DNA in horses refers to the genetic material that carries the hereditary information necessary for the growth, development, functioning, and reproduction of equine species. It consists of sequences of nucleotides that encode the genetic instructions used in the development and functioning of horses. DNA analysis in horses can provide insights into genetic diversity, lineage, and breed characteristics. It is also utilized in identifying genetic disorders, understanding hereditary traits, and assisting in selective breeding programs. This page compiles peer-reviewed research studies and scholarly articles that explore the structure, function, and applications of DNA analysis in equine genetics and breeding.
Klumplerova M, Splichalova P, Oppelt J, Futas J, Kohutova A, Musilova P, Kubickova S, Vodicka R, Orlando L, Horin P.The mammalian Major Histocompatibility Complex (MHC) is a genetic region containing highly polymorphic genes with immunological functions. MHC class I and class II genes encode antigen-presenting molecules expressed on the cell surface. The MHC class II sub-region contains genes expressed in antigen presenting cells. The antigen binding site is encoded by the second exon of genes encoding antigen presenting molecules. The exon 2 sequences of these MHC genes have evolved under the selective pressure of pathogens. Interspecific differences can be observed in the class II sub-region. The family E...
Moro LN, Viale DL, Bastón JI, Arnold V, Suvá M, Wiedenmann E, Olguín M, Miriuka S, Vichera G.The application of new technologies for gene editing in horses may allow the generation of improved sportive individuals. Here, we aimed to knock out the myostatin gene (MSTN), a negative regulator of muscle mass development, using CRISPR/Cas9 and to generate edited embryos for the first time in horses. We nucleofected horse fetal fibroblasts with 1, 2 or 5 µg of 2 different gRNA/Cas9 plasmids targeting the first exon of MSTN. We observed that increasing plasmid concentrations improved mutation efficiency. The average efficiency was 63.6% for gRNA1 (14/22 edited clonal cell lines) and 96.2% ...
Orlando L.The domestication of the horse some 5,500 years ago followed those of dogs, sheep, goats, cattle, and pigs by ∼2,500-10,000 years. By providing fast transportation and transforming warfare, the horse had an impact on human history with no equivalent in the animal kingdom. Even though the equine sport industry has considerable economic value today, the evolutionary history underlying the emergence of the modern domestic horse remains contentious. In the last decade, novel sequencing technologies have revolutionized our capacity to sequence the complete genome of organisms, including from arch...
Bizarria Dos Santos W, Pimenta Schettini G, Fonseca MG, Pereira GL, Loyola Chardulo LA, Rodrigues Machado Neto O, Baldassini WA, Nunes de Oliveira H....With the availability of high-density SNP panels and the establishment of approaches for characterizing homozygosity and heterozygosity sites, it is possible to access fine-scale information regarding genomes, providing more than just comparisons of different inbreeding coefficients. This is the first study that seeks to access such information for the Mangalarga Marchador (MM) horse breed on a genomic scale. To this end, we aimed to assess inbreeding levels using different coefficients, as well as to characterize homozygous and heterozygous runs in the population. Using Axiom ® Equine Genoty...
Liu C, Lei H, Ran X, Wang J.The Guizhou pony (GZP) is an indigenous species of equid found in the mountains of the Guizhou province in southwest China. We selected four regions of the equine leukocyte antigen (ELA), including , , and and used them to assess the diversity of the major histocompatibility complex (MHC) class II gene using direct sequencing technology. had the lowest / ratio (0.560) compared with the other three loci, indicating that was conserved and could be conserved after undergoing selective processes. Nine , five , nine and seven codons were under significant positive selection at the antigen b...
Guimaraes S, Arbuckle BS, Peters J, Adcock SE, Buitenhuis H, Chazin H, Manaseryan N, Uerpmann HP, Grange T, Geigl EM.Despite the important roles that horses have played in human history, particularly in the spread of languages and cultures, and correspondingly intensive research on this topic, the origin of domestic horses remains elusive. Several domestication centers have been hypothesized, but most of these have been invalidated through recent paleogenetic studies. Anatolia is a region with an extended history of horse exploitation that has been considered a candidate for the origins of domestic horses but has never been subject to detailed investigation. Our paleogenetic study of pre- and protohistoric h...
Díaz-Sánchez AA, Chilton NB, Roblejo-Arias L, Fonseca-Rodríguez O, Marrero-Perera R, Diyes CP, Yunik MEM, Lobo-Rivero E, Corona-González B.Spotted fever group (SFG) rickettsiae are obligatory intracellular bacteria that cause disease in humans and other animals. Ixodid ticks are the principal vectors of SFG rickettsiae. The present study aimed to determine the prevalence and species identity of SFG rickettsiae in ticks and horses from urban and rural areas of western Cuba using PCR assays. Tick samples, collected from 79 horses, consisted of 14 Amblyomma mixtum adults, 111 Dermacentor nitens adults and 19 pools of D. nitens nymphs (2-5 individuals/pool). The PCR results revealed the presence of Rickettsia spp. in 64% of the A. mi...
