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Gedon NKY, Bizikova P, Olivry T, Mendoza-Kuznetsova E, Oberkirchner U, Robertson JB, Linder KE. Histopathological characterisation of trunk-dominant canine pemphigus foliaceus, and comparison with classic facial and insecticide-triggered forms. Vet Dermatol 2023; 34:425-440. [PMID: 37316895 DOI: 10.1111/vde.13174] [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: 01/14/2023] [Revised: 03/14/2023] [Accepted: 03/24/2023] [Indexed: 06/16/2023]
Abstract
BACKGROUND While the clinical features were described recently, the histopathological characterisation of trunk-dominant canine pemphigus foliaceus (PF) is lacking, and whether it differs from classic facial or insecticide-triggered PF is unknown. HYPOTHESIS/OBJECTIVES This study describes the histopathological findings of trunk-dominant PF, and compares the results to classic facial and insecticide-triggered PF. ANIMALS Skin biopsies from 103 dogs with clinically characterised trunk-dominant (n = 33), classic facial (n = 26) and insecticide-triggered PF (n = 44) were included. MATERIALS AND METHODS Histological sections, randomised and blinded, were scored for over 50 morphological parameters of pustules, epidermis, dermis, adnexa and crusts. Intact pustule area and width were measured by digital microscopy. RESULTS In trunk-dominant PF, 77 intact pustules were predominantly subcorneal (0.0019-1.940 mm2 area, 0.0470-4.2532 mm wide), and contained from one to over 100 acantholytic keratinocytes. Pustules had boat acantholytic cells, corneocytes, perinuclear eosinophilic rings, neutrophil rosettes, acantholytic cell necrosis, rafts, cling-ons and/or eosinophils. Peripustular epidermal spongiosis, necrosis and lymphocyte exocytosis occurred, as did follicular pustules. Mixed dermal inflammation often contained eosinophils. Trunk-dominant PF did not differ from the other PF groups except for few parameters, such as having fewer rafts (p = 0.003). Additional autoimmune inflammatory patterns occurred in all PF groups. CONCLUSIONS AND CLINICAL RELEVANCE Trunk-dominant PF and other canine PF variants are histologically similar, which indicates shared pathomechanisms. The identification of common boat acantholytic cells and corneocyte separation has implications for the mechanisms of acantholysis. The diversity of histopathological and polyautoimmunity features support complicated immune mechanisms. Finally, results indicate that diagnostic biopsies cannot differentiate between these PF variants in dogs.
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Affiliation(s)
| | - Petra Bizikova
- College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina, USA
| | - Thierry Olivry
- College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina, USA
| | | | | | | | - Keith Emerson Linder
- College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina, USA
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2
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Jackson D, Di Bella A. Concurrent hypoadrenocorticism, immune‐mediated thrombocytopenia and immune‐mediated haemolytic anaemia in a Jack Russell Terrier dog. VETERINARY RECORD CASE REPORTS 2022. [DOI: 10.1002/vrc2.491] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- David Jackson
- Southern Counties Veterinary Specialists Ringwood UK
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Lim D, Jin Y, Son Y, Oh T, Bae S. A suspected case of a multiple autoimmune syndrome in a poodle dog. Vet Med Sci 2022; 8:431-436. [PMID: 35137556 PMCID: PMC8959301 DOI: 10.1002/vms3.741] [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] [Indexed: 11/24/2022] Open
Abstract
A 9‐year‐old castrated male poodle dog was presented with icterus, anorexia, and lethargy. The dog was diagnosed with hypothyroidism 1 month before and was treated with levothyroxine. Severe anaemia with spherocytes, positive saline agglutination test, and hyperbilirubinemia indicated immune‐mediated haemolytic anaemia (IMHA). Therefore, immunosuppressive therapy with prednisolone, mycophenolate mofetil, and danazol was started. Although the IMHA was well controlled, during tapering of prednisolone, acute multiple joint swelling and oedema suspected immune‐mediated polyarthritis occurred twice. First, clinical symptoms improved as the dosage of prednisolone increased. However, the dog showed severe adverse effects to the steroid. Second time, we added leflunomide as another immunosuppressant, and clinical signs of arthritis disappeared. About 3 weeks later, despite the immunosuppressive therapy, skin lesions resembling an autoimmune dermatologic disorder spread throughout the body. Addition of cyclosporine resolved the skin lesions. This is a case report of a dog showing several sporadic clinical signs related to multiple autoimmune syndromes and their management using different immunosuppressant drugs.
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Affiliation(s)
- Dahye Lim
- Department of Veterinary Internal Medicine, College of Veterinary Medicine, Kyungpook National University, Daegu, Korea
| | - Yunseok Jin
- Department of Veterinary Internal Medicine, College of Veterinary Medicine, Kyungpook National University, Daegu, Korea
| | - Youngmin Son
- Department of Veterinary Internal Medicine, College of Veterinary Medicine, Kyungpook National University, Daegu, Korea
| | - Taeho Oh
- Department of Veterinary Internal Medicine, College of Veterinary Medicine, Kyungpook National University, Daegu, Korea
| | - Seulgi Bae
- Department of Veterinary Internal Medicine, College of Veterinary Medicine, Kyungpook National University, Daegu, Korea
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4
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Šnjegota D, Stronen AV, Boljte B, Ćirović D, Djan M, Huber D, Jelenčič M, Konec M, Kusak J, Skrbinšek T. Population genetic structure of wolves in the northwestern Dinaric-Balkan region. Ecol Evol 2021; 11:18492-18504. [PMID: 35003687 PMCID: PMC8717286 DOI: 10.1002/ece3.8444] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Revised: 11/25/2021] [Accepted: 11/26/2021] [Indexed: 11/29/2022] Open
Abstract
The Balkan Peninsula and the Dinaric Mountains possess extraordinary biodiversity and support one of the largest and most diverse wolf (Canis lupus) populations in Europe. Results obtained with diverse genetic markers show west-east substructure, also seen in various other species, despite the absence of obvious barriers to movement. However, the spatial extent of the genetic clusters remains unresolved, and our aim was to combine fine-scale sampling with population and spatial genetic analyses to improve resolution of wolf genetic clusters. We analyzed 16 autosomal microsatellites from 255 wolves sampled in Slovenia, Croatia, Bosnia and Herzegovina (BIH), and Serbia and documented three genetic clusters. These comprised (1) Slovenia and the regions of Gorski kotar and Lika in Croatia, (2) the region of Dalmatia in southern Croatia and BIH, and (3) Serbia. When we mapped the clusters geographically, we observed west-east genetic structure across the study area, together with some specific structure in BIH-Dalmatia. We observed that cluster 1 had a smaller effective population size, consistent with earlier reports of population recovery since the 1980s. Our results provide foundation for future genomic studies that would further resolve the observed west-east population structure and its evolutionary history in wolves and other taxa in the region and identify focal areas for habitat conservation. They also have immediate importance for conservation planning for the wolves in one of the most important parts of the species' European range.
