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.
Guignot F, Bezard J, Palmer E.In the mare only a limited number of oocytes can be successfully collected in vivo, so that when large numbers of oocytes are needed for experimentation, ovaries harvested from slaughtered mares must be used. The resulting temperature changes and time intervals mandated by handling and transport of ovaries from the slaughterhouse to the laboratory adversely affect the rate of oocyte recovery and their quality after IVF and maturation. We chose to study the effect of temperature and time in transit of excised ovaries by evaluating rate of oocyte recovery, nuclear maturation stage reached before...
Moczygemba C, Guidry J, Wittung-Stafshede P.Native myoglobin (Mb) consists of two populations which differ in the orientation of the heme by 180 degrees rotation (as verified by nuclear magnetic resonance) but have identical absorption spectra and equilibrium-thermodynamic stability. Here, we report that these two fractions of native oxidized Mb (from horse) both unfold and refold (chemical denaturant, pH 7, 20 degrees C) in two parallel kinetic reactions with rate constants differing 10-fold. In accord, the oxidized heme remains coordinated to unfolded horse Mb in up to 4 M guanidine hydrochloride (pH 7, 20 degrees C).
Peltier MR, Robinson G, Sharp DC.The effects of melatonin implant treatment over a four week period on LH, estradiol (E2) and progesterone (P4) secretion during the breeding season were studied in ovary-intact and ovariectomized pony mares. Mares with melatonin implants had significantly higher daytime melatonin concentrations than mares with sharm implants (P = 0.0065). In ovariectomized mares, LH secretion did not differ between mares with melatonin and sham implants. In ovary-intact mares, melatonin implants altered the pattern of LH secretion (P = 0.0023) in such a way that an increase in LH secretion was observed during ...
Erice I, Gil L, Josa A, Echegaray A, Martinez F, Espinosa E.Mares (n = 39) were classified according to age as young (less than 1.5 yr, n = 17) or old (more than 1.5 yr, n = 22) and sacrificed. Ovaries were measured and weighed, and the number of follicles and CL were counted. Follicle size and distribution were recorded (external: > 20 mm, 5 mm, < 5 mm). External follicles were aspirated while internal follicles were sliced. The number and Type of oocytes recovered using each method were recorded. Oocyte recovery rates (oocytes/ovary) resulted in a mean of 0.92 oocytes by aspiration and 1.36 oocytes by additional slicing. The mean numbers of av...
Gahne S, Gånheim A, Malmgren L.Different insemination doses have been used for artificial insemination(AI) in horses. Since the insemination dose can affect the pregnancy rate, it is important to ensure that an adequate dose be used regardless of the type of inseminationprotocol used. The aim of this study was to find out if it is possible to decrease the insemination dose from 500 x 10(6) progressively motile spermatozoa to 300 x 10(6) progressively motile spermatozoa and still maintain an acceptable pregnancy rate when using extended fresh semen. Thirteen stallions of known fertility and a well-defined group of 64 mares w...
Merkies K, Buhr MM.Spermatozoal function is affected by the ability to regulate intracellular calcium concentrations ([Ca2+]i), and may be influenced by epididymal maturation as well as environmental components. Regulation of [Ca2+]i in ejaculated and epididymal stallion spermatozoa was monitored over time in various media. Spermatozoa from each of 5 pony stallions (3 ejaculate samples and 1 caput and cauda sample) were labeled with the fluorescent calcium indicator probe Indo-1 in a calcium-free modified Tyrode's buffer. Fluorescent emissions were monitored by a dual wavelength spectrofluorometer over 5 h. Calc...
Gastal EL, Gastal MO, Nogueira GP, Bergfelt DR, Ginther OJ.The effect of altered LH concentrations on the deviation in growth rates between the 2 largest follicles was studied in pony mares. The progestational phase was shortened by administration of PGF2alpha on Day 10 (Day 0=ovulation; n=9) or lengthened by daily administration of 100 mg of progesterone on Days 10 to 30 (n=11; controls, n=10). All follicles > or = 5 mm were ablated on Day 10 in all groups to initiate a new follicular wave. The interovulatory interval was not altered by the PGF2alpha treatment despite a 4-day earlier decrease in progesterone concentrations. Time required for growt...
