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.
Yuen BP, Wong KS, So YM, Kwok WH, Cheung HW, Wan TSM, Ho EN, Wong WT.The development of gene therapy techniques introduces a potential risk of gene doping, which threatens the integrity of sport. In response to this challenge, we have developed a novel analytical method that employs a multiplex polymerase chain reaction (PCR) in conjunction with liquid chromatography high-resolution tandem mass spectrometry (LC-HRMS/MS) for the simultaneous identification of multiple transgenes in equine plasma within a single reaction. The method targets three potential doping transgenes: equine growth hormone 1 (eGH1), equine growth hormone-releasing hormone (eGHRH), and equi...
Ziadi C, Valera M, Laseca N, Perdomo-González D, Demyda-Peyrás S, de Los Terreros AR, Molina A. By simultaneously integrating both genotyped and non-genotyped animals into genetic evaluation, the single-step genomic BLUP method enhanced the accuracy of genetic assessments. This study aimed to compare the increase in prediction reliability (R) between restricted maximum likelihood (REML) and single-step genomic REML (ssGREML) in the Pura Raza Española (PRE) horse breed. The dataset comprised reproductive records for seven fertility traits from 47,502 females, with a total of 57,316 animals represented in the pedigree. A total of 4009 animals were genotyped using the EQUIGENE 90K SNP ar...
Dahlgren AR, Careddu F, Norris JW, Adili R, Kropp EM, Li Q, Holinstat M, Biunno I, Balduini A, Tablin F, Shavit JA, Finno CJ.SEL1L is a well-known protein in the endoplasmic reticulum associated degradation (ERAD) pathway. While it is known to be expressed in platelets, SEL1L has never been shown to play an active role. Here we find evidence that SEL1L regulates platelet function. We first identified SEL1L through the study of Atypical Equine Thrombasthenia (AET), an autosomal recessive platelet disorder found in Thoroughbred horses. A missense variant in (c.1810A>G p.Ile604Val) was found in AET-affected horses, which we show is associated with decreased protein expression. SEL1L is intracellular in equine platelet...
Vychodilova L, Plasil M, Futas J, Kopecka A, Molinkova D, Wijacki T, Jahn P, Knoll A, Horin P.Although the Major Histocompatibility Complex (MHC) has been repeatedly associated with susceptibility to equine sarcoid, a disease associated with bovine papillomavirus infection, the role of the MHC in the mechanisms of the disease is not fully understood. The objectives of our work were to analyze associations between polymorphic markers of the MHC genomic subregions and of the Natural Killer Complex (NKC) genomic region and the presence of sarcoid in Arabian horses. Microsatellite loci located in the MHC class I, II and III subregions and two MHC class II genes (DRA, DQA1), along with a se...
Aleman M, McCue M, Bellone RR.Fatal anesthesia-induced malignant hyperthermia (MH) and rhabdomyolysis with hyperthermia documented in Quarter Horses (QH) breeds are caused by a missense variant in the ryanodine receptor 1 gene (RYR1: XP_023505430.1.:p.(R2454G), designated as MH). The reported cases to date have all been heterozygous, and the allele frequency is suspected to be low. Objective: To determine an accurate estimate of MH allele frequency in multiple horse breeds and investigate whether homozygous animals exist in the population. Methods: In total, 159 227 horses from 16 breeds who were either submitted for cli...
Martinez-Saez L, MarÃn-GarcÃa PJ, Llobat ML.Osteochondrosis (OC) is a frequent manifestation of developmental orthopaedic disease, and its severe clinical presentation is known as OC dissecans (OCD). OC is defined as a disruption of the endochondral ossification process in the epiphyseal cartilage, and this disease has been reported in different mammalian species, including humans, dogs, pigs, and horses. OCD is an important cause of lameness in sport horses and is a common cause of impaired orthopaedic potential, whose clinical signs may be of minimal magnitude or manifest as severe joint effusion or clinically noticeable lameness. The...
Li Y, Lan Y.The gut microbial importance and its crucial roles in host digestion, immunity, and metabolism have received widely attention. Horses, especially indigenous varieties such as Mongolian horses (MGH) and Guizhou horses (GZH), have not received sufficient attention, and the characteristics of their gut microbiota are still unclear. For this purpose, we collected faecal samples from eight MGH and eight GZH to compare their gut microbial differences using amplicon sequencing. The results of alpha diversity analysis indicated that the gut bacterial diversity and gut fungal abundance in GZH were sign...