Morandi L, Sabattini S, Renzi A, Rigillo A, Bettini G, Dervas E, Schauer A, Morandi M, Gissi DB, Tarsitano A, Evangelisti S, Tonon C.Ultra-conserved non-coding elements (UCNEs) are genomic sequences that exhibit > 95% sequence identity between humans, mammals, birds, reptiles, and fish. Recent findings reported their functional role in cancer. The aim of this study was to evaluate the DNA methylation modifications of UNCEs in squamous cell carcinoma (SCC) from different mammal species. Fifty SCCs from 26 humans, 17 cats, 3 dogs, 1 horse, 1 bovine, 1 badger, and 1 porcupine were investigated. Fourteen feline stomatitis and normal samples from 36 healthy human donors, 7 cats, 5 dogs, 5 horses, 2 bovines and 1 badger were c...
Giessler KS, Samoilowa S, Soboll Hussey G, Kiupel M, Matiasek K, Sledge DG, Liesche F, Schlegel J, Fux R, Goehring LS.Upper respiratory tract infections with Equid Herpesvirus 1 (EHV-1) typically result in a peripheral blood mononuclear cell-associated viremia, which can lead to vasculopathy in the central nervous system. Primary EHV-1 infection also likely establishes latency in trigeminal ganglia (TG) via retrograde axonal transport and in respiratory tract-associated lymphatic tissue. However, latency establishment and reactivation are poorly understood. To characterize the pathogenesis of EHV-1 latency establishment and maintenance, two separate groups of yearling horses were experimentally infected intra...
Martinez MM, Costa M, Ratti C.Male-to-female sex reversal in horses is a developmental disorder in which phenotypic females have a male genetic constitution. Male-to-female sex reversal is the second most common genetic sex abnormality, after X chromosome monosomy. All male-to-female sex reversal cases studied to date have been found to be infertile. Therefore, a screening test is particularly useful in laboratories doing DNA genotyping in horses. Our laboratory has tested > 209,000 horses for parentage using a panel of microsatellite markers and the sex marker gene amelogenin (). Suspect XY sex reversal cases are rep...
Bahrami A, Divar MR, Azari M, Kafi M.In the present study, we aimed to evaluate the possible protective effects of the nicotinic acid (NA) at three concentrations (10, 20, and 40 mM) on the equine cooled and frozen-thawed spermatozoa quality markers including viability, plasma membrane or acrosome integrity, DNA fragmentation, lipid peroxidation, and total oxidant levels. We also evaluated the effects of NA on preservation of the post-thaw sperm quality after 6 hours of cold storage before freezing. Five stallions were used for semen collections. The current experiment was repeated six times using pooled semen samples from two ...
Dominguez EM, Moreno-Irusta A, Rodriguez MB, Salamone DF, de Arruda RP, Losinno L, Giojalas LC.The successful use of assisted reproduction techniques (ART) depends in part on the sperm physiological status. Several sperm selection procedures have been applied to improve quality of sperm population when using the ART. There has previously been development of a Sperm Selection Assay (SSA) for humans which is based on the attraction of capacitated sperm by chemotaxis towards progesterone (P), resulting in an enriched sperm population with an optimal physiological status similar to capacitated spermatozoa, with these cells having very little DNA fragmentation and optimal concentrations of r...
Greenwood S, Chow-Lockerbie B, Epp T, Knight C, Wachoski-Dark G, MacDonald-Dickinson V, Wobeser B.Equus caballus papillomavirus type-2 (EcPV-2) has been proposed as a causal factor in equine genital squamous cell carcinoma (SCC). This study had 2 objectives: first, calculate the frequency of papillomavirus (PV) and EcPV-2 infection in papillomas, carcinomas in situ (CIS), and SCCs in Western Canadian horses; and second, determine if EcPV-2 status of equine SCCs is associated with overall survival (OS). EcPV-2 status of 115 archived tissue samples, spanning 6 years, was determined using broad spectrum (MY09/11) and EcPV-2-specific polymerase chain reaction (PCR) assays, EcPV-2-E6/E7 chromog...
Jaworska J, Tobolski D, Janowski T.The failure of the maternal immune system to recognize fetal antigens and vice versa due to MHC similarity between the foal and its dam might result in the lack of placental separation during parturition in mares. The aim of the study was to investigate the influence of MHC similarity between a mare and a foal on the incidence of retained fetal membranes (RFM) in post-partum mares. DNA was sampled from 43 draft mares and their foals. Mares which failed to expel fetal membranes within three hours after foal expulsion were considered the RFM group (n = 14) and mares that expelled fetal membranes...