Shiue Y-L , Millon LV, Skow LC, Honeycutt D, Murray JD, Bowling AT.The hypothesis that the conservation of sex-chromosome-linked genes among placental mammals could be extended to the horse genome was tested using the UCDavis horse-mouse somatic cell hybrid (SCH) panel. By exploiting the fluorescence in-situ hybridization (FISH) technique to localize an anchor locus, X-inactivation-specific transcript (XIST) on the horse X chromosome, together with the fragmentation and translocation of the X- and Y-chromosome fragments in a somatic cell hybrid panel, we regionally assigned 13 type I and 13 type II (microsatellite) markers to the horse X- and Y-chromosomes. T...
Hinrichs K, Provost PJ, Torello EM.A nonovulating, hormone-treated mare was used successfully as an oocyte recipient. The mare's ovarian activity was suppressed using progesterone and estrogen treatment. This treatment was stopped, then estrogen was administered for 3 d prior to the transfer. An oocyte was recovered from the follicle of a donor mare and was transferred via flank laparotomy into the recipient's oviduct. The recipient mare was inseminated 7 h before transfer. The recipient was treated with intramuscular progesterone from the day after transfer until 47 d after transfer, and then with oral altrenogest until 150 d ...
Wierdl M, Morton CL, Danks MK, Potter PM.Butyrylcholinesterases (BuChEs; acylcholine acylhydrolase; EC 3.1.1.8) have been demonstrated to convert the anticancer agent CPT-11 (irinotecan, 7-ethyl-10-[4-(1-piperidino)-1-piperidino]carbonyloxycamptothecin) into its active metabolite SN-38 (7-ethyl-10-hydroxycamptothecin). In addition, significant differences in the extent of drug metabolism have been observed with BuChEs derived from different species. In an attempt to understand these differences, we have isolated the cDNA encoding a horse BuChE. Based upon the NH2-terminal amino acid sequence of a purified horse BuChE, we designed deg...
Provitera P, Bouamr F, Murray D, Carter C, Scarlata S.Human immunodeficiency virus (HIV) and equine infectious anemia virus (EIAV) are closely related lentiviruses that infect immune cells, but their pathogenesis differ. Localization to the cytosolic leaflet of the plasma membrane is critical for replication of both viruses. This localization is accomplished through the matrix (MA) domain of the Gag precursor protein. In HIV-1, association of MA to anionic membranes appears to be primarily driven by a linear cluster of basic residues in the MA domain and an N-myristoylation signal. Interestingly, the MA protein of EIAV does not contain either of ...
Watson JL, Jackson KA, King DP, Stott JL.Expression of the low-affinity IgE receptor (CD23) on the surface of mononuclear cells is a critical event in the development of IgE-mediated immunologic responses. Using PCR and cDNA library screening, a 2.7kb cDNA encoding equine CD23 and a 627bp PCR fragment of cattle CD23 were sequenced and characterized. The equine CD23 sequence encodes a complete and continuous open reading frame of 327 amino acids, while the shorter cattle fragment encodes 209 amino acids corresponding to nucleotides 325-1098 of the equine CD23 transcript. In addition to high identities in their nucleotides and translat...
Valentine BA, McDonough SP, Chang YF, Vonderchek AJ.Polysaccharide storage myopathy is an equine neuromuscular disorder characterized by accumulation of glycogen-related polysaccharide inclusions within skeletal muscle fibers. The pathologic criteria for diagnosis of this disorder are somewhat controversial; however, periodic acid-Schiff-positive, amylase-resistant inclusions are considered pathognomonic. Although these inclusions are most often found in affected horses related to the Quarter Horse, draft horse, and Warmblood breeds, this report describes these characteristic inclusions in muscle of five horses from nonrelated breeds (two Morga...