Ding W, Gong W, Bou T, Shi L, Lin Y, Wu H, Dugarjaviin M, Bai D.Muscle fibers, as the fundamental units of muscle tissue, play a crucial role in determining skeletal muscle function through their growth, development, and composition. To investigate changes in muscle fiber types and their regulatory mechanisms in Mongolian horses (MG), Xilingol horses (XL), and Grassland-Thoroughbreds (CY), we conducted histological and bioinformatic analyses on the gluteus medius muscle of these three horse breeds. Immunofluorescence analysis revealed that Grassland-Thoroughbreds had the highest proportion of fast-twitch muscle fibers at 78.63%, while Mongolian horses had ...
Baatar T, Song D, Weng Y, Wang G, Jin L, Guo R, Li B, Dugarjaviin M.The epigenetic regulation of gene expression through the covalent modification of histones is crucial for developing germline cells. To study the regulatory role of alternative splicing (AS) of euchromatic histone lysine methyltransferase 2 (EHMT2/G9A) in spermatogenesis in Mongolian horses, this study first examines the localization of the EHMT2 gene in testicular support cells and then predicts the higher-order structures of sequences with and without AS. Two types of lentiviral vectors for overexpression were subsequently constructed for the EHMT2 gene, one with AS and one without, to infec...
Bacon EK, Donnelly CG, Finno CJ, Haase B, Velie BD.Multimodal analgesic administration is a promising strategy for mitigating side effects typically associated with analgesia; nevertheless, variation in analgesic effectiveness still poses a considerable safety concern for both horses and veterinarians. Pharmacogenomic studies have started delving into genetic influences on varying drug effectiveness and related side effects. However, current findings have narrow implications and are limited in their ability to individualize analgesic dosages in horses. Hydromorphone and detomidine were administered to a cohort of 48 horses at standardized time...
Sigurðardóttir H, Eriksson S, Niazi A, Rhodin M, Albertsdóttir E, Kristjansson T, Lindgren G.Selection for performance in horse breeding benefits from precise genetic insights at a molecular level, but knowledge remains limited. This study used whole-genome sequences of 39 elite and non-elite Icelandic horses to identify candidate causal variants linked to previously identified haplotypes in the STAU2 and RELN genes affecting pace and other gaits. A frameshift variant in linkage disequilibrium with the previously identified haplotypes in the STAU2 gene (r2 = 0.85) was identified within a predicted STAU2 transcript. This variant alters the amino acid sequence and introduces a prema...
Science (New York, N.Y.)March 28, 2025
Volume 387, Issue 6741 eadr8589 doi: 10.1126/science.adr8589
Castiglione GM, Chen X, Xu Z, Dbouk NH, Bose AA, Carmona-Berrio D, Chi EE, Zhou L, Boronina TN, Cole RN, Wu S, Liu AD, Liu TD, Lu H, Kalbfleisch T....Horses are among nature's greatest athletes, yet the ancestral molecular adaptations fueling their energy demands are poorly understood. Within a clinically important pathway regulating redox and metabolic homeostasis (NRF2/KEAP1), we discovered an ancient mutation-conserved in all extant equids-that increases mitochondrial respiration while decreasing tissue-damaging oxidative stress. This mutation is a de novo premature opal stop codon in KEAP1 that is translationally recoded into a cysteine through previously unknown mechanisms, producing an R15C mutation in KEAP1 that is more sensitive to ...
Blohina NV, Khrabrova LA.Russia has a significant pedigree diversity of horse breeds with unique gene pools that are well adapted to a wide variety of harsh natural and climatic conditions, are characterized by universal performance and high productive qualities, and are of significant interest to the world horse breeding. Genetic studies of population diversity in horse breeding are very relevant, since many domestic horse breeds are under threat of extinction. Biomaterials (hair, blood, semen) from horses of 15 local breeds bred in the Russian Federation and neighboring countries (CIS) were selected for the research...
