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Chalder R, Housby-Skeggs N, Clark C, Pollard D, Hartley C, Blacklock B. Ocular findings in a population of geriatric equids in the United Kingdom. Equine Vet J 2024; 56:121-130. [PMID: 37070252 DOI: 10.1111/evj.13941] [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: 11/25/2022] [Accepted: 03/23/2023] [Indexed: 04/19/2023]
Abstract
BACKGROUND There are a growing number of horses, ponies, and donkeys aged 15 years or older in the United Kingdom, yet there have been no studies utilising a complete ophthalmic examination to investigate the prevalence of ophthalmic pathology within this population. OBJECTIVES To investigate the prevalence of ophthalmic pathology and associations with signalment, in a convenience sample of geriatric equids in the United Kingdom. STUDY DESIGN Cross sectional. METHODS Horses, ponies, and donkeys aged 15 years or older based at The Horse Trust charity underwent a full ophthalmic examination including slit lamp biomicroscopy and indirect ophthalmoscopy. Relationships between signalment and pathology were assessed using Fisher's exact and Mann-Witney U tests. RESULTS Fifty animals were examined ranging from 15 to 33 years (median 24, interquartile range [IQR] 21, 27). The prevalence of ocular pathology was 84.0% (95% confidence interval [CI] 73.8, 94.2%; n = 42). Four animals (8.0%) had adnexal pathology, while 37 (74.0%) and 22 (44.0%) had at least one form of anterior or posterior segment pathology, respectively. Of those with anterior segment pathology, 26 animals (52.0%) had cataract in at least one eye, with the most common location being anterior cortical (65.0% of those animals with cataract). Animals with posterior segment pathology included 21 animals (42.0%) with fundic pathology, with senile retinopathy being the most common (42.9% of all animals with fundic pathology). Despite the high prevalence of ocular pathology, all eyes examined remained visual. The most common breeds were Irish Draught (24.0%, n = 12), Shetland (18.0%, n = 9) and Thoroughbred (10%, n = 5); the majority were geldings (74.0%, n = 37). There was a statistically significant relationship between the presence of anterior segment pathology and breed (p = 0.006), with all Cobs and Shetlands examined having anterior segment pathology. The presence of posterior segment pathology and senile retinopathy were associated with older median age (posterior segment pathology: 26.0 years [interquartile range {IQR} 24.0, 30.0 years] vs. 23.5 years [IRQ 19.5, 26.5 years], p = 0.03; senile retinopathy: 27.0 years [IQR 26.0, 30 years] vs. 24.0 years [IQR 20.0, 27.0], p = 0.04). None of the pathologies investigated were more prone to affect one versus both eyes (p > 0.05; 71.4% of ocular pathologies were bilateral while 28.6% were unilateral). MAIN LIMITATIONS Data were obtained from a relatively small sample size of a single cohort of animals that lacked a control group. CONCLUSIONS There was a high prevalence and wide range of ocular lesions in this subset of geriatric equids.
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Affiliation(s)
- Ria Chalder
- The Royal (Dick) School of Veterinary Studies, University of Edinburgh, Edinburgh, UK
| | | | - Claire Clark
- The Horse Trust, Slad Lane, Princes Risborough, UK
| | | | - Claudia Hartley
- The Royal (Dick) School of Veterinary Studies, University of Edinburgh, Edinburgh, UK
| | - Benjamin Blacklock
- The Royal (Dick) School of Veterinary Studies, University of Edinburgh, Edinburgh, UK
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Wei J, Brophy B, Cole SA, Leath S, Oback B, Boch J, Wells DN, Laible G. Production of light-coloured, low heat-absorbing Holstein Friesian cattle by precise embryo-mediated genome editing. Reprod Fertil Dev 2023; 36:112-123. [PMID: 38064192 DOI: 10.1071/rd23163] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2023] Open
Abstract
CONTEXT Genome editing enables the introduction of beneficial sequence variants into the genomes of animals with high genetic merit in a single generation. This can be achieved by introducing variants into primary cells followed by producing a live animal from these cells by somatic cell nuclear transfer cloning. The latter step is associated with low efficiencies and developmental problems due to incorrect reprogramming of the donor cells, causing animal welfare concerns. Direct editing of fertilised one-cell embryos could circumvent this issue and might better integrate with genetic improvement strategies implemented by the industry. METHODS In vitro fertilised zygotes were injected with TALEN editors and repair template to introduce a known coat colour dilution mutation in the PMEL gene. Embryo biopsies of injected embryos were screened by polymerase chain reaction and sequencing for intended biallelic edits before transferring verified embryos into recipients for development to term. Calves were genotyped and their coats scanned with visible and hyperspectral cameras to assess thermal energy absorption. KEY RESULTS Multiple non-mosaic calves with precision edited genotypes were produced, including calves from high genetic merit parents. Compared to controls, the edited calves showed a strong coat colour dilution which was associated with lower thermal energy absorbance. CONCLUSIONS Although biopsy screening was not absolutely accurate, non-mosaic, precisely edited calves can be readily produced by embryo-mediated editing. The lighter coat colouring caused by the PMEL mutation can lower radiative heat gain which might help to reduce heat stress. IMPLICATIONS The study validates putative causative sequence variants to rapidly adapt grazing cattle to changing environmental conditions.
