Genetics in horses encompasses the study of hereditary traits and the genetic makeup that influences various characteristics and health conditions in equine populations. This field involves the analysis of genes and their functions, inheritance patterns, and the impact of genetic variations on traits such as coat color, performance ability, and susceptibility to diseases. Research in equine genetics employs techniques such as genome mapping, sequencing, and genetic testing to identify specific genes and mutations associated with these traits. This page gathers peer-reviewed research studies and scholarly articles that explore the genetic basis of equine traits, the methodologies used in genetic research, and the implications for breeding, health management, and conservation of horse breeds.
Lee JH, Song KD, Kim JM, Leem HK, Park KD.Jeju horse (Natural Monument number 347) is a breed of horse that has experienced long-term isolation and domestication in Jeju Island, South Korea. We evaluated genetic features of this breed, including SNP, by whole-genome resequencing using an Illumina HiSeq 2000. A total of 5,986,852 SNP were identified in 4 Jeju horses and were divided into homozygous and heterozygous SNP (2,357,099 and 3,629,753 SNP, respectively). It revealed that 63.8% of these SNP resided in intergenic regions. Immune response genes with nonsynonymous SNP were overrepresented in Jeju horses as evidenced by Gene Ontolo...
Velie BD, Shrestha M, FranÒ«ois L, Schurink A, Tesfayonas YG, Stinckens A, Blott S, Ducro BJ, Mikko S, Thomas R, Swinburne JE, Sundqvist M....While susceptibility to hypersensitive reactions is a common problem amongst humans and animals alike, the population structure of certain animal species and breeds provides a more advantageous route to better understanding the biology underpinning these conditions. The current study uses Exmoor ponies, a highly inbred breed of horse known to frequently suffer from insect bite hypersensitivity, to identify genomic regions associated with a type I and type IV hypersensitive reaction. A total of 110 cases and 170 controls were genotyped on the 670K Axiom Equine Genotyping Array. Quality control ...
Barrier Battut I, Kempfer A, Becker J, Lebailly L, Camugli S, Chevrier L.Several laboratories routinely use flow cytometry to evaluate stallion semen quality. However, objective and practical tools for the on-field interpretation of data concerning fertilizing potential are scarce. A panel of nine tests, evaluating a large number of compartments or functions of the spermatozoa: motility, morphology, viability, mitochondrial activity, oxidation level, acrosome integrity, DNA integrity, "organization" of the plasma membrane, and hypoosmotic resistance, was applied to a population of 43 stallions, 33 of which showing widely differing fertilities (19%-84% pregnancy rat...
The climatic and cultural diversity of the Italian Peninsula triggered, over time, the development of a great variety of horse breeds, whose origin and history are still unclear. To clarify this issue, analyses on phenotypic traits and genealogical data were recently coupled with molecular screening. Methods: To provide a comprehensive overview of the horse genetic variability in Italy, we produced and phylogenetically analyzed 407 mitochondrial DNA (mtDNA) control-region sequences from ten of the most important Italian riding horse and pony breeds: Bardigiano, Esperia, Giara, Lipizzan, Maremm...
Gardner SN, McLoughlin K, Be NA, Allen J, Weaver SC, Forrester N, Guerbois M, Jaing C.Venezuelan equine encephalitis virus (VEEV) is a mosquito-borne alphavirus that has caused large outbreaks of severe illness in both horses and humans. New approaches are needed to rapidly infer the origin of a newly discovered VEEV strain, estimate its equine amplification and resultant epidemic potential, and predict human virulence phenotype. We performed whole genome single nucleotide polymorphism (SNP) analysis of all available VEE antigenic complex genomes, verified that a SNP-based phylogeny accurately captured the features of a phylogenetic tree based on multiple sequence alignment, an...
Kydd JH, Case R, Winton C, MacRae S, Sharp E, Ricketts SL, Rash N, Newton JR.Identification of risk factors which are associated with severe clinical signs can assist in the management of disease outbreaks and indicate future research areas. Pregnancy loss during late gestation in the mare compromises welfare, reduces fecundity and has financial implications for horse owners. This retrospective study focussed on the identification of risk factors associated with pregnancy loss among 46 Thoroughbred mares on a single British stud farm, with some but not all losses involving equid herpesvirus-1 (EHV-1) infection. In a sub-group of 30 mares, association between pregnancy ...