Han J, Shao H, Sun M, Gao F, Hu Q, Yang G, Jafari H, Li N, Dang R.Genetic diversity in livestock and poultry is critical for adapting production systems to future challenges. However, inadequate management practices, particularly in developing countries, have led to the extinction or near extinction of several species. Understanding the genetic composition and historical background of local breeds is essential for their effective conservation and sustainable use. This study compared the genomes of 30 newly sequenced Ningqiang ponies with those of 56 other ponies and 104 horses to investigate genetic diversity, genetic differentiation, and the genetic basis o...
Muñoz-Jurado A, Requena F, Agüera EI, Escribano BM.Anti-Müllerian hormone (AMH) is a dimeric glycoprotein belonging to the superfamily of the transforming growth factor-β. Due to the discovery of AMH functions, relative to the ovarian function, it is being postulated as being a highly important marker in studies on mammalian reproduction. Therefore, the objective of this review was to describe the role of this hormone in different reproductive aspects of female mammals, taking women, cows, and mares as reference species. The relationship between ovarian reserve and AMH was analysed, and it has been verified that there is a relationship betwe...
Uprety T, Swan M, Kennedy L, Bryant U, Cassone L, Loynachan A, Janes J, Evely MM, Calvaruso FC, Quick M, Morgan J, Abdelrazek S, Lahmers K, Carter C....Clostridium piliforme is an obligate intracellular filamentous bacterium that causes Tyzzer disease (TD) in many animals. The disease manifests as severe, multifocal necrotizing hepatitis, with a high fatality rate in foals. Through retrospective investigation, we detected C. piliforme in 43 equine necropsy cases from 2012 to 2024. Positive cases were diagnosed from February to July, peaking in May. The age of affected foals ranged from 4 days to 2 months. Histologically, all cases had necrotizing hepatitis with multifocal, coalescing pinpoint, tan or reddish foci. Since only a partial 16S rRN...
Quatember H, Nell B, Richter B, Rigler D, Dolezal M, Sykora S, Wallner B.A missense mutation in damage-specific DNA binding protein 2 (DDB2 c.1013 C>T; p.Thr338Met) has been described as a risk factor for ocular squamous cell carcinoma (OSCC) in the Haflinger breed. Here, we examined the impact of DDB2 C>T allele status on the development of OSCC, squamous cell carcinoma (SCC) at other localisations, or equine sarcoid (ES) in Haflingers and other breeds with a high incidence of these tumour types. We genotyped affected Haflinger, Noriker, Warmblood, and Icelandic horses. Results based on 56 Haflingers confirmed the significantly higher risk for OSCC in DDB2-TT Hafl...
Obradovic NA, McFadden A, Martin K, Vierra M, McLoone K, Martin E, Thomas A, Everts RE, Brooks SA, Lafayette C.This paper reports three novel KIT variants likely responsible for previously unexplained white patterning phenotypes observed in three groups of horses. White spots and markings may have substantial consequences on the value and health of domesticated horses. This study aims to elucidate the genetic mechanisms underlying depigmented coat colors to aid in producing prosperous herds. Aligned whole genome sequences were manually screened to identify three polymorphisms in a family of Anglo-Arabian horses (N = 7), a family of Warmblood horses (N = 5), and a single stock-type mare with unexplained...
Finno CJ.Nutrigenomics defines the interaction between the nutrients in our food and the genes in our body. Examples from human medicine of diseases and associated genes include lactose intolerance (genetic variants in LCT lactase), hypercholesteremia (low density lipoprotein receptor, LDLR) and caffeine sensitivity (adenosine A2A receptor, ADORA2A). In horses, examples include Hyperkalemic Periodic Paralysis (HYPP), where clinical signs of disease are managed through maintaining a diet low in potassium and Polysaccharide Storage Myopathy Type 1 (PSSM1), where low starch and high fat diets are recommen...
Agbani A, Aminou O, Machmoum M, Germot A, Badaoui B, Petit D, Piro M.This Systematic Literature Review (SLR) consolidates current research on mitochondrial DNA (mtDNA) analysis in horses, focusing on genetic variation, maternal lineage tracing, and haplogroup identification. The article selection process screened 1380 articles, with 76 fulfilling the inclusion criteria. Data extraction covered sampling techniques, studied mtDNA regions, sequencing methods, and haplogroup identification. Following the methodology of the PRISMA guidelines, this review encompasses studies published since 2012, obtained from Scopus, PubMed, Research4Life, Web of Science, and Scienc...