Nolte LC, Rosiak M, Baechlein C, Baumgärtner W, Allnoch L.Idiopathic systemic granulomatous disease (ISGD), also known as equine sarcoidosis is an uncommon disease of horses, manifesting in exfoliative dermatitis and granulomatous inflammation in various organs. The current report presents a case of a 15-year-old Hanoverian mare with a 4-month history of weight loss, recurrent fever, skin lesions, and movement disorders. Pathological examination revealed granulomatous and necrotizing inflammation in the skin, regional lymph nodes, and cerebellum. Based on histological, immunohistochemical, and microbiological findings, the diagnosis of ISGD was made....
El-Sayed SAE, AbouLaila M, ElKhatam A, Abdel-Wahab A, Rizk MA.In the present study, we conducted an epidemiological survey of Theileria equi, with sequencing analysis of the PCR product using blood-DNA samples collected from donkeys (n = 149) reared in different Egyptian provinces in Lower Egypt (Menoufia and Mersa Matruh) and middle Egypt (Giza). All animals were tested for the presence of T. equi parasite using species-specific PCR assay targeting the Equi merozoite antigen-1 (EMA-1). Nine- (6.04%) samples were positive for T. equi. The highest positive rate for infection was detected in Giza zoological garden (10.16%). Egyptian EMA-1 gene sequence e...
Chandra Paul R, Ba Nguyen T, Okuda Y, Nu Anh Le T, Mosese Dau Tabuyaqona J, Konishi Y, Kawamoto Y, Nozawa K, Kunieda T.There are currently eight native horse populations in Japan, namely, Hokkaido, Kiso, Noma, Taishu, Misaki, Tokara, Miyako, and Yonaguni horses. Since locomotion traits, including gaitedness, are important for riding and packing horses, the genetic properties associated with these traits could be informative for understanding the characteristics and history of these horses. In this study, we investigated the distribution of the mutant allele of DMRT3 gene (DMRT3:p.Ser301Ter) associated with ambling gaits in the Japanese native horse. We also examined haplotypes of SNPs in the 83-kb region inclu...
Shilton CA, Kahler A, Davis BW, Crabtree JR, Crowhurst J, McGladdery AJ, Wathes DC, Raudsepp T, de Mestre AM.The first 8 weeks of pregnancy is a critical time, with the majority of pregnancy losses occurring during this period. Abnormal chromosome number (aneuploidy) is a common finding in human miscarriage, yet is rarely reported in domestic animals. Equine early pregnancy loss (EPL) has no diagnosis in over 80% of cases. The aim of this study was to characterise aneuploidies associated with equine EPL. Genomic DNA from clinical cases of spontaneous miscarriage (EPLs; 14-65 days of gestation) and healthy control placentae (various gestational ages) were assessed using a high density genotyping arr...
Tozaki T, Ohnuma A, Takasu M, Nakamura K, Kikuchi M, Ishige T, Kakoi H, Hirora KI, Tamura N, Kusano K, Nagata SI.Gene doping has raised concerns in human and equestrian sports and the horseracing industry. There are two possible types of gene doping in the sports and racing industry: (1) administration of a gene-doping substance to postnatal animals and (2) generation of genetically engineered animals by modifying eggs. In this study, we aimed to identify genetically engineered animals by whole-genome resequencing (WGR) for gene-doping control. Transgenic cell lines, in which the erythropoietin gene (EPO) cDNA form was inserted into the genome of horse fibroblasts, were constructed as a model of genetica...
Mousa WM, Abdel-Wahab AM, El-Gameel Sohila M, Mahdy OA.Cystic echinococcosis is an important cosmopolitan parasitic zoonosis that causes public health and economic problems in Egypt. The present study was undertaken to identify genotypes of hydatid cyst (HC) DNA isolated from different animal isolates and to identify the genotype of secondary hydatid cysts (HCs) developed in rabbits experimentally infected with camel HC for detection of any genetic mutation. In the present study, we extracted DNA from the germinal layers of 8 HCs collected from 3 camels, 1 cattle, 1 sheep and 3 donkeys in addition to 3 secondary HCs collected from rabbits experime...
Todd ET, Thomson PC, Hamilton NA, Ang RA, Lindgren G, Viklund Å, Eriksson S, Mikko S, Strand E, Velie BD.Domestic animal populations are often characterised by high rates of inbreeding and low effective population sizes due to selective breeding practices. These practices can result in otherwise rare recessive deleterious alleles drifting to high frequencies, resulting in reduced fertility rates. This study aimed to identify potential recessive lethal haplotypes in the Thoroughbred horse breed, a closed population that has been selectively bred for racing performance. In this study, we identified a haplotype in the LY49B gene that shows strong evidence of being homozygous lethal, despite having h...