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Affiliation(s)
- Jingwei Wei
- Animal Biotechnology, Ruakura Research Centre, AgResearch, Hamilton, New Zealand
| | - Brigid Brophy
- Animal Biotechnology, Ruakura Research Centre, AgResearch, Hamilton, New Zealand
| | - Sally-Ann Cole
- Animal Biotechnology, Ruakura Research Centre, AgResearch, Hamilton, New Zealand
| | - Shane Leath
- Animal Biotechnology, Ruakura Research Centre, AgResearch, Hamilton, New Zealand
| | - Björn Oback
- Animal Biotechnology, Ruakura Research Centre, AgResearch, Hamilton, New Zealand; and School of Sciences, University of Waikato, Hamilton, New Zealand; and Department of Molecular Medicine and Pathology, School of Medical Sciences, University of Auckland, Auckland, New Zealand
| | - Jens Boch
- Institute of Plant Genetics, Leibniz Universität Hannover, Hannover, Germany
| | - David N Wells
- Animal Biotechnology, Ruakura Research Centre, AgResearch, Hamilton, New Zealand
| | - Götz Laible
- Animal Biotechnology, Ruakura Research Centre, AgResearch, Hamilton, New Zealand; and Department of Molecular Medicine and Pathology, School of Medical Sciences, University of Auckland, Auckland, New Zealand
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Herb VM, Zehetner V, Blohm KO. Multiple Congenital Ocular Anomalies in a silver coat Missouri Fox Trotter stallion. Tierarztl Prax Ausg G Grosstiere Nutztiere 2021; 49:350-354. [PMID: 34666370 DOI: 10.1055/a-1581-4810] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
This is the first description of Multiple Congenital Ocular Anomalies (MCOA) in a silver coat Missouri Fox Trotter determined to be heterozygous for the Silver PMEL17 missense mutation associated with MCOA and a silver coat in other breeds. The stallion was treated for meningoencephalitis and bilateral uveitis of unknown origin. A complete ophthalmic examination and ocular ultrasonography were performed. As an incidental finding, the patient exhibited bilateral cystic lesions restricted to the temporal anterior uvea consistent with the Cyst phenotype and was genotyped heterozygous for the Silver mutation. Additionally, 4 other non-silver colored Missouri Fox Trotters were genotyped homozygous for the wild-type allele. Screening for PMEL17 mutation in Missouri Fox Trotters accompanied by ophthalmic phenotype characterization is recommended to determine the allelic frequency and facilitate informed breeding decisions since the silver coat color is particularly popular.
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Affiliation(s)
- Verena Maria Herb
- Department for Companion Animals and Horses, Ophthalmology Unit, University of Veterinary Medicine
| | - Verena Zehetner
- Department for Companion Animals and Horses, Equine Internal Medicine, University of Veterinary Medicine
| | - Klaas-Ole Blohm
- Department for Companion Animals and Horses, Ophthalmology Unit, University of Veterinary Medicine.,AniCura Tierärztliche Spezialisten Hamburg.,Tierarztpraxis Schönhoff
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The Youngest, the Heaviest and/or the Darkest? Selection Potentialities and Determinants of Leadership in Canarian Dromedary Camels. Animals (Basel) 2021; 11:ani11102886. [PMID: 34679907 PMCID: PMC8532867 DOI: 10.3390/ani11102886] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Revised: 09/24/2021] [Accepted: 09/28/2021] [Indexed: 11/23/2022] Open
Abstract
Simple Summary Genetic selection of camels for behavioral traits is not an extended practice in livestock scenarios. Given the existence of pleiotropic genes that influence two or more seemingly unrelated phenotypic traits, here we studied the sociodemographic, zoometric and phaneroptical characteristics potentially determining the intraherd leadership role in Canarian camels. This local endangered breed is mainly reared in same-sex groups because of biased morphostructural preferences, that is, tourism/leisure and milk production for males and females, respectively. The attribute most influencing leadership role was sexual status, as gelded animals more frequently initiated group movements. Furthermore, younger camels were mainly endorsed as group leaders, a condition that could be ascribed to their recognized fluid intelligence and need for constant social and environmental interaction. Referring to zoometrics and phaneroptics, the heaviest and darkest-coated dromedaries were significantly more prone to reaching higher positions in the leadership hierarchy. The presence of white-haired zones in the extremities, head and neck as well as iris depigmentation had non-negligible influence on this type of social organization. This information is valuable for application both in refining animal handling procedures and in genetic selection of animals for their social behavior. Abstract Several idiosyncratic and genetically correlated traits are known to extensively influence leadership in both domestic and wild species. For minor livestock such as camels, however, this type of behavior remains loosely defined and approached only for sex-mixed herds. The interest in knowing those animal-dependent variables that make an individual more likely to emerge as a leader in a single-sex camel herd has its basis in the sex-separated breeding of Canarian dromedary camels for utilitarian purposes. By means of an ordinal logistic regression, it was found that younger, gelded animals may perform better when eliciting the joining of mates, assuming that they were castrated just before reaching sexual maturity and once they were initiated in the pertinent domestication protocol for their lifetime functionality. The higher the body weight, the significantly (p < 0.05) higher the score in the hierarchical rank when leading group movements, although this relationship appeared to be inverse for the other considered zoometric indexes. Camels with darker and substantially depigmented coats were also significantly (p < 0.05) found to be the main initiators. Routine intraherd management and leisure tourism will be thus improved in efficiency and security through the identification and selection of the best leader camels.