Moroudi RS, Mahboudi H, Mahboudi F.The Dareshouri horse breed is one of Iran's native equine breeds, originating from the Dareshouri tribe, a subgroup of the Qashqai nomads. This breed has a history spanning over 500 years. Horses of this breed have smooth nates, tall stature, raised tails and strong skeletal muscles. This is the first study to investigate the effect of genetics on athletic performance in the Dareshouri breed. For this purpose, in this study, the genotype combination of two important variants, including the rs397152648Single nucleotide polymorphism (SNP) and Short interspersed nuclear element (SINE) insertion, ...
Qiu Y, Jiang J, Yi X, Wang S, Sun X.This study investigated the immunoglobulins (IG) gene locus structure and expression diversity in local Chinese horse and donkey breeds, including Ningqiang, Guanzhong horses, and varieties such as Guanzhong, Jiami, and Northern Shaanxi donkey using genome alignment and high-throughput sequencing. The aim was to expand understanding of IG expression patterns in horses, donkeys, and their different breeds. The results revealed that the donkey IGH locus contains 117 VH genes (23 functional), 44 DH genes, and 8 JH genes, arranged in a VH-DH-JH sequence on chromosome 7, spanning approximately 1189...
Dash SK, Panda S, Karna DK, Mishra C, Kalaignazhal G.The present study aimed to identify significant morphometric traits in Malkangiri ponies of Odisha through principal component analysis. The data were collected randomly from 200 ponies aged more than five years and 13 morphometric traits alongwith three indices were recorded. The mean height at wither, height at croup, body length, chest girth, punch girth, height at forearm, height at hock, fetlock to coronet, chest width, neck circumference, poll to wither, wither to croup and croup to head of the tail were 126.7 ± 0.39, 122.6 ± 0.29, 107.9 ± 0.2, 122 ± 0.31, 118.6 ±â...
Sievers J, Distl O.The Rhenish German draught horse is an endangered German horse breed, originally used as working horse in agriculture. Therefore, the objective of this study was to evaluate the breed's genetic diversity using pedigree and genomic data in order to analyze classical and ancestral pedigree-based inbreeding, runs of homozygosity, ROH islands, and consensus ROH. Methods: We studied the genome-wide genotype data of 675 Rhenish German draught horses and collated pedigree-based inbreeding coefficients for these horses. The final dataset contained 64,737 autosomal SNPs. Results: The average number of ...
Yokomori T, Tozaki T, Segawa T, Itou T.Previous studies have examined the relationship between hair characteristics and temperament traits in various animals. A partial genetic association has been suggested in humans because whorl formation and neurological development occur simultaneously during the fetal period. In the horse industry, anecdotal evidence suggests a link between the forehead whorl position and temperament. In our previous study, the heritability of forehead whorl positioning was h=0.653, indicating significant genetic contributions in thoroughbreds. Therefore, in this study, we designed a genome-wide association s...
Trauner AM, McCoski SR, Satterfield MC, Bradbery AN.Reproductive health of male offspring following perturbations in maternal nutrition is not well-described in the horse; therefore, the objective of this study was to determine the effects of maternal overnutrition on neonatal foal testicular development. Sixteen Quarter Horse mares were used in a completely randomized design and stratified by expected foaling date, body weight, and body condition score into 1 of 2 dietary treatments beginning on gestational day 235: control (CON; n = 8) fed to meet nutrient requirements and overfed (HIGH; n = 8) fed 40% above CON. At 5 h postpartum, f...
Liu D, Zhao X, Wang X.Equine herpesvirus 1 (EHV-1), EHV-4, EHV-8, and EHV-9, are classified within the subfamily and are recognized as causative agents of respiratory, urogenital, and neurological disorders in horses. These viruses, collectively referred to as αEHVs, exhibits both unique and shared characteristics in terms of host interaction, pathogenesis, epidemiology, and immune evasion, which arise from both the identities and discrepancies among respective genomic homologs. The genomic architecture of αEHVs is similar to other members of the same subfamily, such as well-known HSV-1, VZV, and PRV. However, r...
