Animal Breeding and Genetics, University of Hohenheim, Stuttgart, Germany
| | - G. Thaller
- Institute of Animal Breeding and Husbandry, Christian-Albrechts-University, Kiel, Germany
| | - D. Hinrichs
- Department of Animal Breeding, University of Kassel, Witzenhausen, Germany
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16
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Bosse M, Megens H, Derks MFL, de Cara ÁMR, Groenen MAM. Deleterious alleles in the context of domestication, inbreeding, and selection. Evol Appl 2019; 12:6-17. [PMID: 30622631 PMCID: PMC6304688 DOI: 10.1111/eva.12691] [Citation(s) in RCA: 63] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2017] [Revised: 05/30/2018] [Accepted: 06/12/2018] [Indexed: 12/21/2022] Open
Abstract
Each individual has a certain number of harmful mutations in its genome. These mutations can lower the fitness of the individual carrying them, dependent on their dominance and selection coefficient. Effective population size, selection, and admixture are known to affect the occurrence of such mutations in a population. The relative roles of demography and selection are a key in understanding the process of adaptation. These are factors that are potentially influenced and confounded in domestic animals. Here, we hypothesize that the series of events of bottlenecks, introgression, and strong artificial selection associated with domestication increased mutational load in domestic species. Yet, mutational load is hard to quantify, so there are very few studies available revealing the relevance of evolutionary processes. The precise role of artificial selection, bottlenecks, and introgression in further increasing the load of deleterious variants in animals in breeding and conservation programmes remains unclear. In this paper, we review the effects of domestication and selection on mutational load in domestic species. Moreover, we test some hypotheses on higher mutational load due to domestication and selective sweeps using sequence data from commercial pig and chicken lines. Overall, we argue that domestication by itself is not a prerequisite for genetic erosion, indicating that fitness potential does not need to decline. Rather, mutational load in domestic species can be influenced by many factors, but consistent or strong trends are not yet clear. However, methods emerging from molecular genetics allow discrimination of hypotheses about the determinants of mutational load, such as effective population size, inbreeding, and selection, in domestic systems. These findings make us rethink the effect of our current breeding schemes on fitness of populations.
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Affiliation(s)
- Mirte Bosse
- Animal Breeding and GenomicsWageningen University & ResearchWageningenThe Netherlands
| | - Hendrik‐Jan Megens
- Animal Breeding and GenomicsWageningen University & ResearchWageningenThe Netherlands
| | - Martijn F. L. Derks
- Animal Breeding and GenomicsWageningen University & ResearchWageningenThe Netherlands
| | - Ángeles M. R. de Cara
- Centre d’Ecologie Fonctionnelle et EvolutiveCNRSUniversité de MontpellierUniversité Paul Valéry Montpellier 3EPHE, IRDMontpellierFrance
| | - Martien A. M. Groenen
- Animal Breeding and GenomicsWageningen University & ResearchWageningenThe Netherlands
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17
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Pohjoismäki JLO, Lampi S, Donner J, Anderson H. Origins and wanderings of the Finnish hunting spitzes. PLoS One 2018; 13:e0199992. [PMID: 29958296 PMCID: PMC6025854 DOI: 10.1371/journal.pone.0199992] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Accepted: 06/17/2018] [Indexed: 11/18/2022] Open
Abstract
Deducing the evolutionary histories of dog breeds can be challenging due to convergent traits and frequent admixture. In this report, we have explored the relationships of indigenous Finnish hunting spitz breeds among other northern Eurasian hunting breeds using commercially available SNP analysis (the MyDogDNA panel test). We find that Nordic hunting breeds Finnish Spitz, Nordic Spitz and the Karelian Bear Dog, as well as the reindeer herding Lapphund and Lapponian herder are all closely related and have common origins with the northeastern Eurasian Laika breeds, rather than with other Scandinavian Spitz breeds, such as Elkhounds and Swedish Vallhund. By tracing admixture events and direction of gene flow, we also elucidate the complex interactions between the breeds and provide new insight into the history of Swedish Elkhound and Russian-European Laika. The findings, together with an analysis of genetic differentiation between the populations, not only help to understand the origins of the breeds but also provide interesting possibilities to revive genetic diversity, lost during the breeding history, by backcrossing breeds to their hypothetical ancestry.
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Affiliation(s)
- Jaakko L O Pohjoismäki
- University of Eastern Finland, Department of Environmental and Biological Sciences, Joensuu, Finland
| | - Sara Lampi
- University of Eastern Finland, Department of Environmental and Biological Sciences, Joensuu, Finland
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18
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Genetic rescue of an endangered domestic animal through outcrossing with closely related breeds: A case study of the Norwegian Lundehund. PLoS One 2017; 12:e0177429. [PMID: 28570553 PMCID: PMC5453418 DOI: 10.1371/journal.pone.0177429] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Accepted: 04/27/2017] [Indexed: 11/19/2022] Open
Abstract
Genetic rescue, outcrossing with individuals from a related population, is used to augment genetic diversity in populations threatened by severe inbreeding and extinction. The endangered Norwegian Lundehund dog underwent at least two severe bottlenecks in the 1940s and 1960s that each left only five inbred dogs, and the approximately 1500 dogs remaining world-wide today appear to descend from only two individuals. The Lundehund has a high prevalence of a gastrointestinal disease, to which all remaining dogs may be predisposed. Outcrossing is currently performed with three Nordic Spitz breeds: Norwegian Buhund, Icelandic Sheepdog, and Norrbottenspets. Examination of single nucleotide polymorphism (SNP) genotypes based on 165K loci in 48 dogs from the four breeds revealed substantially lower genetic diversity for the Lundehund (HE 0.035) than for other breeds (HE 0.209–0.284). Analyses of genetic structure with > 15K linkage disequilibrium-pruned SNPs showed four distinct genetic clusters. Pairwise FST values between Lundehund and the candidate breeds were highest for Icelandic Sheepdog, followed by Buhund and Norrbottenspets. We assessed the presence of outlier loci among candidate breeds and examined flanking genome regions (1 megabase) for genes under possible selection to identify potential adaptive differences among breeds; outliers were observed in flanking regions of genes associated with key functions including the immune system, metabolism, cognition and physical development. We suggest crossbreeding with multiple breeds as the best strategy to increase genetic diversity for the Lundehund and to reduce the incidence of health problems. For this project, the three candidate breeds were first selected based on phenotypes and then subjected to genetic investigation. Because phenotypes are often paramount for domestic breed owners, such a strategy could provide a helpful approach for genetic rescue and restoration of other domestic populations at risk, by ensuring the involvement of owners, breeders and managers at the start of the project.
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