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.
Tozaki T, Ohnuma A, Kikuchi M, Ishige T, Kakoi H, Hirota KI, Kusano K, Nagata SI.One method of gene doping in horseracing is administering of exogenous genetic materials, known as transgenes. Several polymerase chain reaction (PCR)-based methods have been developed for detecting transgenes with high sensitivity and specificity. However, novel designs for reference materials (RMs) and/or positive template controls (PTCs) are necessary for simultaneous analysis of multiple transgene targets. In this study, we designed and developed a novel RM for simultaneously detecting multiple targets via microfluidic quantitative PCR (MFQPCR). Twelve equine genes were selected as targets...
Cosandey J, Hamza E, Gerber V, Ramseyer A, Leeb T, Jagannathan V, Blaszczyk K, Unger L.MicroRNAs have been proposed as biomarkers for equine sarcoids, the most prevalent equine skin tumors globally. This study served to validate the diagnostic and prognostic potential of whole blood microRNAs identified in a previous study for long-term equine sarcoid diagnosis and outcome prediction. Based on findings of a clinical examination at the age of 3 years and a follow-up following a further 5-12 years, 32 Franches-Montagnes and 45 Swiss Warmblood horses were assigned to four groups: horses with regression (n = 19), progression (n = 9), new occurrences of sarcoid lesions (n = 19) and t...
Lee H, Lee SH, Lee YR, Kim HY, Moon BY, Han JE, Rhee MH, Kwon OD, Kwak D.Enterocytozoon bieneusi is a microsporidian pathogen. Recently, the equestrian population is increasing in Korea. The horse-related zoonotic pathogens, including E. bieneusi, are concerns of public health. A total of 1,200 horse fecal samples were collected from riding centers and breeding farms in Jeju Island and inland areas. Of the fecal samples 15 (1.3%) were PCR positive for E. bieneusi. Interestingly, all positive samples came from Jeju Island. Diarrhea and infection in foals were related. Two genotypes (horse1, horse2) were identified as possible zoonotic groups requiring continuous mon...
Timms M, Steel R.The proteotypic human EPO peptides YLLEAK (T4), SLTTLLR (T11), TITADTFR (T14), and VYSNFLR (T17) are often used to confirm the presence of recombinant human EPO (rhEPO) in equine samples. Each of these peptides contains one or more isomeric leucine or isoleucine amino acids, raising the possibility that a simple leucine/isoleucine substitution could lead to a false identification when compared with a rhEPO reference standard. To examine this possibility variants of these four peptides were analysed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). These studies indicate that confir...
Shanmugasundaram K, Singha H, Saini S, Tripathi BN.Glanders is a highly contagious and fatal infection of equids caused by the bacteria known as Burkholderia mallei. It is one of the notifiable equine diseases and is still present in Asia, South America and Africa. In India, glanders re-emerged in 2006, and thereafter, increasing numbers of cases were reported in different regions of the country. Between 2013 and 2019, 39 B. mallei were isolated from glanders-affected horses (n = 30) and mules (n = 9) from seven states of India such as Uttar Pradesh, Haryana, Delhi, Himachal Pradesh, Gujarat, Maharashtra and Tamil Nadu. In this study, ...
Amat JAR, Patton V, Chauché C, Goldfarb D, Crispell J, Gu Q, Coburn AM, Gonzalez G, Mair D, Tong L, Martinez-Sobrido L, Marshall JF, Marchesi F....The mechanisms and consequences of genome evolution on viral fitness following host shifts are poorly understood. In addition, viral fitness -the ability of an organism to reproduce and survive- is multifactorial and thus difficult to quantify. Influenza A viruses (IAVs) circulate broadly among wild birds and have jumped into and become endemic in multiple mammalian hosts, including humans, pigs, dogs, seals, and horses. H3N8 equine influenza virus (EIV) is an endemic virus of horses that originated in birds and has been circulating uninterruptedly in equine populations since the early 1960s. ...
Górecka-Bruzda A, Jaworska J, Siemieniuch M, Jaworski Z, Stanley CR, Wocławek-Potocka I, Lansade L.Equine reproductive behavior is affected by many factors, some remaining poorly understood. This study tested the hypothesis that a period of captivity during the juvenile period and human-controlled reproduction may potentially be involved in the disruption of the development of incestuous mating avoidance behavior in sanctuary-reintroduced male Konik polski horses. Between 1986 and 2000, cases of incestuous behavior in harem stallions born and reared until weaning in the sanctuary were studied. Eight males lived in the sanctuary's feral herd for the rest of their lives (the non-captive group...
