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.
McKenzie HC.Hyperlipidemia is the presence of elevated lipid concentrations in the blood and is associated with periods of negative energy balance and physiologic stress. In increased concentrations, circulating lipids typically occur in the triglyceride form, which may interfere with numerous normal physiologic functions, particularly by reducing insulin sensitivity. Although the hyperlipidemia risk is greatest in ponies, miniature horses, and donkeys, all equids are at risk if they are in a situation involving negative energy balance. The sedentary lifestyle of many modern horses and the frequent feedin...
Hurcombe SD.Hypothalamic-pituitary (HP) dysfunction has been documented in a limited capacity in horses and foals associated with critical illness, stress, and pain. This article reviews species-specific details of anatomy, function, hormones, receptors, and testing of the HP axis in the horse. A discussion of critical care medicine relevant to HP dysfunction in the horse with some reference to current understanding in human medicine is made, focusing primarily on current and relevant literature. A brief mention of other conditions described in human and veterinary medicine is also provided for reference ...
Science (New York, N.Y.)March 10, 2011
Volume 331, Issue 6021 1178-1181 doi: 10.1126/science.1196166
Mihlbachler MC, Rivals F, Solounias N, Semprebon GM.The evolution of high-crowned molars among horses (Family Equidae) is thought to be an adaptation for abrasive diets associated with the spread of grasslands. The sharpness and relief of the worn cusp apices of teeth (mesowear) are a measure of dietary abrasion. We collected mesowear data for North American Equidae for the past 55.5 million years to test the association of molar height and dietary abrasion. Mesowear trends in horses are reflective of global cooling and associated vegetation changes. There is a strong correlation between mesowear and crown height in horses; however, most horse ...
Bedford-Guaus SJ, McPartlin LA, Xie J, Westmiller SL, Buffone MG, Roberson MS.Oocyte activation at fertilization is brought about by the testis-specific phospholipase C zeta (PLCZ), owing to its ability to induce oscillations in intracellular Ca(2+) concentration ([Ca(2+)](i)). Whereas this is a highly conserved mechanism among mammals, important species-specific differences in PLCZ sequence, activity, and expression have been reported. Thus, the objectives of this research were to clone and characterize the intracellular Ca(2+)-releasing activity and expression of equine PLCZ in sperm and testis. Molecular cloning of equine PLCZ yielded a 1914-bp sequence that translat...
Costa MF, Carmona AK, Alves MF, Ryan TM, Davies HM, Anderson GA, Slocombe RF.Angiotensin-I converting enzyme (ACE) is a key regulator of blood pressure, electrolytes and fluid homeostasis through conversion of angiotensin I into angiotensin II. Recently, a genetic polymorphism of the ACE gene, which accounts for 47% of the variation of ACE activity in blood, has been advocated as a biomarker of athletic aptitude. Different methods of analysis and determination of ACE activity in plasma have been used in human and equine research without a consensus of a "gold standard" method. Different methods have often been used interchangeably or cited as being comparable in the ex...
Pinard CL, Basrur PK.To characterize the ocular anomalies, determine their recurrence in families and assess the mode of inheritance of the most prevalent anomalies through pedigree analysis in a herd of Exmoor ponies. Methods: Thirty Exmoor ponies residing in south-western Ontario, Canada. Methods: Ophthalmic examination was performed using direct ophthalmoscopy, slit-lamp biomicroscopy and indirect ophthalmoscopy, pre- and post-pupillary dilation. Following compilation of ocular findings, pedigree analysis was conducted to assess the recurrence pattern of specific anomalies in families and the data were tested f...
Bömcke E, Gengler N, Cothran EG.In Greece, seven native horse breeds have been identified so far. Among these, the Skyros pony is outstanding through having a distinct phenotype. In the present study, the aim was to assess genetic diversity in this breed, by using different types of genetic loci and available genealogical information. Its relationships with the other Greek, as well as foreign, domestic breeds were also investigated. Through microsatellite and pedigree analysis it appeared that the Skyros presented a similar level of genetic diversity to the other European breeds. Nevertheless, comparisons between DNA-based a...