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Affiliation(s)
- Dragana Šnjegota
- Department of Biology and EcologyFaculty of Natural Sciences and MathematicsUniversity of Banja LukaBanja LukaBosnia and Herzegovina
| | - Astrid Vik Stronen
- Department of BiologyBiotechnical FacultyUniversity of LjubljanaLjubljanaSlovenia
| | - Barbara Boljte
- Department of BiologyBiotechnical FacultyUniversity of LjubljanaLjubljanaSlovenia
| | - Duško Ćirović
- Faculty of BiologyUniversity of BelgradeBelgradeSerbia
| | - Mihajla Djan
- Department of Biology and EcologyFaculty of SciencesUniversity of Novi SadNovi SadSerbia
| | - Djuro Huber
- Department of BiologyFaculty of Veterinary MedicineUniversity of ZagrebZagrebCroatia
| | - Maja Jelenčič
- Department of BiologyBiotechnical FacultyUniversity of LjubljanaLjubljanaSlovenia
| | - Marjeta Konec
- Department of BiologyBiotechnical FacultyUniversity of LjubljanaLjubljanaSlovenia
| | - Josip Kusak
- Department of BiologyFaculty of Veterinary MedicineUniversity of ZagrebZagrebCroatia
| | - Tomaž Skrbinšek
- Department of BiologyBiotechnical FacultyUniversity of LjubljanaLjubljanaSlovenia
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Kuijlaars M, Yool DA, Ridyard AE. Autoimmune polyendocrine syndrome in a standard poodle with concurrent non‐endocrine immune‐mediated diseases. VETERINARY RECORD CASE REPORTS 2021. [DOI: 10.1002/vrc2.90] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Margaux Kuijlaars
- University of Glasgow Small Animal Hospital, Division of Small Animal Clinical Sciences, School of Veterinary Medicine Glasgow UK
| | - Donald A. Yool
- University of Glasgow Small Animal Hospital, Division of Small Animal Clinical Sciences, School of Veterinary Medicine Glasgow UK
| | - Alison E. Ridyard
- University of Glasgow Small Animal Hospital, Division of Small Animal Clinical Sciences, School of Veterinary Medicine Glasgow UK
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6
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Stronen AV, Konec M, Boljte B, Bošković I, Gačić D, Galov A, Heltai M, Jelenčič M, Kljun F, Kos I, Kovačič T, Lanszki J, Pintur K, Pokorny B, Skrbinšek T, Suchentrunk F, Szabó L, Šprem N, Tomljanović K, Potočnik H. Population genetic structure in a rapidly expanding mesocarnivore: golden jackals in the Dinaric-Pannonian region. Glob Ecol Conserv 2021. [DOI: 10.1016/j.gecco.2021.e01707] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
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Levy BJ, Linder KE, Mamo LB, Herrmann I, Bizikova P. Cutaneous polyautoimmunity in two unrelated dogs: pemphigus foliaceus and generalized discoid lupus erythematosus. Vet Dermatol 2020; 31:325-e84. [PMID: 32342582 DOI: 10.1111/vde.12851] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/23/2020] [Indexed: 12/22/2022]
Abstract
BACKGROUND Polyautoimmunity, the concurrent expression of two or more distinct autoimmune diseases (ADs) in a single individual, is a known phenomenon in humans and has been rarely reported in dogs. To the best of the authors' knowledge, comorbid pemphigus foliaceus (PF) and generalized discoid lupus erythematosus (GDLE) has not been reported in dogs. HYPOTHESIS/OBJECTIVES To describe the clinical, histological and immunological features and treatment outcome of two unrelated dogs with comorbid PF and GDLE. ANIMALS One 10-year-old, spayed German shepherd dog and one 8-year-old, castrated American Staffordshire terrier presented for evaluation of a symmetrical, facial- and/or pedal-dominant pustular dermatitis with concurrent, truncal scaly plaques. METHODS For each dog, clinicopathological characterization included physical examination, lesion cytological evaluation, bacterial culture and sensitivity testing, skin histopathological investigation and direct and indirect immunofluorescence testing. Additional diagnostic imaging and haematological testing was performed to exclude extracutaneous disease. RESULTS Both dogs exhibited lesions clinically and histologically compatible with PF and GDLE. Moreover, one dog exhibited generalized leucotrichia and chronic superficial keratitis. Remission was achieved with immunosuppressive dosages of prednisolone [high-dose pulse (Case 1) or standard immunosuppressive dosage (Case 2)] and ciclosporin (5-6 mg/kg/day). Tissue-bound antikeratinocyte immunoglobulin (Ig)G and IgM were detected in both dogs. A weak basement membrane zone deposit of C3 was seen in one dog. Circulating antikeratinocyte and anti-desmocollin-1 IgG were detected in one dog. CONCLUSIONS AND CLINICAL IMPORTANCE Cutaneous polyautoimmunity can occur in the dog. Depending on the specific disease combinations, overlapping clinical features may present diagnostic and/or therapeutic challenges. Moreover, these cases should be monitored for development of additional cutaneous or extra-cutaneous AD(s).