Carfora V, Caprioli A, Grossi I, Pepe M, Alba P, Lorenzetti S, Amoruso R, Sorbara L, Franco A, Battisti A.A Methicillin-resistantStaphylococcus aureus(MRSA) was isolated in Italy from a pathological sample of a mare presenting chronic purulent sinusitis and that had undergone frontal-sinus surgery three months before. Humans, horses, dogs and environmental samples were subsequently collected at the mare's stable and at the Veterinary Hospital, where the mare was operated/hospitalized, and screened for the presence of MRSA that was detected from other horses and from the environment at both sites. All the MRSA isolates belonged to clonal complex (CC)8, ST8-t11469-SCCmec-IVa, and showed similar phen...
Terron-Canedo N, Weir W, Nicolson L, Britton C, Nasir L.Bovine papillomavirus (BPV) types 1 and 2 play an important role in the pathogenesis of equine sarcoids (ES), the most common cutaneous tumour affecting horses. MicroRNAs (miRNAs), small non-coding RNAs that regulate essential biological and cellular processes, have been found dysregulated in a wide range of tumours. The aim of this study was to identify miRNAs associated with ES. Differential expression of miRNAs was assessed in control equine fibroblasts (EqPalFs) and EqPalFs transformed with the BPV-1 genome (S6-2 cells). Using a commercially available miRNA microarray, 492 mature miRNAs we...
Lee B, Kang HY, Lee DO, Ahn C, Jeung EB.Claudins, which are known as transmembrane proteins play an essential role in tight junctions (TJs) to form physical barriers and regulate paracellular transportation. To understand equine diseases, it is helpful to measure the tissue-specific expression of TJs in horses. Major equine diseases such as colic and West Nile cause damage to TJs. In this study, the expression level and distribution of claudin-1, -2, -4, and -5 in eight tissues were assessed by Western blotting and immunohistochemistry methods. Claudin-1 was primarily identified in the lung, duodenum, and uterus, claudin-2 was evenl...
Orsztynowicz M, Pawlak P, Podstawski Z, Nizanski W, Partyka A, Gotowiecka M, Kosiniak-Kamysz K, Lechniak D.Predicting male fertility on non-invasive sperm traits is of big importance to human and animal reproduction strategies. Combining the wide range of parameters monitored by computer-assisted sperm analysis (CASA) with some molecular traits (e.g. mtDNA content) may help to identify markers of the male fertility. The aim of this study was to characterize variation in the mtDNA copy number in equine sperm and to investigate whether mtDNA content is correlated with quality traits of stallion spermatozoa and the age of the male. Ejaculates collected from 53 fertile stallions were divided into four ...
Kjöllerström HJ, do Mar Oom M, Chowdhary BP, Raudsepp T.The Sorraia, a critically endangered indigenous Iberian horse breed, is characterized by low genetic variability, high rate of inbreeding, bad sperm quality and subfertility. Here, we studied 11 phenotypically normal but subfertile Sorraia stallions by karyotyping, sex chromosome sperm-FISH and molecular analysis of FKBP6 - a susceptibility locus for impaired acrosome reaction (IAR). The stallions had normal sperm concentration (>300 million cells/ml), but the numbers of progressively motile sperm (21%) and morphologically normal sperm (28%) were invariably low. All stallions had a normal 6...
Gressler LT, Bordin AI, McQueen CM, Cohen ND, de Vargas AC.Rhodococcus equi preferentially infects macrophages causing pyogranulomatous pneumonia in young foals. Both the vapA and rhbC genes are up-regulated in an iron (Fe)-deprived environment, such as that found within macrophages. Chloroquine (CQ) is a drug widely used against malaria that suppresses the intracellular availability of Fe in eukaryotic cells. The main objective of this study was to evaluate the ability of CQ to inhibit replication of virulent R. equi within murine (J774A.1) and foal alveolar macrophages (AMs) and to verify whether the mechanism of inhibition could be Fe-deprivation-d...
West J, Gill WW.Genome editing in large animals has tremendous practical applications, from more accurate models for medical research through improved animal welfare and production efficiency. Although genetic modification in large animals has a 30 year history, until recently technical issues limited its utility. The original methods - pronuclear injection and integrating viruses - were plagued with problems associated with low efficiency, silencing, poor regulation of gene expression, and variability associated with random integration. With the advent of site specific nucleases such as TALEN and CRISPR/Cas9...
