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.
Tompkins D, Hudgens E, Horohov D, Baldwin CL.This report describes the initial cloning and characterization of the equine interleukin-17 (IL-17) expressed gene sequence from mRNA obtained from equine intestinal tissue and interleukin-23 (IL-23) expressed gene sequence from mRNA obtained from equine peripheral blood mononuclear cells. Equine IL-17 has 462 nucleotides in the translated region, determined by homology with known human and mouse sequences, and shares 84% and 75% identity, respectively. For the deduced amino acid sequences, the identity with human and mouse is 76% and 70%. Equine IL-23 has 579 nucleotides in the translated reg...
Lampe V, Dierks C, Komm K, Distl O.In this study we present a newly detected QTL associated with osteochondrosis in Hanoverian warmblood horses on equine chromosome 18 (ECA18). We developed a highly polymorphic and evenly distributed marker set on ECA18 employing the horse genome assembly EquCab2. The marker set included 11 newly developed microsatellites. Average polymorphism information content was 62.1% at an average spacing of 3 Mb. For genotyping of this marker set comprising a total of 27 highly polymorphic microsatellites, we used the same 14 paternal half-sib families as in the previous whole genome scan. The chromosome...
Thirstrup JP, Bach LA, Loeschcke V, Pertoldi C.In this study, we performed a population viability analysis on 3 domestic horse breeds (Equus caballus) of Danish origin, namely, the Frederiksborg, the Knabstrupper, and the Jutland breeds. Because of their small population sizes, these breeds are considered endangered. The Vortex software simulation package was used for the population viability analysis. First, we investigated the future viability of these breeds based on present demographic and environmental parameters. Second, a sensitivity analysis revealed the most important variables for the viability of these breeds. Third, we examined...
Marchetti B, Gault EA, Cortese MS, Yuan Z, Ellis SA, Nasir L, Campo MS.Bovine papillomavirus type 1 is one of the aetiological agents of equine sarcoids. The viral major oncoprotein E5 is expressed in virtually all sarcoids, sarcoid cell lines and in vitro-transformed equine fibroblasts. To ascertain whether E5 behaves in equine cells as it does in bovine cells, we introduced the E5 open reading frame into fetal equine fibroblasts (EqPalF). As observed in primary bovine fibroblasts (BoPalF), E5 by itself could not immortalize EqPalF and an immortalizing gene, such as human telomerase (hTERT/hT), was required for the cells to survive selection. The EqPalF-hT-1E5 c...
Smith KL, Allen GP, Branscum AJ, Frank Cook R, Vickers ML, Timoney PJ, Balasuriya UB.A panel of 426 archived EHV-1 isolates collected (1951-2006) from equine abortions was analyzed using a real-time Taq-Man((R)) allelic discrimination PCR assay. Based on previous findings, isolates possessing adenine at nucleotide position 2254 (A(2254)) in ORF30 were classified as having a non-neuropathogenic genotype and those with guanine at 2254 (G(2254)) were designated as the neuropathogenic genotype. The resultant data demonstrated that viruses with the neuropathogenic genotype existed in the 1950s and isolates with this genotype increased from 3.3% in the 1960s to 14.4% in the 1990s. T...
Hulting G, Flock M, Frykberg L, Lannergård J, Flock JI, Guss B.Streptococcus equi ssp. equi causes strangles, a highly contagious and serious disease in the upper respiratory tract of horses. Streptococcus equi ssp. zooepidemicus, another subspecies of this genus, is regarded as an opportunistic commensal in horses. The present study describes the characterization of two novel immunoglobulin G (IgG) endopeptidases of these subspecies, IdeE2 and IdeZ2. Both enzymes display sequence similarities with two previously characterized IgG endopeptidases, IdeE of S. equi ssp. equi and IdeZ of S. equi ssp. zooepidemicus. IdeE2 and IdeZ2 display high substrate-speci...
Lin M, Zhang C, Gibson K, Rikihisa Y.Neorickettsia risticii is an obligate intracellular bacterium of the trematodes and mammals. Horses develop Potomac horse fever (PHF) when they ingest aquatic insects containing encysted N. risticii-infected trematodes. The complete genome sequence of N. risticii Illinois consists of a single circular chromosome of 879 977 bp and encodes 38 RNA species and 898 proteins. Although N. risticii has limited ability to synthesize amino acids and lacks many metabolic pathways, it is capable of making major vitamins, cofactors and nucleotides. Comparison with its closely related human pathogen N. senn...
