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.
Novak BJ, Brand S, Phelan R, Plichta S, Ryder OA, Wiese RJ.Over 40 years ago, scientists imagined ways cloning could aid conservation of threatened taxa. The cloning of Dolly the sheep from adult somatic cells in 1996 was the breakthrough that finally enabled the conservation potential of the technology. Until the 2020s, conservation cloning research efforts yielded no management applications, leading many to believe cloning is not yet an effective conservation tool. In strong contrast, domestic taxa are cloned routinely for scientific and commercial purposes. In this review, we sought to understand the reasons for these divergent trends. We scoured p...
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...
Bai F, Cai Y, Qiu M, Liang C, Pan L, Liu Y, Feng Y, Cao X, Yang Q, Ren G, Jiao S, Gao S, Lu M, Wang X, Heller R, Lenstra JA, Jiang Y.Natural variants can significantly improve growth traits in livestock and serve as safe targets for gene editing, thus being applied in animal molecular design breeding. However, such safe and large-effect mutations are severely lacking. Using ancestral recombination graphs, we investigated recent selection signatures in beef cattle breeds, pinpointing sweep-driving variants in the LCORL and STC2 loci with notable effects on body size and growth rate. The ACT-to-A frameshift mutation in LCORL occurs mainly in central-European cattle, and stimulates growth. Remarkably, convergent truncating mut...
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...
Liu X, Peng Y, Zhang X, Chen W, Chen Y, Wei L, Zhu Q, Khan MZ, Wang C.Herbivorous livestock, such as cattle, sheep, goats, horses, and donkeys, play a crucial role in agricultural production and possess remarkable resilience to extreme environmental conditions, driven by complex genetic mechanisms. Recent advancements in high-throughput sequencing, genome assembly, and environmental data integration have enabled a deeper understanding of the genetic basis of their environmental adaptation. This review identifies key genes associated with high-altitude, heat, cold, and drought adaptation, providing insights into the molecular mechanisms underlying these traits. B...
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...
Santana ML, Franco TGB, Bignardi AB.Barrel racing is a competitive timed rodeo event that challenges horses and riders to complete a cloverleaf pattern around three barrels in the fastest time possible. In this study, we aimed to estimate the genetic parameters of barrel racing time (BRT) and evaluate the most suitable statistical model for its analysis. We compared a repeatability model and three random regression models (RRM) to analyse the longitudinal BRT data in Brazilian Quarter Horses. A total of 356,877 BRT records from 14,108 horses that competed in various events held across Brazil between 2010 and 2024 were analysed. ...
Abdul-Latif SAK, Yousif AA.Strangles is a highly contagious equine respiratory disease caused by . It is a globally significant pathogen and one of the most common infectious agents in horses. In Iraq, no sequencing data on this pathogen are available, and only two molecular studies have been published to date. This study provides preliminary insights into strain diversity and provides a foundation for future large-scale investigations. Unassigned: This study aimed to investigate the molecular characteristics, identify gene alleles, and perform a phylogenetic analysis of isolates from horses in Baghdad, Iraq. Unassign...
Frontiers in geneticsFebruary 27, 2025
Volume 16 1534461 doi: 10.3389/fgene.2025.1534461
Barber AM, Kingsley NB, Peng S, Giulotto E, Bellone RR, Finno CJ, Kalbfleisch T, Petersen JL.The Functional Annotation of Animal Genomes (FAANG) consortium aims to annotate animal genomes across species, and work in the horse has substantially contributed to that goal. As part of this initiative, chromatin immunoprecipitation with sequencing (ChIP-seq) was performed to identify histone modifications corresponding to enhancers (H3K4me1), promoters (H3K4me3), activators (H3K27ac), and repressors (H3K27me3) in eight tissues from two Thoroughbred stallions: adipose, parietal cortex, heart, lamina, liver, lung, skeletal muscle, and testis. The average genome coverage of peaks identified by...