Larison B, Pinho GM, Haghani A, Zoller JA, Li CZ, Finno CJ, Farrell C, Kaelin CB, Barsh GS, Wooding B, Robeck TR, Maddox D, Pellegrini M, Horvath S.Effective conservation and management of threatened wildlife populations require an accurate assessment of age structure to estimate demographic trends and population viability. Epigenetic aging models are promising developments because they estimate individual age with high accuracy, accurately predict age in related species, and do not require invasive sampling or intensive long-term studies. Using blood and biopsy samples from known age plains zebras (Equus quagga), we model epigenetic aging using two approaches: the epigenetic clock (EC) and the epigenetic pacemaker (EPM). The plains zebra...
Zuidema D, Kerns K, Sutovsky P.Artificial insemination of livestock has been a staple technology for producers worldwide for over sixty years. This reproductive technology has allowed for the rapid improvement of livestock genetics, most notably in dairy cattle and pigs. This field has experienced continuous improvements over the last six decades. Though much work has been carried out to improve the efficiency of AI, there are still many areas which continue to experience improvement, including semen analysis procedures, sperm selection techniques, sperm sexing technologies, and semen storage methods. Additionally, the use ...
Carneiro FP, Alonso MA, Redoan MA, Henriques DA, Lima FM, Oliveira RM, Cogliati B, Canisso IF, Fernandes CB.Nocardioform placentitis is a pathologically unique form of placental disease first diagnosed in central Kentucky in the mid-80s. Since then, the occurrence of nocardioform placentitis in the region has varied over the years, from sporadic cases to outbreaks. The disease has been sporadically detected in other countries and has not been confirmed in South America. A 13-year-old multiparous Mangalarga delivered a healthy filly at 340d gestation. The mare passed the fetal membranes 33 minute after foaling. Gross examination of the fetal membranes identified two focal lesions on the chorionic sur...
Vdovina NV, Yuryeva IB.Mezenskaya horse (Mezenka) is Russia's aboriginal breed. It is a domestic selection in the northern territories of Arkhangelsk region. The breed is perfectly adapted to the conditions of the Far North, and has a number of valuable economic and biological qualities. At present, it has a limited gene pool and is bred only in the Mezensky district, where one gene pool-breeding farm is operating and so is a number of basic farms, where selection and breeding activities take place with the breed. Due to a small population of Mezen horses, the challenge of preserving its intra-breed diversity is ver...
Esdaile E, Kallenberg A, Avila F, Bellone RR.Coat color is a trait of economic significance in horses. Variants in seven genes have been documented to cause white patterning in horses. Of the 34 variants that have been identified in KIT proto-oncogene, receptor tyrosine kinase (), 27 have only been reported in a single individual or family and thus not all are routinely offered for genetic testing. Therefore, to enable proper use of marker-assisted selection, determining breed specificity for these alleles is warranted. Screening 19 unregistered all-white Shetland ponies for 16 white patterning markers identified 14 individuals whose phe...
Liu X, Zhang Y, Liu W, Li Y, Pan J, Pu Y, Han J, Orlando L, Ma Y, Jiang L.Chinese ponies are endemic to the mountainous areas of southwestern China and were first reported in the archaeological record at the Royal Tomb of Zhongshan King, Mancheng, dated to approximately ∼2,100 YBP. Previous work has started uncovering the genetic basis of size variation in western ponies and horses, revealing a limited number of loci, including HMGA2,LCORL/NCAPG,ZFAT, and LASP1. Whether the same genetic pathways also drive the small body size of Chinese ponies, which show striking anatomical differences to Shetland ponies, remains unclear. To test this, we combined whole-genome se...
The Journal of heredityDecember 12, 2021
Volume 113, Issue 3 238-247 doi: 10.1093/jhered/esab070
Esdaile E, Avila F, Bellone RR.American Standardbreds were developed as a harness racing horse breed. The United States Trotting Association closed the studbook in 1973 and implemented a book size cap in 2009. This study aimed to investigate genetic diversity in the American Standardbred after the studbook cap was introduced using short tandem repeats (STRs) and single-nucleotide polymorphisms (SNPs). Sixteen STRs from horses foaled from 2010 to 2015 and their sires and dams (n = 50 621) were utilized to examine allelic richness (Ar), expected heterozygosity (HE), observed heterozygosity (HO), unbiased heterozygosity (HU), ...