Molenkamp R, Rozier BC, Greve S, Spaan WJ, Snijder EJ.Equine arteritis virus (EAV), the type member of the family Arteriviridae, is a single-stranded RNA virus with a positive-stranded genome of approximately 13 kb. EAV uses a discontinuous transcription mechanism to produce a nested set of six subgenomic mRNAs from which its structural genes are expressed. We have generated the first documented arterivirus defective interfering (DI) RNAs by serial undiluted passaging of a wild-type EAV stock in BHK-21 cells. A cDNA copy of the smallest DI RNA (5.6 kb) was cloned. Upon transfection into EAV-infected BHK-21 cells, transcripts derived from this clo...
van Herwerden L, Gasser RB, Blair D.This study investigated sequence heterogeneity in the first internal transcribed spacer (ITS-1) of ribosomal DNA within and among species and strains of Echinococcus. Different ITS-1 sequence variants exist in Echinococcus granulosus and Echinococcus multilocularis, which represent at least four evolutionary lineages: (1) a sheep strain-lineage of E. granulosus, (2) a sister lineage of a cervid and camel E. granulosus ITS-1 variants, (3) a lineage including the ITS-1 variants representing horse, bovine and camel strains of E. granulosus, as well as variants from E. multilocularis, Echinococcus...
Aggarwal N, Holmes MA.Despite the importance of IgG Fc receptors in the regulation of various immunological mechanisms, these receptors have not been well characterised in the domesticated animals including equines. This paper describes the production of two monoclonal antibodies (CVS 59 and CVS 61) that recognise equine IgG Fc receptors. Fusions were conducted using BALB/c mice hyperimmunised with equine peripheral blood mononuclear cells. Hybridoma supernatants were screened on the basis of their ability to inhibit the rosetting of equine antibody coated sheep erythrocytes with equine peripheral blood mononuclear...
Cañon J, Checa ML, Carleos C, Vega-Pla JL, Vallejo M, Dunner S.Partition of the genetic variability, genetic structure and relationships among seven Spanish Celtic horse breeds were studied using PCR amplification of 13 microsatellites on 481 random individuals. In addition, 60 thoroughbred horses were included. The average observed heterozygosity and the mean number of alleles were higher for the Atlantic horse breeds than for the Balearic Islands breeds. Only eight percentage of the total genetic variability could be attributed to differences among breeds (mean FST approximately 0.08; P < 0.01). Atlantic breeds clearly form a separate cluster from th...
Bowling AT, Del Valle A, Bowling M.Through DNA sequence comparisons of a mitochondrial D-loop hypervariable region, we investigated matrilineal diversity for Arabian horses in the United States. Sixty-two horses were tested. From published pedigrees they traced in the maternal line to 34 mares acquired primarily in the mid to late 19th century from nomadic Bedouin tribes. Compared with the reference sequence (GenBank X79547), these samples showed 27 haplotypes with altogether 31 base substitution sites within 397 bp of sequence. Based on examination of pedigrees from a random sampling of 200 horses in current studbooks of the A...
Anzai T, Walker JA, Blair MB, Chambers TM, Timoney JF.To determine whether streptococcal pneumonia is caused by strains of Streptococcus zooepidemicus similar to those obtained from the tonsils of healthy horses. Methods: 5 tonsils from healthy horses, 8 tracheal washes and 6 lung specimens from foals with pneumonia, and 5 nasopharyngeal swab specimens from donkeys with acute bronchopneumonia. Methods: Variable M-like protectively immunogenic SzP proteins of 5 isolates of S. zooepidemicus from each tonsil and clinical specimen were compared, using immunoblots. The SzP gene of 13 isolates representative of various SzP immunoblot phenotypes from 1 ...
Hung GC, Chilton NB, Beveridge I, Gasser RB.In this study, molecular data sets were used to address the controversies relating to the systematics of strongyloid nematodes of equids utilising morphological data sets. DNA sequences of the first and second internal transcribed spacers (ITS-1 and ITS-2) of ribosomal DNA were determined for 30 species of equine strongyles and the systematic relationships reconstructed using phenetic and phylogenetic tree-building methods. The molecular data provided support for the hypothesis that the genera with large subglobular buccal capsules are ancestral to those with small cylindrical buccal capsules,...
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....
Mungall BA, Pollitt CC.To investigate the role of matrix metalloproteinase (MMP) activity in the pathophysiology of equine laminitis, the techniques of in situ zymography and quantitative SDS-PAGE zymography were used to analyse the lamellae and plasma and serum of horses with carbohydrate overload-induced laminitis. The gelatinase activity localised within the epidermal lamellae of laminitic hooves did not differ significantly from normal hooves. In laminitis sections there was an increase in vascular gelatinase activity, possibly associated with the perivascular cuffing of polymorphonucleocytes. Both plasma and se...