Wang Y, Tang C, Xue P, Yang N, Sun X, Serik K, Assanbayer T, Shamekova M, Kozhanov Z, Sapakhova Z, Khurramovich JK, Zhou X, Kairat I, Muhatai G. The Yanqi horse is a distinguished local breed in China, known for its robust physique and strong adaptability. However, due to insufficient breeding populations and a loosely structured breeding system, the number of Yanqi horses has been declining annually. To protect its genetic resources and develop scientific breeding strategies, this study aimed to analyze the genetic diversity, parentage relationships, and genetic structure of the Yanqi horse conservation population using microsatellite markers. A total of 117 Yanqi horses were selected for genotyping analysis using 16 microsatellite ...
Li X, Wang Z, Zhu M, Wang B, Teng S, Yan J, Wang H, Yuan P, Cao S, Qu X, Wang Z, Zhan K, Choudhury MP, Yang X, Bao Q, He S, Liu L, Zhao P, Jiang J....Horse domestication revolutionizes human civilization by transforming transportation, agriculture, and warfare patterns. Despite extensive studies on modern domestic horse origins, the intricate demographic history and genetic signatures underlying pony size remain unexplored. Here, a high-quality genome assembly of the Chinese Debao pony is presented, and 452 qualified individuals from 64 horse breeds worldwide are extensively analyzed. The authors' results reveal the conservation of ancient components in East Asian horses and close relationships between Asian horses and Western pony lineages...
Stefaniuk-Szmukier M, Bieniek A, Ropka-Molik K, Bellone RR.Congenital stationary night blindness (CSNB) has been connected to the leopard complex spotting phenotype (LP) in various horse breeds. CSNB associated with LP is thought to be caused by a 1378 bp insertion in TRPM1, with homozygotes being nightblind and having few to no spots of pigment in their white patterned area. This study aimed to assess the prevalence of CSNB alleles in tarant-colored horses in Poland through a three-primer system for an allele-specific Polymerase Chain Reaction (PCR). The TRPM1 gene insertion was genotyped in 221 horses belonging to Małopolska, Felin and Shetland Pon...
Berglund P, Andonov S, Jansson A, Olsson C, Lundqvist T, Strandberg E, Eriksson S.In equine sports, shoes are used to protect the hooves from wear and tear. In Swedish trotting races, pulling off the shoes to race barefoot is popular because it improves racing time. Good hoof quality is essential for high-performance horses, but not all trotting horses have hooves that tolerate barefoot racing. The ability to race barefoot is a complex trait that is known to be influenced by environmental factors, but the genetic basis of this trait has not been studied. The aim of this study was to estimate genetic parameters and correlations between estimated breeding values for three nov...
Du W, Sun Q, Hu S, Yu P, Kan S, Zhang W.Mitochondria are semi-autonomous organelles that play a crucial role in the energy budget of animal cells and are closely related to the locomotor abilities of animals. Equidae is renowned for including two domesticated species with distinct purposes: the endurance-oriented donkey and the power-driven horse, making it an ideal system for studying the relationship between mitochondria and locomotor abilities. In this study, to cover the genetic diversity of donkeys, we sequenced and assembled six new mitochondrial genomes from China. Meanwhile, we downloaded the published mitochondrial genomes ...
Novak BJ, Ryder OA, Houck ML, Walker K, Russell L, Russell B, Walker S, Arenivas SS, Aston L, Veneklasen G, Ivy JA, Koepfli KP, Rusnak A, Simek J....Cloning from historically cryopreserved cells offers a potential means to restore lost genetic variation or increase the representation of particular lineages within bottlenecked species, provided such biobanked materials are archived for such genetic rescue applications. One species for which cloning can provide genetic management benefits is Przewalski's horse, . All ~1800 living Przewalski's horses, distributed across ex situ breeding facilities and in situ reintroduction sites, are descended from one or more of the five founder lineages established by the 12 horses captured from the wild b...
Kelly RF, Galbraith E, Zahid O, Chaundhry U, Sargison N.Grazing animal species kept in zoological collections can be at risk of significant gastrointestinal nematode (GIN) infections. Little work has been undertaken to understand GIN species dynamics within co-grazed hosts. This study aimed to describe the species diversity of GINs found in faeces of grazing animals in a Scottish zoological collection. Methods: At a single time-point, freshly voided faecal samples were collected randomly from horses, sheep, goats, alpacas and deer. Faecal worm egg counts (FWECs) were conducted using a saturated saline centrifugal flotation cuvette technique. The ne...