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Affiliation(s)
- Britt J Levy
- Department of Clinical Sciences, College of Veterinary Medicine, NC State University, 1060 William Moore Drive, Raleigh, NC, 27607, USA
| | - Keith E Linder
- Department of Population Health and Pathobiology, College of Veterinary Medicine, NC State University, 1060 William Moore Drive, Raleigh, NC, 27607, USA.,Center for Comparative Medicine and Translational Research, NC State University, Raleigh, NC, 27606, USA
| | - Lisa B Mamo
- Department of Clinical Sciences, College of Veterinary Medicine, NC State University, 1060 William Moore Drive, Raleigh, NC, 27607, USA
| | - Ina Herrmann
- Department of Clinical Sciences, College of Veterinary Medicine, NC State University, 1060 William Moore Drive, Raleigh, NC, 27607, USA
| | - Petra Bizikova
- Department of Clinical Sciences, College of Veterinary Medicine, NC State University, 1060 William Moore Drive, Raleigh, NC, 27607, USA.,Center for Comparative Medicine and Translational Research, NC State University, Raleigh, NC, 27606, USA
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8
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Genetic heterogeneity and diversity of North American golden retrievers using a low density STR marker panel. PLoS One 2019; 14:e0212171. [PMID: 30811441 PMCID: PMC6392251 DOI: 10.1371/journal.pone.0212171] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Accepted: 01/29/2019] [Indexed: 01/19/2023] Open
Abstract
Thirty-three autosomal short tandem repeat (STR) markers were used to evaluate genetic heterogeneity and diversity in 525 golden retrievers (GRs). This breed was selected because of its popularity and artificial selection for conformation vs. performance phenotypes. Seven additional STRs were used to evaluate the highly polymorphic dog leukocyte antigen (DLA) class I and class II regions. From 3 to 13 alleles were found at each of the 33 loci (mean 7) and the average effective alleles (Ne) was 3.34. The observed heterozygosity was 0.65 and the expected heterozygosity was 0.68. The resulting fixation index was 0.035 indicating that the population was randomly breeding. We found that modern GRs retain 46% of genomic diversity present in all canids and 21/175 (12%) and 20/90 (22%) of the known DLA class I and class II haplotypes, respectively. Selection for performance or conformation led to a narrowing of genomic and DLA diversity with conformation having a greater effect than performance. A comparison was made between coefficient of inbreeding (COI) determined from 10 or 12 generation pedigrees and DNA based internal relatedness values. A weak but significant correlation was observed between IR score and 10 or 12 generation COI (r = 0.38, p<0.0001 and r = 0.40, p<0.0001, respectively). IR values were higher in conformation than performance lines but only significant at p = 0.17. This was supported by 10 and 12 generation COI values that were significantly (p<0.0001) higher in conformation than performance lines. We demonstrate herein that a low density of STR markers can be utilized to study the genetic makeup of GRs.
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9
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Bove RM. Why monkeys do not get multiple sclerosis (spontaneously): An evolutionary approach. EVOLUTION MEDICINE AND PUBLIC HEALTH 2018; 2018:43-59. [PMID: 29492266 PMCID: PMC5824939 DOI: 10.1093/emph/eoy002] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Accepted: 11/07/2017] [Indexed: 12/20/2022]
Abstract
The goal of this review is to apply an evolutionary lens to understanding the origins of multiple sclerosis (MS), integrating three broad observations. First, only humans are known to develop MS spontaneously. Second, humans have evolved large brains, with characteristically large amounts of metabolically costly myelin. This myelin is generated over long periods of neurologic development—and peak MS onset coincides with the end of myelination. Third, over the past century there has been a disproportionate increase in the rate of MS in young women of childbearing age, paralleling increasing westernization and urbanization, indicating sexually specific susceptibility in response to changing exposures. From these three observations about MS, a life history approach leads us to hypothesize that MS arises in humans from disruption of the normal homeostatic mechanisms of myelin production and maintenance, during our uniquely long myelination period. This review will highlight under-explored areas of homeostasis in brain development, that are likely to shed new light on the origins of MS and to raise further questions about the interactions between our ancestral genes and modern environments.
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Affiliation(s)
- Riley M Bove
- Department of Neurology, UCSF, San Francisco, CA, USA
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10
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Guandalini A, Di Girolamo N, Corvi R, Santillo D, Andreani V, Pinzo B. Epidemiology of ocular disorders presumed to be inherited in three small Italian dog breeds in Italy. Vet Ophthalmol 2017; 21:524-529. [PMID: 29284193 DOI: 10.1111/vop.12542] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
OBJECTIVE To describe the prevalence and the types of eye disorders that are known or presumed to be inherited (KP-HED) in three small Italian dog breeds. ANIMALS Three small Italian dog breeds: Maltese, Bolognese, and Italian Greyhound. PROCEDURES All dogs of the breeds selected for this prospective observational study that underwent a complete ophthalmic examination between 1994 and 2015 were included. General and proportional KP-HED prevalence with 95% confidence intervals were reported. RESULTS Three hundred and six of 462 dogs were affected by at least one KP-HED (66.2%; 95% CI: 61.8%-70.4%). In the entire population, the five most common KP-HED were cataract (n = 122; rate on the total number of KP-HED: 31.4%), entropion (n = 56; 14.4%), keratoconjunctivitis sicca (n = 33; 8.5%), retinal dysplasia (n = 24; 6.2%), and persistent pupillary membrane (iris to iris) (n = 21; 5.4%). The most common KP-HED in each breed were cataracts in the Maltese (35.1%) and in the Bolognese (24.2%), and presentation of vitreous in the anterior chamber in the Italian Greyhound (46.7%). CONCLUSIONS Clinicians should be aware of KP-HED that commonly affect three small Italian dog breeds. Breed standards should be reconsidered, and breeding programs should be directed at limiting such disorders.