Gerber V, Baleri D, Klukowska-Rötzler J, Swinburne JE, Dolf G.Mode of inheritance of equine recurrent airway obstruction (RAO) is unknown. Objective: Major genes are responsible for RAO. Methods: Direct offspring of 2 RAO-affected Warmblood stallions (n = 197; n = 163) and a representative sample of Swiss Warmbloods (n = 401). Methods: One environmental and 4 genetic models (general, mixed inheritance, major gene, and polygene) were tested for Horse Owner Assessed Respiratory Signs Index (1-4, unaffected to severely affected) by segregation analyses of the 2 half-sib sire families, both combined and separately, using prevalences estimated in a representa...
Cehak A, Burmester M, Geburek F, Feige K, Breves G.The aim of this study was to characterize the transport mechanisms of electrolytes and nutrients across the jejunum of nine healthy horses electrophysiologically. The stripped mucosa was mounted in Ussing chambers and tissue conductances (G(t)) and short circuit currents (I(sc)) were continuously monitored. After blocking the sodium and potassium channels with amiloride, tetraethylammonium chloride (TEA) and barium, chloride secretion was stimulated by carbachol and forskolin. Subsequently, chloride channels were inhibited by 4,4'-diisothiocyanato-stilbene-2,2'-disulfonic acid, 5-nitro-2-(3-ph...
Casaite V, Bruzyte S, Bukauskas V, Setkus A, Morozova-Roche LA, Meskys R.Equine lysozyme (EL) is a calcium (Ca)-binding lysozyme and is an intermediary link between non-Ca-binding C-type lysozyme and alpha-lactalbumin. The feature of lysozymes to assemble into the fibrils has recently gained considerable attention for the investigation of the functional properties of these proteins. To study the structural and functional properties of EL, a synthetic gene was cloned and EL was overexpressed in Escherichia coli as a fused protein. The His-tagged recombinant EL was accumulated as inclusion bodies. Up to 50 mg/l of the recombinant EL could be achieved after purificati...
Albright JD, Mohammed HO, Heleski CR, Wickens CL, Houpt KA.Crib-biting is an equine stereotype that may result in diseases such as colic. Certain breeds and management factors have been associated. Objective: To determine: breed prevalence of crib-biting in US horses; the likelihood that one horse learns to crib-bite from another; and owner perceptions of causal factors. Methods: An initial postal survey queried the number and breed of crib-biting horses and if a horse began after being exposed to a horse with this habit. In a follow-up survey, a volunteer subset of owners was asked the number of affected and nonaffected horses of each breed and the e...
Goodrich LR, Choi VW, Carbone BA, McIlwraith CW, Samulski RJ.Cell transplantation for the treatment of joint disease is an important clinical tool. Genetic modification of cells before transplantation has shown enhanced healing. Ex vivo genetic modification of joint tissue cells with various adeno-associated virus (AAV) serotypes has not been investigated. The transduction efficiencies of self-complementary AAV serotypes (1-6 and 8) were determined in joint tissue containing chondrocytes and synoviocytes isolated from equine models. When comparing scAAV serotypes for efficient transduction ex vivo, in chondrocytes versus synoviocytes, serotypes 6 and 2,...
Morita H, Shimazu M, Shiono H, Toh H, Nakajima F, Akita H, Takagi M, Takami H, Murakami M, Masaoka T, Tanabe S, Hattori M.We previously isolated five strains of putative lactobacilli from the faeces of a thoroughbred horse (a 4-year-old male). Of the five strains, four were identified as members of existing Lactobacillus species; however, sequence analysis of the 16S rRNA gene revealed that the fifth isolate, DI70(T), showed approximately 97 % identity (1325/1366 bp) with the type strain of Lactobacillus delbrueckii. Therefore, we considered the possibility that DI70(T) represents a novel species of the genus Lactobacillus. Cells of strain DI70(T) were Gram-stain-positive, catalase-negative, non-spore-forming, no...
Bugno M, Słota E, Pieńkowska-Schelling A, Schelling C.Fluorescent in situ hybridisation (FISH) using a panel of molecular probes for all chromosome pairs obtained by chromosome microdissection of the domestic horse ( Equus caballus ) was used to diagnose karyotype abnormalities in 35 horses (32 mares, 2 stallions and 1 intersex), which were selected for the study due to infertility (23 horses), reduced fertility (10 horses) and developmental anomalies (2 horses). The use of the FISH technique with probes for each horse chromosome pair enabled the diagnosis of many different chromosome aberrations in this population. Among the horses analysed, 21 ...