Grundy FJ, Baumann RP, O'Callaghan DJ.The immediate early (IE) proteins of herpesviruses are important regulatory factors which control the expression of genes at the transcriptional level. We report the DNA sequence of the immediate early gene of the alphaherpesvirus equine herpesvirus type 1 (EHV-1). This sequence is shown to be extremely rich in guanine and cytosine, resulting in a highly biased codon usage. The IE gene region possesses 38 open reading frames (ORFs) greater than 300 bp in length, 11 of which have coding regions of at least 100 amino acids (aa) following potential translation initiator codons. The largest ORF co...
Costa MC, Weese JS.This article provides readers with the basic concepts necessary to understand studies using recent molecular methods performed in intestinal microbiome assessment, with special emphasis on the high throughput sequencing. This review also summarizes the current knowledge on this topic and discusses future insights on the interaction between the intestinal microbiome and equine health.
Lindenberg F, Krych L, Fielden J, Kot W, Frøkiær H, van Galen G, Nielsen DS, Hansen AK.Billions of bacteria inhabit the gastrointestinal tract. Immune-microbial cross talk is responsible for immunological homeostasis, and symbiotic microbial species induce regulatory immunity, which helps to control the inflammation levels. In this study we aimed to identify species within the equine intestinal microbiota with the potential to induce regulatory immunity. These could be future targets for preventing or treating low-grade chronic inflammation occurring as a result of intestinal microbial changes and disruption of the homeostasis. 16S rRNA gene amplicon sequencing was performed on ...
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 ...
Guest DJ, Smith MR, Allen WR.Injury to the superficial digital flexor tendon (SDFT) is common in racing and sport horses and poor tendon regeneration leads to high reinjury rates. Autologous mesenchymal stromal cells (MSCs) are being used clinically to improve tendon regeneration but they have some practical limitations. Embryonic stem cells (ESCs) may overcome these limitations but their fate following injection into the damaged SDFT is unknown. Objective: To inject MSCs and ESCs into distinct areas of damage in the SDFT and monitor their survival over a 3 month period. Methods: MSCs and ESCs expressing different reporte...
Scheel TK, Kapoor A, Nishiuchi E, Brock KV, Yu Y, Andrus L, Gu M, Renshaw RW, Dubovi EJ, McDonough SP, Van de Walle GR, Lipkin WI, Divers TJ....Nonprimate hepacivirus (NPHV) is the closest known relative of hepatitis C virus (HCV) and its study could enrich our understanding of HCV evolution, immunity, and pathogenesis. High seropositivity is found in horses worldwide with ∼ 3% viremic. NPHV natural history and molecular virology remain largely unexplored, however. Here, we show that NPHV, like HCV, can cause persistent infection for over a decade, with high titers and negative strand RNA in the liver. NPHV is a near-universal contaminant of commercial horse sera for cell culture. The complete NPHV 3'-UTR was determined and consists...
Grieder FB, Vogel SN.To investigate the role of type I interferon (IFN) and its regulatory transacting proteins, interferon regulatory factors (IRF-1 and IRF-2), in early protection against infection with virulent Venezuelan equine encephalitis virus (VEE), we utilized mice with targeted mutations in the IFN-alpha/beta receptor, IRF-1, or IRF-2 genes. IFN-alpha/beta-receptor knockout mice are highly susceptible to peripheral infection with virulent or attenuated VEE, resulting in their death within 24 and 48 h, respectively. Treatment of normal macrophages with anti-IFN-alpha/beta antibody prior to and during infe...
Mehdizadeh Gohari I, Parreira VR, Nowell VJ, Nicholson VM, Oliphant K, Prescott JF.A role for type A Clostridium perfringens in acute hemorrhagic and necrotizing gastroenteritis in dogs and in necrotizing enterocolitis of neonatal foals has long been suspected but incompletely characterized. The supernatants of an isolate made from a dog and from a foal that died from these diseases were both found to be highly cytotoxic for an equine ovarian (EO) cell line. Partial genome sequencing of the canine isolate revealed three novel putative toxin genes encoding proteins related to the pore-forming Leukocidin/Hemolysin Superfamily; these were designated netE, netF, and netG. netE a...