Murchie TJ, Monteath AJ, Mahony ME, Long GS, Cocker S, Sadoway T, Karpinski E, Zazula G, MacPhee RDE, Froese D, Poinar HN.The temporal and spatial coarseness of megafaunal fossil records complicates attempts to to disentangle the relative impacts of climate change, ecosystem restructuring, and human activities associated with the Late Quaternary extinctions. Advances in the extraction and identification of ancient DNA that was shed into the environment and preserved for millennia in sediment now provides a way to augment discontinuous palaeontological assemblages. Here, we present a 30,000-year sedimentary ancient DNA (sedaDNA) record derived from loessal permafrost silts in the Klondike region of Yukon, Canada. ...
Ochala J, Finno CJ, Valberg SJ.Myosinopathies are defined as a group of muscle disorders characterized by mutations in genes encoding myosin heavy chains. Their exact molecular and cellular mechanisms remain unclear. In the present study, we have focused our attention on a -related E321G amino acid substitution within the head region of the type IIx skeletal myosin heavy chain, associated with clinical signs of atrophy, inflammation and/or profound rhabdomyolysis, known as equine myosin heavy chain myopathy. We performed Mant-ATP chase experiments together with force measurements on isolated IIx myofibres from control horse...
Atsenova N, Palova N, Mehandjyiski I, Neov B, Radoslavov G, Hristov P.The question about the time and the place of horse domestication, a process which had a profound impact on the progress of mankind, is disputable. According to the most widely accepted hypothesis, the earliest domestication of the horse happened in the western parts of the Eurasian steppes, between the Northern Black Sea region and present-day Kazakhstan and Turkmenistan. It seems that it occurred not earlier than the first half and most probably during the middle (even the last third) of the fourth millennium BC (from ∼ 5.5 kya). The next steps of large-scale horse breeding occurred almost ...
Frontiers in geneticsDecember 2, 2021
Volume 12 758366 doi: 10.3389/fgene.2021.758366
Durward-Akhurst SA, Schaefer RJ, Grantham B, Carey WK, Mickelson JR, McCue ME.Genetic variation is a key contributor to health and disease. Understanding the link between an individual's genotype and the corresponding phenotype is a major goal of medical genetics. Whole genome sequencing (WGS) within and across populations enables highly efficient variant discovery and elucidation of the molecular nature of virtually all genetic variation. Here, we report the largest catalog of genetic variation for the horse, a species of importance as a model for human athletic and performance related traits, using WGS of 534 horses. We show the extent of agreement between two commonl...
Fojtík L, Fiala J, Pompach P, Chmelík J, Matoušek V, Beier P, Kukačka Z, Novák P.Covalent labeling of proteins in combination with mass spectrometry has been established as a complementary technique to classical structural methods, such as X-ray, NMR, or cryogenic electron microscopy (Cryo-EM), used for protein structure determination. Although the current covalent labeling techniques enable the protein solvent accessible areas with sufficient spatial resolution to be monitored, there is still high demand for alternative, less complicated, and inexpensive approaches. Here, we introduce a new covalent labeling method based on fast fluoroalkylation of proteins (FFAP). FFAP u...
de Oliveira Bussiman F, Carvalho RSB, E Silva FF, Ventura RV, Ferraz JBS, Mattos EC, Eler JP, Balieiro JCC.Multitrait models can increase the accuracy of breeding value prediction and reduce bias due to selection by using traits measured before and after it has occurred. However, as the number of traits grows, a similar trend is expected for the number of parameters to be estimated, which directly affects the computing power and the amount of data required. The aim of the present study was to apply reduced rank (principal components model-PCM) and factor analytical models (FAM), to estimate (co)variance components for nineteen traits, jointly evaluated in a single analysis in Campolina horses. A to...
Castaneda C, Ruiz AJ, Tibary A, Raudsepp T.We present a detailed molecular cytogenetic analysis of a reciprocal translocation between horse (ECA) chromosomes Y and 13 in a Friesian stallion with complete meiotic arrest and azoospermia. We use dual-color fluorescence in situ hybridization with select ECAY and ECA13 markers and show that the translocation breakpoint in ECAY is in the multicopy region and in ECA13, at the centromere. One resulting derivative chromosome, Y;13p, comprises of ECAY heterochromatin (ETSTY7 array), a small single copy and partial Y multicopy region, and ECA13p. Another derivative chromosome 13q;Y comprises of E...