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Functional Domains and Evolutionary History of the PMEL and GPNMB Family Proteins. Molecules 2021; 26:molecules26123529. [PMID: 34207849 PMCID: PMC8273697 DOI: 10.3390/molecules26123529] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Revised: 05/31/2021] [Accepted: 06/02/2021] [Indexed: 11/17/2022] Open
Abstract
The ancient paralogs premelanosome protein (PMEL) and glycoprotein nonmetastatic melanoma protein B (GPNMB) have independently emerged as intriguing disease loci in recent years. Both proteins possess common functional domains and variants that cause a shared spectrum of overlapping phenotypes and disease associations: melanin-based pigmentation, cancer, neurodegenerative disease and glaucoma. Surprisingly, these proteins have yet to be shown to physically or genetically interact within the same cellular pathway. This juxtaposition inspired us to compare and contrast this family across a breadth of species to better understand the divergent evolutionary trajectories of two related, but distinct, genes. In this study, we investigated the evolutionary history of PMEL and GPNMB in clade-representative species and identified TMEM130 as the most ancient paralog of the family. By curating the functional domains in each paralog, we identified many commonalities dating back to the emergence of the gene family in basal metazoans. PMEL and GPNMB have gained functional domains since their divergence from TMEM130, including the core amyloid fragment (CAF) that is critical for the amyloid potential of PMEL. Additionally, the PMEL gene has acquired the enigmatic repeat domain (RPT), composed of a variable number of imperfect tandem repeats; this domain acts in an accessory role to control amyloid formation. Our analyses revealed the vast variability in sequence, length and repeat number in homologous RPT domains between craniates, even within the same taxonomic class. We hope that these analyses inspire further investigation into a gene family that is remarkable from the evolutionary, pathological and cell biology perspectives.
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Abstract
Horses perform in a variety of disciplines that are visually demanding, and any disease impacting the eye has the potential to threaten vision and thus the utility of the horse. Advances in equine genetics have enabled the understanding of some inherited ocular disorders and ocular manifestations and are enabling cross-species comparisons. Genetic testing for multiple congenital ocular anomalies, congenital stationary night blindness, equine recurrent uveitis, and squamous cell carcinoma can identify horses with or at risk for disease and thus can assist in clinical management and breeding decisions. This article describes the current knowledge of inherited ocular disorders.
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Affiliation(s)
- Rebecca R Bellone
- Department of Population Health and Reproduction, Veterinary Genetics Laboratory, School of Veterinary Medicine, University of California-Davis, One Shields Avenue, Davis, CA 95616, USA.
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Bruders R, Van Hollebeke H, Osborne EJ, Kronenberg Z, Maclary E, Yandell M, Shapiro MD. A copy number variant is associated with a spectrum of pigmentation patterns in the rock pigeon (Columba livia). PLoS Genet 2020; 16:e1008274. [PMID: 32433666 PMCID: PMC7239393 DOI: 10.1371/journal.pgen.1008274] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Accepted: 04/09/2020] [Indexed: 12/15/2022] Open
Abstract
Rock pigeons (Columba livia) display an extraordinary array of pigment pattern variation. One such pattern, Almond, is characterized by a variegated patchwork of plumage colors that are distributed in an apparently random manner. Almond is a sex-linked, semi-dominant trait controlled by the classical Stipper (St) locus. Heterozygous males (ZStZ+ sex chromosomes) and hemizygous Almond females (ZStW) are favored by breeders for their attractive plumage. In contrast, homozygous Almond males (ZStZSt) develop severe eye defects and often lack plumage pigmentation, suggesting that higher dosage of the mutant allele is deleterious. To determine the molecular basis of Almond, we compared the genomes of Almond pigeons to non-Almond pigeons and identified a candidate St locus on the Z chromosome. We found a copy number variant (CNV) within the differentiated region that captures complete or partial coding sequences of four genes, including the melanosome maturation gene Mlana. We did not find fixed coding changes in genes within the CNV, but all genes are misexpressed in regenerating feather bud collar cells of Almond birds. Notably, six other alleles at the St locus are associated with depigmentation phenotypes, and all exhibit expansion of the same CNV. Structural variation at St is linked to diversity in plumage pigmentation and gene expression, and thus provides a potential mode of rapid phenotypic evolution in pigeons. The genetic changes responsible for different animal color patterns are poorly understood, due in part to a paucity of research organisms that are both genetically tractable and phenotypically diverse. Domestic pigeons (Columba livia) have been artificially selected for many traits, including an enormous variety of color patterns that are variable both within and among different breeds of this single species. We investigated the genetic basis of a sex-linked color pattern in pigeons called Almond that is characterized by a sprinkled pattern of plumage pigmentation. Pigeons with one copy of the Almond allele have desirable color pattern; however, male pigeons with two copies of the Almond mutation have severely depleted pigmentation and congenital eye defects. By comparing the genomes of Almond and non-Almond pigeons, we discovered that Almond pigeons have extra copies of a chromosome region that contains a gene that is critical for the formation of pigment granules. We also found that different numbers of copies of this region are associated with varying degrees of pigment reduction. The Almond phenotype in pigeons bears a remarkable resemblance to Merle coat color mutants in dogs, and our new results from pigeons suggest that similar genetic mechanisms underlie these traits in both species. Our work highlights the role of gene copy number variation as a potential driver of rapid phenotypic evolution.