Labeda DP, Price NP, Kroppenstedt RM, Donahue JM, Williams NM, Sells SF.Two actinomycete strains, NRRL B-24165(T) and NRRL B-24166(T), isolated from lesions on equine placentas in Kentucky, USA, were analysed using a polyphasic taxonomic approach. On the basis of phylogenetic analysis of 16S rRNA gene sequences, morphological observations and the presence of ll-diaminopimelic acid as the diagnostic diamino acid in whole-cell hydrolysates, the new isolates clearly belonged to the genus Streptomyces. Analyses of the phylogenetic positions of strains NRRL B-24165(T) and NRRL B-24166(T) based on 16S rRNA gene sequences of all recognized species of the genus Streptomyc...
Alm YH, Sukjumlong S, Kindahl H, Dalin AM.Sex steroid hormone receptors have been identified in the adrenal gland of rat, sheep and rhesus monkey, indicating a direct effect of sex steroids on adrenal gland function. Methods: In the present study, immunohistochemistry using two different mouse monoclonal antibodies was employed to determine the presence of oestrogen receptor alpha (ERalpha) and progesterone receptor (PR) in the mare adrenal gland. Adrenal glands from intact (n = 5) and ovariectomised (OVX) (n = 5) mares, as well as uterine tissue (n = 9), were collected after euthanasia. Three of the OVX mares were treated with a sing...
Matéos A, Miclo L, Mollé D, Dary A, Girardet JM, Gaillard JL.alpha(S1)-Casein was isolated from Haflinger mare's milk by hydrophobic interaction chromatography and displayed great micro-heterogeneity by 2-dimensional electrophoresis, probably because of a variable degree of phosphorylation and alternative splicing events. The aim of the present work was to investigate the complexity of the mare's alpha(S1)-casein. The different isoforms present in milk were submitted to a double treatment of dephosphorylation, first by using alkaline phosphatase and then acid phosphatase to achieve complete dephosphorylation. The apoforms were then analyzed by electrosp...
Radcliffe CH, Flaminio MJ, Fortier LA.Mesenchymal progenitor cells (MPCs) are often characterized using surface markers after expansion and treatment in culture. There are no studies directly comparing gene and protein markers in undifferentiated samples during the very early phases of culture. The goal of this study was to evaluate temporal gene and protein expression changes during establishment of equine MPC cultures. Bone marrow aspirate was obtained from 35 horses and processed by density gradient centrifugation. In freshly isolated bone marrow, mononuclear cells had variable expression of CD44, CD11a/CD18, CD90, and CD45RB c...
McCue ME, Armién AG, Lucio M, Mickelson JR, Valberg SJ.Polysaccharide storage myopathy (PSSM) has been found in more than 35 different horse breeds through identification of abnormal storage of polysaccharide in muscle biopsies. A dominant mutation in the glycogen synthase 1 gene (GYS1) accounts for a substantial proportion of PSSM cases in at least 17 breeds, including Quarter Horses, but some horses diagnosed with PSSM by muscle histopathologic analysis are negative for the mutation. We hypothesized that a second distinct form of glycogen storage disease exists in GYS1-negative horses with PSSM. The objectives of this study were to compare the h...
Moyaert H, Pasmans F, Decostere A, Ducatelle R, Haesebrouck F.Helicobacter equorum colonizes the caecum, colon and rectum of horses. The agent is highly prevalent in <6-month-old foals. In adult horses, the prevalence of H. equorum seems to be rather low, but these animals may harbour low, subdetectable numbers of this microorganism in their intestines. So far, no association could be made between the presence of H. equorum and clinical disease or intestinal lesions in adult horses. Further research is necessary to elucidate the pathogenic potential of this bacterial species towards young foals. Helicobacter equorum DNA was not detected in human faece...
Morrell JM, Johannisson A, Dalin AM, Rodriguez-Martinez H.The objective of the current study was to optimize the volumes of Androcoll-E and sperm sample used in various sizes of centrifuge tube to scale up single-layer centrifugation (SLC) for routine use in the field. Although sperm suspensions of equivalent quality were produced using Androcoll-E in small and large tubes, the sperm yield was much lower in the latter (P<0.001). In contrast, in 200-mL tubes (XL), the yields were approximately 25% higher than those for the small tubes. An increased volume (4.5 mL) of extended ejaculate in small tubes (SLC-Inc) or 15 to 18 mL extended ejaculate on 1...