Ayad A, Almarzook S, Besseboua O, Aissanou S, Piórkowska K, Musiał AD, Stefaniuk-Szmukier M, Ropka-Molik K.Genetic disorders in horses are mostly fatal or usually cause significant economic losses for breeders and owners. Here we studied a total of 177 Arabian, Barb and Arab-Barb horses from the Middle East and North Africa (MENA) using Sanger Sequencing and PCR-ACRS (polymerase chain reaction-artificially created restriction site) approaches to examine the genetic disorders in the studied horse breeds. We identified the genetic variations related to Cerebellar Abiotrophy (CA), Severe Combined Immunodeficiency (SCID) occurrence, and the studied population was free of the mutant allele determined La...
Bugno-Poniewierska M, Kij-Mitka B, Podstawski Z, Długosz B, Lasek O, Mrowiec P, Tischner M.The use of frozen semen lowers the risk of disease transmission, eliminates geographical limitations and supports the implementation of genetic resource protection programs. However, due to the very rare use of frozen semen from Hutsul stallions, their genetic material is not secured in sperm banks, and very little information is available about their semen, including its suitability for cryopreservation, and sperm survival rates after thawing. The aim of this study was to analyse basic parameters such as sperm motility, vitality and morphology in diluted-stored and post-thawed Hutsul semen, u...
Salis AT, Bray SCE, Lee MSY, Heiniger H, Barnett R, Burns JA, Doronichev V, Fedje D, Golovanova L, Harington CR, Hockett B, Kosintsev P, Lai X....The Bering Land Bridge connecting North America and Eurasia was periodically exposed and inundated by oscillating sea levels during the Pleistocene glacial cycles. This land connection allowed the intermittent dispersal of animals, including humans, between Western Beringia (far northeast Asia) and Eastern Beringia (northwest North America), changing the faunal community composition of both continents. The Pleistocene glacial cycles also had profound impacts on temperature, precipitation and vegetation, impacting faunal community structure and demography. While these palaeoenvironmental impact...
Autry JM, Svensson B, Carlson SF, Chen Z, Cornea RL, Thomas DD, Valberg SJ.We have analyzed the enzymatic activity of the sarcoplasmic reticulum (SR) Ca2+-transporting ATPase (SERCA) from the horse gluteal muscle. Horses are bred for peak athletic performance yet exhibit a high incidence of exertional rhabdomyolysis, with elevated levels of cytosolic Ca2+ proposed as a correlative linkage. We recently reported an improved protocol for isolating SR vesicles from horse muscle; these horse SR vesicles contain an abundant level of SERCA and only trace-levels of sarcolipin (SLN), the inhibitory peptide subunit of SERCA in mammalian fast-twitch skeletal muscle. Here, we re...
Rahmani SS, Malekifard F, Tavassoli M.Neospora caninum is an Apicomplexan parasite that can cause enormous economic losses due to abortions in cattle. The present study investigated the role of Neospora spp. infection in equine abortion in Iranian donkeys using molecular and phylogenetic analyses. Twenty-nine-aborted fetuses and 29 blood samples from their dams were collected from six different regions in the West and Northwest of Iran. They were tested for N. caninum by PCR at the Nc5 locus, followed by sequencing of five of the PCR products. The overall molecular prevalence was 34.5% in blood samples and the prevalence by DNA de...
Amado-Fuentes M, Gozalo M, Garcia-Gomez A, Barrios-Fernandez S.People with disabilities due to genetic origin often present high levels of stress: non-pharmacological interventions such as Equine-Assisted Interventions (EAI) may be a useful strategy. The objective of this pilot study was to evaluate stress levels in two participants with 22q11.2 deletion syndrome diagnosis, immediately after carrying out the EAI. A single case experimental design methodology was chosen due to the small sample size. Two participants with 22q11.2 Deletion Syndrome, a rare disease, with different comorbidities were included. The present study considered the EAI as the indepe...
Vercruysse E, Naranjo C, Sauvage A, Vandersmissen M, Grauwels M, Monclin S.To describe the clinical, diagnostic imaging, and histopathological findings of two visually impaired closely related horses and to identify a possible cause. Methods: Two warmblood horses, with a common dam and sire, were presented to the ophthalmology department of Liège for investigation of impaired vision. Information collected included physical and ophthalmic examination findings, results of ocular ultrasound, electroretinogram, magnetic resonance imaging (MRI), and histopathology. Ophthalmic examination, ocular ultrasound and MRI revealed a complete retinal detachment (RD) in the left e...
