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Bortolini M, Winkler PA, Moreno JCD, Sato MT, Guareschi BLV, Petersen-Jones SM, Montiani-Ferreira F. Preliminary characterization of a novel form of progressive retinal atrophy in the German Spitz dog associated with a frameshift mutation in GUCY2D. Vet Ophthalmol 2023; 26:532-547. [PMID: 36872573 DOI: 10.1111/vop.13079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Revised: 02/13/2023] [Accepted: 02/14/2023] [Indexed: 03/07/2023]
Abstract
OBJECTIVE To describe the clinical, preliminary electroretinographic and optical coherence tomography features of a newly identified form of progressive retinal atrophy (PRA) in German Spitzes, and identify the causal gene mutation. ANIMALS Thirty-three client-owned German Spitz dogs were included. PROCEDURES All animals underwent a full ophthalmic examination, including vision testing. In addition, fundus photography, ERG, and OCT were performed. A DNA-marker-based association analysis was performed to screen potential candidate genes and the whole genomes of four animals were sequenced. RESULTS Initial fundus changes were pale papilla and mild vascular attenuation. Oscillatory nystagmus was noted in 14 of 16 clinically affected puppies. Vision was impaired under both scotopic and photopic conditions. Rod-mediated ERGs were unrecordable in all affected dogs tested, reduced cone-mediated responses were present in one animal at 3 months of age and unrecordable in the other affected animals tested. Multiple small retinal bullae were observed in three clinically affected animals (two with confirmed genetic diagnosis). OCT showed that despite loss of function, retinal structure was initially well-preserved, although a slight retinal thinning developed in older animals with the ventral retina being more severely affected. Pedigree analysis supported an autosomal recessive inheritance. A mutation was identified in GUCY2D, which segregated with the disease (NM_001003207.1:c.1598_1599insT; p.(Ser534GlufsTer20)). Human subjects with GUCY2D mutations typically show an initial disconnect between loss of function and loss of structure, a feature recapitulated in the affected dogs in this study. CONCLUSION We identified early-onset PRA in the German Spitz associated with a frameshift mutation in GUCY2D.
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Affiliation(s)
- Mariza Bortolini
- Department of Veterinary Medicine, Federal University of Paraná, Curitiba, Puerto Rico, Brazil
| | - Paige A Winkler
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, Michigan, USA
| | | | - Mario Teruo Sato
- Department of Ophthalmology, Federal University of Paraná, Curitiba, Paraná, USA
| | | | - Simon M Petersen-Jones
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, Michigan, USA
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2
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Preclinical Models of Retinitis Pigmentosa. Methods Mol Biol 2022; 2560:181-215. [PMID: 36481897 DOI: 10.1007/978-1-0716-2651-1_19] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Retinitis pigmentosa (RP) is the name for a group of phenotypically-related heritable retinal degenerative disorders. Many genes have been implicated as causing variants of RP, and while the clinical phenotypes are remarkably similar, they may differ in age of onset, progression, and severity. Common inheritance patterns for specific genes connected with the development of the disorder include autosomal dominant, autosomal recessive, and X-linked. Modeling the disease in animals and other preclinical systems offers a cost-conscious, ethical, and time-efficient method for studying the disease subtypes. The history of RP models is briefly examined, and both naturally occurring and transgenic preclinical models of RP in many different organisms are discussed. Syndromic forms of RP and models thereof are reviewed as well.
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3
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Zueva L, Zayas-Santiago A, Rojas L, Sanabria P, Alves J, Tsytsarev V, Inyushin M. Multilayer subwavelength gratings or sandwiches with periodic structure shape light reflection in the tapetum lucidum of taxonomically diverse vertebrate animals. JOURNAL OF BIOPHOTONICS 2022; 15:e202200002. [PMID: 35243792 PMCID: PMC9487202 DOI: 10.1002/jbio.202200002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/02/2022] [Revised: 02/09/2022] [Accepted: 02/24/2022] [Indexed: 06/14/2023]
Abstract
Eye shine in the dark has attracted many researchers to the field of eye optics, but the initial studies of subwavelength arrangements in tapetum began only with the development of electronic microscopy at the end of the 20th century. As a result of a number of studies, it was shown that the reflective properties of the tapetum are due to their specialized cellular subwavelength microstructure (photonic crystals). These properties, together with the mutual orientation of the crystals, lead to a significant increase in reflection, which, in turn, enhances the sensitivity of the eye. In addition, research confirmed that optical mechanisms of reflection in the tapetum are very similar even for widely separated species. Due to progress in the field of nano-optics, researchers now have a better understanding of the main principles of this phenomenon. In this review, we summarize electron microscopic and functional studies of tapetal structures in the main vertebrate classes. This allows data on the microstructure of the tapetum to be used to improve our understanding of the visual system.