Timoney JF, Kalimuthusamy N, Velineni S, Donahue JM, Artiushin SC, Fettinger M.Although serologic data indicate horses in N. America are exposed to a variety of leptospiral serovars, abortion is almost always associated with Leptospira interrogans serovar Pomona type kennewicki. A variety of wildlife including raccoons, white tailed deer, striped skunks, opossums, and red and grey foxes have been shown to host serovar Pomona and have therefore been suspect as sources of infection for pregnant mares. The aim of the present study was to examine genetic diversity in serovar Pomona type kennewicki in wildlife and in aborting mares. Our approach utilized PCR that targeted tan...
Nagy K, Sung HK, Zhang P, Laflamme S, Vincent P, Agha-Mohammadi S, Woltjen K, Monetti C, Michael IP, Smith LC, Nagy A.The domesticated horse represents substantial value for the related sports and recreational fields, and holds enormous potential as a model for a range of medical conditions commonly found in humans. Most notable of these are injuries to muscles, tendons, ligaments and joints. Induced pluripotent stem (iPS) cells have sparked tremendous hopes for future regenerative therapies of conditions that today are not possible to cure. Equine iPS (EiPS) cells, in addition to bringing promises to the veterinary field, open up the opportunity to utilize horses for the validation of stem cell based therapi...
Zielińska-Dawidziak M, Błaszak R, Piasecka-Kwiatkowska D.The presented experiments show the model of expectation of equine spleen ferritin extraction in a new aqueous two-phase system which was formed by mixing polyethylene glycol (PEG) and hydroxyethyl starch (HES). The tendency of the protein to migrate in the analyzed systems was dependent on the concentrations of HES and PEG as well as PEG molecular weight. The highest concentration of ferritin in the top phase (rich in PEG) was recorded in the system composed of 6% PEG 3000 and 3% HES. The obtained concentration was 0.88 mg mL(-1). The lowest concentration was 0.42 mg mL(-1) in the system compo...
Waller AP, Kohler K, Burns TA, Mudge MC, Belknap JK, Lacombe VA.Although the importance of adipose tissue (AT) glucose transport in regulating whole-body insulin sensitivity is becoming increasingly evident and insulin resistance (IR) has been widely recognized, the underlying mechanisms of IR are still not well understood. The purpose of the present study was to determine the early pathological changes in glucose transport by characterizing the alterations in glucose transporters (GLUT) in multiple visceral and subcutaneous adipose depots in a large animal model of naturally occurring compensated IR. AT biopsies were collected from horses, which were clas...
Pitzer JB, Kaufman PE, Tenbroeck SH, Maruniak JE.A species-specific multiplex polymerase chain reaction targeting the cytochrome b gene of cattle, horses, humans, and dogs was developed to determine the blood meal sources of stable flies, Stomoxys calcitrans (L.), collected from Florida equine facilities. Of 595 presumptive blood-fed stable flies analyzed, successful host amplification was obtained in 350, for a field host-detection efficiency of 58.8%. The majority of analyzed stable flies had fed on cattle (64.6%), followed by horses (24.3%), humans (9.5%), and dogs (1.6%). A survey of animal-enclosed pastures occurring within 3 km of stab...
Marshall VL, Secombe C, Nicholls PK.A 6-week-old Warmblood colt foal was presented for investigation of multiple haematoma formation in various locations, poor wound healing and abnormal scar formation. Based on the history and clinical presentation of hyperextensible skin with prolonged skin tenting, the foal was diagnosed with cutaneous asthenia and euthanased because of the poor prognosis. Histopathological and electron microscopic findings were inconclusive. This is the first case report of cutaneous asthenia in a Warmblood horse in Australia. Cutaneous asthenia is reviewed with particular reference to hereditary equine regi...
Bugno-Poniewierska M, Kozub D, Pawlina K, Tischner M, Tischner M, Słota E, Wnuk M.The aim of this study was a cytogenetic analysis of stallions semen to find sex chromosome aberrations and to determine if there was an association between stallion's age and aberration frequency for the sex chromosomes. Sperm samples were collected from 22 stallions of various age from 3 to 23 years. Multicolour FISH was performed on each sample, using probes for the sex chromosomes and EGFR gene, localized on 4p12 in domestic horse. A total of 26199 sperm cells were analysed (from 1 070 to 1 532 per animal). Among the analysed cells, there were 50.318% with X chromosome, 48.543% with Y chrom...