Anzai T, Eguchi M, Sekizaki T, Kamada M, Yamamoto K, Okuda T.In order to establish a rapid diagnostic method for contagious equine metritis (CEM), we developed and evaluated a polymerase chain reaction (PCR) test. Species-specific PCR primer sets were derived from the DNA sequence of a cloned DNA fragment of Taylorella equigenitalis that did not hybridize with the genome of a taxomonically related species, Oligella urethralis. Single step PCR with primer set P1-N2 and two-step semi-nested PCR with primer sets P1-N2 and P2-N2 detected as low as 100 and 10 CFU of the bacteria, respectively. Single-step PCR detected T. equigenitalis from genital swabs of e...
Schambony A, Hess O, Gentzel M, Töpfer-Petersen E.Cysteine rich secretory proteins (CRISPs) have been detected immunochemically in the equine male genital tract. CRISPs are secretory products of the epididymis, the ampulla and the seminal vesicle. A particular feature of the horse is the abundance of CRISPs in seminal plasma. CRISPs can also be detected in extracts of testicular, epididymal and ejaculated spermatozoa in increasing amounts. Unlike other seminal plasma proteins, they cannot be removed completely from spermatozoa by high salt treatment. The remaining CRISP antigens are localized on the midpiece, and the postacrosomal and equator...
Shin EK, Rijkers T, Pastink A, Meek K.We reported previously that the genetic SCID disease observed in Arabian foals is explained by a defect in V(D)J recombination that profoundly affects both coding and signal end joining. As in C.B-17 SCID mice, the molecular defect in SCID foals is in the catalytic subunit of the DNA-dependent protein kinase (DNA-PKCS); however, in SCID mice, signal end resolution remains relatively intact. Moreover, recent reports indicate that mice that completely lack DNA-PKCS also generate signal joints at levels that are indistinguishable from those observed in C.B-17 SCID mice, eliminating the possibilit...
Deriusheva SE, Loginova IuA, Chiriaeva OG, Iaschak K.A high-resolution cytogenetic map (670 bands per haploid set) of RBA-banded chromosomes has been constructed in the domestic horse Equus caballus. The size and distribution of the replication-based R(G)-bands were analyzed using the computer program VideoTest-Karyo. The obtained data were compared to the results of cytogenetic mapping in other mammalian species and human.
Ramos MI, Hermosura ME, Nakabayashi T.Horse, calf and bovine serum were successfully used as human serum substitutes in the in vitro cultivation of Plasmodium falciparum. Positive results were obtained only after gradually adapting the parasites to the substitute serum. Adapted lines were established within 4-5 weeks. 10% horse serum was observed to be the best substitute with growth rates comparable or even surprising that obtained in human serum. Pure calf or bovine serum supported stable growths of 20-30% less which was enhanced to comparable levels after addition of 1% glucose-peptone to the medium. Direct transfers of adapted...
Gmel AI, Brem G, Neuditschko M.Conformation traits are important selection criteria in equine breeding, as they describe the exterior aspects of the horse (height, joint angles, shape). However, the genetic architecture of conformation is not well understood, as data of these traits mainly consist of subjective evaluation scores. Here, we performed genome-wide association studies on two-dimensional shape data of Lipizzan horses. Based on this data, we identified significant quantitative trait loci (QTL) associated with cresty neck on equine chromosome (ECA)16 within the MAGI1 gene, and with type, hereby differentiating heav...
Taniwaki SA, Magro AJ, Gorino AC, Oliveira-Filho JP, Fontes MR, Borges AS, Araujo JP.Papillomaviruses (PVs) infect a wide range of animal species and show great genetic diversity. To date, excluding equine sarcoids, only three species of PVs were identified associated with lesions in horses: Equus caballus papillomavirus 1 (EcPV1-cutaneous), EcPV2 (genital) and EcPV3 (aural plaques). In this study, we identified a novel equine PV from aural plaques, which we designated EcPV4. Cutaneous samples from horses with lesions that were microscopically diagnosed as aural plaques were subjected to DNA extraction, amplification and sequencing. Rolling circle amplification and inverse PCR...
