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Genomic Diversity and Runs of Homozygosity in Bernese Mountain Dogs. Genes (Basel) 2023; 14:genes14030650. [PMID: 36980922 PMCID: PMC10048372 DOI: 10.3390/genes14030650] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Revised: 02/23/2023] [Accepted: 03/02/2023] [Indexed: 03/08/2023] Open
Abstract
Bernese mountain dogs are a large dog breed formed in the early 1900s in Switzerland. While originally farm dogs that were used for pulling carts, guarding, and driving cattle, today they are considered multi-purpose companion and family dogs. The breed is predisposed to several complex diseases, such as histiocytic sarcoma, degenerative myelopathy, or hip dysplasia. Using whole-genome sequencing (WGS) data, we assessed the genomic architecture of 33 unrelated dogs from four countries: France, Sweden, Switzerland, and the United States. Analysis of runs of homozygosity (ROH) identified 12,643 ROH with an average length of 2.29 Mb and an average inbreeding coefficient of 0.395. Multidimensional scaling analysis of the genetic relatedness revealed limited clustering of European versus USA dogs, suggesting exchanges of breeding stock between continents. Furthermore, only two mtDNA haplotypes were detected in the 33 studied dogs, both of which are widespread throughout multiple dog breeds. WGS-based ROH analyses revealed several fixed or nearly fixed regions harboring discreet morphological trait-associated as well as disease-associated genetic variants. Several genes involved in the regulation of immune cells were found in the ROH shared by all dogs, which is notable in the context of the breed’s strong predisposition to hematopoietic cancers. High levels of inbreeding and relatedness, strongly exaggerated in the last 30 years, have likely led to the high prevalence of specific genetic disorders in this breed.
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Cerebellar Abiotrophy in Australian Working Kelpies Is Associated with Two Major Risk Loci. Genes (Basel) 2022; 13:genes13101709. [PMID: 36292596 PMCID: PMC9602046 DOI: 10.3390/genes13101709] [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: 09/01/2022] [Revised: 09/20/2022] [Accepted: 09/20/2022] [Indexed: 11/16/2022] Open
Abstract
An autosomal recessive form of inherited cerebellar abiotrophy (CA) that is characterized by a degeneration of Purkinje and granule cells in the cerebellar cortex occurs in the Australian working kelpie dog breed. The clinical signs of CA include ataxia, head tremor, motor in-coordination, wide-based stance, and high-stepping gait. Investigation of clinical and pathological features indicated two closely related diseases with differences in age of onset. A genome-wide association study on 45 CA affected and 290 normal healthy Kelpies identified two significantly associated loci, one on CFA9 and a second on CFA20. Dogs homozygous for the risk haplotype on CFA20 (23 dogs) show clinical signs before ten weeks of age. Missense variants in the sixth exon of disruptor of telomeric silencing 1-like (DOT1Lp.R200Q) and in the only exon of Leucine Rich Repeat And Ig Domain Containing 3 (LINGO3p.R359C), both on CFA20, segregate with the associated risk marker which has incomplete penetrance (42%). Affected dogs homozygous for the risk haplotype on CFA9 have later onset ataxia. A missense variant in exon 5 of Vacuole Membrane Protein 1 (VMP1 p.P160Q) on CFA9 segregates as a fully penetrant Mendelian recessive with later-onset CA. Across mammals, the variety of causative loci so far identified as influencing cerebellar disorders reinforces the complexity of the pathways that contribute to cerebellar development and function, and to the pathophysiological mechanisms that may lead to cerebellar ataxia.
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Haase B, Willet CE, Chew T, Samaha G, Child G, Wade CM. De-novo and genome-wide meta-analyses identify a risk haplotype for congenital sensorineural deafness in Dalmatian dogs. Sci Rep 2022; 12:15439. [PMID: 36104420 PMCID: PMC9474838 DOI: 10.1038/s41598-022-19535-4] [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: 12/15/2021] [Accepted: 08/30/2022] [Indexed: 11/29/2022] Open
Abstract
Congenital sensorineural deafness (CSD) has been reported to affect up to 30% of Dalmatian dogs world-wide and while unilaterally deaf dogs can live a close to normal life, dogs suffering bilateral deafness are frequently euthanized. Extreme-white coat patterning as encoded by the gene Melanocyte Inducing Transcription Factor (MITF) has long been postulated as the major risk factor for CSD in the Dalmatian breed. While attempts to identify causative risk variants associated with CSD have been numerous, no genome-wide association study has positively identified MITF as a risk locus for either bilateral or unilateral deafness in the Dalmatian breed to date. In this study, we identified an association with CSD on CFA20 in the vicinity of MITF within Australian Dalmatian dogs. Although not genome-wide significant, the association signal was validated by reanalysing publicly available data and merging the wider data resource with the local data to improve statistical power. The merged data, representing three major global populations of Dalmatian dogs, enabled us to identify a single, well-defined genome-wide significant risk haplotype for CSD. The haplotype was formed by three genome-wide significant associated markers (BICF2G630233852T>C, BICF2G630233861T>C, BICF2G630233888G>A) on CFA20 with 62% of bilaterally deaf dogs homozygous for the risk haplotype (CCA), while 30% of bilaterally deaf and 45% of hearing dogs carried one copy of the risk haplotype. Animals homozygous or heterozygous for the low-risk haplotype were less likely to be unilaterally deaf. While the association between the risk haplotype and deafness is incomplete, animals homozygous for the risk haplotype were 10-times more likely to be bilaterally deaf. Although the underlying causative variants are yet to be discovered, results from this study can now assist with reducing deafness in Dalmatian dogs.