Müller N, Welle M, Lobsiger L, Stoffel MH, Boghenbor KK, Hilbe M, Gottstein B, Frey CF, Geyer C, von Bomhard W.The present report describes a novel etiological agent of cutaneous leishmaniasis in horses that, at least for some cases, sporadically appeared as autochthonous infections in geographically distant regions of Germany and Switzerland. The infection was initially diagnosed upon clinical and immunohistological findings. Subsequent comparative sequence analysis of diagnostic PCR products from the internal transcribed spacer 1 (ITS1) of ssrRNA classified the respective isolates as neither Old World nor New World Leishmania species. However, four isolates subjected to molecular analyses all exhibit...
Bossart KN, Wang LF, Eaton BT, Broder CC.Hendra virus (HeV) is an emerging paramyxovirus first isolated from cases of severe respiratory disease that fatally affected both horses and humans. Understanding the mechanisms of host cell infection and cross-species transmission is an important step in addressing the risk posed by such emerging pathogens. We have initiated studies to characterize the biological properties of the HeV envelope glycoproteins. Recombinant vaccinia viruses encoding the HeV F and G open reading frames were generated and glycoprotein expression was verified by metabolic labeling and detection using specific antis...
Pirie RS.Recurrent airway obstruction is a widely recognised airway disorder, characterised by hypersensitivity-mediated neutrophilic airway inflammation and lower airway obstruction in a subpopulation of horses when exposed to suboptimal environments high in airborne organic dust. Over the past decade, numerous studies have further advanced our understanding of different aspects of the disease. These include clarification of the important inhaled airborne agents responsible for disease induction, improving our understanding of the underlying genetic basis of disease susceptibility and unveiling the fu...
Waller BM, Julle-Daniere E, Micheletta J.Darwin observed that form, and in his view, meaning, of facial behaviour (observable changes in the appearance of the face, often termed facial 'expression') is similar between a wide range of species and concluded that this must be due to a shared ancestral origin. Yet, as with all social behaviours, exactly how to define similarity and determine homology is debated. Facial behaviour is linked to specific facial muscle movements, so one important factor in determining homology is the anatomical basis of facial behaviours that appear similar in both appearance and social function. The Facial A...
Lyons S, Kapoor A, Sharp C, Schneider BS, Wolfe ND, Culshaw G, Corcoran B, McGorum BC, Simmonds P.Although the origin of hepatitis C virus infections in humans remains undetermined, a close homolog of this virus, termed canine hepacivirus (CHV) and found in respiratory secretions of dogs, provides evidence for a wider distribution of hepaciviruses in mammals. We determined frequencies of active infection among dogs and other mammals in the United Kingdom. Samples from dogs (46 respiratory, 99 plasma, 45 autopsy samples) were CHV negative by PCR. Screening of 362 samples from cats, horses, donkeys, rodents, and pigs identified 3 (2%) positive samples from 142 horses. These samples were gene...
Lobsiger L, Müller N, Schweizer T, Frey CF, Wiederkehr D, Zumkehr B, Gottstein B.The present case report describes a novel etiological agent of cutaneous leishmaniasis that appears for the first time in a cow. A similar agent had recently been described as causing autochthonous infections in horses of Germany and Switzerland. The infection in the cow was initially diagnosed upon clinical and immunohistological findings. Subsequent comparative sequence analysis of diagnostic PCR products from the internal transcribed spacer 1 (ITS1) of ssrRNA classified the respective isolate as neither Old World nor New World Leishmania species, but yielded complete identity of the analyse...