Khoshtariya DE, Dolidze TD, Shushanyan M, van Eldik R.Horse muscle myoglobin (Mb) was tightly immobilized at Au-deposited ~15-Å-thick mixed-type (1:1) alkanethiol SAMs, HS-(CH₂)₁₁-COOH/HS-(CH₂)₁₁-OH, and placed in contact with buffered H₂O or D₂O solutions. Fast-scan cyclic voltammetry (CV) and a Marcus-equation-based analysis were applied to determine unimolecular standard rate constants and reorganization free energies for electron transfer (ET), under variable-temperature (15-55 °C) and -pressure (0.01-150 MPa) conditions. The CV signal was surprisingly stable and reproducible even after multiple temperature and pressure cycl...
Kölle S, Dubois CS, Caillaud M, Lahuec C, Sinowatz F, Goudet G.In the equine, the zona pellucida (ZP) is the major barrier to successful in vitro fertilization. Therefore the aim of our studies was to analyze species-specific features of the equine ZP in regard to structure and glycoprotein ZPB and ZPC expression sites during oocyte development and embryogenesis. The equine ZP revealed high immunological cross-reactivity to porcine ZPB and ZPC. In the ovary, the distribution of ZPB and ZPC was co-localized and correlated with the developmental stage of the follicle. ZPB and ZPC expression started in the oocyte of the late primordial and primary follicle. ...
Nixon AJ, Brower-Toland BD, Sandell LJ.To isolate, clone, and determine primary nucleotide sequence of equine insulin-like growth factor I (IGF-I) and to examine IGF-I gene expression in tissues and cartilage from horses. Methods: Horses of various ages. Methods: Total RNA was isolated from tissues and purified. Complementary DNA (cDNA) was derived by reverse transcription and polymerase chain reaction (PCR) amplification and subcloned to plasmid vectors for sequencing and comparison with other species. Total RNA from various tissues was probed with radiolabeled cDNA or complimentary RNA constructs by use of northern blotting, tube...
Uhlenbruck F, Sinowatz F, Amselgruber W, Kirchhoff C, Ivell R.cDNA probes derived from genes expressed specifically in the human epididymis were used to examine gene expression in the epididymides of boar, bull and stallion by Northern hybridization. Two probes for the HE1 and HE4 gene products were found to recognize tissue-specific transcripts in all three species, with a regionally differential distribution within the epididymis. Additionally, antibodies recognizing the HE4 protein were shown to react specifically in the epididymis of the boar and bull. An extensive study of the boar showed that, whereas mRNA for the HE1-homologue was up-regulated mar...
Pedler C, Nath L, Agne GF, Hebart M, Franklin S.Atrial fibrillation (AF) is the most common performance-limiting arrhythmia of racehorses. A genetic contribution has been suggested in Standardbred racehorses but has not been investigated in Thoroughbreds. The objective of this study was to determine the heritability of AF in Thoroughbred racehorses. Methods: Horses racing between 2007 and 2019 in Hong Kong and Australia that had AF detected postrace via auscultation (n = 463 cases) were compared with five randomly selected racing contemporaries (n = 2,315 controls). The ASReml-R programme was used to fit an animal model to the AF data t...
de Vries C, Vanhaesebrouck E, Govaere J, Hoogewijs M, Bosseler L, Chiers K, Ducatelle R.A premature dead equine fetus with excessive fluctuating distension of the abdomen was delivered by extraction. Post-mortem examination revealed ascites and a solitary, irregular, bulging, multinodular, firm, yellow mass of 25 cm in diameter in the right liver lobe. Extensive peritoneal implantation metastases were present. The masses were composed of polygonal embryonal cells arranged in sheets and nests. Based on the immunohistochemical expression of Ki67, low molecular weight cytokeratin and alpha-1 fetoprotein, a diagnosis of hepatoblastoma with peritoneal implantation metastases was made....