Beghelli D, Giacconi R, Mocchegiani E, Cipriano C, Malavolta M, Renieri C.The aim of this study was to validate an A/T single nucleotide polymorphism (SNP) corresponding to a LINE2 sequence located ∼1.1kb downstream of the IL-6 gene (SNP BIEC2-911738) and to determine if this variant is correlated with interleukin 6 (IL-6) modulation or with different plasma concentrations of Zn, Cu, Se and Fe. The frequency of the newly described variant T ranged from 0 to 23.1% among different breeds of horses. SBIEC2-911738 was not associated with changes in IL-6 plasma levels. Increased Cu:Zn ratios were observed in horses carrying the AT genotype independently of breed when s...
Charvat RA, Breitenbach JE, Ahn B, Zhang Y, O'Callaghan DJ.Defective interfering particles (DIP) of equine herpesvirus 1 (EHV-1) inhibit standard virus replication and mediate persistent infection. The DIP genome is comprised of only three genes: UL3, UL4, and a hybrid gene composed of portions of the IR4 (EICP22) and UL5 (EICP27) genes. The hybrid gene is important for DIP interference, but the function(s) of the UL3 and UL4 genes are unknown. Here, we show that UL4 is an early gene activated solely by the immediate early protein. The UL4 protein (UL4P) was detected at 4hours post-infection, was localized throughout the nucleus and cytoplasm, and was...
Sairanen J, Katila T, Virtala AM, Ojala M.Racing and fertility are connected with each other in many ways. Stress and increased body temperature induced by racing may have negative effects on fertility, but on the other hand, high quality nutrition and management of racing horses may have positive effects. Fertility may also be genetically associated with racing performance. The analysed data consisted of Finnish mating records of Standardbreds (n=33,679) and Finnhorses (n=32,731), from 1991 to 2005, and the harness racing records of both mares and stallions. Fertility was measured by foaling outcome, and racing performance was measur...
Bründler P, Frey CF, Gottstein B, Nussbaumer P, Neuhaus S, Gerber V.An association between equine recurrent airway obstruction (RAO) and increased resistance to intestinal parasites has been demonstrated in descendants of an RAO-affected stallion. It was hypothesised that members of another high-incidence RAO family (F) and unrelated RAO-affected Warmblood horses (UA) would shed fewer strongylid eggs than unrelated RAO-unaffected pasture mates (PM) under the same environmental conditions. Faecal worm egg counts were performed on faecal samples (63 F, 86 UA, 149 PM) and classified into three categories: 0, 1-100 and >100 eggs per gram. While results for F di...
Sasaki M, Hasebe R, Makino Y, Suzuki T, Fukushi H, Okamoto M, Matsuda K, Taniyama H, Sawa H, Kimura T.The endotheliotropism of equine herpesvirus-1 (EHV-1) leads to encephalomyelitis secondary to vasculitis and thrombosis in the infected horse central nervous system (CNS). To identify the host factors involved in EHV-1 infection of CNS endothelial cells, we performed functional cloning using an equine brain microvascular endothelial cell cDNA library. Exogenous expression of equine major histocompatibility complex (MHC) class I heavy chain genes conferred susceptibility to EHV-1 infection in mouse NIH3T3 cells, which are not naturally susceptible to EHV-1 infection. Equine MHC class I molecule...
Kokotovic B, Angen Ø, Bisgaard M.Genetic diversity detected by analysis of amplified fragment length polymorphisms (AFLPs) of 54 Actinobacillus lignieresii isolates from different hosts and geographic localities is described. On the basis of variances in AFLP profiles, the strains were grouped in two major clusters; one comprising strains isolated from horses and infected wounds of humans bitten by horses and another consisting of strains isolated from bovine and ovine hosts. The present data indicate a comparatively higher degree of genetic diversity among strains isolated from equine hosts and confirm the existence of a sep...