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Affiliation(s)
- Adolfo Guandalini
- Department of Ophthalmology, Centro Veterinario Specialistico (CVS), Via Sandro Giovannini 51/53, 00137, Rome, Italy
| | - Nicola Di Girolamo
- Department of Ophthalmology, Centro Veterinario Specialistico (CVS), Via Sandro Giovannini 51/53, 00137, Rome, Italy.,EBMVet, Via Sigismondo Trecchi 20, Cremona, Italy
| | - Roberta Corvi
- Department of Ophthalmology, Centro Veterinario Specialistico (CVS), Via Sandro Giovannini 51/53, 00137, Rome, Italy
| | - Daniele Santillo
- Department of Ophthalmology, Centro Veterinario Specialistico (CVS), Via Sandro Giovannini 51/53, 00137, Rome, Italy
| | - Valentina Andreani
- Department of Ophthalmology, Centro Veterinario Specialistico (CVS), Via Sandro Giovannini 51/53, 00137, Rome, Italy
| | - Barbara Pinzo
- Department of Ophthalmology, Centro Veterinario Specialistico (CVS), Via Sandro Giovannini 51/53, 00137, Rome, Italy
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Pedersen NC, Shope B, Liu H. An autosomal recessive mutation in SCL24A4 causing enamel hypoplasia in Samoyed and its relationship to breed-wide genetic diversity. Canine Genet Epidemiol 2017; 4:11. [PMID: 29201383 PMCID: PMC5699110 DOI: 10.1186/s40575-017-0049-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Accepted: 09/17/2017] [Indexed: 01/29/2023] Open
Abstract
Background Pure breeding of dogs has led to over 700 heritable disorders, of which almost 300 are Mendelian in nature. Seventy percent of the characterized mutations have an autosomal recessive mode of inheritance, indicative of positive selection during bouts of inbreeding primarily for new desired conformational traits. Samoyed suffer from several common complex genetic disorders, but up to this time only two X-linked and one autosomal dominant disorder have been identified. Previous studies based on pedigrees and SNP arrays have concluded that Samoyed breeders have done a good job in maintaining genetic diversity and avoiding excessive inbreeding. This may explain why autosomal recessive disorders have not occurred to the extent observed in many other breeds. However, an enamel hypoplasia analogous to a form of autosomal recessive amelogenesis imperfecta (ARAI) in humans has been recently characterized in Samoyed, although the causative mutation appears to have existed for three or more decades. The rise of such a mutation indicates that bouts of inbreeding for desired conformational traits are still occurring despite an old and well-defined breed standard. Therefore, the present study has two objectives: 1) measure genetic diversity in the breed using DNA and short tandem repeats (STR), and 2) identify the exact mutation responsible for enamel hypoplasia in the breed, possible explanations for its recent spread, and the effect of eliminating the mutation on existing genetic diversity. Results The recent discovery of an autosomal recessive amelogenesis imperfecta (ARAI) in Samoyed provides an opportunity to study the mutation as well as genetic factors that favored its occurrence and subsequent spread. The first step in the study was to use 33 short tandem repeat (STR) loci on 25/38 autosomes and seven STRs across the dog leukocyte antigen (DLA) class I and II regions on CFA12 to determine the DNA-based genetic profile of 182 individuals from North America, Europe and Australia. Samoyed from the three continents constituted a single breed with only slight genetic differences. Breed-wide genetic diversity was low, most likely from a small founder population and subsequent artificial genetic bottlenecks. Two alleles at each autosome locus occurred in 70–95% of the dogs and 54% of alleles were homozygous. The number of DLA class I and II haplotypes was also low and three class I and two class II haplotypes occurred in 80–90% of individuals. Therefore, most Samoyed belong to two lines, with most dogs possessing a minority of existing genetic diversity and a minority of dogs containing a majority of diversity. Although contemporary Samoyed lack genetic diversity, the bulk of parents are as unrelated as possible with smaller subpopulations either more inbred or outbred than the total population. A familial disorder manifested by hypocalcification of enamel has been recently identified. A genome wide association study (GWAS) on seven affected and five unrelated healthy dogs pointed to a region of extended homozygosity on Canis familiaris autosome 8 (CFA8). The region contained a gene in the solute carrier 24 family (SCL24A4) that encodes a protein involved in potassium dependent sodium/calcium exchange and transport. Mutations in this gene were recently found to cause a similar type of enamel hypoplasia in people. Sequencing of this candidate gene revealed a 21 bp duplication in exon 17. A test for the duplication was in concordance with the disease phenotype. The exact incidence of affected dogs is unknown, but 12% of the 168 healthy dogs tested were heterozygous for the mutation. This population was biased toward close relatives, so a liberal estimate of the incidence of affected dogs in the breed would be around 3.6/1000. Theoretical calculations based on the comparison of the whole population with a population devoid of carriers indicated that eliminating the trait would not affect existing genetic diversity at this time. Conclusions The contemporary Samoyed, like many other breeds, has retained only a small portion of the genetic diversity that exists among all dogs. This limited genetic diversity along with positive genetic selection for desirable traits has led to at least three simple non-recessive genetic disorders and a low incidence of complex genetic traits such as autoimmune disease and hip dysplasia. Unlike many other pure breeds, the Samoyed has been spared the spate of deleterious autosomal recessive traits that have plagued many other pure breeds. However, ARAI due to a mutation in the SCL24A4 gene has apparently existed in the breed for several decades but is being increasingly diagnosed. The increase in diseased dogs is most likely due to a period of intensified positive selection for some desired conformational trait. A genetic test has been developed for identifying the mutation carriers which will enable the breeders to eliminate enamel hypoplasia in Samoyed by selective breeding and it appears that this mutation can be eliminated now without loss of genetic diversity.
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Affiliation(s)
- Niels C Pedersen
- Center for Companion Animal Health, University of California, One Shields Avenue, Davis, CA 95616 USA
| | - Bonnie Shope
- Veterinary Dental Services, LLC, 530 Massachusetts Ave, Boxborough, MA 01719 USA
| | - Hongwei Liu
- Department of Veterinary Pathology, Microbiology and Immunology, University of California, One Shields Avenue, Davis, CA 65616 USA
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12
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Dahlgren S, Ziener ML, Lingaas F. A genome-wide association study identifies a region strongly associated with symmetrical onychomadesis on chromosome 12 in dogs. Anim Genet 2016; 47:708-716. [PMID: 27629549 DOI: 10.1111/age.12469] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/15/2016] [Indexed: 12/26/2022]
Abstract
Symmetrical onychomadesis causes periodic loss of claws in otherwise healthy dogs. Genome-wide association analysis in 225 Gordon Setters identified a single region associated with symmetrical onychomadesis on chromosome 12 (spanning about 3.3 mb). A meta-analysis including also English Setters indicated that this genomic region predisposes for symmetrical onychomadesis in English Setters as well. The associated region spans most of the major histocompatibility complex and nearly 1 Mb downstream. Like many other autoimmune diseases, associations of symmetrical onychomadesis with DLA class II alleles have been reported. In this study, no associated markers were revealed within any of the DLA-DRB1, -DQA1 or -DQB1 genes, and the odds for symmetrical onychomadesis in the Gordon Setters were much higher, carrying significant single nucleotide polymorphisms compared to the odds of any of the recorded DLA-DRB1/DQA1/DQB1 haplotypes. We noticed that some of the associated DLA haplotypes were different between the English Setters and the Gordon Setters. Interestingly, associated SNP chip markers showed a more consistent pattern of allelic variants related to cases or controls regardless of breed. In conclusion, the associated genetic markers identified in this study hold the potential to aid in selection of breeding animals to reduce the frequency of symmetrical onychomadesis in the dog.