Schraiber JG, Evans SN, Slatkin M.The advent of accessible ancient DNA technology now allows the direct ascertainment of allele frequencies in ancestral populations, thereby enabling the use of allele frequency time series to detect and estimate natural selection. Such direct observations of allele frequency dynamics are expected to be more powerful than inferences made using patterns of linked neutral variation obtained from modern individuals. We developed a Bayesian method to make use of allele frequency time series data and infer the parameters of general diploid selection, along with allele age, in nonequilibrium populati...
Gottschalk M, Sieme H, Martinsson G, Distl O.The objectives of the present study were to evaluate genetic parameters for semen quality traits of 241 fertile German Warmblood stallions regularly employed in artificial insemination (AI). Stallions were owned by the National Studs Celle and Warendorf in Germany. Semen traits analyzed were gel-free volume, sperm concentration, total number of sperm, progressive motility and total number of progressively motile sperm. Semen protocols from a total of 63,972 ejaculates were collected between the years 2001 and 2014 for the present analysis. A multivariate linear animal model was employed for es...
Wang Y, Mao Q, Chang H, Wu Y, Pan S, Li Y, Zhang Y.Integrins can function as receptors for foot-and-mouth disease virus (FMDV) in epithelium. Horses are believed to be insusceptible to this disease, but the mechanism of resistance remains unclear. To detect whether FMDV can use integrin to attach to equine epithelial, we compared the utilities of αvβ3 and αvβ6 between bovine and equine kidney epithelial cells (KECs). Equine KECs showed almost equal efficiency to those of bovine. Further, the integrin αv, β3, and β6 subunits from bovine and equine were cloned and vectors were transfected into SW480 cells and COS-1 cells alone or together...
Sánchez MJ, Azor PJ, Molina A, Parkin T, Rivero JL, Valera M.Cresty neck is a relatively common morphological defect in Pura Raza Español horses and other Baroque type horse breeds, which adversely affects the breeding industry. Objective: To establish the within-breed prevalence, possible associated factors and heritability of cresty neck in Pura Raza Español horses. Methods: Cross-sectional analysis of a large worldwide database of Pura Raza Español horses. Methods: The database included evaluations of 10,929 Pura Raza Español horses from 24 countries. Cresty neck score, on a 9 point scale, girth-to-height ratio, height at the withers, length of n...
Alves Beuttemmüller E, Woodward A, Rash A, Dos Santos Ferraz LE, Fernandes Alfieri A, Alfieri AA, Elton D.An extensive outbreak of equine influenza occurred across multiple countries in South America during 2012. The epidemic was first reported in Chile then spread to Brazil, Uruguay and Argentina, where both vaccinated and unvaccinated animals were affected. In Brazil, infections were widespread within 3months of the first reported cases. Affected horses included animals vaccinated with outdated vaccine antigens, but also with the OIE-recommended Florida clade 1 strain South Africa/4/03. Methods: Equine influenza virus strains from infected horses were isolated in eggs, then a representative stra...
McElhone RL, Meakin GE, French JC, Alexander T, Morgan RM.A study was designed to investigate the effects of external variables, including blood type, flooring surface, footwear tread depth and blood dryness, on the appearance of blood-based footwear marks, with particular reference to simulating a specific casework scenario. Results showed that footwear marks left in human blood tended to be of greater quality than those in equine blood, highlighting a potential issue in applying data generated with equine blood to human bloodstains in casework. Footwear tread effects were also dependent on blood type, but the type of flooring surface did not affect...
Duan H, Gao JF, Su X, Fu X, Yue DM, Gao Y, Qiu JH, Wang CR.Triodontophorus spp. parasitizes the large intestine of equine, causing strongylid diseases. The present study assessed genetic variation in five gene regions within and between Triodontophorus brevicauda and Triodontophorus nipponicus from Heilongjiang Province and the Inner Mongolia Autonomous region. The five gene markers were three mitochondrial (mt) genes, cytochrome c oxidase subunit I (cox1), NADH dehydrogenase subunit 5 (nad5), cytochrome b (cytb); and two ribosomal RNA genes, the internal transcribed spacer 1 (ITS1) and the internal transcribed spacer 2 (ITS2). Partial (p) sequences o...