Almeida J, Conley AJ, Mathewson L, Ball BA.In the mammalian testis, Leydig cells are primarily responsible for steroidogenesis. In adult stallions, the major endocrine products of Leydig cells include testosterone and estrogens. 3β-hydroxysteroid dehydrogenase/Δ(5)-Δ(4)-isomerase (3βHSD) and 17α-hydroxylase/17,20-lyase (P450c17) are two key steroidogenic enzymes that regulate testosterone synthesis. Androgens produced by P450c17 serve as substrate for estrogen synthesis. The aim of this study was to investigate localization of the steroidogenic enzymes P450c17, 3βHSD, and P450arom and to determine changes in expression during dev...
Sanz MG, Wills TB, Christopherson P, Hines MT.A 17-year-old Peruvian Paso mare was evaluated for bilateral epistaxis that had been present for at least 3 years. The mare had mild anemia, platelet count within the reference interval, unremarkable coagulation times, and a negative Coggins test. On endoscopic examination, structural abnormalities were not observed in the nasal cavities, pharynx, larynx, trachea, or either guttural pouch, but petechiation was noted in the nasal mucosa. Additional tests revealed prolonged cutaneous bleeding time, normal concentration of von Willebrand factor antigen, an abnormal clot retraction test, and failu...
Zoonoses and public healthFebruary 1, 2011
Volume 58, Issue 7 514-518 doi: 10.1111/j.1863-2378.2011.01394.x
Adaszek Ł, Winiarczyk S.This study was aimed at determining the cause of the diseases in five horses exhibiting symptoms of fever, joint oedema and ataxia and thrombocytopenia. The PCR technique revealed the presence in the blood of 16S RNA Anaplasma/Ehrlichia spp. genetic material. DNA amplification with primers EHR 521 and EHR 747 gave a product with a size of 247 bp. The sequence of the PCR product obtained showed a 97.6-99.6% similarity with a sequence of a fragment of 16S RNA Anaplasma phagocytophilum, gene number EU 090186 from GenBank. Intravenous administration of oxytetracycline at a dose of 8 mg/kg of body ...
Fontanel M, Todd E, Drabbe A, Ropka-Molik K, Stefaniuk-Szmukier M, Myćka G, Velie BD.Arabian horses are not only one of the most ancient breeds in the world, but they are also one of the most appreciated racehorse breeds today. The breed generates attention for their phenomenal endurance ability and their capability for gallop racing. Consequently, genetic testing to select the best individuals is attracting ever increasing interests from the Arabian industry. As such, the aim of this study was to further investigate associations between performance and variation at candidate genes suspected of having a key role in Arabian gallop racing performance. Generalized linear models w...
Gmel AI, Burger D, Neuditschko M.The use of frozen-thawed semen is an important reproduction tool to preserve the biodiversity of small, native horse breeds such as the Franches-Montagnes (FM). However, not all stallions produce cryotolerant semen with a progressive motility after thaw ≥ 35%. To improve our understanding of the genetic background of male fertility traits in both fresh and frozen-thawed semen, we performed genome-wide association studies (GWAS) on gel-free volume, sperm cell concentration, total sperm count, and progressive motility in fresh and frozen-thawed semen from 109 FM stallions using 335,494 genome-...
Demyda-Peyrás S, Membrillo A, Bugno-Poniewierska M, Pawlina K, Anaya G, Moreno-Millán M.Chromosomal abnormalities associated to sex chromosomes are reported as a problem more common than believed to be in horses. Most of them remain undiagnosed due to the complexity of the horse karyotype and the lack of interest of breeders and veterinarians in this type of diagnosis. Approximately 10 years ago, the Spanish Purebred Breeders Association implemented a DNA paternity test to evaluate the pedigree of every newborn foal. All candidates who showed abnormal or uncertain results are routinely submitted to cytogenetical analysis to evaluate the presence of chromosomal abnormalities. We s...
Bengtsson RJ, Wee BA, Yebra G, Bacigalupe R, Watson E, Guedes RMC, Jacobson M, Stadejek T, Archibald AL, Fitzgerald JR, Ait-Ali T.Lawsonia intracellularis is a Gram-negative obligate intracellular bacterium that is the aetiological agent of proliferative enteropathy (PE), a common intestinal disease of major economic importance in pigs and other animal species. To date, progress in understanding the biology of L. intracellularis for improved disease control has been hampered by the inability to culture the organism in vitro. In particular, our understanding of the genomic diversity and population structure of clinical L. intercellularis is very limited. Here, we utilized a metagenomic shotgun approach to directly sequenc...