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Affiliation(s)
- Lidia Zueva
- Universidad Central del Caribe School of Medicine, Bayamon, Puerto Rico, USA
| | | | - Legier Rojas
- Universidad Central del Caribe School of Medicine, Bayamon, Puerto Rico, USA
| | - Priscila Sanabria
- Universidad Central del Caribe School of Medicine, Bayamon, Puerto Rico, USA
| | - Janaina Alves
- Universidad Central del Caribe School of Medicine, Bayamon, Puerto Rico, USA
| | | | - Mikhail Inyushin
- Universidad Central del Caribe School of Medicine, Bayamon, Puerto Rico, USA
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4
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Urkasemsin G, Pongpanich M, Sariya L, Kongcharoen A, Buddhirongawatr R, Rungarunlert S, Ferreira JN, Chetruengchai W, Phokaew C, Srichomthong C, Shotelersuk V. Whole genome sequencing identifies a homozygous nonsense mutation in the JPH2 gene in Shih Tzu dogs with progressive retinal atrophy. Anim Genet 2021; 52:714-719. [PMID: 34231238 DOI: 10.1111/age.13118] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/24/2021] [Indexed: 11/28/2022]
Abstract
Progressive retinal atrophy (PRA), common autosomal recessive disorder affecting several dog breeds including Shih Tzu, is characterized by degeneration of photoreceptors leading to blindness. To identify PRA genetic variants, three affected and 15 unaffected Shih Tzu and 20 non-Shih Tzu were recruited. Dogs underwent ophthalmologic examination and electroretinography, revealing hallmark retina pathological changes and an abnormal electroretinography in all affected dogs but not in unaffected dogs. WGS was performed. Non-synonymous homozygous variants were searched in coding regions of genes involved in retinal diseases/development; the criterion was that variants should only be present in affected dogs and should be absent in both unaffected and 46 genomes of dogs (from an available evolutionary database). Only one out of the 109 identified variants is predicted to harbor a high-impact consequence, a nonsense c.452A>C (p.L151X) in the JPH2 gene. The genotype of JPH2 variant in all 38 dogs was determined with Sanger sequencing. All three affected dogs, but none of the 35 unaffected, were homozygous for the nonsense variant. JPH2 has been previously found to be expressed in several excitable cells/tissues including retina photoreceptors. Hence, JPH2 is a candidate gene for PRA in Shih Tzu.
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Affiliation(s)
- G Urkasemsin
- Department of Preclinic and Applied Animal Science, Faculty of Veterinary Science, Mahidol University, Nakhon Pathom, 73170, Thailand
| | - M Pongpanich
- Department of Mathematics and Computer Science, Faculty of Science, Chulalongkorn University, Bangkok, 10330, Thailand.,Age-related Inflammation and Degeneration Research Unit, Chulalongkorn University, Bangkok, 10330, Thailand
| | - L Sariya
- The Monitoring and Surveillance Center for Zoonotic Diseases in Wildlife and Exotic Animals, Faculty of Veterinary Science, Mahidol University, Nakhon Pathom, 73170, Thailand
| | - A Kongcharoen
- Prasu-Arthorn Animal Hospital, Faculty of Veterinary Science, Mahidol University, Nakhon Pathom, 73170, Thailand
| | - R Buddhirongawatr
- Department of Clinical Sciences and Public Health, Faculty of Veterinary Science, Mahidol University, Nakhon Pathom, 73170, Thailand
| | - S Rungarunlert
- Department of Preclinic and Applied Animal Science, Faculty of Veterinary Science, Mahidol University, Nakhon Pathom, 73170, Thailand
| | - J N Ferreira
- Exocrine Gland Biology and Regeneration Research Group, Faculty of Dentistry, Chulalongkorn University, Bangkok, 10330, Thailand
| | - W Chetruengchai
- Department of Pediatrics, Faculty of Medicine, Center of Excellence for Medical Genomics, Medical Genomics Cluster, Chulalongkorn University, Bangkok, 10330, Thailand.,Excellence Center for Genomics and Precision Medicine, King Chulalongkorn Memorial Hospital, The Thai Red Cross Society, Bangkok, 10330, Thailand
| | - C Phokaew
- Department of Pediatrics, Faculty of Medicine, Center of Excellence for Medical Genomics, Medical Genomics Cluster, Chulalongkorn University, Bangkok, 10330, Thailand.,Excellence Center for Genomics and Precision Medicine, King Chulalongkorn Memorial Hospital, The Thai Red Cross Society, Bangkok, 10330, Thailand
| | - C Srichomthong
- Department of Pediatrics, Faculty of Medicine, Center of Excellence for Medical Genomics, Medical Genomics Cluster, Chulalongkorn University, Bangkok, 10330, Thailand.,Excellence Center for Genomics and Precision Medicine, King Chulalongkorn Memorial Hospital, The Thai Red Cross Society, Bangkok, 10330, Thailand