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Affiliation(s)
- Rebecca Bruders
- School of Biological Sciences, University of Utah, Salt Lake City, Utah, United States of America
| | - Hannah Van Hollebeke
- School of Biological Sciences, University of Utah, Salt Lake City, Utah, United States of America
| | - Edward J. Osborne
- Department of Human Genetics, University of Utah, Salt Lake City, Utah, United States of America
| | - Zev Kronenberg
- Department of Human Genetics, University of Utah, Salt Lake City, Utah, United States of America
| | - Emily Maclary
- School of Biological Sciences, University of Utah, Salt Lake City, Utah, United States of America
| | - Mark Yandell
- Department of Human Genetics, University of Utah, Salt Lake City, Utah, United States of America
| | - Michael D. Shapiro
- School of Biological Sciences, University of Utah, Salt Lake City, Utah, United States of America
- * E-mail:
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Ahmad HI, Ahmad MJ, Jabbir F, Ahmar S, Ahmad N, Elokil AA, Chen J. The Domestication Makeup: Evolution, Survival, and Challenges. Front Ecol Evol 2020. [DOI: 10.3389/fevo.2020.00103] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
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Woicke J, Haile S, Mysore J, Peden WM, Lejeune T, Sanderson T, Brodie T. Spontaneous Findings in the Eyes of Cynomolgus Monkeys (Macaca fascicularis) of Mauritian Origin. Toxicol Pathol 2018; 46:273-282. [DOI: 10.1177/0192623318758619] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Spontaneous findings noted in the eyes of Mauritian cynomolgus monkeys are described and descriptions are supplemented with illustrations. Findings observed after extensive histopathologic examinations (20 to 44 sections per eye) from 20 control, 17 treatment-naive stock monkeys, and 2 findings noted in drug-treated monkeys that were considered to be spontaneous are included. Also included are findings from 361 control monkeys of routine toxicity studies performed at our laboratories, for most of which a standard histopathological examination of 1 section per eye was conducted. Common observations in monkeys examined extensively and in historical controls were limited to lymphocytic or mononuclear cell infiltrations of the uvea and/or conjunctiva/sclera and, less commonly observed, melanocytoma of the ciliary body or iris. Findings noted only in monkeys examined extensively consisted of inflammation of the conjunctiva, ora serrata cysts, glial nodules, focal degeneration of the retina, cystoid degeneration of the central retina, ballooning degeneration of the ciliary epithelium, cyst of the ciliary body, and decreased pigmentation of the retinal pigment epithelium. Changes recorded only in historical controls included retinal atrophy and nuclear displacement in the retina. Lesions are discussed and compared with pertinent literature.
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Affiliation(s)
- Jochen Woicke
- Pathology, Research and Development, Bristol-Myers Squibb, Mount Vernon, Indiana, USA
| | - Solomon Haile
- Charles River Laboratories Montreal ULC, Senneville, Quebec, Canada
| | - Jagannatha Mysore
- Pathology, Research and Development, Bristol-Myers Squibb, New Brunswick, New Jersey, USA
| | - W. Michael Peden
- Pathology, Research and Development, Bristol-Myers Squibb, Mount Vernon, Indiana, USA
| | - Typhaine Lejeune
- Charles River Laboratories Montreal ULC, Senneville, Quebec, Canada
| | - Thomas Sanderson
- Pathology, Research and Development, Bristol-Myers Squibb, Mount Vernon, Indiana, USA
| | - Thomas Brodie
- Pathology, Research and Development, Bristol-Myers Squibb, New Brunswick, New Jersey, USA
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Genetic Testing as a Tool to Identify Horses with or at Risk for Ocular Disorders. Vet Clin North Am Equine Pract 2017; 33:627-645. [DOI: 10.1016/j.cveq.2017.08.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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Townsend WM. Disease and Surgery of the Equine Lens. Vet Clin North Am Equine Pract 2017; 33:483-497. [PMID: 29103558 DOI: 10.1016/j.cveq.2017.07.004] [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: 10/18/2022] Open
Abstract
Examination of the lens is critical, particularly when evaluating horses with visual impairment or performing prepurchase examinations. To adequately evaluate the lens, the pupil must be pharmacologically dilated. A cataract is any lens opacity. The size, density, and position of a cataract determine the impact on vision. Cataracts may be congenital or inherited or occur secondary to trauma or equine recurrent uveitis. Surgical removal is the only treatment option for vision impairing cataracts, but careful selection of surgical candidates is critical for successful outcomes.