Ogorek TJ, Golden JE.Venezuelan, western, and eastern equine encephalitic alphaviruses (VEEV, WEEV, and EEEV, respectively) are arboviruses that are highly pathogenic to equines and cause significant harm to infected humans. Currently, human alphavirus infection and the resulting diseases caused by them are unmitigated due to the absence of approved vaccines or therapeutics for general use. These circumstances, combined with the unpredictability of outbreaks-as exemplified by a 2019 EEE surge in the United States that claimed 19 patient lives-emphasize the risks posed by these viruses, especially for aerosolized V...
Grady JK, Zang J, Laue TM, Arosio P, Chasteen ND.Sodium dodecyl sulfate-capillary gel electrophoresis (SDS-CGE) was used to characterize the H- and L-subunit ratios of several mammalian ferritins and one bacterioferritin. Traditionally, SDS-PAGE has been used to characterize the H- and L-subunit ratios in ferritin; however, this technique is relatively slow and requires staining, destaining, and scanning before the data can be processed. In addition, the H- and L-subunits of ferritin are fairly close in molecular weight (approximately 21,000 and approximately 20,000, respectively) and are often difficult to resolve in SDS-PAGE slab gels. In ...
Lindquist CD, Evans JJ, Wictum EJ.Accurate DNA quantification is essential for optimizing DNA testing and minimizing sample consumption. Real-time quantitative polymerase chain reaction (qPCR) assays have been published for human and canine nuclear DNA, and the need for quantifying other forensically important species was evident. Following the strategy employed for the canine qPCR assay, we developed individual assays to accurately quantify feline, bovine, equine, and cervid nuclear DNA. Each TaqMan-based assay incorporates a genus-specific probe targeting the Melanocortin-1 Receptor gene and includes a piece of synthetic DNA...
Ayoub C, Arroyo LG, Renaud D, Weese JS, Gomez DE.The objective of this study was to compare the fecal microbiota of two healthy teaching horse herds with that of client-owned horses from the same geographic areas. The fecal microbiota of client-owned horses from Ontario Canada (n = 15) and Florida, USA (n = 11) was compared with that teaching horses from the University of Guelph, Ontario, Canada (n = 10) and the University of Florida, Florida, USA (n = 15). The fecal microbiota was characterized by sequencing of bacterial DNA using the V4 hypervariable region of the 16S rRNA gene. The diversity (inverse Simpson index) of the fecal mi...
Pesch S, Bostedt H, Failing K, Bergmann M.Routine semen analysis of stallions is based on light microscopy (LM). However, there are still a number of animals that are subfertile or even infertile not being identified with conventional semen analysis. The objective of this study was to investigate the suitability of transmission electron microscopy (TEM) for advanced fertility diagnosis in stallion. We examined ejaculates of 46 stallions with known fertility. Animals were divided into three different groups: group 1, fertile stallions (pregnant mares> or =70%, n=29); group 2, subfertile stallions (pregnant mares 10-69%, n=14); group 3,...
Scare JA, Dini P, Norris JK, Steuer AE, Scoggin K, Gravatte HS, Howe DK, Slusarewicz P, Nielsen MK.Ascarid parasites infect a variety of hosts and regular anthelmintic treatment is recommended for all species. Parascaris spp. is the only ascarid species with widespread anthelmintic resistance, which allows for the study of resistance mechanisms. The purpose of this study was to establish an in vitro drug exposure protocol for adult anthelmintic-naïve Parascaris spp. and report a preliminary transcriptomic analysis in response to drug exposure. Live worms were harvested from foal necropsies and maintained in RPMI-1640 at 37 °C. Serial dilutions of oxibendazole (OBZ) and ivermectin (IVM) we...