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Genome-Wide Association Analysis for Chronic Superficial Keratitis in the Australian Racing Greyhound. Genes (Basel) 2022; 13:genes13081328. [PMID: 35893065 PMCID: PMC9332392 DOI: 10.3390/genes13081328] [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: 06/28/2022] [Revised: 07/21/2022] [Accepted: 07/23/2022] [Indexed: 11/17/2022] Open
Abstract
Chronic superficial keratitis (CSK) is a progressive inflammatory condition of the eye (cornea) that can cause discomfort and blindness. Differential disease risk across dog breeds strongly suggests that CSK has a genetic basis. In addition to genetic risk, the occurrence of CSK is exacerbated by exposure to ultraviolet light. Genome-wide association analysis considered 109 greyhounds, 70 with CSK and the remainder with normal phenotype at an age over four years. Three co-located variants on CFA18 near the 5' region of the Epidermal Growth Factor Receptor (EGFR) gene were associated with genome-wide significance after multiple-test correction (BICF2P579527, CFA18: 6,068,508, praw = 1.77 × 10-7, pgenome = 0.017; BICF2P1310662, CFA18: 6,077,388, praw = 4.09 × 10-7, pgenome = 0.040; BICF2P160719, CFA18: 6,087,347, praw = 4.09 × 10-7, pgenome = 0.040) (canFam4)). Of the top 10 associated markers, eight were co-located with the significantly associated markers on CFA18. The associated haplotype on CFA18 is protective for the CSK condition. EGFR is known to play a role in corneal healing, where it initiates differentiation and proliferation of epithelial cells that in turn signal the involvement of stromal keratocytes to commence apoptosis. Further validation of the putative functional variants is required prior to their use in genetic testing for breeding programs.
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Before Azaria: A Historical Perspective on Dingo Attacks. Animals (Basel) 2022; 12:ani12121592. [PMID: 35739928 PMCID: PMC9219548 DOI: 10.3390/ani12121592] [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: 04/22/2022] [Revised: 06/10/2022] [Accepted: 06/16/2022] [Indexed: 12/22/2022] Open
Abstract
This paper investigates the origin of the once popular belief in Australian society that wild dingoes do not attack humans. To address this problem, a digital repository of archived newspaper articles and other published texts written between 1788 and 1979 were searched for references to dingoes attacking non-Indigenous people. A total of 52 accounts spanning the period between 1804 and 1928 was identified. A comparison of these historical accounts with the details of modern dingo attacks suggests that at least some of the former are credible. The paper also examined commonly held attitudes towards dingoes in past Australian society based on historical print media articles and other records. Early chroniclers of Australian rural life and culture maintained that dingoes occasionally killed and ate humans out of a predatory motivation. By the early decades of the 20th century, however, an opposing view of this species had emerged: namely, that dingoes were timid animals that continued to pose a danger to livestock, but never to people. This change in the cultural image of dingoes can possibly be linked to more than a century of lethal dingo control efforts greatly reducing the frequency of human–dingo interactions in the most populous parts of the country. This intensive culling may also have expunged the wild genetic pool of dingoes that exhibited bold behaviour around people and/or created a dingo population that was largely wary of humans.