Lee SK, Park D, Lee I.Equine parvovirus-hepatitis (EqPV-H) causes equine hepatitis. The prevalence of EqPV-H in healthy horses has been reported in the United States, China, Germany, and Austria. The present study determined the prevalence of EqPV-H in the sera of clinically healthy horses in South Korea to identify the potential factors for infection and examine the genetic diversity of EqPV-H DNA sequences through comparison with foreign strains. Serum samples collected from 321 horses were tested for EqPV-H using non-structural protein 1 (NS1)-specific polymerase chain reaction. The associations of EqPV-H infect...
Monthoux C, de Brot S, Jackson M, Bleul U, Walter J.Skin malformations that resembled manifestations of Ehlers-Danlos-Syndrome were described in a variety of domestic animals during the last century as cutis hyperelastica, hyperelastosis cutis, dermatosparaxis, dermal/collagen dysplasia, dermal/cutaneous asthenia or Ehlers-Danlos-like syndrome/s. In 2007, the mutation responsible for Hereditary Equine Regional Dermal Asthenia (HERDA) in Quarter Horses was discovered. Several case reports are available for similar malformations in other breeds than Quarter Horses (Draught Horses, Arabians, and Thoroughbreds) including four case reports for Warmb...
The Journal of heredityOctober 26, 2005
Volume 96, Issue 6 663-669 doi: 10.1093/jhered/esi116
Royo LJ, Alvarez I, Beja-Pereira A, Molina A, Fernández I, Jordana J, Gómez E, Gutiérrez JP, Goyache F.Despite a number of recent studies that have focused on the origin of domestic horses, genetic relationships between major geographical clusters still remain poorly understood. In this study we analyzed a 296 bp mtDNA fragment from the HVI region of 171 horses representing 11 native Iberian, Barb, and Exmoor breeds to assess the maternal phylogeography of Iberian horses. The mtDNA haplogroup with a CCG motif (nucleotide position 15,494 to 15,496) was the most frequent in Iberian and Barb breeds (0.42 and 0.57, respectively), regardless of geographic location or group of breeds. This finding su...
Liu C, Guo W, Lu G, Xiang W, Wang X.A new strain of equine herpesvirus type 8 (EHV-8), Wh, has been isolated from horses in China, and its complete genome has been sequenced and analyzed. The result indicates that the new strain has the same constitution and arrangement of open read frames as EHV-1 and EHV-9. This work is the first announced complete genome sequence of EHV-8.
Dias de Castro LL, Abrahão CLH, Buzatti A, Molento MB, Bastianetto E, Rodrigues DS, Lopes LB, Silva MX, de Freitas MG, Conde MH, Borges FA.The aim of this study was to compare two fecal egg count (FEC) techniques; McMaster (McM) and Mini-FLOTAC (mF), for the detection of cattle and horse gastrointestinal nematode eggs, in different locations. Experiment 1: feces were collected from 16 cattle and FEC was performed individually, using mF with the sensitivity of 5 eggs per gram of feces (EPG) and McM with a sensitivity of 50 EPG at Empresa de Pesquisa Agropecuária de Minas Gerais - EPAMIG and the Laboratory of Parasitic Diseases of the University of Parana - LDP/UFPR. Experiment 2: Fecal samples from 30 horses were analyzed with mF...
Glowatzki-Mullis ML, Muntwyler J, Pfister W, Marti E, Rieder S, Poncet PA, Gaillard C.Genetic characterization helps to assure breed integrity and to assign individuals to defined populations. The objective of this study was to characterize genetic diversity in six horse breeds and to analyse the population structure of the Franches-Montagnes breed, especially with regard to the degree of introgression with Warmblood. A total of 402 alleles from 50 microsatellite loci were used. The average number of alleles per locus was significantly lower in Thoroughbreds and Arabians. Average heterozygosities between breeds ranged from 0.61 to 0.72. The overall average of the coefficient of...
Martens A, De Moor A, Ducatelle R.The purpose of this study was to examine if bovine papilloma virus (BPV) DNA can be detected in superficial swabs or scrapings from equine sarcoids. Samples were obtained from 92 sarcoids and 20 non-sarcoidal control lesions. The polymerase chain reaction technique was used with a first primer set to check whether DNA extraction was successful, and with a second primer set specific for BPV-DNA. DNA isolation was successful in 88% of the swabs and 93% of the scrapings. All control lesions were negative for BPV-DNA.