Woodrow JS, Hines M, Sommardahl C, Flatland B, Lo Y, Wang Z, Sheats MK, Lennon EM.Equine asthma is a naturally occurring lung disease characterized by chronic, partially reversible airway obstruction, pulmonary remodeling, and lower airway inflammation. Asthma is currently divided into two major groups, mild to moderate asthma (mEA) and severe asthma (sEA), but further subtyping by phenotype (i.e., clinical presentation) and/or endotype (i.e., cellular mechanisms) may be warranted. For this study, we were interested in further investigation of cellular and inflammatory characteristics of EA, including airway mast cells. The purpose of this study was to: (1) compare mast cel...
Lepage N, St-Laurent G, Carman S, Archambault D.The genetic variation in equine arteritis virus (EAV) Gs protein encoding gene was investigated. Nucleic and deduced amino acid sequences from eight different EAV isolates (one European, two American and five Canadian isolates) were compared with those of the Bucyrus reference strain. Nucleotide and amino acid identities between these isolates and the Bucyrus reference strain ranged from 92.3 to 96.4%, and 93.2 to 95.5%, respectively. However, phylogenetic tree analysis and estimation of genetic distances based on the Gs protein encoding gene sequences showed that the European prototype Vienna...
Janda J, Plattet P, Torsteinsdottir S, Jonsdottir S, Zurbriggen A, Marti E.Allergic horses react to innocuous environmental substances by activation of Th2 cells and production of allergen-specific IgE antibodies. The mechanisms leading to Th2 differentiation are not well understood. In humans and mice, epithelial cell-derived thymic stromal lymphopoietin (TSLP) plays a central role in this process. Little is known about equine TSLP (eqTSLP) and its role in allergic diseases and our current knowledge is limited to the assessment of TSLP mRNA expression. In order to be able to study eqTSLP at the protein level, the aim of the present study was to produce recombinant e...
Ryan MP, McAuliffe O, Ross RP, Hill C.Lacticin 3147 is a broad-spectrum, two-component, lanthionine-containing bacteriocin produced by Lactococcus lactis DPC3147 which has widespread food and biomedical applications as a natural antimicrobial. Other two-component lantibiotics described to date include cytolysin and staphylococcin C55. Interestingly, cytolysin, produced by Enterococcus faecalis, has an associated haemolytic activity. The objective of this study was to compare the biological activity of lacticin 3147 with cytolysin. The lacticin 3147-encoding determinants were heterologously expressed in Ent. faecalis FA2-2, a plasm...
Musilova P, Kubickova S, Horin P, Vodicka R, Rubes J.Cross-species chromosome painting has been applied to most of the species making up the numerically small family Equidae. However, comparative mapping data were still lacking in Asiatic asses kulan (Equus hemionus kulan) and kiang (E. kiang). The set of horse arm-specific probes generated by laser microdissection was hybridized onto kulan (E. hemionus kulan) and kiang (E. kiang) chromosomes in order to establish a genome-wide chromosomal correspondence between these Asiatic asses and the horse. Moreover, region-specific probes were generated to determine fusion configuration and orientation of...
Permyakov SE, Khokhlova TI, Uversky VN, Permyakov EA.The triggering of Ca(2+) signaling pathways relies on Ca(2+)/Mg(2+) specificity of proteins mediating these pathways. Two homologous milk Ca(2+)-binding proteins, bovine alpha-lactalbumin (bLA) and equine lysozyme (EQL), were analyzed using the simplest "four-state" scheme of metal- and temperature-induced structural changes in a protein. The association of Ca(2+)/Mg(2+) by native proteins is entropy-driven. Both proteins exhibit strong temperature dependences of apparent affinities to Ca(2+) and Mg(2+), due to low thermal stabilities of their apo-forms and relatively high unfavorable enthalpi...
Nasir L, Gault E, Morgan IM, Chambers G, Ellsmore V, Campo MS.BPV-1 DNA is the predominant viral type detected in equine sarcoids and represents the only reported natural cross species infection of papillomaviruses. In this study, nucleotide variations in the LCR and the E2 regions of equine sarcoid-associated BPV-1 were characterised by sequence analysis. Variants particular to sarcoid BPV-1 were identified in both the LCR and E2 sequence. The functionality of the most common LCR variant was examined in equine and bovine cells. These studies showed that the activity of the variant LCR was higher in equine cells than bovine cells; the activity of the var...