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Affiliation(s)
- S Dahlgren
- Department of Basic Sciences and Aquatic Medicine, Norwegian University of Life Sciences, Oslo, Norway.
| | - M Lund Ziener
- Department of Basic Sciences and Aquatic Medicine, Norwegian University of Life Sciences, Oslo, Norway.,Fredrikstad Animal Hospital, Fredrikstad, Norway
| | - F Lingaas
- Department of Basic Sciences and Aquatic Medicine, Norwegian University of Life Sciences, Oslo, Norway
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Joonè CJ, De Cramer KGM, Nöthling JO. The first case of genetically confirmed monozygotic twinning in the dog. Reprod Domest Anim 2016; 51:835-9. [DOI: 10.1111/rda.12746] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Accepted: 07/03/2016] [Indexed: 01/12/2023]
Affiliation(s)
- CJ Joonè
- Department of Production Animal Studies; Faculty of Veterinary Science; University of Pretoria; Pretoria South Africa
- Division of Tropical Health and Medicine; College of Public Health; Medical and Veterinary Sciences; James Cook University; Townsville Australia
| | - KGM De Cramer
- Rant en Dal Animal Hospital; Mogale City South Africa
| | - JO Nöthling
- Department of Production Animal Studies; Faculty of Veterinary Science; University of Pretoria; Pretoria South Africa
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Polymorphisms in ERAP1 and ERAP2 are shared by Caninae and segregate within and between random- and pure-breeds of dogs. Vet Immunol Immunopathol 2016; 179:46-57. [PMID: 27590425 DOI: 10.1016/j.vetimm.2016.08.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Revised: 08/03/2016] [Accepted: 08/04/2016] [Indexed: 01/01/2023]
Abstract
Specific polymorphisms in the endoplasmic reticulum amino peptidase genes ERAP1 and ERAP2, when present with certain MHC class receptor types, have been associated with increased risk for specific cancers, infectious diseases and autoimmune disorders in humans. This increased risk has been linked to distinct polymorphisms in both ERAPs and MHC class I receptors that affect the way cell-generated peptides are screened for antigenicity. The incidence of cancer, infectious disease and autoimmune disorders differ greatly among pure breeds of dogs as it does in humans and it is possible that this heightened susceptibility is also due to specific polymorphisms in ERAP1 and ERAP2. In order to determine if such polymorphisms exist, the ERAP1 and ERAP2 genes of 10 dogs of nine diverse breeds were sequenced and SNPs causing synonymous or non-synonymous amino acid changes, deletions or insertions were identified. Eight ERAP1 and 10 ERAP2 SNPs were used to create a Sequenom MassARRAY iPLEX based test panel which defined 24 ERAP1, 36 ERAP2 and 128 ERAP1/2 haplotypes. The prevalence of these haplotypes was then measured among dog, wolf, coyote, jackal and red fox populations. Some haplotypes were species specific, while others were shared across species, especially between dog, wolf, coyote and jackal. The prevalence of these haplotypes was then compared among various canid populations, and in particular between various populations of random- and pure-bred dogs. Human-directed positive selection has led to loss of ERAP diversity and segregation of certain haplotypes among various dog breeds. A phylogenetic tree generated from 45 of the most common ERAP1/2 haplotypes demonstrated three distinct clades, all of which were rooted with haplotypes either shared among species or specific to contemporary dogs, coyote and wolf.
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Friedenberg SG, Buhrman G, Chdid L, Olby NJ, Olivry T, Guillaumin J, O'Toole T, Goggs R, Kennedy LJ, Rose RB, Meurs KM. Evaluation of a DLA-79 allele associated with multiple immune-mediated diseases in dogs. Immunogenetics 2015; 68:205-17. [PMID: 26711123 DOI: 10.1007/s00251-015-0894-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2015] [Accepted: 12/18/2015] [Indexed: 11/30/2022]
Abstract
Immune-mediated diseases are common and life-threatening disorders in dogs. Many canine immune-mediated diseases have strong breed predispositions and are believed to be inherited. However, the genetic mutations that cause these diseases are mostly unknown. As many immune-mediated diseases in humans share polymorphisms among a common set of genes, we conducted a candidate gene study of 15 of these genes across four immune-mediated diseases (immune-mediated hemolytic anemia, immune-mediated thrombocytopenia, immune-mediated polyarthritis (IMPA), and atopic dermatitis) in 195 affected and 206 unaffected dogs to assess whether causative or predictive polymorphisms might exist in similar genes in dogs. We demonstrate a strong association (Fisher's exact p = 0.0004 for allelic association, p = 0.0035 for genotypic association) between two polymorphic positions (10 bp apart) in exon 2 of one allele in DLA-79, DLA-79*001:02, and multiple immune-mediated diseases. The frequency of this allele was significantly higher in dogs with immune-mediated disease than in control dogs (0.21 vs. 0.12) and ranged from 0.28 in dogs with IMPA to 0.15 in dogs with atopic dermatitis. This allele has two non-synonymous substitutions (compared with the reference allele, DLA-79*001:01), resulting in F33L and N37D amino acid changes. These mutations occur in the peptide-binding pocket of the protein, and based upon our computational modeling studies, are likely to affect critical interactions with the peptide N-terminus. Further studies are warranted to confirm these findings more broadly and to determine the specific mechanism by which the identified variants alter canine immune system function.
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Affiliation(s)
- Steven G Friedenberg
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, 27607, USA. .,Comparative Medicine Institute, North Carolina State University, Raleigh, NC, 27607, USA.