Carr EA, Théon AP, Madewell BR, Griffey SM, Hitchcock ME.To determine the incidence of bovine papillomavirus (BPV) type 1 or 2 in sarcoids and other samples of cutaneous tissues collected from horses in the western United States. Methods: 55 horses with sarcoids and 12 horses without sarcoids. Methods: Tissue samples (tumor and normal skin from horses with sarcoids and normal skin, papillomas, and nonsarcoid cutaneous neoplasms from horses without sarcoids) were collected. Tissue samples were analyzed for BPV-1 or -2 DNA, using a polymerase chain reaction (PCR) and restriction fragment length polymorphism. The PCR products from 7 sarcoid-affected ho...
Alves Beuttemmüller E, Woodward A, Rash A, Dos Santos Ferraz LE, Fernandes Alfieri A, Alfieri AA, Elton D.An extensive outbreak of equine influenza occurred across multiple countries in South America during 2012. The epidemic was first reported in Chile then spread to Brazil, Uruguay and Argentina, where both vaccinated and unvaccinated animals were affected. In Brazil, infections were widespread within 3months of the first reported cases. Affected horses included animals vaccinated with outdated vaccine antigens, but also with the OIE-recommended Florida clade 1 strain South Africa/4/03. Methods: Equine influenza virus strains from infected horses were isolated in eggs, then a representative stra...
Li F, Leroux C, Craigo JK, Cook SJ, Issel CJ, Montelaro RC.Equine infectious anemia virus (EIAV) is genetically one of the simplest lentiviruses in that the viral genome encodes only three accessory genes, tat, rev, and S2. Although serological analyses demonstrate the expression of the S2 protein in persistently infected horses, the role of this viral gene remains undefined. We recently reported that the S2 gene is not essential for EIAV replication in primary equine macrophages, as EIAV mutants lacking the S2 gene replicate to levels similar to those of the parental virus (F. Li, B. A. Puffer, and R. C. Montelaro, J. Virol. 72:8344-8348, 1998). We n...
Arnold C, Pilla R, Chaffin K, Lidbury J, Steiner J, Suchodolski J.Diarrhea is an adverse effect of antimicrobial therapy in horses. This matched, case-controlled study compared the fecal microbiome and metabolome of horses on antibiotics that developed diarrhea (AAD, = 17) to those that did not develop diarrhea (ABX, = 15) and to a control population not exposed to antibiotics (CON, = 31). Fecal samples were collected from horses that were matched for diet and antimicrobial agent (including dose, route, and duration of therapy). Illumina sequencing of 16S rRNA genes was performed, and QIIME 2.0 was used to generate alpha and beta diversity metrics. Untarg...
Dall'Olio S, Fontanesi L, Nanni Costa L, Tassinari M, Minieri L, Falaschini A.Myostatin (MSTN) is a negative modulator of muscle mass. We characterized the horse (Equus caballus) MSTN gene and identified and analysed single nucleotide polymorphisms (SNPs) in breeds of different morphological types. Sequencing of coding, untranslated, intronic, and regulatory regions of MSTN gene in 12 horses from 10 breeds revealed seven SNPs: two in the promoter, four in intron 1, and one in intron 2. The SNPs of the promoter (GQ183900:g.26T>C and GQ183900:g.156T>C, the latter located within a conserved TATA-box like motif) were screened in 396 horses from 16 breeds. The g.26C an...
Goetting-Minesky MP, Makova KD.In mammals, males undergo a greater number of germline cell divisions compared with females. Thus, the male germline accumulates more DNA replication errors, which result in male mutation bias-a higher mutation rate for males than for females. The phenomenon of male mutation bias has been investigated mostly for rodents and primates, however, it has not been studied in detail for other mammalian orders. Here we sequenced and analyzed five introns of three genes (DBX/DBY, UTX/UTY, and ZFX/ZFY) homologous between X and Y chromosomes in several species of perissodactyls (horses and rhinos) and of...
Stothart MR, Greuel RJ, Gavriliuc S, Henry A, Wilson AJ, McLoughlin PD, Poissant J.Studies of microbiome variation in wildlife often emphasize host physiology and diet as proximate selective pressures acting on host-associated microbiota. In contrast, microbial dispersal and ecological drift are more rarely considered. Using amplicon sequencing, we characterized the bacterial microbiome of adult female (n = 86) Sable Island horses (Nova Scotia, Canada) as part of a detailed individual-based study of this feral population. Using data on sampling date, horse location, age, parental status, and local habitat variables, we contrasted the ability of spatiotemporal, life history...