Hamza E, Torsteinsdottir S, Eydal M, Frey CF, Mirkovitch J, Brcic M, Wagner B, Wilson AD, Jungi TW, Marti E.Insect bite hypersensitivity (IBH) is an IgE-mediated dermatitis of horses caused by bites of Culicoides spp. IBH does not occur in Iceland where Culicoides are absent. However, following importation into continental Europe where Culicoides are present, >or=50% of Icelandic horses (1st generation) develop IBH but
Mugnier S, Dell'Aquila ME, Pelaez J, Douet C, Ambruosi B, De Santis T, Lacalandra GM, Lebos C, Sizaret PY, Delaleu B, Monget P, Mermillod P....The mechanism of fertilization remains largely enigmatic in mammals. Most studies exploring the molecular mechanism underlying fertilization have been restricted to a single species, generally the mouse, without a comparative approach. However, the identification of divergences between species could allow us to highlight key components in the mechanism of fertilization. In the pig, in vitro fertilization (IVF) and polyspermy rates are high, and spermatozoa penetrate easily through the zona pellucida (ZP). In contrast, IVF rates are low in the horse, and polyspermy is scarce. Our objective was ...
Asher RJ, Bennett N, Lehmann T.An unprecedented level of confidence has recently crystallized around a new hypothesis of how living placental mammals share a pattern of common descent. The major groups are afrotheres (e.g., aardvarks, elephants), xenarthrans (e.g., anteaters, sloths), laurasiatheres (e.g., horses, shrews), and euarchontoglires (e.g., humans, rodents). Compared with previous hypotheses this tree is remarkably stable; however, some uncertainty persists about the location of the placental root, and (for example) the position of bats within laurasiatheres, of sea cows and aardvarks within afrotheres, and of der...
Dall'Olio S, Davoli R, Costa LN.The research focuses on the analysis of the catechol-O-methyltransferase (COMT) gene in horses. The study was specifically interested in the role this gene might have in behavioral trait variability due […]
Castanheira M, Paiva SR, Louvandini H, Landim A, Fiorvanti MC, Paludo GR, Dallago BS, McManus C.The environment in which the horse is reared affects its ability to maintain thermal balance which is in turn related to thermal characteristics and regulatory physiological mechanisms. In this study a multivariate analysis of physiological traits in relation to heat tolerance in horses was carried out in the Federal District, Brazil. The aim was to test the ability of these analyses to separate groups of animals and determine which physiological traits are most important in the adaptation to heat stress. Forty adult horses (4 to 13 years) were used, ten from each of four different genetic gro...
Perkins JD, Windley Z, Dixon PM, Smith M, Barakzai SZ.To evaluate the use of sinoscopy for detection and treatment of ventral conchal sinus (VCS) and/or rostral maxillary sinus (RMS) disease in horses. Methods: Case series Methods: Horses (n=60) with suspected paranasal sinus disease. Methods: Horses were evaluated by sinoscopy through a conchofrontal sinus (CFS) portal with ventral conchal bulla (VCB) fenestration. Other endoscopic sinus approaches and adjunctive diagnostic tests; oral examination, computed tomography, radiography, scintigraphy and endoscopic examination of the upper portion of the respiratory tract were used in some horses. Res...
Ghosh S, Carden CF, Juras R, Mendoza MN, Jevit MJ, Castaneda C, Phelps O, Dube J, Kelley DE, Varner DD, Love CC, Raudsepp T.We report 2 novel autosomal translocations in the horse. In Case 1, a breeding stallion with a balanced t(4p;30) had produced normal foals and those with congenital abnormalities. Of his 9 phenotypically normal offspring, 4 had normal karyotypes, 4 had balanced t(4p;30), and 1 carried an unbalanced translocation with tertiary trisomy of 4p. We argue that unbalanced forms of t(4p;30) are more tolerated and result in viable congenital abnormalities, without causing embryonic death like all other known equine autosomal translocations. In Case 2, two stallions produced by somatic cell nuclear tran...