| | - Greg Buhrman
- Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, NC, 27695, USA
| | - Lhoucine Chdid
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, 27607, USA
| | - Natasha J Olby
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, 27607, USA.,Comparative Medicine Institute, North Carolina State University, Raleigh, NC, 27607, USA
| | - Thierry Olivry
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, 27607, USA.,Comparative Medicine Institute, North Carolina State University, Raleigh, NC, 27607, USA
| | - Julien Guillaumin
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, The Ohio State University, Columbus, OH, 43210, USA
| | - Theresa O'Toole
- Department of Clinical Sciences, Cummings School of Veterinary Medicine, Tufts University, North Grafton, MA, 01536, USA
| | - Robert Goggs
- Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853, USA
| | - Lorna J Kennedy
- Centre for Integrated Genomic Medical Research, University of Manchester, Manchester, UK, M13 9PT
| | - Robert B Rose
- Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, NC, 27695, USA.,Comparative Medicine Institute, North Carolina State University, Raleigh, NC, 27607, USA
| | - Kathryn M Meurs
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, 27607, USA.,Comparative Medicine Institute, North Carolina State University, Raleigh, NC, 27607, USA
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Pedersen NC, Liu H, Leonard A, Griffioen L. A search for genetic diversity among Italian Greyhounds from Continental Europe and the USA and the effect of inbreeding on susceptibility to autoimmune disease. Canine Genet Epidemiol 2015; 2:17. [PMID: 26526059 PMCID: PMC4628233 DOI: 10.1186/s40575-015-0030-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Accepted: 10/15/2015] [Indexed: 12/22/2022] Open
Abstract
Background Previous studies documented the problem of inbreeding among Italian Greyhounds (IG) from the USA and its possible role in a multiple autoimmune disease syndrome. The present study is an extension of these earlier experiments and had two objectives: 1) to identify pockets of additional genetic diversity that might still exist among IG from the USA and Continental Europe, and 2) to determine how loss of genetic diversity within the genome and in the dog leukocyte antigen (DLA) complex relates to the problem of autoimmune disease in IG from the USA. Genetic testing was conducted using 33 short tandem repeat (STR) loci across 25 chromosomes and 7 STR loci that associated with specific dog leukocyte antigen (DLA) class I and II haplotypes. Standard genetic assessment tests based on allele frequencies and internal relatedness (IR) were used as measures of breed-wide and individual heterozygosity. Results The results of these tests demonstrated that IG from the USA and Continental Europe belonged to a single breed but were genetically distinguishable by genomic allele frequencies, DLA class I and II haplotypes, and principal coordinate analysis (PCoA). In the second part of the study, 85 IG from the USA that had suffered various autoimmune disorders (case) and 104 healthy dogs (control) of comparable age were studied for genetic associations with disease. Case dogs were found to be significantly more homozygous in the DLA regions than control dogs. Principal coordinate analysis did not differentiate case from control populations. No specific STR-associated DLA-class I or II haplotype was associated with increased autoimmune disease risks. Reasons for the loss of genetic diversity and increased homozygosity among IG from the USA were studied using registration data and deep pedigrees. The breed in the USA started from a small number of founders from Europe and has remained relatively isolated and small in numbers, limiting breeding choices especially in the period before modern transportation and artificial insemination. An additional cause of lost diversity and increased homozygosity has been the influence of famous sires and their show-winning progeny. The most influential of these sires was Ch. Dasa’s King of the Mountain (King) born in 1978. Virtually all contemporary IG from the USA have King at least once in 10 generation pedigrees and 18 % of the genome of contemporary IG from the USA is shared with King. Conclusions It was concluded that artificial genetic bottlenecks have concentrated numerous genetic polymorphisms responsible for autoimmune disease and that these risk factors did not originate in a specific individual or bloodline of the breed. Rather, they were of ancestral origin in both purebred and random bred dogs and inherited by descent. Italian Greyhound breeders in the USA have several options to improve breed health: 1) breed against homozygosity within the genome and in the DLA region, 2) avoid breeding dogs that have suffered an autoimmune disorder, 3) increase diversity by incorporating the genetic differences that exist in IG from Continental Europe, or 4) outcross to other small sighthound breeds. The latter two approaches must be undertaken with care to avoid introduction of new deleterious traits and to maximize retention and dissemination of new genetic diversity.
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Affiliation(s)
- Niels C Pedersen
- Center for Companion Animal Health, School of Veterinary Medicine, University of California, One Shields Avenue, Davis, CA 95616 USA
| | - Hongwei Liu
- Center for Companion Animal Health, School of Veterinary Medicine, University of California, One Shields Avenue, Davis, CA 95616 USA
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Pedersen NC, Brucker L, Tessier NG, Liu H, Penedo MCT, Hughes S, Oberbauer A, Sacks B. The effect of genetic bottlenecks and inbreeding on the incidence of two major autoimmune diseases in standard poodles, sebaceous adenitis and Addison's disease. Canine Genet Epidemiol 2015; 2:14. [PMID: 26401342 PMCID: PMC4579369 DOI: 10.1186/s40575-015-0026-5] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2015] [Accepted: 08/06/2015] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND Sebaceous adenitis (SA) and Addison's disease (AD) increased rapidly in incidence among Standard Poodles after the mid-twentieth century. Previous attempts to identify specific genetic causes using genome wide association studies and interrogation of the dog leukocyte antigen (DLA) region have been non-productive. However, such studies led us to hypothesize that positive selection for desired phenotypic traits that arose in the mid-twentieth century led to intense inbreeding and the inadvertent amplification of AD and SA associated traits. RESULTS This hypothesis was tested with genetic studies of 761 Standard, Miniature, and Miniature/Standard Poodle crosses from the USA, Canada and Europe, coupled with extensive pedigree analysis of thousands more dogs. Genome-wide diversity across the world-wide population was measured using a panel of 33 short tandem repeat (STR) loci. Allele frequency data were also used to determine the internal relatedness of individual dogs within the population as a whole. Assays based on linkage between STR genomic loci and DLA genes were used to identify class I and II haplotypes and disease associations. Genetic diversity statistics based on genomic STR markers indicated that Standard Poodles from North America and Europe were closely related and reasonably diverse across the breed. However, genetic diversity statistics, internal relatedness, principal coordinate analysis, and DLA haplotype frequencies showed a marked imbalance with 30 % of the diversity in 70 % of the dogs. Standard Poodles with SA and AD were strongly linked to this inbred population, with dogs suffering with SA being the most inbred. No single strong association was found between STR defined DLA class I or II haplotypes and SA or AD in the breed as a whole, although certain haplotypes present in a minority of the population appeared to confer moderate degrees of risk or protection against either or both diseases. Dogs possessing minor DLA class I haplotypes were half as likely to develop SA or AD as dogs with common haplotypes. Miniature/Standard Poodle crosses being used for outcrossing were more genetically diverse than Standard Poodles and genetically distinguishable across the genome and in the DLA class I and II region. CONCLUSIONS Ancestral genetic polymorphisms responsible for SA and AD entered Standard Poodles through separate lineages, AD earlier and SA later, and were increasingly fixed by a period of close linebreeding that was related to popular bloodlines from the mid-twentieth century. This event has become known as the midcentury bottleneck or MCB. Sustained positive selection resulted in a marked imbalance in genetic diversity across the genome and in the DLA class I and II region. Both SA and AD were concentrated among the most inbred dogs, with genetic outliers being relatively disease free. No specific genetic markers other than those reflecting the degree of inbreeding were consistently associated with either disease. Standard Poodles as a whole remain genetically diverse, but steps should be taken to rebalance diversity using genetic outliers and if necessary, outcrosses to phenotypically similar but genetically distinct breeds.