Mochizuki M, Hayakawa N, Minowa F, Saito A, Ishioka K, Ueda F, Okubo K, Tazaki H.In this study, iodine and thyroxin (T4) concentrations in the serum of 69 horses were investigated. Higher iodine concentrations were obtained from the horses housed in Chiba Prefecture. In contrast, T4 concentrations of horses at Shizuoka Prefecture were higher than those of horses at Chiba Prefecture. There was a significant correlation (r = 0.643, P < 0.001) between the iodine and T4 concentrations of horses at Saitama and Shizuoka prefectures. Although a significant correlation (r = 0.794, P < 0.001) was also observed in the investigation of all horses at Chiba Prefec...
Roy Chowdhury P, DeMaere M, Chapman T, Worden P, Charles IG, Darling AE, Djordjevic SP.Clostridium difficile infections (CDI) are a significant health problem to humans and food animals. Clostridial toxins ToxA and ToxB encoded by genes tcdA and tcdB are located on a pathogenicity locus known as the PaLoc and are the major virulence factors of C. difficile. While toxin-negative strains of C. difficile are often isolated from faeces of animals and patients suffering from CDI, they are not considered to play a role in disease. Toxin-negative strains of C. difficile have been used successfully to treat recurring CDI but their propensity to acquire the PaLoc via lateral gene transfe...
Qi M, Wang R, Wang H, Jian F, Li J, Zhao J, Dong H, Zhu H, Ning C, Zhang L.In present study, 262 fecal specimens were collected from 12 groups of grazing horses in the Xinjiang Uyghur Autonomous Region of China. The specimens were subjected to PCR and sequencing analyses of the ribosomal internal transcribed spacer (ITS). The overall prevalence of E. bieneusi in horses was 30.9% (81/262). No significant differences in prevalence were observed between horses of different ages or sexes. Nineteen genotypes were identified: 15 known genotypes (BEB6, CHG19, CM6, CM7, CM8, CS-1, CS-4, D, EpbA, EbpC, G, horse1, horse2, O, and Peru8) and four new genotypes (XJH1-XJH4). Six ...
Liu Q, Meli ML, Zhang Y, Meili T, Stirn M, Riond B, Weibel B, Hofmann-Lehmann R.A reverse line blot (RLB) hybridization assay was adapted and applied for equine blood samples collected at the animal hospital of the University of Zurich to determine the presence of piroplasms in horses in Switzerland. A total of 100 equine blood samples were included in the study. The V4 hypervariable region of the 18S rRNA gene was amplified by polymerase chain reaction and analyzed using the RLB assay. Samples from seven horses hybridized to a Theileria/Babesia genus-specific and a Theileria genus-specific probe. Of these, two hybridized also to the Theileria equi-specific probe. The oth...
Kumar CS, Sivaramakrishna D, Ravi SK, Swamy MJ.Seminal fibronectin type-II (Fn-II) proteins interact with choline phospholipids present on the sperm plasma membrane and play a crucial role in sperm capacitation. Crystal structure of phosphorylcholine (PrC) complex of PDC-109, the major bovine Fn-II protein, together with fluorescence spectroscopic studies has shown that tryptophan residues are crucial for its specific interaction with choline phospholipids. In the present study, the heterogeneity and microenvironment of tryptophan residues in HSP-1/2, a major protein of horse seminal plasma (which is homologous to PDC-109) were investigate...
Patterson Rosa L, Martin K, Vierra M, Foster G, Lundquist E, Brooks SA, Lafayette C.Over 30 polymorphisms in the KIT Proto-Oncogene Receptor Tyrosine Kinase (KIT) gene have been implicated in white spotting patterns ranging from small areas to full dermal depigmentation in the horse. We performed a candidate-gene exon sequencing approach on KIT and MITF, 2 known causatives of white spotting patterns, within 2 families of horses of unknown white spotting. Family 1 (Fam1, N = 5) consisted of a Quarter Horse stallion and 4 offspring with white spotting pattern ranging from legs, lower ventral, and head regions with jagged borders, to almost complete white. The second family (Fam...
Górecka A, Słoniewski K, Golonka M, Jaworski Z, Jezierski T.There are studies on the relationship between the position and shape of hair whorls on bovine forehead and phenotypic traits. According to anecdotal beliefs by horse users and handlers, temperamental traits may be related to the position of hair whorls in horses. No previous research on the mechanisms of inheritance of hair whorls has been performed, so the aim of the present study was to determine the heritability of the position of the hair whorl on the forehead of Konik horses. The horses (n = 362) were classified into five groups based on the whorl position on forehead with respect to the ...