Patterson Rosa L, Walker N, Mallicote M, MacKay RJ, Brooks SA.Similar to humans, the horse relies predominantly on the evaporation of sweat from the skin surface to dissipate excess body heat. Loss of the sweat response or anhidrosis can result in life-threatening hyperthermia. Anhidrosis occurs more frequently in some breeds as well as occurs at an increased frequency among individuals with a family history, suggesting a heritable component to the pathology. Given the natural occurrence and indications of genetic components in the etiology, we utilized genomics to better understand the molecular mechanisms involved in sweat response. We performed a case...
Hegreberg GA, Reed SM.A progressive neuromuscular disorder in young horses, clinically apparent as early as 1 month of age, is characterized by generalized myotonia, muscle stiffness, muscle weakness and atrophy. Myotonia is identified by percussion dimpling and myotonic EMG discharges. Changes in one case included testicular hypoplasia, cataract formation, and glucose intolerance, indicating a systemic involvement. Pathologic changes in skeletal muscles from three affected foals were examined. Sarcoplasmic masses, ringed fibers, internal positioning of sarcolemmal nuclei, and nuclear rowing were among the primary ...
Hori Y, Ozaki T, Yamada Y, Tozaki T, Kim HS, Takimoto A, Endo M, Manabe N, Inoue-Murayama M, Fujita K.Genetic polymorphisms in genes related to neurotransmitters or hormones affect personality or behavioral traits in many animal species including humans. In domestic animals, the allele frequency of such genes has been reported to be different among breeds and it may account for breed differences in behavior. In this study, we investigated breed differences in horses in the dopamine receptor D4 gene (DRD4), which has been reported to affect horse personality. We collected samples from seven horse breeds including those native to Japan and Korea, and compared the sequence of the DRD4 exon3 regio...
Kinne J, Joseph M, Wernery U, Nogradi N, Hagen F.During the past decades there has been an increase in cryptococcal infections caused by the basidiomycetous yeast species Cryptococcus gattii sensu lato, among humans and animals that live in endemic regions in Australia, Europe and the Americas. Unlike human cryptococcosis, little epidemiological data are available about C. gattii sensu lato infections in horses. Methods: A fatal case of a disseminated C. gattii sensu lato infection in an 11-year-old Arabian gelding imported from South Africa into the United Arab Emitares is reported. Tissue samples were studied by conventional mycology proce...
Smits K, Govaere J, Hoogewijs M, Piepers S, Van Soom A.Intracytoplasmic sperm injection (ICSI) is the method of choice for the in vitro production (IVP) of equine embryos. However, conventional ICSI has been associated with mechanical damage to the oocyte caused by the deformation of the zona pellucida (ZP) and exposure of the oolemma to negative pressure during injection. Introduction of the less traumatic and more efficient piezo drill-assisted ICSI (PDAI) yielded higher cleavage rates and more consistent results. Nevertheless, PDAI is also associated with disadvantages such as the use of mercury and possible DNA damage. This led us to explore a...
Racine T, Denizot M, Pannetier D, Nguyen L, Pasquier A, Raoul H, Saluzzo JF, Kobinger G, Veas F, Herbreteau CH.There is no vaccine or approved therapy against lethal Ebola virus (EBOV). We investigated a proven technology platform to produce polyclonal IgG fragments, F(ab')2, against EBOV. Horses immunized with nanoparticles harboring surface glycoprotein trimers of EBOV-Zaire/Makona produced anti-Ebola IgG polyclonal antibodies with high neutralization activity. Highly purified equine anti-Ebola F(ab')2 showed strong cross-neutralization of 2 Zaire EBOV strains (Gabon 2001 and Makona) and in vivo 3 or 5 daily F(ab')2 intraperitoneal injections provided 100% protection to BALB/c mice against lethal EBO...
Barrey E, Valette JP, Jouglin M, Blouin C, Langlois B.The purpose of this study was to determine the percentage of fast myosin heavy chains (fast MHCs = MHC 2A + 2B) in 2 propelling muscles to estimate the heritability and to identify any relationship with performance. The gluteus medius and the biceps femoris muscles were biopsied in 100 related French Anglo-Arabian horses. The percentages of slow and fast myosin heavy chains were measured using an ELISA technique. The heritability (s.e.) of the fast MHCs percentage was estimated at 13% (0.1) using a restricted maximum likelihood resolution of a mixed animal model. There were significant (P < 0....