| | - V Shotelersuk
- Department of Pediatrics, Faculty of Medicine, Center of Excellence for Medical Genomics, Medical Genomics Cluster, Chulalongkorn University, Bangkok, 10330, Thailand.,Excellence Center for Genomics and Precision Medicine, King Chulalongkorn Memorial Hospital, The Thai Red Cross Society, Bangkok, 10330, Thailand
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5
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Sher I, Moverman D, Ketter-Katz H, Moisseiev E, Rotenstreich Y. In vivo retinal imaging in translational regenerative research. ANNALS OF TRANSLATIONAL MEDICINE 2020; 8:1096. [PMID: 33145315 PMCID: PMC7575995 DOI: 10.21037/atm-20-4355] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Regenerative translational studies must include a longitudinal assessment of the changes in retinal structure and function that occur as part of the natural history of the disease and those that result from the studied intervention. Traditionally, retinal structural changes have been evaluated by histological analysis which necessitates sacrificing the animals. In this review, we describe key imaging approaches such as fundus imaging, optical coherence tomography (OCT), OCT-angiography, adaptive optics (AO), and confocal scanning laser ophthalmoscopy (cSLO) that enable noninvasive, non-contact, and fast in vivo imaging of the posterior segment. These imaging technologies substantially reduce the number of animals needed and enable progression analysis and longitudinal follow-up in individual animals for accurate assessment of disease natural history, effects of interventions and acute changes. We also describe the benefits and limitations of each technology, as well as outline possible future directions that can be taken in translational retinal imaging studies.
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Affiliation(s)
- Ifat Sher
- Goldschleger Eye Institute, Sheba Medical Center, Tel-Hashomer, Israel.,Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Daniel Moverman
- Goldschleger Eye Institute, Sheba Medical Center, Tel-Hashomer, Israel
| | - Hadas Ketter-Katz
- Goldschleger Eye Institute, Sheba Medical Center, Tel-Hashomer, Israel.,Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Elad Moisseiev
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.,Department of Ophthalmology, Meir Medical Center, Kfar Saba, Israel
| | - Ygal Rotenstreich
- Goldschleger Eye Institute, Sheba Medical Center, Tel-Hashomer, Israel.,Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
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6
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A systematic review and meta-analysis of canine, feline and human Toxocara infections in sub-Saharan Africa. J Helminthol 2019; 94:e96. [PMID: 31679534 DOI: 10.1017/s0022149x19000889] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Toxocariasis is an emerging zoonotic disease caused by Toxocara canis and T. cati. Toxocariasis and its etiological agents are of global public health importance, whose burden appears underestimated, especially in sub-Saharan Africa (SSA). The diversity in the transmission routes of these parasites contributes to disease prevalence and often hinders disease control measures. This study aimed to review the epidemiological distribution of Toxocara infections in SSA region. A systematic review and meta-analysis were performed using PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analysis). We identified 94 relevant, peer-reviewed articles, out of which, 75 articles were found eligible based on Toxocara infections in dogs, cats and humans. Overall, 27,102 samples were examined for T. canis in dogs, T. cati in cats and Toxocara serology in humans, out of which 6142 were positive for Toxocara infection: 3717 (13.7%) in dogs (faecal, 3487; necropsy, 180; hair, 50); 266 (1%) in cats (faecal, 101; necropsy, 165); and 2159 (8%) in humans (serology). Overall mean prevalences of 19% (95% confidence interval (CI): 14-23%), 9% (95% CI: 0-28%) and 36% (95% CI: 24-49%) were recorded in dogs, cats and humans, respectively. Substantial heterogeneity was observed between studies and subgroups (I2 = 99%, P < 0.01). Findings from the review showed that studies on the epidemiology of Toxocara infections in the SSA region are limited. We strongly recommend focused, collaborative and coordinated studies to determine Toxocara spp. prevalence in various hosts, including food animals and the environment, through a 'One Health' approach across SSA countries.