Semik-Gurgul E.Sarcoids are the most commonly diagnosed skin tumours in equines. Bovine papillomaviruses (BPVs) are the primary causative agent of sarcoids. There has been intensive research to discover the molecular mechanisms that may contribute to the aetiopathogenesis of this disease and tumour suppressors and proto-oncogenes known to play a role in human neoplastic conditions have been investigated in equine sarcoids. Current approaches include the identification of gene expression profiles, characterising sarcoid and normal skin tissues, and an assessment of epigenetic alterations such as microRNA diff...
Al-Kass Z, Guo Y, Vinnere Pettersson O, Niazi A, Morrell JM.Bacteria colonize stallion semen during collection and processing which may cause disease in inseminated females or negatively affect sperm quality during storage prior to insemination. Antibiotics are added to semen extenders to control the growth of these bacteria but may induce antimicrobial resistance. Research into alternatives to antibiotics for this purpose requires knowledge of which bacteria are present in semen. Not all bacteria in semen, however, can be identified by conventional microbiological techniques. The objectives of the study were to: i) determine which bacteria are present...
Schmitt S, Stephan R, Huebschke E, Schaefle D, Merz A, Johler S.Methicillin-resistant Staphylococcus aureus (MRSA) is a leading cause of severe infections in humans and animals worldwide. Studies elucidating the population structure, staphylococcal cassette chromosome mec types, resistance phenotypes, and virulence gene profiles of animal-associated MRSA are needed to understand spread and transmission. Objective: The objective of this study was to determine 1) clonal complexes and spa types, 2) resistance phenotypes, and 3) virulence/resistance gene profiles of MRSA isolated from animals in Switzerland. Methods: We analyzed 31 presumptive MRSA isolates co...
Aimaletdinov A, Mindubaeva G, Khalikova S, Kabwe E, Salmakova A, Alexandrova N, Rutland C, Rizvanov A, Zakirova E.Tendon injuries are one of the most common causes of orthopedic disorders in horses. Such injuries involve a long course of treatment and recovery. The most promising method of treating these injuries is the use of recombinant proteins and gene therapy. In this work, we evaluated the therapeutic efficacy of plasmid DNA (pDNA) containing two species-specific coding sequences, i.e. vascular endothelial growth factor 164 (VEGF164) and fibroblast growth factor 2 (FGF2), in the treatment of severe damage to the tendon of the superficial digital flexor. A pDNA construct was used to restore the damag...
Peters-Kennedy J, Lange CE, Ortved K.Aural plaques are associated with and thought to be caused by one or more Equus caballus papillomaviruses (EcPV). Aural plaques have not previously been reported to be associated with squamous cell carcinoma (SCC). Objective: To describe a horse with aural plaques and squamous cell carcinoma (SCC) on the right pinna. Methods: A 28-year-old thoroughbred gelding presented for multiple plaques and a mass on the right pinna. Methods: Pinnal resection, histopathological investigation, multiple conventional PCRs for papillomavirus DNA and Sanger sequencing were performed. Results: Multiple, raised, ...
Veronesi F, Di Palma S, Gabrielli S, Morganti G, Milardi GL, Middleton B, Lepri E.The only species currently known to inhabit the fibers of skeletal and cardiac muscles in horses are , and . We describe herein the invasion of myofibers in a horse by , a sheep-specific species with low virulence in the original host. A hunter gelding was referred to a veterinary surgeon in Newmarket (UK). The anamnestic data reported that the horse had an initial history of swelling of the right forelimb with fluid on the front of the carpus and edema spreading up the forearm. Subsequently, 2 firm lumps were found on the left pectoral muscle adjacent to the axilla of the left forelimb. Hist...
Curi RA, Pereira GL, Alvarez MVN, Baldassini WA, Machado Neto OR, Chardulo LAL.The main objectives of this study were to identify and functionally classify SNPs and indels by exome sequencing of animals of the racing line of Quarter Horses. Based on the individual genomic estimated breeding values (GEBVs) for maximum speed index (SImax) obtained for 349 animals, two groups of 20 extreme animals were formed. Of these individuals, 20 animals with high GEBVs for SImax and 19 with low GEBVs for SImax had their exons and 5' and 3' UTRs sequenced. Considering SNPs and indels, 105 182 variants were identified in the expressed regions of the Quarter Horse genome. Of these, 72 ...
Brooks SA, Palermo KM, Kahn A, Hein J.The American Paint Horse Association (APHA) records pedigree and performance information for their breed, a stock-type horse valued as a working farm or ranch horse and as a pleasure horse. As the name implies, the breed is also valued for its attractive white-spotting patterns on the coat. The APHA utilizes visual inspections of photographs to determine if coat spotting exceeds threshold anatomical landmarks considered characteristic of desirable patterns. Horses with sufficient white patterning enter the 'Regular' registry, rather than the 'Solid Paint-Bred' division, providing a threshold m...