Drogemuller M, Failing K, Schnieder T, von Samson-Himmelstjerna G.This study was designed to investigate the effect of repeated treatments with increasingly high fenbendazole (FBZ) dosages on the phenotype and genotype of a benzimidazole (BZ)-resistant cyathostomin population. An experimentally infected horse was treated repeatedly with FBZ dose rates between 7.5 and 30.0 mg/kg body weight (bw) over approximately 2 years. Faecal egg counts (FECs) and larval cultures were performed weekly. A total of 45 faecal egg count reduction tests (FECRTs) were analysed, revealing a high variability during the course of experiment with a mean value in faecal egg count re...
von Samson-Himmelstjerna G, Janssen IJI, Ramünke S, Goday C, Borges FA, Koudela B, Niedźwiedź A, Tomczuk K, Studzińska MB, Kornas S, Krücken J.Equines were over decades considered to be infected by two morphologically virtually indistinguishable ascarid species, Parascaris univalens and Parascaris equorum. Reliable species discrimination is only possible using enzyme isoelectric focussing and karyotyping with P. univalens having one and P. equorum two chromosome pairs. However, presumably the complexity of both methods prevented their routine use in nearly all previous studies about prevalence and drug resistance of Parascaris spp. These have barely been performed on the species level although most studies stated presence of one or t...
van Gennip RGP, van de Water SGP, Potgieter CA, van Rijn PA.The Reoviridae family consists of nonenveloped multilayered viruses with a double-stranded RNA genome consisting of 9 to 12 genome segments. The Orbivirus genus of the Reoviridae family contains African horse sickness virus (AHSV), bluetongue virus, and epizootic hemorrhagic disease virus, which cause notifiable diseases and are spread by biting Culicoides species. Here, we used reverse genetics for AHSV to study the role of outer capsid protein VP2, encoded by genome segment 2 (Seg-2). Expansion of a previously found deletion in Seg-2 indicates that structural protein VP2 of AHSV is not essen...
Guidolin FR, Tambourgi DV, Guidolin R, Marcelino JR, Okamoto CK, Magnoli FC, Queiroz GP, Dias da Silva W.Crotalus durissus terrificus, C. d. collilineatus, C. d. cascavella and C. d. marajoensis are responsible minor but severe snake bites in Brazil. The venoms of these snakes share the presence of crotoxin, a neurotoxin comprising of two associated components, crotapotin and phospholipase A2 (PLA2). Treatment of the victims with specific antiserum is the unique effective therapeutic measure. The ability of anti-Crotalus antisera produced by the routine using crude venom to immunize horses or purified crotoxin and PLA2 as individual immunogens was compared. Antisera obtained from horses immunized...
Granier T, Comberton G, Gallois B, d'Estaintot BL, Dautant A, Crichton RR, Précigoux G.We refined the structure of the tetragonal form of recombinant horse L-chain apoferritin to 2.0 A and we compared it with that of the cubic form previously refined to the same resolution. The major differences between the two structures concern the cadmium ions bound to the residues E130 at the threefold axes of the molecule. Taking advantage of the significant anomalous signal (f" = 3.6 e-) of cadmium at 1.375 A, the wavelength used here, we performed anomalous Fourier difference maps with the refined model phases. These maps reveal the positions of anomalous scatterers at different locations...
Nagy P, Huszenicza G, Reiczigel J, Juhász J, Kulcsár M, Abaváry K, Guillaume D.Factors influencing plasma progesterone concentration were investigated in seven mares. Two-phase logistic curves were fitted (r=0.98) to plasma progesterone concentrations of blood samples collected once daily. In addition to the effect of time (P<0.001), there were differences (P<0.01) among mares in the peak height of the progesterone plateau and in the (area under the curve) AUC. Plasma progesterone concentrations were higher (P<0.001) after a multiple versus single ovulation. There was an effect of season (P<0.001), but no significant effect of luteal morphology. The retrospec...