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7
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Everson R, Pettitt L, Forman OP, Dower-Tylee O, McLaughlin B, Ahonen S, Kaukonen M, Komáromy AM, Lohi H, Mellersh CS, Sansom J, Ricketts SL. An intronic LINE-1 insertion in MERTK is strongly associated with retinopathy in Swedish Vallhund dogs. PLoS One 2017; 12:e0183021. [PMID: 28813472 PMCID: PMC5558984 DOI: 10.1371/journal.pone.0183021] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Accepted: 07/30/2017] [Indexed: 12/31/2022] Open
Abstract
The domestic dog segregates a significant number of inherited progressive retinal diseases, several of which mirror human retinal diseases and which are collectively termed progressive retinal atrophy (PRA). In 2014, a novel form of PRA was reported in the Swedish Vallhund breed, and the disease was mapped to canine chromosome 17. The causal mutation was not identified, but expression analyses of the retinas of affected Vallhunds demonstrated a 6-fold increased expression of the MERTK gene compared to unaffected dogs. Using 24 retinopathy cases and 97 controls with no clinical signs of retinopathy, we replicated the chromosome 17 association in Swedish Vallhunds from the UK and aimed to elucidate the causal variant underlying this association using whole genome sequencing (WGS) of an affected dog. This revealed a 6-8 kb insertion in intron 1 of MERTK that was not present in WGS of 49 dogs of other breeds. Sequencing and BLASTN analysis of the inserted segment was consistent with the insertion comprising a full-length intact LINE-1 retroelement. Testing of the LINE-1 insertion for association with retinopathy in the UK set of 24 cases and 97 controls revealed a strong statistical association (P-value 6.0 x 10-11) that was subsequently replicated in the original Finnish study set (49 cases and 89 controls (P-value 4.3 x 10-19). In a pooled analysis of both studies (73 cases and 186 controls), the LINE-1 insertion was associated with a ~20-fold increased risk of retinopathy (odds ratio 23.41, 95% confidence intervals 10.99-49.86, P-value 1.3 x 10-27). Our study adds further support for regulatory disruption of MERTK in Swedish Vallhund retinopathy; however, further work is required to establish a functional overexpression model. Future work to characterise the mechanism by which this intronic mutation disrupts gene regulation will further improve the understanding of MERTK biology and its role in retinal function.
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Affiliation(s)
- Richard Everson
- Centre for Small Animal Studies–Ophthalmology Unit, Animal Health Trust, Kentford, Newmarket, Suffolk, United Kingdom
| | - Louise Pettitt
- Canine Genetics Research Group, Kennel Club Genetics Centre, Animal Health Trust, Kentford, Newmarket, Suffolk, United Kingdom
| | - Oliver P. Forman
- Canine Genetics Research Group, Kennel Club Genetics Centre, Animal Health Trust, Kentford, Newmarket, Suffolk, United Kingdom
| | - Olivia Dower-Tylee
- Canine Genetics Research Group, Kennel Club Genetics Centre, Animal Health Trust, Kentford, Newmarket, Suffolk, United Kingdom
| | - Bryan McLaughlin
- Canine Genetics Research Group, Kennel Club Genetics Centre, Animal Health Trust, Kentford, Newmarket, Suffolk, United Kingdom
| | - Saija Ahonen
- Department of Veterinary Biosciences and Research Programs Unit, Molecular Neurology, University of Helsinki, Helsinki, Finland
- The Folkhälsan Institute of Genetics, Helsinki, Finland
| | - Maria Kaukonen
- Department of Veterinary Biosciences and Research Programs Unit, Molecular Neurology, University of Helsinki, Helsinki, Finland
- The Folkhälsan Institute of Genetics, Helsinki, Finland
| | - András M. Komáromy
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, Michigan, United States of America
- Department of Clinical Studies, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Hannes Lohi
- Department of Veterinary Biosciences and Research Programs Unit, Molecular Neurology, University of Helsinki, Helsinki, Finland
- The Folkhälsan Institute of Genetics, Helsinki, Finland
| | - Cathryn S. Mellersh
- Canine Genetics Research Group, Kennel Club Genetics Centre, Animal Health Trust, Kentford, Newmarket, Suffolk, United Kingdom
| | - Jane Sansom
- Centre for Small Animal Studies–Ophthalmology Unit, Animal Health Trust, Kentford, Newmarket, Suffolk, United Kingdom
| | - Sally L. Ricketts
- Canine Genetics Research Group, Kennel Club Genetics Centre, Animal Health Trust, Kentford, Newmarket, Suffolk, United Kingdom
- * E-mail:
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8
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Kelawala DN, Patil DB, Parikh PV, Sheth MJ, Joshi CG, Reddy B. Clinical studies on progressive retinal atrophy in 31 dogs. IRANIAN JOURNAL OF VETERINARY RESEARCH 2017; 18:119-123. [PMID: 28775752 PMCID: PMC5534255] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 06/08/2016] [Revised: 11/22/2016] [Accepted: 12/10/2016] [Indexed: 06/07/2023]
Abstract
During a 2-year period, 31 cases of a hereditary retinal degeneration in dogs bred in India were found mainly suspected for progressive retinal atrophy (PRA) with typical history of initial nyctalopia followed by hemeralopia. Out of 31 PRA suspected dogs, 8 dogs (26%) were from the age group of 1-5 years, 15 (48%) 6-10 years and the rest (26%) 11-15 years. The most predominant breed was Spitz (18 dogs, 58%). Detailed ophthalmologic examinations included Schirmer's tear test, fluorescein stain, applanation tonometry, slit lamp biomicroscopy and ocular ultrasound in appropriate cases. Ophthalmoscopic and fundoscopic changes included hyperreflectivity and discoloration of the tapetal area, marked attenuation of retinal vessels, depigmentation in non-tapetal area and optic disc atrophy with scalloped borders. Electroretinograms (ERG) recorded in 13 PRA-affected cases revealed non-recordable extinguished (flatline) ERG responses. A reduction mainly of a- and b-wave amplitudes in the ERG indicated a generalized photoreceptor disease.