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Affiliation(s)
- Wendy M Townsend
- Department of Veterinary Clinical Sciences, Purdue University, 625 Harrison Street, West Lafayette, IN 47907-2026, USA.
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Johansson MK, Jäderkvist Fegraeus K, Lindgren G, Ekesten B. The refractive state of the eye in Icelandic horses with the Silver mutation. BMC Vet Res 2017; 13:153. [PMID: 28577553 PMCID: PMC5455091 DOI: 10.1186/s12917-017-1059-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Accepted: 05/15/2017] [Indexed: 11/26/2022] Open
Abstract
Background The syndrome Multiple Congenital Ocular Anomalies (MCOA) is a congenital eye disorder in horses. Both the MCOA syndrome and the Silver coat colour in horses are caused by the same missense mutation in the premelanosome protein (PMEL) gene. Horses homozygous for the Silver mutation (TT) are affected by multiple ocular defects causing visual impairment or blindness. Horses heterozygous for the Silver mutation (CT) have less severe clinical signs, usually cysts arising from the ciliary body iris or retina temporally. It is still unknown if the vision is impaired in horses heterozygous for the Silver mutation. A recent study reported that Comtois horses carrying the Silver mutation had significantly deeper anterior chambers of the eye compared to wild-type horses. This could potentially cause refractive errors. The purpose of the present study was to investigate if Icelandic horses with the Silver mutation have refractive errors compared to wild-type horses. One hundred and fifty-two Icelandic horses were included in the study, 71 CT horses and five TT horses. All horses were genotyped for the missense mutation in PMEL. Each CT and TT horse was matched by a wild-type (CC) horse of the same age ± 1 year. Skiascopy and a brief ophthalmic examination were performed in all horses. Association between refraction and age, eye, genotype and sex was tested by linear mixed-effect model analysis. TT horses with controls were not included in the statistical analyses as they were too few. Results The interaction between age and genotype had a significant impact on the refractive state (P = 0.0001). CT horses older than 16 years were on average more myopic than wild-type horses of the same age. No difference in the refractive state could be observed between genotypes (CT and CC) in horses younger than 16 years. TT horses were myopic (−2 D or more) in one or both eyes regardless of age. Conclusion Our results indicate that an elderly Icelandic horse (older than 16 years) carrying the Silver mutation is more likely to be myopic than a wild-type horse of the same age. Electronic supplementary material The online version of this article (doi:10.1186/s12917-017-1059-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Maria K Johansson
- Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, -750 07, Uppsala, SE, Sweden.
| | - Kim Jäderkvist Fegraeus
- Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, -750 07, Uppsala, SE, Sweden
| | - Gabriella Lindgren
- Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, -750 07, Uppsala, SE, Sweden
| | - Björn Ekesten
- Department of Clinical Sciences, Swedish University of Agricultural Sciences, -750 07, Uppsala, SE, Sweden
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Distribution of coat-color-associated alleles in the domestic horse population and Przewalski's horse. J Appl Genet 2016; 57:519-525. [PMID: 27194311 DOI: 10.1007/s13353-016-0352-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2015] [Revised: 04/03/2016] [Accepted: 05/04/2016] [Indexed: 10/21/2022]
Abstract
Considering the hidden mode of inheritance of some coat-color-associated alleles, we investigated the presence/absence of coat-color-associated alleles in 1093 domestic horses of 55 breeds and 20 specimens of Przewalski's horse. For coat-color genotyping, allele specific PCR, pyrosequencing and Li-Cor analyses were conducted on 12 coat-color-associated alleles of five genes. Our data provide deep insight into the distribution of coat-color-associated alleles within breeds. We found that the alleles for the basic colorations (bay, black, and chestnut) are widely distributed and occur in nearly all breeds. Alleles leading to dilutions or patterns are rare in domestic breeds and were not found in Przewalski's horse. Higher frequencies of these alleles are only found in breeds that are selected for their expressed phenotypes (e.g., Kinsky horse, Lewitzer, Tinker). Nevertheless, our study produced strong evidence that molecular testing of the coat color is necessary for well-defined phenotyping to avoid unexpected colorations of offspring that can result in legal action.