Peckle M, Pires MS, Dos Santos TM, Roier ECR, da Silva CB, Vilela JAR, Paulino PG, Santos HA, Massard CL.The epidemiological aspects of Babesia caballi infection were evaluated in 516 horse samples from Rio de Janeiro, Brazil. The presence and infestation level of ticks on horses, breed conditions, and animal management were evaluated on each farm through an epidemiological questionnaire. The gene that codes for rhoptry-associated protein-1 (RAP-1) of B. caballi was amplified by nested PCR (nPCR). Among the horses sampled, 17.2% (n = 89/516) presented B. caballi DNA. The characterized samples showed 99-100% similarity with other isolates of B. caballi based on the RAP-1 gene, available in GenBa...
McDonald TL, Burger D.Initial separation and concentration of Clq from fresh, normal equine serum was accomplished by precipitation in 0.02 M acetate buffer, pH 5.5, at 4 degrees for 24 h. The re-dissolved precipitate was clarified by centrifugation at 80,000 g for 1 h and then dialysed against Tris-HCl buffer (0.05 M, pH 8.0) containing 10-3 M EDTA. The clarified dialysate remained biologically active at 5 degrees for at least 4 weeks. Biological activity of equine Clq was determined by assay of its ability to agglutinate sensitized sheep erythrocytes (EA). Following ammonium sulphate fractionation, Sepharose 4B g...
Exertional rhabdomyolysis (ER) and its familial basis in Warmblood horses is incompletely understood. Objective: To describe the case details, clinical signs and management of ER-affected Warmblood horses from a family with a high prevalence of ER, to determine if histopathological signs of polysaccharide storage myopathy (PSSM) and the glycogen synthase (GYS1) mutation are associated with ER in this family, and to investigate potential risk factors for development of ER. Methods: A family consisting of a sire with ER and 71 of his descendants was investigated. History of episodes of ER, husba...
Grosenbaugh DA, Amoss MS, Hood DM, Morgan SJ, Williams JD.Epidermal growth factor (EGF) receptor binding kinetics and EGF-mediated stimulation of DNA synthesis and cellular proliferation were studied in cultured vascular smooth muscle cells (VSMC) from the equine thoracic aorta. Binding studies, using murine 125I-labeled EGF, indicate the presence of a single class of high-affinity binding sites (apparent KD = 2.8 X 10(-11) M), with an estimated maximal binding capacity of 5,800 sites/cell. EGF stimulated [3H]thymidine uptake in confluent quiescent monolayers in a dose-dependent fashion, half-maximal stimulation occurring at 7.5 X 10(-11) M. Likewise...
Bos H, van der Meij GJ, Dik KJ.Bone structure, nutrient canals, form and definition, and a total evaluation of both fore navicular bones were radiologically evaluated in 169 three- and four-year-old Dutch warmblood mares divided into eleven daughter (half sister) groups. On the basis of the 'total evaluation', differences between the three- and four-year-old horses were detectable. Using the 'total evaluation', significant differences were found between daughter groups consisting of three-year-old mares. These differences support the theory that podotrochleosis may be (partly) due to the presence of genetic factors. The pos...
Hartig W, Houe H, Andersen PH.The plentiful data on Danish horses are currently neither organized nor easily accessible, impeding register-based epidemiological studies on Danish horses. A common database could be beneficial. In principle, databases can contain a wealth of information, but no single database can serve every purpose. Hence the establishment of a Danish equine health database should be preceded by careful consideration of its purpose and content, and stakeholder attitudes should be investigated. The objectives of the present study were to identify stakeholder attitudes to the importance, purpose, research ar...
McFadden A, Martin K, Foster G, Vierra M, Lundquist EW, Everts RE, Martin E, Volz E, McLoone K, Brooks SA, Lafayette C.Mutations in KIT, a gene that influences melanoblast migration and pigmentation, often result in mammalian white spotting. As of February 2023, over 30 KIT variants associated with white spotting were documented in Equus caballus (horse). Here we report an association of increased white spotting on the skin and coat with a variant in the 5'UTR of KIT (rs1149701677: g.79,618,649A>C). Horses possessing at least one alternate allele demonstrate phenotypic characteristics similar to other KIT mutations: clear borders around unpigmented regions on the body, face, and limbs. Using a quantitative ...