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Affiliation(s)
- Niels C Pedersen
- Center for Companion Animal Health, School of Veterinary Medicine, University of California, One Shields Avenue, 95616 Davis, CA USA
| | - Lynn Brucker
- 1635 Grange Hall Road, 45432 Beavercreek, OH USA
| | | | - Hongwei Liu
- Center for Companion Animal Health, School of Veterinary Medicine, University of California, One Shields Avenue, 95616 Davis, CA USA
| | - Maria Cecilia T Penedo
- Veterinary Genetics Laboratory, School of Veterinary Medicine, University of California, One Shields Avenue, 95616 Davis, CA USA
| | - Shayne Hughes
- Veterinary Genetics Laboratory, School of Veterinary Medicine, University of California, One Shields Avenue, 95616 Davis, CA USA
| | - Anita Oberbauer
- Department of Animal Science, College of Agricultural and Environmental Sciences, University of California, One Shields Avenue, 95616 Davis, CA USA
| | - Ben Sacks
- Veterinary Genetics Laboratory, School of Veterinary Medicine, University of California, One Shields Avenue, 95616 Davis, CA USA
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Malerba E, Morini M, Fracassi F. Generalized vitiligo in a dog with primary hypoadrenocorticism. Vet Dermatol 2015; 26:376-8, e86. [PMID: 26104920 DOI: 10.1111/vde.12228] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/27/2015] [Indexed: 11/28/2022]
Abstract
BACKGROUND Vitiligo is presumed to be an autoimmune disorder in the dog; primary adrenal insufficiency (Addison's disease) is associated with immune-mediated destruction of the adrenal cortex. HYPOTHESIS/OBJECTIVES In this case report we describe a dog with primary hypoadrenocorticism that developed generalized vitiligo. CASE REPORT A 4-year-old spayed female cross-bred dog developed signs of Addison's disease and this was confirmed by biochemical testing; the dog was treated with fludrocortisone acetate and then desoxycorticosterone pivalate. Three months after the diagnosis, the dog developed depigmentation of the whole hair coat and of several focal areas of the skin. Histopathological findings were consistent with vitiligo. CONCLUSIONS AND CLINICAL IMPORTANCE Dogs with immune-mediated disease may develop other manifestations of immune-mediated disease, including a combination of Addison's disease and vitiligo. The cause in this case was not determined.
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Affiliation(s)
- Eleonora Malerba
- Department of Veterinary Medical Sciences, University of Bologna, Via Tolara di Sopra 50, Ozzano dell'Emilia, 40064, Italy
| | - Maria Morini
- Department of Veterinary Medical Sciences, University of Bologna, Via Tolara di Sopra 50, Ozzano dell'Emilia, 40064, Italy
| | - Federico Fracassi
- Department of Veterinary Medical Sciences, University of Bologna, Via Tolara di Sopra 50, Ozzano dell'Emilia, 40064, Italy
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Threlfall AJ, Boag AM, Soutter F, Glanemann B, Syme HM, Catchpole B. Analysis of DLA-DQB1 and polymorphisms in CTLA4 in Cocker spaniels affected with immune-mediated haemolytic anaemia. Canine Genet Epidemiol 2015; 2:8. [PMID: 26401336 PMCID: PMC4579385 DOI: 10.1186/s40575-015-0020-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2015] [Accepted: 04/30/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Cocker spaniels are predisposed to immune-mediated haemolytic anaemia (IMHA), suggesting that genetic factors influence disease susceptibility. Dog leukocyte antigen (DLA) class II genes encode major histocompatibility complex (MHC) molecules that are involved in antigen presentation to CD4(+) T cells. Several DLA haplotypes have been associated with autoimmune disease, including IMHA, in dogs, and breed specific differences have been identified. Cytotoxic T lymphocyte antigen 4 (CTLA4) is a critical molecule involved in the regulation of T-cell responses. Single nucleotide polymorphisms (SNPs) in the CTLA4 promoter have been shown to be associated with several autoimmune diseases in humans and more recently with diabetes mellitus and hypoadrenocorticism in dogs. The aim of the present study was to investigate whether DLA-DQB1 alleles or CTLA4 promoter variability are associated with risk of IMHA in Cocker spaniels. RESULTS There were a restricted number of DLA-DQB1 alleles identified, with a high prevalence of DLA-DQB1*007:01 in both groups. A high prevalence of DLA-DQB1 homozygosity was identified, although there was no significant difference between IMHA cases and controls. CTLA4 promoter haplotype diversity was limited in Cocker spaniels, with all dogs expressing at least one copy of haplotype 8. There was no significant difference comparing haplotypes in the IMHA affected group versus control group (p = 0.23). Homozygosity for haplotype 8 was common in Cocker spaniels with IMHA (27/29; 93 %) and in controls (52/63; 83 %), with no statistically significant difference in prevalence between the two groups (p = 0.22). CONCLUSIONS DLA-DQB1 allele and CTLA4 promoter haplotype were not found to be significantly associated with IMHA in Cocker spaniels. Homozygosity for DLA-DQB1*007:01 and the presence of CTLA4 haplotype 8 in Cocker spaniels might increase overall susceptibility to IMHA in this breed, with other genetic and environmental factors involved in disease expression and progression.
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Affiliation(s)
- Anna J Threlfall
- Department of Clinical Science and Services, Royal Veterinary College, North Mymms, Hatfield, AL9 7TA Hertfordshire UK
| | - Alisdair M Boag
- The Royal (Dick) School of Veterinary Studies, The University of Edinburgh, Easter Bush Campus, Midlothian, EH25 9RG UK
| | - Francesca Soutter
- Department of Pathology and Pathogen Biology, Royal Veterinary College, North Mymms, Hatfield, AL9 7TA Hertfordshire UK
| | - Barbara Glanemann
- Department of Clinical Science and Services, Royal Veterinary College, North Mymms, Hatfield, AL9 7TA Hertfordshire UK
| | - Harriet M Syme
- Department of Clinical Science and Services, Royal Veterinary College, North Mymms, Hatfield, AL9 7TA Hertfordshire UK
| | - Brian Catchpole
- Department of Pathology and Pathogen Biology, Royal Veterinary College, North Mymms, Hatfield, AL9 7TA Hertfordshire UK
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Abstract
Hypoadrenocorticism is an uncommon disease in dogs and rare in humans, where it is known as Addison disease (ADD). The disease is characterized by a deficiency in corticosteroid production from the adrenal cortex, requiring lifelong hormone replacement therapy. When compared with humans, the pathogenesis of hypoadrenocorticism in dogs is not well established, although the evidence supports a similar autoimmune etiology of adrenocortical pathology. Several immune response genes have been implicated in determining susceptibility to Addison disease in humans, some of which are shared with other autoimmune syndromes. Indeed, other types of autoimmune disease are common (approximately 50%) in patients affected with ADD. Several lines of evidence suggest a genetic component to the etiology of canine hypoadrenocorticism. Certain dog breeds are overrepresented in epidemiologic studies, reflecting a likely genetic influence, supported by data from pedigree analysis. Molecular genetic studies have identified similar genes and signaling pathways, involved in ADD in humans, to be also associated with susceptibility to canine hypoadrenocorticism. Immune response genes such as the dog leukocyte antigen (DLA) and cytotoxic T-lymphocyte-associated protein 4 (CTLA4) genes seem to be particularly important. It is clear that there are genetic factors involved in determining susceptibility to canine hypoadrenocorticism, although similar to the situation in humans, this is likely to represent a complex genetic disorder.