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Henriksen MDL, La Croix N, Wilkie DA, Lassaline-Utter M, Brantman KR, Beamer GL, Teixeira LBC, Dubielzig RR. Glaucoma with Descemet's membrane detachment in five horses. Vet Ophthalmol 2016; 20:273-279. [PMID: 27191927 DOI: 10.1111/vop.12388] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
PURPOSE To describe the clinical and histopathologic features of glaucoma associated with Descemet's membrane (DM) detachment in five horses without prior history of intraocular surgery. ANIMALS STUDIED Three Appaloosa horses and two Thoroughbreds were included in this study. The affected horses ranged in age from 16 to 27 years and presented with severe diffuse corneal edema. PROCEDURE Five eyes were enucleated due to intraocular hypertension and/or chronic corneal ulceration. The enucleated globes were evaluated by the Comparative Ocular Pathology Laboratory of Wisconsin (COPLOW). Each globe was routinely processed for histopathology and analyzed by light microscopy. A histologic diagnosis of glaucoma was reached by demonstrating a loss of optic nerve axonal tissue by measuring neurofilament-immunopositive axons with automated image analysis software. RESULTS All five horses presented with unilateral severe diffuse corneal edema that had developed between 2 and 16 weeks prior to enucleation. Intraocular pressures for the affected eyes were between 9 and 87 mmHg prior to enucleation. Descemet's membrane detachment was identified histopathologically in all five globes (5/5, 100%). All five eyes had an avascular spindle cell proliferation filling the space between the displaced peripheral DM and the corneal stroma. Neurofilament immunostaining revealed axonal loss consistent with glaucoma. CONCLUSION Equine glaucoma may be associated with Descemet's membrane detachment. This detachment and glaucoma is a possible differential diagnosis for severe equine corneal edema. In this case series, an eye with a DM detachment had a poor prognosis for retention.
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Affiliation(s)
- Michala de Linde Henriksen
- Comparative Ophthalmology Service, Department of Veterinary Clinical Sciences, College of Veterinary Medicine, University of Minnesota, 1352 Boyd Avenue, Saint Paul, MN 55108, USA
| | - Noelle La Croix
- The Veterinary Medical Center of Long Island, 75 Sunrise Highway, West Islip, NY, 11795, USA
| | - David A Wilkie
- Department of Veterinary Clinical Sciences, Comparative Ophthalmology, The Ohio State University, 1900 Coffey Road, Columbus, OH 43210, USA
| | - Mary Lassaline-Utter
- Department of Radiological and Surgical Sciences, University of California-Davis, Davis, CA 95616, USA
| | - Karen R Brantman
- Northwest Animal Eye Specialists, 13020 NE 85th Street, Kirkland, WA, 98033, USA
| | - Gillian L Beamer
- Department of Infectious Disease and Global Health, Cummings School of Veterinary Medicine, Tufts University, 200 Westboro Road, North Grafton, MA 01536, USA
| | - Leandro B C Teixeira
- Comparative Ocular Pathology Laboratory of Wisconsin, University of Wisconsin, 2015 Linden Dr. #3308, Madison, WI, 53706, USA
| | - Richard R Dubielzig
- Comparative Ocular Pathology Laboratory of Wisconsin, University of Wisconsin, 2015 Linden Dr. #3308, Madison, WI, 53706, USA
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Affiliation(s)
- W. M. Townsend
- Department of Veterinary Clinical Sciences; College of Veterinary Medicine; Purdue University; West Lafayette Indiana USA
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Oosterlinck M, Grebert A, Gielen I, Bosseler L, Ducatelle R, Gasthuys F. Post mortemmagnetic resonance imaging of multiple congenital ocular anomalies in a Comtois mare. EQUINE VET EDUC 2015. [DOI: 10.1111/eve.12293] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- M. Oosterlinck
- Department of Surgery and Anaesthesiology of Domestic Animals; Faculty of Veterinary Medicine; Ghent University; Merelbeke Belgium
| | - A. Grebert
- Department of Surgery and Anaesthesiology of Domestic Animals; Faculty of Veterinary Medicine; Ghent University; Merelbeke Belgium
| | - I. Gielen
- Department of Veterinary Medical Imaging and Small Animal Orthopedics; Faculty of Veterinary Medicine; Ghent University; Merelbeke Belgium
| | - L. Bosseler
- Department of Pathology, Bacteriology and Poultry Diseases; Faculty of Veterinary Medicine; Ghent University; Merelbeke Belgium
| | - R. Ducatelle
- Department of Pathology, Bacteriology and Poultry Diseases; Faculty of Veterinary Medicine; Ghent University; Merelbeke Belgium
| | - F. Gasthuys
- Department of Surgery and Anaesthesiology of Domestic Animals; Faculty of Veterinary Medicine; Ghent University; Merelbeke Belgium