Haile J, Froese DG, Macphee RD, Roberts RG, Arnold LJ, Reyes AV, Rasmussen M, Nielsen R, Brook BW, Robinson S, Demuro M, Gilbert MT, Munch K....Causes of late Quaternary extinctions of large mammals ("megafauna") continue to be debated, especially for continental losses, because spatial and temporal patterns of extinction are poorly known. Accurate latest appearance dates (LADs) for such taxa are critical for interpreting the process of extinction. The extinction of woolly mammoth and horse in northwestern North America is currently placed at 15,000-13,000 calendar years before present (yr BP), based on LADs from dating surveys of macrofossils (bones and teeth). Advantages of using macrofossils to estimate when a species became extinc...
Pacini S, Spinabella S, Trombi L, Fazzi R, Galimberti S, Dini F, Carlucci F, Petrini M.It has been proven that mesenchymal stromal cells (MSCs) can differentiate into tenocytes. Attempts to repair tendon lesions have been performed, mainly using scaffold carriers in experimental settings. In this article, we describe the clinical use of undifferentiated MSCs in racehorses. Significant clinical recovery was achieved in 9 of 11 horses evaluated using ultrasound analysis and their ability to return to racing. Our results show that the suspension of a small number of undifferentiated MSCs may be sufficient to repair damaged tendons without the use of scaffold support. Ultrasound sca...
van Aken D, Zevenhoven-Dobbe J, Gorbalenya AE, Snijder EJ.The positive-stranded RNA genome of the arterivirus Equine arteritis virus (order Nidovirales) encodes the partially overlapping replicase polyproteins pp1a (1727 aa) and pp1ab (3175 aa). Previously, three viral proteinases were reported to cleave these large polyproteins into 12 non-structural proteins (nsps). The chymotrypsin-like viral main proteinase residing in nsp4 is responsible for eight of these cleavages. Processing of the C-terminal half of pp1a (the nsp3-8 region) was postulated to occur following either of two alternative proteolytic pathways (the 'major' and 'minor' pathways). He...
Murcia PR, Wood JL, Holmes EC.Equine influenza viruses (EIVs) of the H3N8 and H7N7 subtypes are the causative agents of an important disease of horses. While EIV H7N7 apparently is extinct, H3N8 viruses have circulated for more than 50 years. Like human influenza viruses, EIV H3N8 caused a transcontinental pandemic followed by further outbreaks and epidemics, even in populations with high vaccination coverage. Recently, EIV H3N8 jumped the species barrier to infect dogs. Despite its importance as an agent of infectious disease, the mechanisms that underpin the evolutionary and epidemiological dynamics of EIV are poorly und...
Schaefer RJ, Schubert M, Bailey E, Bannasch DL, Barrey E, Bar-Gal GK, Brem G, Brooks SA, Distl O, Fries R, Finno CJ, Gerber V, Haase B, Jagannathan V....To date, genome-scale analyses in the domestic horse have been limited by suboptimal single nucleotide polymorphism (SNP) density and uneven genomic coverage of the current SNP genotyping arrays. The recent availability of whole genome sequences has created the opportunity to develop a next generation, high-density equine SNP array. Using whole genome sequence from 153 individuals representing 24 distinct breeds collated by the equine genomics community, we cataloged over 23 million de novo discovered genetic variants. Leveraging genotype data from individuals with both whole genome sequence, ...
Toupadakis CA, Wong A, Genetos DC, Cheung WK, Borjesson DL, Ferraro GL, Galuppo LD, Leach JK, Owens SD, Yellowley CE.To determine the optimal osteogenic source of equine mesenchymal stem cells (eMSCs) and optimize collection of and expansion conditions for those cells. Methods: 10 adult Quarter Horses and 8 newborn Thoroughbred foals. Methods: eMSCs were isolated from bone marrow (BM), adipose tissue, and umbilical cord blood and tissue, and the osteogenic potential of each type was assessed. Effects of anatomic site, aspiration volume, and serum type on eMSC yield from BM were investigated. Results: BM-eMSCs had the highest overall expression of the osteogenic genes Cbfa1, Osx, and Omd and staining for ALP ...
De Schauwer C, Meyer E, Van de Walle GR, Van Soom A.Mesenchymal stromal cells (MSC) are a very promising subpopulation of adult stem cells for cell-based regenerative therapies in veterinary medicine. Despite major progress in the knowledge on adult stem cells during recent years, a proper identification of MSC remains a challenge. In human medicine, the Mesenchymal and Tissue Stem Cell Committee of the International Society for Cellular Therapy (ISCT) recently proposed three criteria to define MSC. Firstly, cells must be plastic-adherent when maintained under standard culture conditions. Secondly, MSC must express CD73, CD90 and CD105, and lac...