Milinovich GJ, Burrell PC, Pollitt CC, Bouvet A, Trott DJ.Four Gram-positive, catalase-negative, coccoid-shaped isolates were obtained from the caecum and rectum of horses with oligofructose-induced equine laminitis. Phenotypic and phylogenetic studies were performed on these isolates. Initial biochemical profiling assigned two of the isolates to Streptococcus bovis. The other two isolates, however, could not be assigned conclusively on the basis of their biochemical profiles. Gene sequence analysis demonstrated that the four new isolates were related most closely to Streptococcus suis based on the 16S rRNA gene and to Streptococcus orisratti based o...
Rendo F, Iriondo M, Manzano C, Estonba A.Here, we present the results of a genetic analysis of 463 Pottoka ponies corresponding to four generations, using 17 microsatellite markers. Ten years after the beginning of the Pottoka conservation programme, the values for the genetic diversity of the breed are still high and stable, indicating the success of the programme. We found null alleles in Pottoka for the ASB23, HMS3 and HTG10 microsatellites. Together with information obtained from other pony breeds from the Iberian Peninsula, this finding indicates that these microsatellites should not be used for phylogenetic analyses or parentag...
Stewart JM, Blakely JA, Johnson MD.Non-covalent modification of cytochrome c may have implications for electron transport and energy metabolism. We examined the interaction of various fatty acids (FAs), their coenzyme A and carnitine esters, and fatty alcohols with horse heart ferrocytochrome c. A comparison of FAs indicated a minimum chain length of 14 carbons was required for significant effect on the ferroheme chromophore and major changes in electronic spectra. Coenzyme A and carnitine esters interacted less strongly than FAs whereas long-chain alcohols did not interact with the protein. We found a single, saturable FA bind...
Davidson TR, Chamberlain CS, Bridges TS, Spicer LJ.Little is known regarding the hormonal regulation of granulosa cell steroidogenesis and the ovarian insulin-like growth factor (IGF) system in the mare. The objectives of this study were to determine, first, if estradiol, insulin, and/or FSH affect steroid production by equine granulosa cells (experiment 1) and, second, if the components of the IGF system are produced by equine granulosa cells in culture as well as whether estradiol, insulin, and/or FSH affects IGF and/or IGF-binding protein (IGFBP) production by equine granulosa cells (experiment 2). Granulosa cells from small (6-15 mm), medi...
Langemeier JL, Cook SJ, Cook RF, Rushlow KE, Montelaro RC, Issel CJ.Control of equine infectious anemia (EIA) is currently based on detection of anti-EIA virus (EIAV) antibodies. However, serologic diagnostic methods may give false-negative results in infected horses that fail to respond adequately or are in the early stages of infection. We developed a reverse transcriptase nested PCR (RT-nPCR) assay for the detection of viral gag gene sequences in plasma from EIAV-infected horses. The ability of RT-nPCR to detect field strains of EIAV was investigated by assaying plasma samples from 71 horses stabled on EIA quarantine ranches. Positive PCR signals were detec...
Osteochondrosis (OC) develops in growing horses due to disturbed differentiation and maturation of cartilage, particularly at the predilection sites of the fetlock, hock and stifle joints. Horses with osteochondrotic lesions are at a high risk of developing orthopaedic problems later in life. This article briefly reviews the published heritability estimates for OC and offers perspectives for selection in the horse industry. Heritabilities for OC in Warmblood and Standardbred horses have been estimated at 0.1-0.4 in animal threshold models. Whole genome scans using microsatellites have identifi...
Bhoora R, Buss P, Guthrie AJ, Penzhorn BL, Collins NE.Seventy EDTA blood samples collected from plains zebra (Equus quagga burchellii) and Cape mountain zebra (Equus zebra zebra) were screened for the presence of piroplasm parasite DNA using quantitative T. equi-specific and B. caballi-specific TaqMan real-time PCR (qPCR) tests. T. equi parasite DNA was detected in 60 samples, 19 of which were also positive for B. caballi. Approximately 1480bp of the piroplasm 18S rRNA gene was amplified and sequenced from 17 samples, while the V4 hypervariable region of the 18S rRNA gene was amplified, cloned and sequenced from 31 samples. BLASTN analysis reveal...