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Affiliation(s)
- D. N. Kelawala
- Ph.D. Scholar in Veterinary Surgery and Radiology, Department of Veterinary Surgery and Radiology, College of Veterinary Science and Animal Husbandry, Anand Agricultural University, Anand, Gujarat-388001, India
| | - D. B. Patil
- Department of Veterinary Surgery and Radiology, College of Veterinary Science and Animal Husbandry, Anand Agricultural University, Anand, Gujarat-388001, India
| | - P. V. Parikh
- Department of Veterinary Surgery and Radiology, College of Veterinary Science and Animal Husbandry, Anand Agricultural University, Anand, Gujarat-388001, India
| | - M. J. Sheth
- Consultant Vitreoretinal Surgeon, Govind Eye Clinic, Vadodara, India
| | - C. G. Joshi
- Department of Animal Biotechnology, College of Veterinary Science and Animal Husbandry, Anand Agricultural University, Anand, Gujarat-388001, India
| | - B. Reddy
- Department of Animal Biotechnology, College of Veterinary Science and Animal Husbandry, Anand Agricultural University, Anand, Gujarat-388001, India
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9
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Somma AT, Moreno JCD, Sato MT, Rodrigues BD, Bacellar-Galdino M, Occelli LM, Petersen-Jones SM, Montiani-Ferreira F. Characterization of a novel form of progressive retinal atrophy in Whippet dogs: a clinical, electroretinographic, and breeding study. Vet Ophthalmol 2016; 20:450-459. [PMID: 27896899 DOI: 10.1111/vop.12448] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
OBJECTIVE To describe a form of progressive retinal atrophy (PRA) in Whippets including clinical, electroretinographic, optical coherence tomographic changes and pedigree analysis. ANIMALS STUDIED Client-owned Whippet dogs (n = 51) living in Brazil. PROCEDURES All animals were submitted for routine ophthalmic screening for presumed inherited ocular disease, which included the following: visual tests, such as obstacle course tests, in scotopic and photopic conditions, cotton ball test, dazzle reflex, ocular fundus evaluation by indirect ophthalmoscopy followed by fundus photography. Additionally, electroretinography (ERG) and optical coherence tomography (OCT) were performed in 24 and four dogs, respectively. RESULTS Sixteen dogs were diagnosed with PRA. Vision deficits in dim light were detected in dogs examined at a young age associated with nystagmus. Funduscopic changes included the development of multifocal retinal bullae from 6 months of age. Retinal thinning became apparent later, at which time the bullae were no longer detected. OCT examination of selected young dogs revealed that the retinal bullae were due to separation between photoreceptors and the retinal pigment epithelium, and of dogs with more advanced disease confirmed the development of retinal thinning. Electroretinography in young dogs revealed a negative ERG due to a lack of b-wave in both scotopic and photopic recordings. With progression, the ERG became unrecordable. Pedigree analysis suggested an autosomal recessive mode of inheritance. CONCLUSION The retinal dystrophy reported here in Whippet dogs has a unique phenotype of an initial lack of ERG b-wave, development of retinal bullae then a progressive generalized retinal degeneration.