McNulty SN, Tort JF, Rinaldi G, Fischer K, Rosa BA, Smircich P, Fontenla S, Choi YJ, Tyagi R, Hallsworth-Pepin K, Mann VH, Kammili L, Latham PS....Food borne trematodes (FBTs) are an assemblage of platyhelminth parasites transmitted through the food chain, four of which are recognized as neglected tropical diseases (NTDs). Fascioliasis stands out among the other NTDs due to its broad and significant impact on both human and animal health, as Fasciola sp., are also considered major pathogens of domesticated ruminants. Here we present a reference genome sequence of the common liver fluke, Fasciola hepatica isolated from sheep, complementing previously reported isolate from cattle. A total of 14,642 genes were predicted from the 1.14 GB gen...
Bryant NA, Rash AS, Russell CA, Ross J, Cooke A, Bowman S, MacRae S, Lewis NS, Paillot R, Zanoni R, Meier H, Griffiths LA, Daly JM, Tiwari A....Equine influenza virus (EIV) surveillance is important in the management of equine influenza. It provides data on circulating and newly emerging strains for vaccine strain selection. To this end, antigenic characterisation by haemaggluttination inhibition (HI) assay and phylogenetic analysis was carried out on 28 EIV strains isolated in North America and Europe during 2006 and 2007. In the UK, 20 viruses were isolated from 28 nasopharyngeal swabs that tested positive by enzyme-linked immunosorbent assay. All except two of the UK viruses were characterised as members of the Florida sublineage w...
Cunningham EP, Dooley JJ, Splan RK, Bradley DG.The thoroughbred (TB) horse is one of the oldest breeds of domestic animals, with pedigree records spanning three centuries. Because the population is essentially closed, there is concern about loss of genetic variation. Here we report two parallel analyses. In the first, genetic variation in the current population is measured using data from 13 microsatellite loci in 211 horses with relationships calculated based on allele sharing. In the second analysis, pedigree information is used to calculate genetic relationships between animals based on shared ancestry. These two measures of relationshi...
Costa MC, Weese JS.The equine intestinal tract contains a complex microbial population (microbiota) that plays an important role in health and disease. Despite the undeniable importance of a 'normal' microbiota, understanding of the composition and function of this population is currently limited. As methods to characterize the microbiota and its genetic makeup (the microbiome) have evolved, the composition and complexity of this population are starting to be revealed. As is befitting a hindgut fermenter, members of the Firmicutes phylum appear to predominate, yet there are significant populations of numerous ot...
Kubickova S, Cernohorska H, Musilova P, Rubes J.Laser microbeam microdissection and laser pressure catapulting procedure were used for the construction of chromosome-specific painting probes, arm-specific probes and probes for chromosomal subfragments. We report on a method for generation of fluorescence in-situ hybridization probes from laser dissected chromosomes of farm animals. So far, using the described method, a set of chromosome-specific painting probes has been obtained for all porcine chromosomes, 17 chromosomes of cattle and selected equine chromosomes. It is concluded that the laser technology appears to be a useful and powerful...
Kumar N, Bera BC, Greenbaum BD, Bhatia S, Sood R, Selvaraj P, Anand T, Tripathi BN, Virmani N.Equine influenza viruses (EIVs) of H3N8 subtype are culprits of severe acute respiratory infections in horses, and are still responsible for significant outbreaks worldwide. Adaptability of influenza viruses to a particular host is significantly influenced by their codon usage preference, due to an absolute dependence on the host cellular machinery for their replication. In the present study, we analyzed genome-wide codon usage patterns in 92 EIV strains, including both H3N8 and H7N7 subtypes by computing several codon usage indices and applying multivariate statistical methods. Relative synon...
Kaplan RM.Suppressive anthelmintic treatment strategies originally designed to control Strongylus vulgaris in horses were extremely successful in reducing morbidity and mortality from parasitic disease. Unfortunately, this strategy has inadvertently resulted in the selection of drug-resistant cyathostomes (Cyathostominea), which are now considered the principal parasitic pathogens of horses. Resistance in the cyathostomes to benzimidazole drugs is highly prevalent throughout the world, and resistance to pyrantel appears to be increasingly common. However, there are still no reports of ivermectin resista...