Shin EK, Perryman LE, Meek K.The equine SCID defect is more severe than its murine counterpart in that SCID foals are incapable of forming either coding or signal joints, whereas SCID mice manifest normal signal joint formation. To determine the basis of this difference and whether DNA-dependent kinase, catalytic subunit (DNA-PK(CS)), is involved in signal joint formation, equine DNA-PK(CS) transcripts were cloned and sequenced from normal and SCID cell lines. In the mutant allele, a frame-shift mutation truncates the protein N terminal of the domain with homology to the phosphatidylinositol 3-kinase family resulting in c...
von Bargen K, Haas A.The soil actinomycete Rhodococcus equi is a pulmonary pathogen of young horses and AIDS patients. As a facultative intracellular bacterium, R. equi survives and multiplies in macrophages and establishes its specific niche inside the host cell. Recent research into chromosomal virulence factors and into the role of virulence plasmids in infection and host tropism has presented novel aspects of R. equi infection biology and pathogenicity. This review will focus on new findings in R. equi biology, the trafficking of R. equi-containing vacuoles inside host cells, factors involved in virulence and ...
Morgan M.Methicillin-resistant Staphylococcus aureus (MRSA) is increasing worldwide. Occasionally, animals are colonized or infected incidentally with human strains. Recently, however, new strains of MRSA emerging from within the animal kingdom, particularly in pigs, are causing human infection. MRSA has been reported in species as diverse as companion animals, horses and pigs, through to chinchillas, bats and parrots. In contrast, whereas strains of community-associated MRSA, the majority of which carry genes encoding Panton-Valentine leucocidin, are spreading rapidly in human populations, only sporad...
Radcliffe CH, Flaminio MJ, Fortier LA.Mesenchymal progenitor cells (MPCs) are often characterized using surface markers after expansion and treatment in culture. There are no studies directly comparing gene and protein markers in undifferentiated samples during the very early phases of culture. The goal of this study was to evaluate temporal gene and protein expression changes during establishment of equine MPC cultures. Bone marrow aspirate was obtained from 35 horses and processed by density gradient centrifugation. In freshly isolated bone marrow, mononuclear cells had variable expression of CD44, CD11a/CD18, CD90, and CD45RB c...
Corbin LJ, Blott SC, Swinburne JE, Vaudin M, Bishop SC, Woolliams JA.Many genomic methodologies rely on the presence and extent of linkage disequilibrium (LD) between markers and genetic variants underlying traits of interest, but the extent of LD in the horse has yet to be comprehensively characterized. In this study, we evaluate the extent and decay of LD in a sample of 817 Thoroughbreds. Horses were genotyped for over 50,000 single nucleotide polymorphism (SNP) markers across the genome, with 34,848 autosomal SNPs used in the final analysis. Linkage disequilibrium, as measured by the squared correlation coefficient (r(2)), was found to be relatively high bet...
Koolhaas JM, Van Reenen CG.This paper will argue that understanding animal welfare and the individual vulnerability to stress-related disease requires a fundamental understanding of functional individual variation as it occurs in nature as well as the underlying neurobiology and neuroendocrinology. Ecological studies in feral populations of mice, fish, and birds start to recognize the functional significance of phenotypes that individually differ in their behavioral and neuroendocrine response to environmental challenge. Recent studies indicate that the individual variation within a species may buffer the species for st...
Brault AC, Powers AM, Chavez CL, Lopez RN, Cachón MF, Gutierrez LF, Kang W, Tesh RB, Shope RE, Weaver SC.Eastern equine encephalitis virus (EEEV), the sole species in the EEE antigenic complex, is divided into North and South American antigenic varieties based on hemagglutination inhibition tests. Here we describe serologic and phylogenetic analyses of representatives of these varieties, spanning the entire temporal and geographic range available. Nucleotide sequencing and phylogenetic analyses revealed additional genetic diversity within the South American variety; 3 major South/Central American lineages were identified including one represented by a single isolate from eastern Brazil, and 2 lin...
Costa MC, Stämpfli HR, Allen-Vercoe E, Weese JS.The intestinal microbiota is a complex polymicrobial ecosystem that exerts extremely important roles in the development and maintenance of health. Recently, as new sequencing technologies have become more available, there has been a revolution in the understanding of the equine intestinal microbiota. However, studies characterising the pioneer intestinal bacteria colonising foals and its development over time are still limited. Objective: The objectives of this study were to characterise the intestinal bacterial colonisation of newborn foals and to follow individual animals over time until age...