Asadollahpour Nanaei H, Esmailizadeh A, Ayatollahi Mehrgardi A, Han J, Wu DD, Li Y, Zhang YP.Body size is considered as one of the most fundamental properties of an organism. Due to intensive breeding and artificial selection throughout the domestication history, horses exhibit striking variations for heights at withers and body sizes. Debao pony (DBP), a famous Chinese horse, is known for its small body size and lives in Guangxi mountains of southern China. In this study, we employed comparative population genomics to study the genetic basis underlying the small body size of DBP breed based on the whole genome sequencing data. To detect genomic signatures of positive selection, we ap...
Trapp S, von Einem J, Hofmann H, Köstler J, Wild J, Wagner R, Beer M, Osterrieder N.Key problems using viral vectors for vaccination and gene therapy are antivector immunity, low transduction efficiencies, acute toxicity, and limited capacity to package foreign genetic information. It could be demonstrated that animal and human cells were efficiently transduced with equine herpesvirus 1 (EHV-1) reconstituted from viral DNA maintained and manipulated in Escherichia coli. Between 13 and 23% of primary human CD3+, CD4+, CD8+, CD11b+, and CD19+ cells and more than 70% of CD4+ MT4 cells or various human tumor cell lines (MeWo, Huh7, HeLa, 293T, or H1299) could be transduced with o...
Bond SL, Workentine M, Hundt J, Gilkerson JR, Léguillette R.Prolonged exposure to environmental antigens or allergens elicits an immune response in both healthy horses and those with mild asthma. Corticosteroids often are used to treat lower airway inflammation. Objective: To investigate the changes in equine herpesvirus (EHV)-1,2,4,5 glycoprotein B gene expression and changes in respiratory bacterial and fungal communities after nebulized dexamethasone treatment of horses with asthma. Methods: Horses with naturally occurring mild asthma (n = 16) and healthy control horses (n = 4). Methods: Prospective, randomized, controlled, blinded clinical trial. P...
Silveira I, Martins TF, Olegário MM, Peterka C, Guedes E, Ferreira F, Labruna MB.A previous study in Paulicéia Municipality, south-eastern Brazil, reported 9.7% of the Amblyomma triste ticks to be infected by Rickettsia parkeri, a bacterial pathogen that causes spotted fever in humans. These A. triste ticks were shown to be associated with marsh areas, where the marsh deer Blastocerus dichotomus is a primary host for this tick species. During 2008-2009, blood serum samples were collected from 140 horses, 41 dogs, 5 opossums (Didelphis albiventris) and 26 humans in farms from Pauliceia Municipality. Ticks were collected from these animals, from vegetation and from addition...
Bogaert L, Martens A, De Baere C, Gasthuys F.The purpose of the present study was to examine whether bovine papillomavirus (BPV) DNA can be detected on the normal skin and in the habitual surroundings of horses with and without equine sarcoids by means of superficially taken swabs. In affected horses, no significant difference in presence of BPV-DNA could be observed between samples obtained from the equine sarcoid surface, from normal skin close to the tumour and from a normal skin site in direct contact with the tumour. From the group of healthy horses living in contact with affected horses, 44% were BPV-DNA positive. The surroundings ...
Tyma JF, Epstein KL, Whitfield-Cargile CM, Cohen ND, Giguère S.OBJECTIVE To determine the effects of oral omeprazole administration on the fecal and gastric microbiota of healthy adult horses. ANIMALS 12 healthy adult research horses. PROCEDURES Horses were randomly assigned to receive omeprazole paste (4 mg/kg, PO, q 24 h) or a sham (control) treatment (tap water [20 mL, PO, q 24 h]) for 28 days. Fecal and gastric fluid samples were collected prior to the first treatment (day 0), and on days 7, 28, 35, and 56. Sample DNA was extracted, and bacterial 16S rRNA gene sequences were amplified and sequenced to characterize α and β diversity and differential ...
Ramsauer AS, Wachoski-Dark GL, Fraefel C, Tobler K, Brandt S, Knight CG, Favrot C, Grest P.There is growing evidence that equine papillomavirus type 2 (EcPV2) infection is causally associated with the development of equine genital squamous cell carcinomas (SCCs). Early stages of disease present clinically as plaques or wart-like lesions which can gradually progress to tumoural lesions. Histologically these lesions are inconsistently described as benign hyperplasia, papilloma, penile intraepithelial neoplasia (PIN), carcinoma in situ (CIS) or SCC. Guidelines for histological classification of early SCC precursor lesions are not precisely defined, leading to potential misdiagnosis. Th...