Lazary S, Marti E, Szalai G, Gaillard C, Gerber H.The equine leucocyte antigen (ELA) types and the clinical diagnosis for equine sarcoid and summer dermatitis were evaluated in 2026 horses representing five breeds. Data were analysed in unrelated animals and in family material. In the case of equine sarcoid, a strong association was observed between the ELA class II DW13 antigen and its effect on Swiss (cP < 0.001), French (cP < 0.0001) and Irish (cP < 0.01) Warmblood horses. The class I antigen A3 occurred more frequently in sarcoid-affected French horses (cP < 0.001). These results confirm our earlier findings (Gerber et al. 1988). Among Fr...
Binns MM, Daly JM, Chirnside ED, Mumford JA, Wood JM, Richards CM, Daniels RS.The haemagglutinin (HA) gene from the equine influenza H3N8 isolate Suffolk/89 has been cloned by reverse transcription and polymerase chain reaction amplification. The nucleotide sequence of the HA gene was determined from two independently cloned copies of the gene and was found to be most closely related to recent American isolates supporting the idea that most isolates of equine H3N8 are evolving as a single lineage. When the predicted amino acid sequence of the Suffolk/89 HA was examined, changes had taken place in at least four of the major antigenic sites, A, B, C, and D when compared t...
Broström H, Fahlbrink E, Dubath ML, Lazary S.The distribution of equine leucocyte antigens (ELA) in Swedish Halfbreds affected by sarcoid tumors was determined and compared with that of control horses of the same breed. ELA-haplotype A3W13 appeared more frequently in affected horses, resulting in a chi 2 value of 4.45 (P = 0.034) for A3 and 9.05 (P = 0.0026) for W13, respectively. The relative risk factor (RR) could be estimated to 2.13 and 3.00 for A3 and W13, respectively. The etiology fraction (EF) was calculated to 28% and 37% for A3 and W13, respectively. Thus, in the population of Swedish Halfbreds approximately 40% (at least) of t...
Gross MK, Toscano DG, Toscano WA.Calmodulin (CaM), the calcium binding protein that modulates the activity of a number of key regulatory enzymes, is present at high levels in sperm. To determine whether CaM regulates adenylate cyclase in mammalian sperm, the actions of EGTA and selected CaM antagonists on a solubilized adenylate cyclase from mature equine sperm were examined. The activity of equine sperm adenylate cyclase was inhibited by EGTA in a concentration-dependent manner with a half-maximal inhibitory concentration (IC50) of 2 mM. Equine sperm adenylate cyclase was also inhibited in a concentration-dependent manner by...
Sant C, Allicock OM, d'Abadie R, Charles RA, Georges K.The agents of equine piroplasmosis, Theileria equi and Babesia caballi, are endemic in Trinidad, West Indies. While transmission is mainly by ixodid ticks, transplacental transmission of T. equi has also been reported. This disease has contributed to foetal losses as well as morbidity and mortality of neonatal foals and adult horses. Previous 18S rRNA-based phylogenetic studies indicated a noticeable degree of variation within and among B. caballi and T. equi isolates from different geographical regions. The objective of this study was to evaluate the diversity of T. equi and B. caballi obtain...
Ibrahim ES, Kinoh M, Matsumura T, Kennedy M, Allen GP, Yamaguchi T, Fukushi H.Equine herpesvirus 1 was isolated from an onager in 1985, a zebra in 1986 and a Thomson's gazelle in 1996 in USA. The genetic relatedness and pathogenicity of these three viruses were investigated based on the nucleotide sequences of the glycoprotein G (gG) gene, experimental infection in hamsters, and comparison with horse isolates. The gG gene sequences of EHV-1 from onager and zebra were identical. The gG gene sequences of the gazelle isolate showed 99.5% identity to those of onager and zebra isolates. The gG gene sequences of EHV-1 isolated from horses were 99.9-100% identical and 98, 98 a...
Ewart SL, Ramsey DT, Xu J, Meyers D.Anterior segment dysgenesis syndrome occurs frequently in Rocky Mountain horses and has two distinct ocular phenotypes: (1) large cysts originating from the temporal ciliary body or peripheral retina and (2) multiple anterior segment anomalies including ciliary cysts, iris hypoplasia, iridocorneal adhesions and opacification, nuclear cataract, and megalocornea. To determine if anterior segment dysgenesis syndrome is heritable in horses we performed ophthalmic examinations and collected pedigree information on horses (n = 516) in an extended Rocky Mountain horse pedigree. Logistic regressive se...