Jung H, Yoon M.The production of donor-derived sperm using spermatogonial stem cell transplantation has been studied in various animals including mice, rats, goats, boar, dogs, sheep, and monkeys. However, germ cell transplantation has not been applied in stallions. The objective of this study was to produce donor germ cell-derived sperm using germ cell transplantation in stallions. Donor germ cells were transplanted into the parenchyma of 3 recipient stallions that had been treated with busulfan IV injections of 15 mg/kg body weight. For the preparation of donor single germ cells, tissue (20 g) from each te...
Mlekoday JA, Mickelson JR, Valberg SJ, Horton JH, Gallant EM, Thompson LV.To determine whether the basis for recurrent exertional rhabdomyolysis (RER) in Thoroughbreds lies in an alteration in the activation and regulation of the myofibrillar contractile apparatus by ionized calcium. Methods: 4 Thoroughbred mares with RER and 4 clinically normal (control) Thoroughbreds. Methods: Single chemically-skinned type-I (slow-twitch) and type-II (fast-twitch) muscle fibers were obtained from punch biopsy specimens, mounted to a force transducer, and the tensions that developed in response to a series of calcium concentrations were measured. In addition, myofibril preparation...
Zhang Y, Xu WW, Guo DH, Liu ZX, Duan H, Su X, Fu X, Yue DM, Gao Y, Wang CR.The equine pinworm Oxyuris equi (Nematoda: Oxyuridomorpha) is the most common horse nematode, has a worldwide distribution, and causes major economic losses. In the present study, the complete O. equi mitochondrial (mt) genome was sequenced, and the mt genome structure and organization were compared with those of other closely related pinworm species, Enterobius vermicularis and Wellcomia siamensis. The O. equi mt genome is a 13,641-bp circular DNA molecule that encodes 36 genes (12 protein-coding genes, 22 tRNAs, and two rRNAs) and one non-coding region, which is slightly shorter than that ...
Seo HJ, Truong AT, Kim KH, Lim JY, Min S, Kim HC, Yoo MS, Yoon SS, Klein TA, Cho YS.The horse industry has grown rapidly as a leisure industry in the Republic of Korea (ROK) in parallel with an increased demand for equestrian activities. As a result, there has been an increase in horse breeding and equestrian population and potential exposure to ticks and their associated pathogens. To provide a better understanding of the potential disease risks of veterinary and medical importance, a study was conducted to determine the geographical distribution and diversity of ticks collected from horses and vegetation associated with horse racetracks/ranches throughout the ROK. This incl...
Boudreaux MK, Humphries DM.Platelet alloantigens in horses may play an important role in the development of neonatal alloimmune thrombocytopenia (NAIT). Objective: The objective of this study was to evaluate genes encoding major platelet glycoproteins within the Equidae family in an effort to identify potential alloantigens. Methods: DNA was isolated from blood samples obtained from Equidae family members, including a Holsteiner-Oldenburg cross, a Quarter horse, a donkey, and a Plains zebra (Equus burchelli). Gene sequences encoding equine platelet membrane glycoproteins IIb, IIIa (integrin subunits αIIb and β3), Ia (...
Citek J, Vostry L, Vostra-Vydrova H, Brzakova M, Prantlova V.The objective of this study was to assess the genetic parameters of insect bite hypersensitivity (IBH) in the Old Grey Kladruber horse, an original Czech warmblood horse breed. Insect bite hypersensitivity is a recurrent allergic skin disease affecting horses worldwide. Its etiology is multifactorial. The defect is genetically controlled, and the starting impulse is a bite by midges of the spp. and less frequently spp. Knowledge about the associated genes is limited. Horses were kept by the National Stud in Kladruby (1,146 measurements) and by 10 private breeders (63 measurements). The horses ...
Miclo L, Girardet JM, Egito AS, Mollé D, Martin P, Gaillard JL.Highly phosphorylated casein with a low molecular mass was isolated from Haflinger mare's milk by RP-HPLC. It accounts for 4.0% of the casein content. Its mass was determined by LC-ESI-MS before and after treatment by alkaline phosphatase. The molecular mass found for the apo-form (10,591 +/- 2 Da) is in agreement with its primary structure, which was established by ESI-MS/MS from tryptic peptides. It appeared that this short protein (94 amino acid residues) is an internally truncated form of the full-length equine beta-casein (226 residues). This low-Mr variant of equine beta-casein displays ...