Cotuțiu VD, Ionică AM, Lefkaditis M, Cazan CD, Hașaș AD, Mihalca AD.Equine thelaziosis is a neglected vector-borne parasitic disease in modern veterinary medicine, lacking recent reports. It is transmitted by Musca autumnalis, and potentially other Muscidae species, by ingesting the lachrymal secretions of its equine host. The distribution of both Thelazia lacrymalis and its intermediate hosts remains largely unknown throughout Europe, with most studies dating back 20 years. The aim of this study was to assess the presence, prevalence and distribution of T. lacrymalis in horses from Romania. Methods: The eyes of 273 horses, slaughtered at two abattoirs from t...
The commentary by Gallup and Anderson (Anim Cogn https://doi.org/10.1007/s10071-021-01538-9 , 2021) on the original article by Baragli, Scopa, Maglieri, and Palagi (Anim Cogn https://doi.org/10.1007/s10071-021-01502-7 , 2021) raised some concerns about the methodological approach used by the authors to demonstrate Mirror Self-Recognition (MSR) in horses. The commentary does not take into account horse physiology and psychology, leading Gallup and Anderson to inappropriately discredit the findings obtained by Baragli et al. Anim Cogn 2021. In this reply, we underlined the importance of a blinke...
Griffin RA, Baker M, Aitken RJ, Swegen A, Gibb Z.Stallions experience lower per-cycle conception rates compared to other livestock species, largely because they are selected for breeding based on athletic prowess and not reproductive fitness. Mares are seasonal breeders, and pregnancies cannot be detected until 10-14 days post cover via transrectal ultrasonography. This means the detection of stallion fertility fluctuations is delayed by at least 2 weeks, which within the short breeding season employed by the thoroughbred horse breeding industry, can prove quite costly. For these reasons, there is increased demand for robust laboratory assay...
Bhardwaj A, Nayan V, Legha RA, Bhattacharya TK, Pal Y, Giri SK.Equines' ability in racing and riding as well as gaitedness have influenced the human civilization. Aim of this study was to identify and characterize the novel polymorphisms or SNPs in gene in Indian horse and donkey breeds. In this study, the gene was sequenced and characterized in 72 Indian horses' and 33 Indian donkeys' samples. One SNP (A > C) at 878 was found in studied horses while identical SNPs (A > C) at two different nucleotide positions i.e., 878 and 942 in gene (chromosome 23) were observed in studied Indian donkey breeds. Horses and donkeys both have a non-synony...
Koskinen E, Lindeberg H, Kuntsi H, Katila T.Twenty-four Finnhorse mares were examined by rectal palpation and ultrasonography every 6 h during late oestrus to determine the time of ovulation. Milk and serum samples were collected every 6 h after the detected ovulation for progesterone analysis. The progesterone rises took place within 0-54 h and 0-60 h after ovulation, in milk and serum, respectively. Statistically significant differences (p less than 0.05) in progesterone levels were observed for the first time 12-18 h and 18-24 h after ovulation, in serum and milk, respectively, as compared to progesterone levels 0-6 h after ovulation...
Sangal V, Jones AL, Goodfellow M, Sutcliffe IC, Hoskisson PA.Rhodococcus equi ('Prescottella equi') is a pathogenic actinomycete primarily infecting horses but has emerged as an opportunistic human pathogen. We have sequenced the genome of the type strain of this species, R. equi strain C7(T) , and compared the genome with that of another foal isolate 103S and of a human isolate ATCC 33707. The R. equi strains are closely related to each other and yet distantly related to other rhodococci and Nocardia brasiliensis. The comparison of gene contents among R. equi strains revealed minor differences that could be associated with host adaptation from foals to...
Vaiman M, Chardon P, Cohen D.In the past few years it has been possible by combining enzymatic cleavage of genomic DNA and the Southern blot hybridization technique to explore the endonuclease recognition site polymorphism of the MHC. HLA class I and DR and DQ alpha and beta class II specific probes as well as human C4 and Bf class III probes were used. All these probes were shown to cross-hybridize with DNA from pigs, cattle, sheep and horses. Hybridization of human genomic DNA with a class I probe showed 15-25 bands per genome depending on the enzyme used. Distinct endonucleases generated clusters of restriction fragmen...
Kikuchi N, Blakeslee JR, Hiramune T.Plasmid profiles of Klebsiella pneumoniae isolated from horses were examined. Thirty-nine strains of K. pneumoniae capsular type 1 (K1) isolated from cervical swabs of mares suffering from metritis, and from semen of stallions showed similar plasmid profile patterns, and all strains possessed a 125 megadaltons (Md) plasmid. There was no difference in plasmid profiles between the heavily-encapsulated and the less heavily-encapsulated strains of K. pneumoniae K1. Non-capsulated variants derived from the strains of K1 showed the same plasmid profile pattern as the parent strains. Plasmid profiles...