Abe N, Matsubara K.The Cryptosporidium horse genotype, a zoonotic protozoan parasite first found in a Prezewalski wild horse, has not been found in any other mammal but calves, horses, and humans. Hedgehogs, popular exotic pet animals in Japan, are a reservoir of two zoonotic Cryptosporidum: C. parvum and C. erinacei (previously known as the hedgehog genotype). Recently, after finding Cryptosporidium infection in a four-toed hedgehog (Atelerix albiventris), we identified the isolate genetically as the Cryptosporidium horse genotype. Its subtype (VIbA13) was the same as that of an isolate from a pet shop employee...
Ansari HA, Hediger R, Fries R, Stranzinger G.The first gene assignment to a horse chromosome is reported for equine leucocyte antigen (ELA), the major histocompatibility complex of the horse. A cloned DNA sequence derived from a class I gene of the porcine major histocompatibility complex was used as a probe for an in situ hybridization experiment. We present the regional localization of ELA, using this sequence, to equine chromosome 20q14-q22.
Duan H, Gao JF, Hou MR, Zhang Y, Liu ZX, Gao DZ, Guo DH, Yue DM, Su X, Fu X, Wang CR.The complete mitochondrial (mt) genome sequence of Triodontophorus brevicauda, an intestinal equine nematode parasite was determined for the first time. The circular T. brevicauda mt genome is 14,305 bp in length and contains 36 genes, of which 12 code for protein, 22 for transfer RNA, and two for ribosomal RNA, and lacks atp8 mtDNA gene. Phylogenetic analysis based on the concatenated amino acid sequence of the 12 protein-coding genes was performed using three different tree-building methods. The Strongyloidea cluster divides into two large branches, and each nematode family included in our s...
Higuchi RG, Wrischnik LA, Oakes E, George M, Tong B, Wilson AC.Sequences are reported for portions of two mitochondrial genes from a domestic horse and a plains zebra and compared to those published for a quagga and a mountain zebra. The extinct quagga and plains zebra sequences are identical at all silent sites, whereas the horse sequence differs from both of them by 11 silent substitutions. Postmortem changes in quagga DNA may account for the two coding substitutions between the quagga and plains zebra sequences. The hypothesis that the closest relative of the quagga is the domestic horse receives no support from these data. From the extent of sequence ...
Terry RB, Archer S, Brooks S, Bernoco D, Bailey E.A single autosomal dominant locus, leopard complex (LP) controls the presence of appaloosa pigmentation patterns in the horse. The causative gene for LP is unknown. This study was undertaken to map LP in the horse. Two paternal half sib families segregating for the LP locus and including a total of 47 offspring were used to perform a genome scan which localized LP to horse chromosome 1 (ECA1). LP was linked to ASB08 (LOD = 9.99 at Theta = 0.02) and AHT21 (LOD = 5.03 at Theta = 0.14). To refine the map position of LP, eight microsatellite markers on ECA1 (UM041, LEX77, 1CA41, TKY374, COR046, 1C...
Rolão N, Martins MJ, João A, Campino L.The present report describes the first case of equine leishmaniasis in Portugal. Leishmania infection was detected in one animal, which presented an ulcerated skin lesion. Diagnosis was based on serology by CIE, and parasite DNA detection by real-time PCR using a probe specific for L. infantum. This finding requests further leishmaniasis equine surveys in order to clarify the role of the horse as reservoir host in european endemic areas.
Swinburne J, Gerstenberg C, Breen M, Aldridge V, Lockhart L, Marti E, Antczak D, Eggleston-Stott M, Bailey E, Mickelson J, Røed K, Lindgren G....Two 3-generation full-sibling reference families have been produced and form a unique resource for genetic linkage mapping studies in the horse. The F(2) generations, now comprising 61 individuals, consist of 28- to 32-day-old embryos removed nonsurgically from two pairs of identical twin mares. The same stallion sired all F(2)s such that the two full-sibling families are half-sibling with respect to each other. The families are crossbred to maximize levels of heterozygosity and include Arabian, Thoroughbred, Welsh Cob, and Icelandic Horse breeds. Milligram quantities of DNA have been isolated...
Gao Y, Zhang Y, Yang X, Qiu JH, Duan H, Xu WW, Chang QC, Wang CR.Equine strongyles, the significant nematode pathogens of horses, are characterized by high quantities and species abundance, but classification of this group of parasitic nematodes is debated. Mitochondrial (mt) genome DNA data are often used to address classification controversies. Thus, the objectives of this study were to determine the complete mt genomes of three Cyathostominae nematode species (, and ) of horses and reconstruct the phylogenetic relationship of Strongylidae with other nematodes in Strongyloidea to test the hypothesis that spp. belong to Cyathostominae using the mt genomes...