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Andersson LS, Wilbe M, Viluma A, Cothran G, Ekesten B, Ewart S, Lindgren G. Equine multiple congenital ocular anomalies and silver coat colour result from the pleiotropic effects of mutant PMEL. PLoS One 2013; 8:e75639. [PMID: 24086599 PMCID: PMC3781063 DOI: 10.1371/journal.pone.0075639] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2013] [Accepted: 08/18/2013] [Indexed: 11/19/2022] Open
Abstract
Equine Multiple Congenital Ocular Anomalies (MCOA) syndrome is a heritable eye disorder mainly affecting silver colored horses. Clinically, the disease manifests in two distinct classes depending on the horse genotype. Horses homozygous for the mutant allele present with a wide range of ocular defects, such as iris stromal hypoplasia, abnormal pectinate ligaments, megaloglobus, iridociliary cysts and cataracts. The phenotype of heterozygous horses is less severe and predominantly includes iridociliary cysts, which occasionally extend into the temporal retina. In order to determine the genetic cause of MCOA syndrome we sequenced the entire previously characterized 208 kilobase region on chromosome 6 in ten individuals; five MCOA affected horses from three different breeds, one horse with the intermediate Cyst phenotype and four unaffected controls from two different breeds. This was performed using Illumina TruSeq technology with paired-end reads. Through the systematic exclusion of all polymorphisms barring two SNPs in PMEL, a missense mutation previously reported to be associated with the silver coat colour and a non-conserved intronic SNP, we establish that this gene is responsible for MCOA syndrome. Our finding, together with recent advances that show aberrant protein function due to the coding mutation, suggests that the missense mutation is causative and has pleiotrophic effect, causing both the horse silver coat color and MCOA syndrome.
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Affiliation(s)
- Lisa S. Andersson
- Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Maria Wilbe
- Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Agnese Viluma
- Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Gus Cothran
- Department of Veterinary Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas, United States of America
| | - Björn Ekesten
- Department of Clinical Sciences, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Susan Ewart
- Department of Large Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, Michigan, United States of America
| | - Gabriella Lindgren
- Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, Uppsala, Sweden
- * E-mail:
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Depecker M, Ségard E, Cadoré JL. Phenotypic description of multiple congenital ocular anomalies in Comtois horses. EQUINE VET EDUC 2013. [DOI: 10.1111/eve.12075] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- M. Depecker
- Centre International de Santé du Cheval d'ONIRIS (CISCO); LUNAM Université, ONIRIS
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Icelandic horses with the Silver coat colour show altered behaviour in a fear reaction test. Appl Anim Behav Sci 2013. [DOI: 10.1016/j.applanim.2013.04.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Reissmann M, Ludwig A. Pleiotropic effects of coat colour-associated mutations in humans, mice and other mammals. Semin Cell Dev Biol 2013; 24:576-86. [PMID: 23583561 DOI: 10.1016/j.semcdb.2013.03.014] [Citation(s) in RCA: 99] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2012] [Revised: 03/27/2013] [Accepted: 03/28/2013] [Indexed: 12/20/2022]
Abstract
The characterisation of the pleiotropic effects of coat colour-associated mutations in mammals illustrates that sensory organs and nerves are particularly affected by disorders because of the shared origin of melanocytes and neurocytes in the neural crest; e.g. the eye-colour is a valuable indicator of disorders in pigment production and eye dysfunctions. Disorders related to coat colour-associated alleles also occur in the skin (melanoma), reproductive tract and immune system. Additionally, the coat colour phenotype of an individual influences its general behaviour and fitness. Mutations in the same genes often produce similar coat colours and pleiotropic effects in different species (e.g., KIT [reproductive disorders, lethality], EDNRB [megacolon] and LYST [CHS]). Whereas similar disorders and similar-looking coat colour phenotypes sometimes have a different genetic background (e.g., deafness [EDN3/EDNRB, MITF, PAX and SNAI2] and visual diseases [OCA2, RAB38, SLC24A5, SLC45A2, TRPM1 and TYR]). The human predilection for fancy phenotypes that ignore disorders and genetic defects is a major driving force for the increase of pleiotropic effects in domestic species and laboratory subjects since domestication has commenced approximately 18,000 years ago.