Oldenhof H, Schütze S, Wolkers WF, Sieme H.Sperm chromatin structure and condensation determine accessibility for damage, and hence success of fertilization and development. The aim of this study was to reveal characteristic spectral features coinciding with abnormal sperm chromatin packing (i.e., DNA-protein interactions) and decreased fertility, using Fourier transform infrared spectroscopy. Chromatin structure in spermatozoa obtained from different stallions was investigated. Furthermore, spermatozoa were exposed to oxidative stress, or treated with thiol-oxidizing and disulfide-reducing agents, to alter chromatin structure and pack...
Savage VL, Christley R, Pinchbeck G, Morrison LJ, Hodgkinson J, Peachey LE.Trypanosomosis is a major cause of morbidity and mortality in working equids in The Gambia. Recently, a progressive, severe neurological syndrome characterised by a diffuse lymphoplasmacytic meningoencephalitis has been identified and associated with Trypanosoma brucei infection of the central nervous system. The pathogenesis of cerebral trypanosomosis is unclear and the clinical syndrome not well described. This observational cross-sectional study aimed to identify host and parasite related risk factors associated with the development of cerebral trypanosomosis and to describe the neurologica...
Acharya KR, Stuart DI, Phillips DC, McKenzie HA, Teahan CG.Similarities in amino acid sequences, three-dimensional structures, and the exon-intron patterns of their genes have indicated that c-type lysozymes and alpha-lactalbumins are homologous proteins, i.e., descended by divergent evolution from a common ancestor. Like the alpha-lactalbumins, echidna milk, horse milk, and pigeon eggwhite lysozymes all bind Ca(II). Models of their three-dimensional structures, based on their amino acid sequences and the known crystal structures of domestic hen eggwhite and human lysozymes and baboon and human alpha-lactalbumins, have been built. The several structur...
Theelen MJP, Luiken REC, Wagenaar JA, Sloet van Oldruitenborgh-Oosterbaan MM, Rossen JWA, Schaafstra FJWC, van Doorn DA, Zomer AL.Hospitalisation and antimicrobial treatment are common in horses and significantly impact the intestinal microbiota. Antimicrobial treatment might also increase levels of resistant bacteria in faeces, which could spread to other ecological compartments, such as the environment, other animals and humans. In this study, we aimed to characterise the short- and long-term effects of transportation, hospitalisation and trimethoprim-sulfadiazine (TMS) administration on the faecal microbiota and resistome of healthy equids. In a longitudinal experimental study design, in which the ponies served as the...
Martino NA, Marzano G, Mastrorocco A, Lacalandra GM, Vincenti L, Hinrichs K, Dell Aquila ME.Time-lapse imaging was used to establish the morphokinetics of equine embryo development to the blastocyst stage after invitro oocyte maturation (IVM), intracytoplasmic sperm injection (ICSI) and embryo culture, in oocytes held overnight at room temperature (22-27°C; standard conditions) before IVM. Embryos that developed to the blastocyst stage underwent precleavage cytoplasmic extrusion and cleavage to the 2-, 3- and 4-cell stages significantly earlier than did embryos that arrested in development. We then determined the rate of blastocyst formation after ICSI in oocytes held for 2 days at ...
Xie J, Tong P, Zhang L, Ren M, Song X, Jia C, Palidan N, Zhang L, Kuang L.In November 2018, an outbreak of respiratory disease occurred in foals at an equestrian club in Changji, northern Xinjiang, China. We applied viral metagenomics to investigate this outbreak and identify potential pathogens involved in this equine respiratory syndrome. The metagenomics data revealed the presence of sequences matching those of equid herpesvirus (EHV) 2, 4, and 5. PCR with specific primers targeting ORF33 of EHV-4 and ORF8 of EHV-2 and EHV-5 revealed coinfection with these viruses in this respiratory syndrome. To investigate the prevalence of these viruses in China, 453 nasal swa...
Unlike in Warmblood horses, aortic rupture is quite common in Friesian horses, in which a hereditary trait is suspected. The aortic connective tissue in affected Friesians shows histological changes such as medial necrosis, elastic fibre fragmentation, mucoid material accumulation and fibrosis with aberrant collagen morphology. However, ultrastructural examination of the collagen fibres of the mid-thoracic aorta has been inconclusive in further elucidating the pathogenesis of the disease. Objective: To assess several extracellular matrix (ECM) components biochemically in order to explore a pos...