Chung C, Leib SR, Fraser DG, Ellis SA, McGuire TC.Improved typing of horse classical MHC class I is required to more accurately define these molecules and to extend the number identified further than current serological assays. Defining classical MHC class I alleleic polymorphism is important in evaluating cytotoxic T lymphocyte (CTL) responses in horses. In this study, horse classical MHC class I genes were analyzed based on reverse transcription (RT)-PCR amplification of sequences encoding the polymorphic peptide binding region and the more conserved alpha 3, transmembrane and cytoplasmic regions followed by cloning and sequencing. Primer s...
Pusterla N, Chae JS, Kimsey RB, Berger Pusterla J, DeRock E, Dumler JS, Madigan JE.Most human granulocytic ehrlichiosis (HGE) studies carried out in horses use needle inoculation of infected leucocytes or cell cultures. This route of inoculation does not accurately reflect natural infection of the tick-borne agent. To investigate whether tick transmission influences the course of granulocytic ehrlichiosis in the horse model, experimental transmission through infected laboratory-reared Ixodes scapularis ticks was attempted into two healthy horses. One additional horse served as negative control and was exposed to uninfected ticks. Eleven days after exposure to nymphal or adul...
Studdert MJ.DNA was prepared from 43 equine herpesvirus type 1 (EHV 1) isolates, 11 of which were from horses with respiratory disease, 22 from aborted equine foetuses, and 10 from foals that died perinatally. The restriction endonuclease DNA fingerprints of 10 of the 11 respiratory isolates, known with certainty to have been recovered from horses with respiratory disease, were entirely different from all but 3 of the 32 foetal or perinatal foal isolates. The exceptional respiratory isolate, EHV 1 Army 183, had a foetal (F) strain fingerprint but this virus cannot be said with certainty to have been isola...
Baumber J, Ball BA, Linfor JJ.To evaluate the effect of the addition of enzyme scavengers and antioxidants to the cryopreservation extender on characteristics of equine spermatozoa after freezing and thawing. Methods: 2 ejaculates collected from each of 5 stallions. Methods: Equine spermatozoa were cryopreserved in freezing extender alone (control samples) or with the addition of catalase (200 U/mL), superoxide dismutase (200 U/mL), reduced glutathione (10 mM), ascorbic acid (10 mM), alpha-tocopherol (25, 50, 100, or 500 microM or 1 mM), or the vehicle for alpha-tocopherol (0.5% ethanol). After thawing, spermatozoal motili...
Bailey E, Petersen JL, Kalbfleisch TS.Thoroughbred horses have been selected for racing performance for more than 400 years. Despite continued selection, race times have not improved significantly during the past 60 years, raising the question of whether genetic variation for racing performance still exists. Studies using phenotypes such as race time, money earned, and handicapping, however, demonstrate that there is extensive variation within these traits and that they are heritable. Even so, these are poor measures of racing success since Thoroughbreds race at different ages and distances and on different types of tracks, and so...
Baumann RP, Staczek J, O'Callaghan DJ.Equine herpesvirus type one (EHV-1) defective interfering (DI) particle DNA fragments were inserted into the XbaI site of the plasmid vector pACYC184. Five DI XbaI fragments, which ranged in molecular weight from 4.5 to 6.7 MDa, were selected for detailed analysis. Each DI DNA clone was labeled with 32P-deoxynucleotides by nick translation and hybridized to genomic digests of EHV-1 standard (STD) DNA bound to nitrocellulose. All five clones were shown to hybridize to DNA sequences derived from the left terminus (0.0-0.04 map units) of the long (L) region and from the short (S) region inverted ...
Endo A, Roos S, Satoh E, Morita H, Okada S.Two strains of lactic acid bacteria were isolated from faeces of two actively racing thoroughbred horses. The isolates formed a subcluster in the Lactobacillus reuteri phylogenetic group, closely related to Lactobacillus fermentum, L. gastricus, L. ingluviei and L. mucosae, by phylogenetic analysis based on 16S rRNA gene sequences. Levels of DNA-DNA relatedness revealed that the isolates belonged to the same taxon and were genetically separated from their phylogenetic relatives. Biochemical and physiological characteristics also distinguished the isolates from their phylogenetic relatives. The...
Han SH, Yang BC, Ko MS, Oh HS, Lee SS.we analyzed the sex chromosome-encoding ZFX-ZFY genes and tested molecular sexing using the amplification patterns of intron 9 of ZFX-ZFY in the horse. Results: the amplification of the ZFX-ZFY produced two distinct patterns, reflecting sexual dimorphism based on a length difference between the X and Y chromosomes. The amplification products from foals showed two distinct bands: one was common to all foals and mares, indicating that this band was amplified from ZFX, while the other was specific to some foals, indicating that it was from ZFY. The result based on the PCR assay was identical to t...