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Key Words
- AS
- ASIP
- ATRN
- Agouti signalling protein
- Albino
- Angelman syndrome
- Attractin (mahogany)
- BLOC
- Biogenesis of lysosomal organelles complex
- CCSD
- CHS
- CSD
- CSNB
- Canine congenital sensorineural deafness
- Chediak-Higashi syndrome
- Coat colour gene
- Congenital sensorineural deafness
- Congenital stationary night blindness
- Disorder
- EDN3
- EDNRB
- Endothelin 3
- Endothelin receptor type B
- Epistasis
- Fitness
- GS
- Griscelli syndrome (type 1 or 2)
- HPS
- HSCR
- Hermansky-Pudlak syndrome with different types
- Hirschsprung disease
- IPE
- Iris pigment epithelium
- KIT
- KIT ligand (steel factor)
- KITLG
- LFS
- LYST
- Lavender foal syndrome
- Lethal
- Leucism
- Lysosomal trafficking regulator
- MC1R
- MCOA
- MCOLN3
- MGRN1
- MITF
- MYO5A
- Mahogunin ring finger 1 (E3 ubiquitin protein ligase)
- Melanocortin 1 receptor
- Melanoma
- Microphthalmia-associated transcription factor
- Mucolipin 3 (TRPML3)
- Multiple congenital ocular anomalies
- Myosin VA (heavy chain 12, myoxin)
- OA
- OCA
- OCA2
- OLWS
- OSTM1
- Ocular albinism
- Oculocutaneous albinism II (pink-eye dilution homolog)
- Oculocutaneous albinism type 1–4
- Osteopetrosis associated transmembrane protein 1 (Grey lethal osteopetrosis)
- Overo lethal white syndrome
- PAX3
- PMEL
- PWS
- Paired box 3
- Pleiotropy
- Prader-Willi syndrome
- Premelanosome protein (Pmel17, SILV)
- RAB27A
- RAB27A member RAS oncogene family
- RAB38
- RAB38 member RAS oncogene family
- RPE
- Reproduction
- Retinal pigmented epithelium
- SLC24A5
- SLC2A9
- SLC45A2
- SNAI2
- STX17
- Snail homolog 2 (Drosophila), (SLUG), SOX10, SRY (sex determining region Y)-box 10
- Solute carrier family 2 (facilitated glucose transporter), member 9
- Solute carrier family 24, member 5
- Solute carrier family 45, member 2, MATP
- Syntaxin 17
- TRPM1
- TYR
- Tameness
- Transient receptor potential cation channel, subfamily M, member 1 (melastatin-1)
- Tyrosinase, TYRP1, Tyrosinase-related protein 1
- V-kit Hardy-Zuckerman 4 feline sarcoma viral oncogene homolog, tyrosine kinase receptor (c-kit)
- WS
- Waardenburg syndrome (type 1, type 2 combined with Tietz syndrome type 3 Klein-Waardenburg syndrome, type 4 Waardenburg-Shah syndrome)
- alpha-melanocyte-stimulating hormone
- αMSH
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Affiliation(s)
- Monika Reissmann
- Humboldt University Berlin, Department for Crop and Animal Sciences, Berlin, Germany.
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Premont JE, Andersson L, Grauwels M. Multiple congenital ocular anomalies syndrome in a family of Shetland and Deutsches Classic ponies in Belgium. EQUINE VET EDUC 2013. [DOI: 10.1111/eve.12009] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Affiliation(s)
- J. E. Premont
- Department of Clinical Sciences, Ophthalmology; Faculty of Veterinary Medicine; Université de Liège; Liège; Belgium
| | - L. Andersson
- Department of Animal Breeding and Genetics; Swedish University Agricultural Sciences; Uppsala; Sweden
| | - M. Grauwels
- Department of Clinical Sciences, Ophthalmology; Faculty of Veterinary Medicine; Université de Liège; Liège; Belgium
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Ségard EM, Depecker MC, Lang J, Gemperli A, Cadoré JL. Ultrasonographic features of PMEL17 (Silver) mutant gene-associated multiple congenital ocular anomalies (MCOA) in Comtois and Rocky Mountain horses. Vet Ophthalmol 2013; 16:429-35. [PMID: 23278951 DOI: 10.1111/vop.12021] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
OBJECTIVE (1) To describe the ultrasonographic appearance of multiple congenital ocular anomalies (MCOA) in the eyes of horses with the PMEL17 (Silver) mutant gene. (2) To compare the accuracy of B-mode ocular ultrasound to conventional direct ophthalmoscopy. ANIMALS STUDIED Sixty-seven Comtois and 18 Rocky Mountain horses were included in the study. PROCEDURES Horses were classified as being carriers or noncarriers of the PMEL17 mutant allele based on coat color or genetic testing. Direct ophthalmoscopy followed by standardized ultrasonographic examination was performed in all horses. RESULTS Seventy-five of 85 horses (88.24%) carried at least one copy of the Silver mutant allele. Cornea globosa, severe iridal hypoplasia, uveal cysts, cataracts, and retinal detachment could be appreciated with ultrasound. Carrier horses had statistically significantly increased anterior chamber depth and decreased thickness of anterior uvea compared with noncarriers (P < 0.05). Uveal cysts had a wide range of location and ultrasonographic appearances. In 51/73 (69.86%) carrier horses, ultrasound detected ciliary cysts that were missed with direct ophthalmoscopy. CONCLUSIONS In this study, ultrasonography was useful to identify uveal cysts in PMEL17 mutant carriers and to assess anterior chamber depth.
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Affiliation(s)
- Emilie M Ségard
- Equine Department, Université de Lyon, Marcy l'Etoile, F-69003, France; VetAgro-Sup, Campus Vétérinaire de Lyon, Marcy l'Etoile, Lyon, F-69280, France
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