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Affiliation(s)
- André Tavares Somma
- Veterinary Medicine Department, Comparative Ophthalmology Laboratory, Rua dos Funcionários, 1540, Curtiba, 80035-050, Brazil
| | - Juan Carlos Duque Moreno
- Veterinary Medicine Department, Comparative Ophthalmology Laboratory, Rua dos Funcionários, 1540, Curtiba, 80035-050, Brazil
| | - Mario Teruo Sato
- Universidade Federal do Parana, R. Padre Camargo, 280, Curtiba, 80060-240, Brazil
| | - Blanche Dreher Rodrigues
- Ophthalmology Service, Centro Integrado de Especialidades Veterinárias, Rua André Zanetti, 144, Curtiba, 808010-280, Brazil
| | - Marianna Bacellar-Galdino
- Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, 736 Wilson Road D-208, East Lansing, MI, 48824, USA
| | - Laurence Mireille Occelli
- Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, 736 Wilson Road D-208, East Lansing, MI, 48824, USA
| | - Simon Michael Petersen-Jones
- Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, 736 Wilson Road D-208, East Lansing, MI, 48824, USA
| | - Fabiano Montiani-Ferreira
- Veterinary Medicine Department, Comparative Ophthalmology Laboratory, Rua dos Funcionários, 1540, Curtiba, 80035-050, Brazil
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10
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Dreger DL, Rimbault M, Davis BW, Bhatnagar A, Parker HG, Ostrander EA. Whole-genome sequence, SNP chips and pedigree structure: building demographic profiles in domestic dog breeds to optimize genetic-trait mapping. Dis Model Mech 2016; 9:1445-1460. [PMID: 27874836 PMCID: PMC5200897 DOI: 10.1242/dmm.027037] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2016] [Accepted: 10/26/2016] [Indexed: 12/30/2022] Open
Abstract
In the decade following publication of the draft genome sequence of the domestic dog, extraordinary advances with application to several fields have been credited to the canine genetic system. Taking advantage of closed breeding populations and the subsequent selection for aesthetic and behavioral characteristics, researchers have leveraged the dog as an effective natural model for the study of complex traits, such as disease susceptibility, behavior and morphology, generating unique contributions to human health and biology. When designing genetic studies using purebred dogs, it is essential to consider the unique demography of each population, including estimation of effective population size and timing of population bottlenecks. The analytical design approach for genome-wide association studies (GWAS) and analysis of whole-genome sequence (WGS) experiments are inextricable from demographic data. We have performed a comprehensive study of genomic homozygosity, using high-depth WGS data for 90 individuals, and Illumina HD SNP data from 800 individuals representing 80 breeds. These data were coupled with extensive pedigree data analyses for 11 breeds that, together, allowed us to compute breed structure, demography, and molecular measures of genome diversity. Our comparative analyses characterize the extent, formation and implication of breed-specific diversity as it relates to population structure. These data demonstrate the relationship between breed-specific genome dynamics and population architecture, and provide important considerations influencing the technological and cohort design of association and other genomic studies. Summary: Successful application of whole-genome sequencing and genome-wide association studies for identifying both loci and mutations in canines is influenced by breed structure and demography, motivating researchers to generate breed-specific strategies for canine genetic studies.
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Affiliation(s)
- Dayna L Dreger
- Cancer Genetics and Comparative Genomics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Maud Rimbault
- Cancer Genetics and Comparative Genomics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA.,Institut de Génétique et Développement de Rennes, Rennes 35043, France
| | - Brian W Davis
- Cancer Genetics and Comparative Genomics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Adrienne Bhatnagar
- Cancer Genetics and Comparative Genomics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA.,PIC North America, Hendersonville, TN 37075, USA
| | - Heidi G Parker
- Cancer Genetics and Comparative Genomics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Elaine A Ostrander
- Cancer Genetics and Comparative Genomics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA
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11
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Palanova A. The genetics of inherited retinal disorders in dogs: implications for diagnosis and management. VETERINARY MEDICINE-RESEARCH AND REPORTS 2016; 7:41-51. [PMID: 30050836 PMCID: PMC6042528 DOI: 10.2147/vmrr.s63537] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
Dogs are affected by many hereditary diseases just as humans are. One group of these diseases comprises of retinal disorders, which are a growing problem in canine breeding. These disorders are heterogeneous, with diverse causative mutations and modes of inheritance. Some affect only one breed, while others may affect many breeds; some breeds are affected by only one disease, while others can be affected by two or more. Dog breeders should take into account the presence of any deleterious alleles when choosing parents for the next generation.
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Affiliation(s)
- Anna Palanova
- Department of Tumor Biology, Institute of Animal Physiology and Genetics, v. v. i., Academy of Sciences of the Czech Republic, Libechov, Czech Republic,
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12
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Reddy B, Kelawala DN, Shah T, Patel AB, Patil DB, Parikh PV, Patel N, Parmar N, Mohapatra AB, Singh KM, Menon R, Pandya D, Jakhesara SJ, Koringa PG, Rao MV, Joshi CG. Identification of putative SNPs in progressive retinal atrophy affected Canis lupus familiaris using exome sequencing. Mamm Genome 2015; 26:638-49. [PMID: 26515695 DOI: 10.1007/s00335-015-9607-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2015] [Accepted: 10/08/2015] [Indexed: 11/30/2022]
Abstract
Progressive retinal atrophy (PRA) is one of the major causes of retinal photoreceptor cell degeneration in canines. The inheritance pattern of PRA is autosomal recessive and genetically heterogeneous. Here, using targeted sequencing technology, we have performed exome sequencing of 10 PRA-affected (Spitz=7, Cocker Spaniel=1, Lhasa Aphso=1 and Spitz-Labrador cross breed=1) and 6 normal (Spitz=5, Cocker Spaniel=1) dogs. The high-throughput sequencing using 454-Roche Titanium sequencer generated about 2.16 Giga bases of raw data. Initially, we have successfully identified 25,619 single nucleotide polymorphisms (SNPs) that passed the stringent SNP calling parameters. Further, we performed association study on the cohort, and the highly significant (0.001) associations were short-listed and investigated in-depth. Out of the 171 significant SNPs, 113 were previously unreported. Interestingly, six among them were non-synonymous coding (NSC) SNPs, which includes CPPED1 A>G (p.M307V), PITRM1 T>G (p.S715A), APP G>A (p.T266M), RNF213 A>G (p.V1482A), C>A (p.V1456L), and SLC46A3 G>A (p.R168Q). On the other hand, 35 out of 113 unreported SNPs were falling in regulatory regions such as 3'-UTR, 5'-UTR, etc. In-depth bioinformatics analysis revealed that majority of NSC SNPs have damaging effect and alter protein stability. This study highlighted the genetic markers associated with PRA, which will help to develop genetic assay-based screening in effective breeding.