Shubitowski DM, Venta PJ, Douglass CL, Zhou RX, Ewart SL.The continued discovery of polymorphisms in the equine genome will be important for future studies using genomic screens and fine mapping for the identification of disease genes. Segments of 50 equine genes were examined for variability in 10 different horse breeds using a pool-and-sequence method. We identified 11 single nucleotide polymorphisms (SNPs) in 9380 bp of sequenced exon, and 25 SNPs, six microsatellites, and one insertion/deletion in 16961 bp of sequenced intron. Of all genes studied 52% contained at least one polymorphism, and polymorphisms were found at an overall rate of 1/613 b...
Henson FMD, Davies ME, Schofield PN, Jeffcott LB.The synthesis and expression of collagen types II, VI and X were investigated in growth cartilage selected from a group of 31 horses and ponies in the age range 157 days of gestation to 12 years. Collagen isolation, immunolocalisation and in situ hybridisation techniques were used in order to provide information on the pattern of synthesis of these 3 collagens during endochondral ossification in normal horses. Type II collagen immunoreactivity and mRNA expression was found in each of the 3 zones of growth cartilage chondrocytes in all samples studied, whereas the localisation of both collagen ...
Laughlin AM, Welsh TH, Love CC, Varner DD, Parrish AR, Forrest DW, Ing NH.In vitro culture systems are valuable tools for investigating reproductive mechanisms in the testis. Here, we report the use of the precision-cut in vitro system using equine testicular slices. Testes were collected from immature light breed stallions (n=3) and cut into slices (mean slice weight= 13.85 ± 0.20 mg; mean slice thickness=515.00 ± 2.33 μm) using the precision-cut tissue-slicing method. Four tissue slices were placed on a grid floating on medium in individual vials. After a 1-h preincubation, they were exposed to medium containing ovine luteinizing hormone (oLH) at concentrations...
Silva AC, Paiva SR, Albuquerque MS, Egito AA, Santos SA, Lima FC, Castro ST, Mariante AS, Correa PS, McManus CM.Genetic variability at 11 microsatellite markers was analyzed in five naturalized/local Brazilian horse breeds or genetic groups. Blood samples were collected from 328 animals of the breeds Campeira (Santa Catarina State), Lavradeira (Roraima State), Pantaneira (Pantanal Mato-Grossense), Mangalarga Marchador (Minas Gerais State), as well as the genetic group Baixadeiro (Maranhão State), and the exotic breeds English Thoroughbred and Arab. We found significant genetic variability within evaluated microsatellite loci, with observed heterozygosis varying between 0.426 and 0.768 and polymorphism ...
Gabner S, Hlavaty J, Velde K, Renner M, Jenner F, Egerbacher M.Osteoarthritis, a chronic and progressive degenerative joint disorder, ranks amongst the top five causes of disability. Given the high incidence, associated socioeconomic costs and the absence of effective disease-modifying therapies of osteoarthritis, cell-based treatments offer a promising new approach. Owing to their paracrine, differentiation and self-renewal abilities, mesenchymal stem cells (MSCs) have great potential for regenerative medicine, which might be further enhanced by targeted gene therapy. Hence, the development of systems allowing transgene expression, particularly when regu...
Zhang YW, Davis EG, Blecha F, Wilkerson MJ.Innate immunity relies on a series of germline-encoded pattern recognition receptors (PRRs), such as Toll-like receptors (TLRs), to detect conserved microbial components. TLR9 is typically expressed intracellularly in immune cells such as dendritic cells and recognizes unmethylated bacterial or viral cytosine-phosphate-guanine DNA (CpG-DNA). To investigate innate immune responses through TLR9 signaling pathway in horses, we cloned and characterized equine TLR9. Protein sequence analysis shows that equine TLR9 has a typically conserved cytosolic Toll/interleukin-1 receptor (TIR) domain, three l...
Gianino GM, Valberg SJ, Perumbakkam S, Henry ML, Gardner K, Penedo C, Finno CJ.Immune-mediated myositis (IMM) in American Quarter Horses (QHs) causes acute muscle atrophy and lymphocytic infiltration of myofibers. Recently, an E321G mutation in a highly conserved region of the myosin heavy chain 1 (MYH1) gene was associated with susceptibility to IMM and nonexertional rhabdomyolysis. Objective: To estimate prevalence of the E321G MYH1 variant in the QH breed and performance subgroups. Methods: Three-hundred seven elite performance QHs and 146 random registered QH controls. Methods: Prospective genetic survey. Elite QHs from barrel racing, cutting, halter, racing, reining...