Vilstrup JT, Seguin-Orlando A, Stiller M, Ginolhac A, Raghavan M, Nielsen SC, Weinstock J, Froese D, Vasiliev SK, Ovodov ND, Clary J, Helgen KM....The genus Equus is richly represented in the fossil record, yet our understanding of taxonomic relationships within this genus remains limited. To estimate the phylogenetic relationships among modern horses, zebras, asses and donkeys, we generated the first data set including complete mitochondrial sequences from all seven extant lineages within the genus Equus. Bayesian and Maximum Likelihood phylogenetic inference confirms that zebras are monophyletic within the genus, and the Plains and Grevy's zebras form a well-supported monophyletic group. Using ancient DNA techniques, we further charact...
Posthuma CC, Pedersen KW, Lu Z, Joosten RG, Roos N, Zevenhoven-Dobbe JC, Snijder EJ.The replication/transcription complex of the arterivirus equine arteritis virus (EAV) is associated with paired membranes and/or double-membrane vesicles (DMVs) that are thought to originate from the endoplasmic reticulum. Previously, coexpression of two putative transmembrane nonstructural proteins (nsp2 and nsp3) was found to suffice to induce these remarkable membrane structures, which are typical of arterivirus infection. Here, site-directed mutagenesis was used to investigate the role of nsp3 in more detail. Liberation of the hydrophobic N terminus of nsp3, which is normally achieved by c...
Prokhorov NS, Riccio C, Zdorovenko EL, Shneider MM, Browning C, Knirel YA, Leiman PG, Letarov AV.Bacteriophages recognize and bind to their hosts with the help of receptor-binding proteins (RBPs) that emanate from the phage particle in the form of fibers or tailspikes. RBPs show a great variability in their shapes, sizes, and location on the particle. Some RBPs are known to depolymerize surface polysaccharides of the host while others show no enzymatic activity. Here we report that both RBPs of podovirus G7C - tailspikes gp63.1 and gp66 - are essential for infection of its natural host bacterium E. coli 4s that populates the equine intestinal tract. We characterize the structure and funct...
Lupo A, Saras E, Madec JY, Haenni M.In Asian countries, blaCTX-M-55 is the second most common ESBL-encoding gene. blaCTX-M-55 frequently co-localizes with fosA and rmtB genes on epidemic plasmids, which remain sporadic outside Asia. During 2010-13, we investigated CTX-M-55-producing Escherichia coli isolates and their co-resistance to fosfomycin, aminoglycosides, fluoroquinolones and colistin as part of a global survey of ESBLs in animals in France. blaCTX-M-55, fosA, rmtB and plasmidic quinolone and colistin resistance genes were characterized by PCR, sequencing and hybridization experiments. Plasmids were classified according ...
Baker TS, Newcomb WW, Booy FP, Brown JC, Steven AC.Cryoelectron microscopy and three-dimensional computer reconstruction techniques have been used to compare the structures of two types of DNA-free capsids of equine herpesvirus 1 at a resolution of 4.5 nm. "Light" capsids are abortive, whereas "intermediate" capsids are related to maturable intracellular precursors. Their T = 16 icosahedral outer shells, approximately 125 nm in diameter, are indistinguishable and may be described in terms of three layers of density, totalling 15 nm in thickness. The outermost layer consists of protruding portions of both the hexon and the penton capsomers, ris...
Smith RK, Zunino L, Webbon PM, Heinegård D.A protein prominent in guanidine hydrochloride extracts of adult bovine and equine digital flexor tendons was confirmed to be Cartilage Oligomeric Matrix Protein (COMP) by non-reducing and reducing SDS-PAGE, reaction with rabbit anti-COMP polyclonal antiserum on Western blots, trypsin digestion followed by HPLC on a C2/C18 column, and identification of COMP mRNA from tendon on Northern blots. Immunohistochemistry and Western blots of extracts showed COMP to be present in all regions of digital flexor tendons. Equine tendon COMP was purified by ion exchange chromatography and gel filtration and...
Jamieson A, Taylor SC.Three general formulae calibrate the average capability of marker systems to dispute falsely reported pedigree records in uniparous species. The most familiar exclusion formula applies to paternity, although the same formula applies equally to maternity. Another formula faults the relationship of a single offspring with its putative parent; for example, where the genotype of the other parent is not available. The remaining formulae excludes both of the falsely recorded parents of a substituted offspring. Simplified forms of the three general formulae facilitate the calculation of maximal avera...