Carrade DD, Affolter VK, Outerbridge CA, Watson JL, Galuppo LD, Buerchler S, Kumar V, Walker NJ, Borjesson DL.BACKGROUND AIMS. The use of allogeneic mesenchymal stem cells (MSC) to treat acute equine lesions would greatly expand equine cellular therapy options; however, the safety and antigenicity of these cells have not been well-studied. We hypothesized that equine allogeneic umbilical cord tissue (UCT)-derived MSC would not elicit acute graft rejection or a delayed-type hypersensitivity response when injected intradermally. METHODS. Six Quarterhorse yearlings received 12 intradermal injections (autologous MSC, allogeneic MSC, positive control and negative control, in triplicate) followed by the sam...
Xu S, Luosang J, Hua S, He J, Ciren A, Wang W, Tong X, Liang Y, Wang J, Zheng X.To investigate genetic mechanisms of high altitude adaptations of animals living in the Tibetan Plateau, three mitochondrial genomes (mt-genome) of Tibetan horses living in Naqu (4,500 m) of Tibetan, Zhongdian (3,300 m) and Deqin (3,100 m) of Yunnan province were sequenced. The structures and lengths of these three mt-genomes are similar to the Cheju horse, which is related to Tibetan horses, but little shorter than the Swedish horse. The pair-wise identity of these three horses on nucleotide level is more than 99.3%. When the gene encoding the mitochondrial protein of Tibetan horses was analy...
Kapoor A, Simmonds P, Cullen JM, Scheel TK, Medina JL, Giannitti F, Nishiuchi E, Brock KV, Burbelo PD, Rice CM, Lipkin WI.The recent identification of nonprimate hepaciviruses in dogs and then in horses prompted us to look for pegiviruses (GB virus-like viruses) in these species. Although none were detected in canines, we found widespread natural infection of horses by a novel pegivirus. Unique genomic features and phylogenetic analyses confirmed that the tentatively named equine pegivirus (EPgV) represents a novel species within the Pegivirus genus. We also determined that EPgV causes persistent viremia whereas its clinical significance is undetermined.
Alhassan A, Pumidonming W, Okamura M, Hirata H, Battsetseg B, Fujisaki K, Yokoyama N, Igarashi I.With the aim of developing more simple diagnostic alternatives, a differential single-round and multiplex polymerase chain reaction (PCR) method was designed for the simultaneous detection of Babesia caballi and Babesia equi, by targeting 18S ribosomal RNA genes. The multiplex PCR amplified DNA fragments of 540 and 392 bp from B. caballi and B. equi, respectively, in one reaction. The PCR method evaluated on 39 blood samples collected from domestic horses in Mongolia yielded similar results to those obtained from confirmative PCR methods that had been established earlier. Thus, the single-roun...
Bartsch S, Bauer B, Wiemann A, Clausen PH, Steuber S.Host feeding patterns of engorged sibling species of the Culicoides obsoletus and Culicoides pulicaris groups captured during three nights on two selected farms maintaining either cattle, sheep, horses, and pigs (Seedorf, Brandenburg) or cattle, sheep, moufflons, and red and fallow deer (Paulinenaue, Brandenburg) were determined by polymerase chain reaction amplification using conserved primers and sets of species-specific primers derived from vertebrates mitochondrial cytochrome b. Out of a total of 177 blood meals analysed, 115 (65%) tested positive for a blood meal from vertebrates. 63.5% (...
Julliand V, Grimm P.In the early 1990s, the equine hindgut microbial ecosystem looked like a "black box." Its vital role in hydrolyzing and fermenting fiber, thus providing energy to the host, was recognized. Although there was a critical lack of information on the hindgut microbes, their role in preventing intestinal diseases was suggested. Traditionally, the microbes of the horse hindgut were studied using culture-dependent techniques. More recently, culture-independent methods have been used and provided further insight. This review presents the history and updated knowledge regarding the microbes that live in...