Khan SH, Islam A, Hassan MI, Sharma S, Singh TP, Ahmad F.A sequence alignment of horse cytochrome c (cyt c) with all known cyts c shows that Leu at position 94 is conserved, except in 14 species which have either Val or Ile at this position. It is also known that Leu94 of the mammalian cyt c plays an important role in folding and stability. The important question here is as to what will happen in terms of folding and stability if Leu94 of the mammalian cyt c is substituted by Val or Ile. To answer this question, we introduced natural substitutes of Leu94 by Val and Ile in horse cyt c. The purified L94V and L94I mutants under native condition (pH 6.0...
Corrêa MJ, da Mota MD.The aim of this study was to estimate genetic parameters for racing performance traits in Quarter Horses in Brazil. The data (provided by the Sorocaba Jockey Club) came from 3 Brazilian hippodromes in 1994-2003, with 11 875 observations of race time and 7775 of the speed index (SI), distributed in 2403 and 2169 races, respectively. The variance components were estimated by the MTGSAM program, under animal models including the random additive genetic effect, random permanent environmental effect, and the fixed effects of sex, age and race. Heritabilities for race time and the SI, for the 3 dist...
Myćka G, Klecel W, Stefaniuk-Szmukier M, Jaworska J, Musiał AD, Ropka-Molik K.The Polish draft horse (PDH) breed is a result of crossing local mares with imported cold-blooded stallions, such as Belgians, Ardennes, Fjords, and others. A part of the broodmare stock investigated in this study was also imported from various countries, such as Denmark. In this study, we investigate the genetic composition of the PDH by analyzing the whole mitochondrial d-loop variability and comparing it to previously demonstrated whole d-loop sequences of other cold-blooded breeds: Ardennais, Belgian, Breton, Clydesdale, Noriker, Norwegian Fjord, Percheron, and Suffolk. Our results show hi...
Jung YH, Han SH, Shin T, Oh MY.We determined the nucleotide sequences of the hypervariable D-loop region of mitochondrial DNA (mtDNA) from horse bone (humerus, A.D. 700 to A.D. 800) that was excavated from the Kwakji archaeological site, Jeju, Korea. We compared them with ones from extant horses. We designed three pairs of oligonucleotide primers from the tRNA-Thr and tRNA-Phe gene regions of mtDNA that are highly conserved among many other animal species. We cloned 232, 336, and 644 bp from the horse bone in order to determine the mtDNA D-loop sequence. The sequence was 1,124 bp long; the middle contained 19 tandem repeats...
Johansson MK, Jäderkvist Fegraeus K, Lindgren G, Ekesten B.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 Sil...
Canisso IF, Ball BA, Erol E, Claes A, Scoggin KE, McDowell KJ, Williams NM, Dorton AR, Wolfsdorf KE, Squires EL, Troedsson MH.Nocardioform placentitis in horses is poorly understood, and the development of an experimental model would be of help in understanding the pathogenesis of the disease. Objective: To investigate whether (1) intrauterine inoculation of Crossiela equi during the periovulatory period or (2) i.v., oral or intranasopharyngeal inoculation of C. equi during midgestation would result in nocardioform placentitis, and (3) before and after mating endometrial swabs present evidence of nocardioform placentitis-associated organisms (C. equi or Amycolatopsis spp.). Methods: In Study I, mares (n = 20) rec...
Bhardwaj A, Tandon G, Pal Y, Sharma NK, Nayan V, Soni S, Iquebal MA, Jaiswal S, Legha RA, Talluri TR, Bhattacharya TK, Kumar D, Rai A, Tripathi BN.The horse, one of the most domesticated animals, has been used for several purposes, like transportation, hunting, in sport, or for agriculture-related works. Kathiawari, Marwari, Manipuri, Zanskari, Bhutia, Spiti, and Thoroughbred are the main breeds of horses, particularly due to their agroclimatic adaptation and role in any kind of strong physical activity, and these characteristics are majorly governed by genetic factors. The genetic diversity and phylogenetic relationship of these Indian equine breeds using microsatellite markers have been reported, but further studies exploring the SNP d...