Lewis NS, Daly JM, Russell CA, Horton DL, Skepner E, Bryant NA, Burke DF, Rash AS, Wood JL, Chambers TM, Fouchier RA, Mumford JA, Elton DM, Smith DJ.Equine influenza virus is a major respiratory pathogen in horses, and outbreaks of disease often lead to substantial disruption to and economic losses for equestrian industries. The hemagglutinin (HA) protein is of key importance in the control of equine influenza because HA is the primary target of the protective immune response and the main component of currently licensed influenza vaccines. However, the influenza virus HA protein changes over time, a process called antigenic drift, and vaccine strains must be updated to remain effective. Antigenic drift is assessed primarily by the hemagglu...
Lippold S, Matzke NJ, Reissmann M, Hofreiter M.DNA target enrichment by micro-array capture combined with high throughput sequencing technologies provides the possibility to obtain large amounts of sequence data (e.g. whole mitochondrial DNA genomes) from multiple individuals at relatively low costs. Previously, whole mitochondrial genome data for domestic horses (Equus caballus) were limited to only a few specimens and only short parts of the mtDNA genome (especially the hypervariable region) were investigated for larger sample sets. Results: In this study we investigated whole mitochondrial genomes of 59 domestic horses from 44 breeds an...
Rubin JE, Pitout JD.Organisms in the family Enterobactericeae including, Escherichia coli, commonly cause community and hospital-associated infections in both humans and companion animals. The increasing prevalence of infections with organisms producing broad spectrum β-lactamses such as the ESBLs (particularly the CTX-M type), AmpC and carbapenemase enzymes are threatening the future of the β-lactam drugs. While a number of organisms within the Enterobacteriaceae producing these enzymes have been isolated from cats, dogs and horses, E. coli, including isolates indistinguishable from strains found in people, ha...
Salinovich O, Payne SL, Montelaro RC, Hussain KA, Issel CJ, Schnorr KL.Previous results from our laboratory have demonstrated that equine infectious anemia virus displays structural variations in its surface glycoproteins and RNA genome during passage and chronic infections in experimentally infected Shetland ponies (Montelaro et al., J. Biol. Chem. 259:10539-10544, 1984; Payne et al., J. Gen. Virol. 65:1395-1399, 1984). The present study was undertaken to obtain an antigenic and biochemical characterization of equine infectious anemia virus isolates recovered from an experimentally infected pony during sequential disease episodes, each separated by intervals of ...
Johnson L, Thompson DL, Varner DD.Testicular function is under the control of expression and repression of several genes and gene products, and many of these works through Sertoli cells. The capability of Sertoli cells to regulate spermatogenesis is dependent on Sertoli cell functions and Sertoli cell number. Sertoli cell number has long been thought to be stable in adults with no proliferation of Sertoli cells once adult numbers have been reached. However, adult horses do not have stable Sertoli cell numbers, and new studies indicate that adult Sertoli cells can be made to re-enter mitotic phase under certain experimental con...
Metallinos DL, Bowling AT, Rine J.Lethal White Foal Syndrome is a disease associated with horse breeds that register white coat spotting patterns. Breedings between particular spotted horses, generally described as frame overo, produce some foals that, in contrast to their parents, are all white or nearly all white and die shortly after birth of severe intestinal blockage. These foals have aganglionosis characterized by a lack of submucosal and myenteric ganglia from the distal small intestine to the large intestine, similar to human Hirschsprung Disease. Some sporadic and familial cases of Hirschsprung Disease are due to muta...
Vick MM, Adams AA, Murphy BA, Sessions DR, Horohov DW, Cook RF, Shelton BJ, Fitzgerald BP.Recent studies associate obesity and insulin resistance in horses with development of abnormal reproductive function and debilitating laminitis. The factors contributing to insulin resistance in obese horses are unknown. However, human studies provide evidence that elevated inflammatory cytokines such as tumor necrosis factor alpha (TNFalpha), IL1, and IL6 play direct roles in development of obesity-associated insulin resistance. Thus, inflammation may be a key link between obesity and insulin resistance in horses. The aim of the current investigation was to examine possible relationships betw...