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Affiliation(s)
- Bhaskar Reddy
- Ome Research Facility, Department of Animal Biotechnology, Anand Agricultural University, Anand, Gujarat, 388001, India.,Department of Zoology, Genetic Diagnostic Centre, University School of Sciences, Gujarat University, Ahmedabad, Gujarat, 380009, India
| | - Divyesh N Kelawala
- Department of Veterinary Surgery & Radiology, College of Veterinary Science & Animal Husbandry, Anand Agricultural University, Anand, Gujarat, 388001, India
| | - Tejas Shah
- Ome Research Facility, Department of Animal Biotechnology, Anand Agricultural University, Anand, Gujarat, 388001, India
| | - Anand B Patel
- Ome Research Facility, Department of Animal Biotechnology, Anand Agricultural University, Anand, Gujarat, 388001, India
| | - Deepak B Patil
- Department of Veterinary Surgery & Radiology, College of Veterinary Science & Animal Husbandry, Anand Agricultural University, Anand, Gujarat, 388001, India
| | - Pinesh V Parikh
- Department of Veterinary Surgery & Radiology, College of Veterinary Science & Animal Husbandry, Anand Agricultural University, Anand, Gujarat, 388001, India
| | - Namrata Patel
- Ome Research Facility, Department of Animal Biotechnology, Anand Agricultural University, Anand, Gujarat, 388001, India
| | - Nidhi Parmar
- Ome Research Facility, Department of Animal Biotechnology, Anand Agricultural University, Anand, Gujarat, 388001, India
| | - Amit B Mohapatra
- Ome Research Facility, Department of Animal Biotechnology, Anand Agricultural University, Anand, Gujarat, 388001, India
| | - Krishna M Singh
- Datar Genetics Ltd, F-8, D Road, Ambad, Nasik, Maharashtra, 422010, India
| | - Ramesh Menon
- Ome Research Facility, Department of Animal Biotechnology, Anand Agricultural University, Anand, Gujarat, 388001, India
| | - Dipal Pandya
- Ome Research Facility, Department of Animal Biotechnology, Anand Agricultural University, Anand, Gujarat, 388001, India
| | - Subhash J Jakhesara
- Ome Research Facility, Department of Animal Biotechnology, Anand Agricultural University, Anand, Gujarat, 388001, India
| | - Prakash G Koringa
- Ome Research Facility, Department of Animal Biotechnology, Anand Agricultural University, Anand, Gujarat, 388001, India
| | - Mandava V Rao
- Department of Zoology, Genetic Diagnostic Centre, University School of Sciences, Gujarat University, Ahmedabad, Gujarat, 380009, India
| | - Chaitanya G Joshi
- Ome Research Facility, Department of Animal Biotechnology, Anand Agricultural University, Anand, Gujarat, 388001, India.
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Canine CNGA3 Gene Mutations Provide Novel Insights into Human Achromatopsia-Associated Channelopathies and Treatment. PLoS One 2015; 10:e0138943. [PMID: 26407004 PMCID: PMC4583268 DOI: 10.1371/journal.pone.0138943] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Accepted: 09/06/2015] [Indexed: 12/27/2022] Open
Abstract
Cyclic nucleotide-gated (CNG) ion channels are key mediators underlying signal transduction in retinal and olfactory receptors. Genetic defects in CNGA3 and CNGB3, encoding two structurally related subunits of cone CNG channels, lead to achromatopsia (ACHM). ACHM is a congenital, autosomal recessive retinal disorder that manifests by cone photoreceptor dysfunction, severely reduced visual acuity, impaired or complete color blindness and photophobia. Here, we report the first canine models for CNGA3-associated channelopathy caused by R424W or V644del mutations in the canine CNGA3 ortholog that accurately mimic the clinical and molecular features of human CNGA3-associated ACHM. These two spontaneous mutations exposed CNGA3 residues essential for the preservation of channel function and biogenesis. The CNGA3-R424W results in complete loss of cone function in vivo and channel activity confirmed by in vitro electrophysiology. Structural modeling and molecular dynamics (MD) simulations revealed R424-E306 salt bridge formation and its disruption with the R424W mutant. Reversal of charges in a CNGA3-R424E-E306R double mutant channel rescued cGMP-activated currents uncovering new insights into channel gating. The CNGA3-V644del affects the C-terminal leucine zipper (CLZ) domain destabilizing intersubunit interactions of the coiled-coil complex in the MD simulations; the in vitro experiments showed incompetent trimeric CNGA3 subunit assembly consistent with abnormal biogenesis of in vivo channels. These newly characterized large animal models not only provide a valuable system for studying cone-specific CNG channel function in health and disease, but also represent prime candidates for proof-of-concept studies of CNGA3 gene replacement therapy for ACHM patients.