Vincelette AR, Renders E, Scott KM, Falkingham PL, Janis CM.The traditional story of the evolution of the horse (family Equidae) has been in large part about the evolution of their feet. How did modern horses come to have a single toe (digit III), with the hoof bearing a characteristic V-shaped keratinous frog on the sole, and what happened to the other digits? While it has long been known that the proximal portions of digits II and IV are retained as the splint bones, a recent hypothesis suggested that the distal portion of these digits have also been retained as part of the frog, drawing upon the famous Laetoli footprints of the tridactyl (three-toed...
Friedlander M, Sobotka H, Banzhaf EJ.The precipitin indices for a number of monovalent and polyvalent antipneumococcus sera were determined under known conditions, and found to vary as did the number of protective units. The ratio precipitin index/protective units in monovalent sera was found to lie between 2.8 and 4.8 for Type I and to be about ten times greater for Type III. Lower values were found in polyvalent horses and when mixing heterologous monovalent sera with each other. The influence of the duration of treatment upon the quotient was studied. Several refined and concentrated preparations showed a relative increase in ...
MacNicol JL, Renwick S, Ganobis CM, Allen-Vercoe E, Weese JS, Pearson W.The equine gastrointestinal (GI) microbiota is intimately related to the horse. The objective of the current study was to evaluate the microbiome and metabolome of cecal inoculum maintained in an anaerobic chamber or chemostat batch fermenter, as well as the fecal slurry maintained in an anaerobic chamber over 48 h. Cecal and fecal content were collected from healthy adult horses immediately upon death. Cecal fluid was used to inoculate chemostat vessels (chemostat cecal, = 11) and vessels containing cecal fluid (anaerobic cecal, = 15) or 5% fecal slurry (anaerobic fecal, = 6) were maintain...
Socha W, Sztromwasser P, Dunowska M, Jaklinska B, Rola J.Equine arteritis virus (EAV) is maintained in the horse populations through persistently infected stallions. The aims of the study were to monitor the spread of EAV among Polish Hucul horses, to analyse the variability of circulating EAVs both between- and within-horses, and to identify allelic variants of the serving stallions EqCXCL16 gene that had been previously shown to strongly correlate with long-term EAV persistence in stallions. Serum samples (n = 221) from 62 horses including 46 mares and 16 stallions were collected on routine basis between December 2010 and May 2013 and tested f...
Meulenbroeks C, van der Lugt JJ, van der Meide NM, Willemse T, Rutten VP, Zaiss DM.The immunological mechanisms explaining development of an allergy in some individuals and not in others remain incompletely understood. Insect bite hypersensitivity (IBH) is a common, seasonal, IgE-mediated, pruritic skin disorder that affects considerable proportions of horses of different breeds, which is caused by bites of the insect Culicoides obsoletus (C. obsoletus). We investigated the allergen-specific immune status of individual horses that had either been diagnosed to be healthy or to suffer of IBH. Following intradermal allergen injection, skin biopsies were taken of IBH-affected an...
Gandini G, Pizzi F, Stella A, Boettcher PJ.The aim of this work was to compare costs, in the horse, cattle, sheep, swine, and rabbit species, for the creation of gene banks for reconstruction of an extinct breed, using different strategies: embryos-only, embryos in combination with semen, and semen-only. Three cost measures were used: time required for population reconstruction, cost for creation of the gene bank, number of years-keeping-female to reach reconstruction. Semen costs were estimated across four scenarios: the presence or absence of a commercial market for semen, purchase of semen donors, and semen extracted from the epidid...
Padilla AW, Foote RH.Slow-cooled stallion spermatozoa, with and without seminal plasma removed by centrifugation, were diluted in Kenney's extender (KE) containing nonfat dry skim milk with glucose and antibiotics or in KE supplemented by adding a modified high-potassium Tyrode's medium (KMT). Four ejaculates from each of four stallions were collected and divided factorially across these four treatments. Percentage of motile sperm, path velocity, and linearity immediately after treatment (0 h) and after storage at 4 degrees C for 24, 48, and 72 h were evaluated objectively by use of a HTM-2030 sperm motility analy...