Valberg SJ, Nicholson AM, Lewis SS, Reardon RA, Finno CJ.To report a novel exertional myopathy, myofibrillar myopathy (MFM) in Warmblood (WB) horses. Objective: To 1) describe the distinctive clinical and myopathic features of MFM in Warmblood horses and 2) investigate the potential inheritance of MFM in a Warmblood family. Methods: Retrospective selection of MFM cases and prospective evaluation of a Warmblood family. Methods: Retrospectively, muscle biopsies were selected from Warmblood horses diagnosed with MFM and clinical histories obtained (n = 10). Prospectively, muscle biopsies were obtained from controls (n = 8) and a three generation WB...
Bellone RR, Ocampo NR, Hughes SS, Le V, Arthur R, Finno CJ, Penedo MCT.Catastrophic fractures are among the most common cause of fatalities in racehorses. Several factors, including genetics, likely contribute to increased risk for fatal injuries. A variant in the procollagen-lysine, 2-oxoglutarate 5-dioxygenase1 gene (PLOD1 c.2032G>A) was shown to cause Warmblood fragile foal syndrome type 1 (WFFS), a fatal recessive defect of the connective tissue. Screening of multiple horse breeds identified the presence of the WFFS allele in the Thoroughbred. PLOD1 is involved in cross-linking of collagen fibrils and thus could potentially increase the risk of catastrophic b...
McBride SD, Hemmings A.Stress-induced changes in mesoaccumbens dopamine neurophysiology have been associated with the development of stereotypic behaviour in in-bred strains of laboratory rodents. This experiment evaluated whether similar changes are associated with environmentally-induced stereotypic behaviour in a higher-vertebrate species, the horse. D1- and D2-like dopamine receptor densities (B(max)) and dissociation constants (K(d)) were measured in control (n=9) and stereotypy (n=9) horses in the nucleus accumbens, caudate nucleus, putamen, substantia nigra and ventral tegmentum brain regions. Results reveale...
Hamond C, Martins G, Bremont S, Medeiros MA, Bourhy P, Lilenbaum W.A strain of Leptospira kirschneri (serogroup Grippotyphosa) was cultured from urine of a mare post-abortion in Brazil and characterized by serogrouping, multiple-locus variable-number tandem repeat analysis, PGFE, and sequencing of genes rrs and secY. Strains of L. kirschneri have apparently never been recovered from horses in tropical area, only in Europe and USA. Knowledge of local epidemiology is important to interpret genetic profiles of leptospires circulating in an area.
Ma CL, Ye YL, Wen T, Huang ZM, Pan J, Hu JJ, Tao JP, Song JL.Three cyst-forming Sarcocystis species have been identified in horsemeat; however, there exists considerable confusion concerning their relationships. Here, 74% (34/46) of the examined tissue samples from horses contained sarcocysts based on examination by light microscopy (LM), and the organism was identified as Sarcocystis bertrami based on cyst structure. The S. bertrami cysts were microscopic (up to 6750 μm in length) and exhibited a striated wall with 2.0-5.1 μm villar protrusions (vps) under LM. Transmission electron microscopy (TEM) observations showed that the vps were tightly pack...
Demircan K, Onder Z, Duzlu O, Yildirim A, Okur M, Ciloglu A, Yetismis G, Inci A.The goal of our study was to investigate the molecular prevalence of Giardia intestinalis in naturally infected horses in Kayseri, Central Anatolia Region in Turkey, to determine the molecular characterization of the obtained isolates and to exhibit the potential role of horses in zoonotic transmission of G. intestinalis. Fecal samples were randomly collected from totally 150 horses with clinically healthy between March and June of 2018. After the genomic DNA extractions, 25 (16.6%) of the 150 fecal samples, were found positive for G. intestinalis by nested PCR analyses of β-giardin gene. P...
Dong JB, Zhu W, Cook FR, Goto Y, Horii Y, Haga T.Equine infectious anemia (EIA) has posed a major challenge and caused significant losses to the equine industry worldwide. PCR detection methods have considerable potential as an adjunct to conventional serological diagnostic techniques. However, most published PCR methods, including that recommended by the OIE, were designed using laboratory-adapted virus strains and do not function with field isolates of EIA virus (EIAV). In the present study, a nested PCR assay for detection of EIAV proviral DNA in peripheral blood cells of naturally infected horses was developed. Primer sets were designed ...