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Correction: A novel form of progressive retinal atrophy in Swedish vallhund dogs. PLoS One 2015; 10:e0118128. [PMID: 25668302 PMCID: PMC4323118 DOI: 10.1371/journal.pone.0118128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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15
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Ahonen SJ, Arumilli M, Seppälä E, Hakosalo O, Kaukonen MK, Komáromy AM, Lohi H. Increased expression of MERTK is associated with a unique form of canine retinopathy. PLoS One 2014; 9:e114552. [PMID: 25517981 PMCID: PMC4269413 DOI: 10.1371/journal.pone.0114552] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2014] [Accepted: 11/10/2014] [Indexed: 01/25/2023] Open
Abstract
Progressive retinal degenerations are among the most common causes of blindness both in human and in dogs. Canine progressive retinal atrophy (PRA) resembles human retinitis pigmentosa (RP) and is typically characterized by a progressive loss of rod photoreceptors followed by a loss of cone function. The disease gradually progress from the loss of night and day vision to a complete blindness. We have recently described a unique form of retinopathy characterized by the multifocal gray/brown discoloration and thinning of the retina in the Swedish Vallhund (SV) breed. We aimed to identify the genetic cause by performing a genome wide association analysis in a cohort of 18 affected and 10 healthy control dogs using Illumina's canine 22k SNP array. We mapped the disease to canine chromosome 17 (p = 7.7×10−5) and found a 6.1 Mb shared homozygous region in the affected dogs. A combined analysis of the GWAS and replication data with additional 60 dogs confirmed the association (p = 4.3×10−8, OR = 11.2 for homozygosity). A targeted resequencing of the entire associated region in four cases and four controls with opposite risk haplotypes identified several variants in the coding region of functional candidate genes, such as a known retinopathy gene, MERTK. However, none of the identified coding variants followed a compelling case- or breed-specific segregation pattern. The expression analyses of four candidate genes in the region, MERTK, NPHP1, ANAPC1 and KRCC1, revealed specific upregulation of MERTK in the retina of the affected dogs. Collectively, these results indicate that the retinopathy is associated with overexpression of MERTK, however further investigation is needed to discover the regulatory mutation for the better understanding of the disease pathogenesis. Our study establishes a novel gain-of-function model for the MERTK biology and provides a therapy model for retinopathy MERTK inhibitors. Meanwhile, a marker-based genetic counseling can be developed to revise breeding programs.
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Affiliation(s)
- Saija J. Ahonen
- Department of Veterinary Biosciences and Research Programs Unit, Molecular Neurology, University of Helsinki, Helsinki, Finland
- The Folkhälsan Institute of Genetics, Helsinki, Finland
| | - Meharji Arumilli
- Department of Veterinary Biosciences and Research Programs Unit, Molecular Neurology, University of Helsinki, Helsinki, Finland
- The Folkhälsan Institute of Genetics, Helsinki, Finland
| | - Eija Seppälä
- Department of Veterinary Biosciences and Research Programs Unit, Molecular Neurology, University of Helsinki, Helsinki, Finland
- The Folkhälsan Institute of Genetics, Helsinki, Finland
| | - Osmo Hakosalo
- Department of Veterinary Biosciences and Research Programs Unit, Molecular Neurology, University of Helsinki, Helsinki, Finland
- The Folkhälsan Institute of Genetics, Helsinki, Finland
| | - Maria K. Kaukonen
- Department of Veterinary Biosciences and Research Programs Unit, Molecular Neurology, University of Helsinki, Helsinki, Finland
- The Folkhälsan Institute of Genetics, Helsinki, Finland
| | - András M. Komáromy
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, Michigan, United States of America
- Department of Clinical Studies, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Hannes Lohi
- Department of Veterinary Biosciences and Research Programs Unit, Molecular Neurology, University of Helsinki, Helsinki, Finland
- The Folkhälsan Institute of Genetics, Helsinki, Finland
- * E-mail:
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