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Niego A, Benítez-Burraco A. Are feralization and domestication truly mirror processes? ETHOL ECOL EVOL 2021. [DOI: 10.1080/03949370.2021.1975314] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Amy Niego
- PhD Program, Faculty of Philology, University of Seville, C/Palos de la Frontera s/n, 41004 Sevilla, Spain
| | - Antonio Benítez-Burraco
- Department of Spanish, Linguistics, and Theory of Literature (Linguistics), Faculty of Philology, University of Seville, C/Palos de la Frontera s/n, 41004 Sevilla, Spain (E-mail: )
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Raymond PW, Velie BD, Wade CM. Forensic DNA phenotyping: Canis familiaris breed classification and skeletal phenotype prediction using functionally significant skeletal SNPs and indels. Anim Genet 2021; 53:247-263. [PMID: 34963196 DOI: 10.1111/age.13165] [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: 10/21/2020] [Revised: 11/30/2021] [Accepted: 12/12/2021] [Indexed: 11/29/2022]
Abstract
This review highlights a novel application of breed identification and prediction of skeletal traits in forensic investigations using canine DNA evidence. Currently, genotyping methods used for canine breed classification involve the application of highly polymorphic short tandem repeats in addition to larger commercially available SNP arrays. Both applications face technical challenges. An additional approach to breed identification could be through genotyping SNPs and indels that characterise the array of skeletal differences displayed across domestic dog populations. Research has shown that a small number of genetic variants of large effect drive differences in skeletal phenotypes among domestic dog breeds. This feature makes functionally significant canine skeletal variants a cost-effective target for forensic investigators to classify individuals according to their breed. Further analysis of these skeletal variants would enable the prediction of external appearance. To date, functionally significant genes with genetic variants associated with differences in size, bulk, skull shape, ear shape, limb length, digit type, and tail morphology have been uncovered. Recommendations of a cost-effective genotyping method that can be readily designed and applied by forensic investigators have been given. Further advances to improve the field of canine skeletal forensic DNA phenotyping include the refinement of phenotyping methods, further biological validation of the skeletal genetic variants and establishing a publicly available database for storage of allele frequencies of the skeletal genetic variants in the wider domestic dog population.
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Affiliation(s)
- Patrick W Raymond
- School of Life and Environmental Sciences, University of Sydney, Sydney, Australia
| | - Brandon D Velie
- School of Life and Environmental Sciences, University of Sydney, Sydney, Australia
| | - Claire M Wade
- School of Life and Environmental Sciences, University of Sydney, Sydney, Australia
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Cairns KM, Newman KD, Crowther MS, Letnic M. Pelage variation in dingoes across southeastern Australia: implications for conservation and management. J Zool (1987) 2021. [DOI: 10.1111/jzo.12875] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- K. M. Cairns
- Centre for Ecosystem Science School of Biological, Earth and Environmental Sciences University of New South Wales Sydney NSW Australia
- Evolution and Ecology Research Centre School of Biological, Earth and Environmental Sciences University of New South Wales Sydney NSW Australia
| | - K. D. Newman
- School of Biosciences University of Melbourne Parkville VIC Australia
| | - M. S. Crowther
- School of Life and Environmental Sciences University of Sydney Sydney NSW Australia
| | - M. Letnic
- Centre for Ecosystem Science School of Biological, Earth and Environmental Sciences University of New South Wales Sydney NSW Australia
- Evolution and Ecology Research Centre School of Biological, Earth and Environmental Sciences University of New South Wales Sydney NSW Australia
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O'Brien MJ, Beijerink NJ, Sansom M, Thornton SW, Chew T, Wade CM. A large deletion on CFA28 omitting ACSL5 gene is associated with intestinal lipid malabsorption in the Australian Kelpie dog breed. Sci Rep 2020; 10:18223. [PMID: 33106515 PMCID: PMC7589484 DOI: 10.1038/s41598-020-75243-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Accepted: 10/06/2020] [Indexed: 12/31/2022] Open
Abstract
Inborn errors of metabolism are genetic conditions that can disrupt intermediary metabolic pathways and cause defective absorption and metabolism of dietary nutrients. In an Australian Kelpie breeding population, 17 puppies presented with intestinal lipid malabsorption. Juvenile dogs exhibited stunted postnatal growth, steatorrhea, abdominal distension and a wiry coat. Using genome-wide association analysis, an associated locus on CFA28 (Praw = 2.87E-06) was discovered and validated in a closely related population (Praw = 1.75E-45). A 103.3 kb deletion NC_006610.3CFA28:g.23380074_23483377del, containing genes Acyl-CoA Synthetase Long Chain Family Member 5 (ACSL5) and Zinc Finger DHHC-Type Containing 6 (ZDHHC6), was characterised using whole transcriptomic data. Whole transcriptomic sequencing revealed no expression of ACSL5 and disrupted splicing of ZDHHC6 in jejunal tissue of affected Kelpies. The ACSL5 gene plays a key role in long chain fatty acid absorption, a phenotype similar to that of our affected Kelpies has been observed in a knockout mouse model. A PCR-based diagnostic test was developed and confirmed fully penetrant autosomal recessive mode of inheritance. We conclude the structural variant causing a deletion of the ACSL5 gene is the most likely cause for intestinal lipid malabsorption in the Australian Kelpie.