Damborg P, Marskar P, Baptiste KE, Guardabassi L.The objective of this longitudinal study was to investigate the occurrence and genetic background of faecal Escherichia coli resistant to cefotaxime (CTX) in horses receiving broad-spectrum antimicrobial prophylaxis after admission to a veterinary teaching hospital. The ten horses enrolled in the study were treated with cefquinome either alone (n=4) or in combination with metronidazole (n=3) or other antimicrobial agents (n=3). CTX-resistant coliforms in faeces collected before, during and after treatment were quantified on selective MacConkey agar supplemented with CTX, and a colony isolated ...
Ishida N, Oyunsuren T, Mashima S, Mukoyama H, Saitou N.The noncoding region between tRNAPro and the large conserved sequence block is the most variable region in the mammalian mitochondrial DNA D-loop region. This variable region (ca. 270 bp) of four species of Equus, including Mongolian and Japanese native domestic horses as well as Przewalskii's (or Mongolian) wild horse, were sequenced. These data were compared with our recently published Thoroughbred horse mitochondrial DNA sequences. The evolutionary rate of this region among the four species of Equus was estimated to be 2-4 x 10(-8) per site per year. Phylogenetic trees of Equus species demo...
Bamberg WM, Pape WJ, Beebe JL, Nevin-Woods C, Ray W, Maguire H, Nucci J, Massung RF, Gershman K.Coxiella burnetii is a bacterium located worldwide that can cause Q fever when inhaled. We describe an outbreak of Q fever associated with a horse-boarding ranch that had acquired two herds of goats. We conducted case finding and cohort studies among persons who boarded horses on the ranch and ranchers and among residents in the surrounding community, and conducted sampling of the goats and environment, to determine risk factors for infection and guide public health interventions. Sixty-six ranchers and persons who boarded horses on the ranch were interviewed; 62 (94%) were not professional ra...
Zheng YH, Sentsui H, Nakaya T, Kono Y, Ikuta K.Equine infectious anemia virus (EIAV) is a good model for studying mechanisms generating escaped retrovirus variants. We previously sequenced the entire gp90-encoding region of 22 cDNA clones obtained from five antigenically distinct isolates (F1V to F5V) recovered during febrile episodes in horse 493 experimentally infected with the Japanese virulent EIAV strain V70. The results showed that the mutations occurred in the principal neutralizing domain (PND) by insertions/duplications. In this study, we further characterized the PND of virus isolates sequentially recovered during 22 febrile epis...
Schurink A, Wolc A, Ducro BJ, Frankena K, Garrick DJ, Dekkers JC, van Arendonk JA.Insect bite hypersensitivity is a common allergic disease in horse populations worldwide. Insect bite hypersensitivity is affected by both environmental and genetic factors. However, little is known about genes contributing to the genetic variance associated with insect bite hypersensitivity. Therefore, the aim of our study was to identify and quantify genomic associations with insect bite hypersensitivity in Shetland pony mares and Icelandic horses in the Netherlands. Methods: Data on 200 Shetland pony mares and 146 Icelandic horses were collected according to a matched case-control design. C...
Mach N, Midoux C, Leclercq S, Pennarun S, Le Moyec L, Rué O, Robert C, Sallé G, Barrey E.Emerging evidence indicates that the gut microbiome contributes to endurance exercise performance. Still, the extent of its functional and metabolic potential remains unknown. Using elite endurance horses as a model system for exercise responsiveness, we built an integrated horse gut gene catalog comprising ~25 million unique genes and 372 metagenome-assembled genomes. This catalog represents 4179 genera spanning 95 phyla and functional capacities primed to exploit energy from dietary, microbial, and host resources. The holo-omics approach shows that gut microbiomes enriched in Lachnospiraceae...
Marklund S, Ellegren H, Eriksson S, Sandberg K, Andersson L.Ten (TG)n positive clones, isolated from an equine genomic library and sequenced, contained 12-19 uninterrupted TG repeats. Primers for polymerase chain reaction (PCR) were synthesized and nine of these (TG)n loci (HTG7-15) were successfully amplified and utilized in this study together with five previously reported equine microsatellite loci (HTG2-6). The PCR products were analysed by polyacrylamide gel electrophoresis followed by automated laser fluorescence detection or autoradiography. All microsatellites showed polymorphism and stable Mendelian inheritance. Differences in microsatellite v...