Komáromy AM, Rowlan JS, La Croix NC, Mangan BG.To describe the clinical phenotype and genetics of equine Multiple Congenital Ocular Anomalies (MCOA) syndrome in PMEL17 (Silver) mutant ponies. Methods: Five presumably unrelated ponies. Methods: The ponies were examined under field conditions in their barn by slit lamp biomicroscopy, indirect ophthalmoscopy, and applanation tonometry. Blood was collected and genomic DNA extracted for MCOA genotyping using the PMEL17ex11 marker. Results: One pony solely presented with temporal ciliary body cysts, suggestive of the less severe Cyst phenotype of MCOA; the animal was heterozygous at the MCOA loc...
Eizema K, van den Burg M, Kiri A, Dingboom EG, van Oudheusden H, Goldspink G, Weijs WA.The horse is one of the few animals kept and bred for its athletic performance and is therefore an interesting model for human sports performance. The regulation of the development of equine locomotion in the first year of life, and the influence of early training on later performance, are largely unknown. The major structural protein in skeletal muscle, myosin heavy-chain (MyHC), is believed to be primarily transcriptionally controlled. To investigate the expression of the MyHC genes at the transcriptional level, we isolated cDNAs encoding the equine MyHC isoforms type 1 (slow), type 2a (fast...
Love CC, Brinsko SP, Rigby SL, Thompson JA, Blanchard TL, Varner DD.The relationship between seminal plasma level (0, 10, or 20%) and extender type [Kenney type (EZ-Mixin-CST) or Kenney-modified Tyrodes-KMT] to the susceptibility of sperm DNA to denaturation and sperm motility measures were investigated in cooled (5 degrees C) stallion sperm. Three ejaculates from each of three fertile stallions were collected in an artificial vagina and processed as follows: diluted one part uncentrifuged semen with four parts of extender to a final concentration of 20% seminal plasma in either CST or KMT (20% CST; 20% KMT); diluted to a final concentration of 25 million sper...
Reshadi P, Heydari F, Ghanbarpour R, Bagheri M, Jajarmi M, Amiri M, Alizade H, Badouei MA, Sahraei S, Adib N.Transmission of antimicrobial resistant and virulent Escherichia coli (E. coli) from animal to human has been considered as a public health concern. This study aimed to determine the phylogenetic background and prevalence of diarrheagenic E. coli and antimicrobial resistance in healthy riding-horses in Iran. In this research, the genes related to six main pathotypes of E. coli were screened. Also, genotypic and phenotypic antimicrobial resistance against commonly used antibiotics were studied, then phylo-grouping was performed on all the isolates. Results: Out of 65 analyzed isolates, 29.23â€...
Racine J, Gerber V, Feutz MM, Riley CP, Adamec J, Swinburne JE, Couetil LL.Recurrent airway obstruction (RAO) is a severe chronic respiratory disease affecting horses worldwide, though mostly in the Northern hemisphere. Environmental as well as genetic factors strongly influence the course and prognosis of the disease. Research has been focused on characterization of immunologic factors contributing to inflammatory responses, on genetic linkage analysis, and, more recently, on proteomic analysis of airway secretions from affected horses. The goal of this study was to investigate the interactions between eight candidate genes previously identified in a genetic linkage...
Hess S, Gulati R, Peluso JJ.The present studies showed that sequential treatment with equine CG (eCG) and hCG not only induced an increase in ovarian weight, but also caused an estimated 4.6-fold increase in the number of ovarian surface epithelial cells. In addition, eCG-hCG treatment increased ovarian hepatocyte growth factor (HGF) messenger RNA levels. These studies also demonstrated that rat primary ovarian surface epithelial cells as well as a cell line derived from rat ovarian surface epithelium (i.e. ROSE-179 cells) do not express the LH (hCG) receptor. Both of these cells express c-Met, the receptor for HGF. To a...
He HY, Liu LL, Chen B, Xiao HX, Liu WJ.Donkey milk has high nutritional and medicinal value, but there are few researches in donkey milk traits, especially on genome. The whole lactation of 89 donkeys was recorded and it was found that Xinjiang donkey had good lactation performance while great differences among individuals. In our previous study, four genes including , , and were identified as milk-associated with Chinese Kazakh house, based on Equine 670k Chip genomic analysis. And then 15 SNPs of the four key genes were conducted for genotyping in Xinjiang donkey in this study, one of Chinese indigenous breed, 14 SNPs were succ...