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Affiliation(s)
- Mitchell J O'Brien
- School of Life and Environmental Sciences, Faculty of Science, University of Sydney, Camperdown, NSW, 2006, Australia.
| | - Niek J Beijerink
- Sydney School of Veterinary Science, Faculty of Science, University of Sydney, Camperdown, NSW, 2006, Australia.,Veterinaire Specialisten Vught, Reutsedijk 8a, 5264 PC, Vught, The Netherlands
| | - Mandy Sansom
- Callicoma Kelpies, Grafton, NSW, 2460, Australia
| | - Sarah W Thornton
- Sydney School of Veterinary Science, Faculty of Science, University of Sydney, Camperdown, NSW, 2006, Australia.,Unaffiliated, Los Altos, USA
| | - Tracy Chew
- Sydney Informatic Hub, University of Sydney, Camperdown, NSW, 2006, Australia
| | - Claire M Wade
- School of Life and Environmental Sciences, Faculty of Science, University of Sydney, Camperdown, NSW, 2006, Australia.
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Paris JM, Letko A, Häfliger IM, Ammann P, Drögemüller C. Ear type in sheep is associated with the MSRB3 locus. Anim Genet 2020; 51:968-972. [PMID: 32805068 DOI: 10.1111/age.12994] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/27/2020] [Indexed: 12/01/2022]
Abstract
Ear morphology is an important determinant of sheep breeds. It includes different variable traits such as ear size and erectness, suggesting a polygenic architecture. Here, we performed a comprehensive genome-wide analysis to identify regions under selection for ear morphology in 515 sheep from 17 breeds fixed for diverse ear phenotypes using 34k SNP genotyping data. GWASs for two ear type traits, size and erectness, revealed a single genome-wide significant association on ovine chromosome 3. The derived marker alleles were enriched in sheep with large and/or floppy ears. The GWAS signal harboured the MSRB3 gene encoding methionine sulphoxide reductase B3, which has already been found to be associated with different ear types in other species. We attempted whole-genome resequencing to identify causal variant(s) within a 1 Mb interval around MSRB3. This experiment excluded major copy number variants in the interval, but failed to identify a compelling candidate causal variant. Fine-mapping suggested that the causal variant for large floppy ears most likely resides in a 175 kb interval downstream of the MSRB3 coding region.
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Affiliation(s)
- J M Paris
- Vetsuisse Faculty, Institute of Genetics, University of Bern, Bern, 3001, Switzerland
| | - A Letko
- Vetsuisse Faculty, Institute of Genetics, University of Bern, Bern, 3001, Switzerland
| | - I M Häfliger
- Vetsuisse Faculty, Institute of Genetics, University of Bern, Bern, 3001, Switzerland
| | - P Ammann
- ProSpecieRara, Basel, 4052, Switzerland
| | - C Drögemüller
- Vetsuisse Faculty, Institute of Genetics, University of Bern, Bern, 3001, Switzerland
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Marín Navas C, Navas González FJ, Castillo López V, Payeras Capellà L, Gómez Fernández M, Delgado Bermejo JV. Impact of breeding for coat and spotting patterns on the population structure and genetic diversity of an islander endangered dog breed. Res Vet Sci 2020; 131:117-130. [PMID: 32334156 DOI: 10.1016/j.rvsc.2020.04.003] [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: 10/19/2019] [Revised: 03/31/2020] [Accepted: 04/02/2020] [Indexed: 01/20/2023]
Abstract
First references of the endangered autochthonous Majorcan Ca Mè dog date from the 13th century and enhance its skills and adaptability to the orography. Genealogical historical records were traced back to founders. Founder number in the reference population (397), maximum generations traced, and average number of complete generations were 32, 5, and 2.75, respectively. Structure assessment revealed the existence of subpopulations regarding criteria such as owners (402), breeders (55), coat colours (liver, lemon, black and orange) and spotting patterns (piebald, roan, solid colour, tie or star presence). Average inbreeding (F) within colour groups ranged from 6.3-10.4%, for orange and black populations, respectively. F ranged from 9.43-12.22% for roan patterns and star presence, respectively. Tan point markings showed an F coefficient of 5.85%. The study of genetic diversity revealed a slightly different genetic background between subpopulations. Average coancestry between and within coat colours suggested orange and roan traits could be ascribed to the original nuclei, without omitting the high relationships among other subpopulations. Breeding strategy should select breeding pairs holding a relatedness coefficient below 15%. Hence, coat patterns in dog breeds can help preserving the genetic diversity in endangered dogs, even when these are geographically isolated.
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Affiliation(s)
- Carmen Marín Navas
- Department of Genetics, Faculty of Veterinary Sciences, University of Córdoba, Córdoba, Spain
| | | | - Vanesa Castillo López
- Servei de Caça de la Direcció Insular de Cooperació Local i Caça del Departament de Desenvolupament Local del Consell de Mallorca, Majorca, Spain
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