Reuter G, Maza N, Pankovics P, Boros A.Non-primate hepacivirus (NPHV) is a recently identified hepacivirus (family Flaviviridae) in dog and horse; however, the disease associations remain unknown. This study reports the detection of natural NPHV infection in a horse with apparent hepatitis, liver damage and high-level viraemia. NPHV could be hepatotropic and associated with hepatitis in horses.
Marín Navas C, Delgado Bermejo JV, McLean AK, León Jurado JM, Torres ARBYR, Navas González FJ.Genetic diversity and population structure were analyzed using the historical and current pedigree information of the Arabian (PRá), Spanish Purebred (PRE), and Hispano-Arabian (Há) horse breeds. Genetic diversity parameters were computed and a canonical discriminant analysis was used to determine the contributions of ancestor breeds to the genetic diversity of the Há horse. Pedigree records were available for 207,100 animals born between 1884 and 2019. Nei's distances and the equivalent subpopulations number indicated the existence of a highly structured, integrated population for the Há ...
Payne S, Parekh B, Montelaro RC, Issel CJ.The unique periodic nature of equine infectious anaemia (EIA) is believed to result from the ability of the infecting virus. EIAV, to undergo relatively rapid antigenic variations which circumvent host immune responses resulting in distinct virus populations in sequential clinical episodes in the persistently infected horse. This model was examined by oligonucleotide mapping comparisons of the RNA genomes of selected isolates of EIAV. Variations in oligonucleotide maps could be reproducibly demonstrated (i) after adaptation of the laboratory strain of EIAV to replication in a pony, (ii) after ...
Swinburne JE, Boursnell M, Hill G, Pettitt L, Allen T, Chowdhary B, Hasegawa T, Kurosawa M, Leeb T, Mashima S, Mickelson JR, Raudsepp T, Tozaki T....A genetic linkage map of the horse consisting of 742 markers, which comprises a single linkage group for each of the autosomes and the X chromosome, is presented. The map has been generated from two three-generation full-sibling reference families, sired by the same stallion, in which there are 61 individuals in the F2 generation. Each linkage group has been assigned to a chromosome and oriented with reference to markers mapped by fluorescence in situ hybridization. The average interval between markers is 3.7 cM and the linkage groups collectively span 2772 cM. The 742 markers comprise 734 mic...
Gokbulut C, McKellar QA.Internal parasites of horses comprise an intractable problem conferring disease, production and performance losses. Parasitism can rarely be controlled in grazing horses by management alone and anthelmintic drugs have formed the basis of therapy and prophylaxis for the last sixty years. The pharmacology of the anthelmintic drugs available dictate their spectrum of activity and degree of efficacy, their optimal routes of administration and characteristics which prevent some routes of administration, their safety tolerance and potential toxicities and as a consequence of their persistence in the...
Ishida N, Hasegawa T, Takeda K, Sakagami M, Onishi A, Inumaru S, Komatsu M, Mukoyama H.The D-loop regions in equine mitochondrial DNA were cloned from three thoroughbred horses by polymerase chain reaction (PCR). The total number of bases in the D-loop region were 1114 bp, 1115 bp and 1146 bp. The equine D-loop region is A/T rich like many other mammalian D-loops. The large central conserved sequence block and small conserved sequence blocks 1, 2 and 3, that are common to other mammals, were observed. Between conserved sequence blocks 1 and 2 there were tandem repeats of an 8 bp equine-specific sequence TGTGCACC, and the number of tandem repeats differed among individual horses....
Bellone RR, Liu J, Petersen JL, Mack M, Singer-Berk M, Drögemüller C, Malvick J, Wallner B, Brem G, Penedo MC, Lassaline M.Squamous cell carcinoma (SCC) is the most common cancer of the equine eye, frequently originating at the limbus, with the potential to invade the cornea, cause visual impairment, and result in loss of the eye. Several breeds of horses have a high occurrence of limbal SCC implicating a genetic basis for limbal SCC predisposition. Pedigree analysis in the Haflinger breed supports a simple recessive mode of inheritance and a genome-wide association study (N = 23) identified a 1.5 Mb locus on ECA12 significantly associated with limbal SCC (Pcorrected = 0.04). Sequencing the most physiologicall...