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Affiliation(s)
- Alisdair M Boag
- Hospital for Small Animals, Royal (Dick) School of Veterinary Studies, University of Edinburgh, Midlothian, Scotland.
| | - Brian Catchpole
- Department of Pathology and Pathogen Biology, Royal Veterinary College, University of London, Hatfield, UK
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Gandolfi B, Liu H, Griffioen L, Pedersen NC. Simple recessive mutation inENAMis associated with amelogenesis imperfecta in Italian Greyhounds. Anim Genet 2013; 44:569-78. [DOI: 10.1111/age.12043] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/21/2013] [Indexed: 11/29/2022]
Affiliation(s)
- Barbara Gandolfi
- Center for Companion Animal Health; Koret Center for Veterinary Genetics; School of Veterinary Medicine; University of California; One Shields Avenue; Davis; CA; 95616; USA
| | - Hongwei Liu
- Center for Companion Animal Health; Koret Center for Veterinary Genetics; School of Veterinary Medicine; University of California; One Shields Avenue; Davis; CA; 95616; USA
| | - Layle Griffioen
- Center for Companion Animal Health; Koret Center for Veterinary Genetics; School of Veterinary Medicine; University of California; One Shields Avenue; Davis; CA; 95616; USA
| | - Niels C. Pedersen
- Center for Companion Animal Health; Koret Center for Veterinary Genetics; School of Veterinary Medicine; University of California; One Shields Avenue; Davis; CA; 95616; USA
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Pedersen N, Liu H, Theilen G, Sacks B. The effects of dog breed development on genetic diversity and the relative influences of performance and conformation breeding. J Anim Breed Genet 2012; 130:236-48. [PMID: 23679949 DOI: 10.1111/jbg.12017] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2012] [Accepted: 10/02/2012] [Indexed: 12/22/2022]
Abstract
Genetic diversity was compared among eight dog breeds selected primarily for conformation (Standard Poodle, Italian Greyhound and show English Setter), conformation and performance (Brittany), predominantly performance (German Shorthaired and Wirehaired Pointers) or solely performance (field English Setter and Red Setter). Modern village dogs, which better reflect ancestral genetic diversity, were used as the standard. Four to seven maternal and one to two Y haplotypes were found per breed, with one usually dominant. Diversity of maternal haplotypes was greatest in village dogs, intermediate in performance breeds and lowest in conformation breeds. Maternal haplotype sharing occurred across all breeds, while Y haplotypes were more breed specific. Almost all paternal haplotypes were identified among village dogs, with the exception of the dominant Y haplotype in Brittanys, which has not been identified heretofore. The highest heterozygosity based on 24 autosomal microsatellites was found in village dogs and the lowest in conformation (show) breeds. Principal coordinate analysis indicated that conformation-type breeds were distinct from breeds heavily used for performance, the latter clustering more closely with village dogs. The Brittany, a well-established dual show and field breed, was also genetically intermediate between the conformation and performance breeds. The number of DLA-DRB1 alleles varied from 3 to 10 per breed with extensive sharing. SNPs across the wider DLA region were more frequently homozygous in all pure breeds than in village dogs. Compared with their village dog relatives, all modern breed dogs exhibit reduced genetic diversity. Genetic diversity was even more reduced among breeds under selection for show/conformation.
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Affiliation(s)
- N Pedersen
- Koret Foundation Center for Veterinary Genetics of the Center for Companion Animal Health, School of Veterinary Medicine, University of California, Davis, CA 95616, USA.
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Pedersen NC, Liu H, McLaughlin B, Sacks BN. Genetic characterization of healthy and sebaceous adenitis affected Standard Poodles from the United States and the United Kingdom. ACTA ACUST UNITED AC 2012; 80:46-57. [PMID: 22512808 DOI: 10.1111/j.1399-0039.2012.01876.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The degree of heterogeneity associated with geographic origin and sebaceous adenitis (SA) status in Standard Poodles from the United States (US) and the United Kingdom (UK) was assessed. Healthy and SA-affected Standard Poodles from the US and the UK shared a major mitochondrial DNA (mtDNA) haplotype and a single Y chromosome haplotype. However, minor mtDNA haplotypes and frequencies were somewhat different between US and UK dogs and were significantly less associated with SA than major haplotypes across both populations. The US and UK populations exhibited recent divergence from a common gene pool, based on allele frequencies of 24 highly polymorphic short tandem repeats and principle coordinates and cluster analyses of genotype frequencies. However, there was no differentiation between SA affected and unaffected dogs. Over 90% of US and UK Poodles shared a common dog leukocyte antigen (DLA) class II haplotype, but showed some differentiation in minor haplotype frequency. No difference was observed in haplotype heterozygosity between SA affected and unaffected dogs from the same country and no disease association for SA was found within the DLA region by a high density single nucleotide polymorphism (SNP) scan. Zygosity mapping in the DLA region of Poodles indicated much lower site-specific diversity than in an outbred population of street dogs from Bali, Indonesia, reflecting the degree that breed associated historical bottlenecks have reduced diversity in a polymorphic region of the genome. This study shows possible pitfalls in more extensive genome-wide association studies, such as case and control numbers, population stratification, the involvement of multiple genes, and/or the possibility that SA susceptibility is fixed or nearly fixed within the breed, which can reduce power to detect genetic associations.
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Affiliation(s)
- N C Pedersen
- Center for Companion Animal Health, School of Veterinary Medicine, University of California-Davis, Davis, CA 95616, USA.
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