Balao da Silva CM, Ortega-Ferrusola C, Morrell JM, Rodriguez Martínez H, Peña FJ.To date, the only repeatable method to select spermatozoa for chromosomal sex is the Beltsville sorting technology using flow cytometry. Improvement of this technology in the equine species requires increasing awareness of the modifications that the sorting procedure induces on sperm intactness. Oxidative stress is regarded as the major damaging phenomenon, and increasing evidence regards handling of spermatozoa - including sex sorting - as basic ground for oxidative damage. The aim of this study was to disclose whether the flow cytometric sorting procedure increases the production of reactive...
Bell SA, Pusterla N, Balasuriya UB, Mapes SM, Nyberg NL, MacLachlan NJ.Equids are commonly infected by herpesviruses, but isolation of herpesviruses from mules has apparently not been previously reported. Furthermore, the genomic relationships among the various equid herpesviruses are poorly characterized. We describe the isolation and preliminary characterization of a mule gammaherpesvirus tentatively identified as asinine herpesvirus-2 (AHV-2; also designated equid herpesvirus-7 (EHV-7)) from the nasal secretions (NS) of a healthy mule in northern California. The virus was initially identified by transmission electron microscopic examination of lysates of cell ...
Raudsepp T, Christensen K, Chowdhar BP.With the expansion of comparative genome analysis across different mammals, there is an increasing need to have well-defined banded karyotypes for the species chosen for investigation. In this context, the steadily growing gene mapping data in the donkey urgently require a framework whereby alignment/comparison of genetic information can be readily made with equids and other mammalian species. Hence a GTG-banded karyotype of the donkey (Equus asinus; EAS) is presented, along with schematic drawings and nomenclature of the banded chromosomes. In addition, the most characteristic features of ind...
Coxiella burnetii is the causative agent of Q fever. In order to explore the occurrence of C. burnetii in ticks, samples were collected from horses, dogs and humans living in a Cuban occidental community. The species most commonly recovered were Amblyomma mixtum (67%), Rhipicephalus sanguineus s.l. (27%) and Dermacentor nitens (6%). Specific IS1111 PCR and amplicon sequencing allowed the identification of C. burnetii DNA in A. mixtum collected from a domestic horse. These findings, for first time in Cuba, indicate the need for an in-depth assessment of the C. burnetii occurrence in hosts and h...
Senju N, Tozaki T, Kakoi H, Shinjo A, Matsuyama R, Almunia J, Takasu M.Thirty-two microsatellites and a mitochondrial DNA haplotypes of endangered Yonaguni horses were analyzed to establish a pedigree registration system and to understand their genetic diversity for planning effective conservation. Blood samples were collected from 78 of the 130 horses in existence, and DNA was extracted and genotyped. There were two major findings. One is that it is possible to use microsatellites for Yonaguni horse pedigree registration in the future because the power of exclusion of parentage testing is reliable at 0.999998. The second is the clarification of the current genet...
Dechant JE, Baxter GM, Frisbie DD, Trotter GW, McIlwraith CW.Osteoarthritis is a frequent sequela of joint disease, especially with severe injuries or if attempts at therapy are unsuccessful. Negative and positive effects of corticosteroid treatment of articular cartilage have been demonstrated by in vitro and in vivo studies. Objective: To assess the metabolic effects of varying dosages of methylprednisolone acetate (MPA) and triamcinolone acetonide (TA) on interleukin-1alpha (IL-1) conditioned equine cartilage explants. Our hypothesis was that lower dosages of corticosteroids would be less detrimental to cartilage metabolism than higher dosages. TA wo...
Campos-Chillon F, Farmerie TA, Bouma GJ, Clay CM, Carnevale EM.We hypothesised that advanced mare age is associated with follicle and oocyte gene alterations. The aims of the study were to examine quantitative and temporal differences in mRNA for LH receptor (LHR), amphiregulin (AREG) and epiregulin (EREG) in granulosa cells, phosphodiesterase (PDE) 4D in cumulus cells and PDE3A, G-protein-coupled receptor 3 (GPR3), growth differentiation factor 9 (GDF9), bone morphogenetic protein 15 (BMP15) and mitochondrial (mt) DNA in oocytes. Samples were collected from dominant follicles of Young (3-12 years) and Old (≥20 years) mares at 0, 6, 9 and 12h after admi...
Lopes MS, Mendonça D, Cymbron T, Valera M, da Costa-Ferreira J, Machado Ada C.The analysis of mitochondrial D-loop sequences (408 bp) from 145 Lusitano founder mares yielded a total of 27 different haplotypes. The distribution of these mtDNA sequences was quite unequal, with the three most frequent ones representing 56.5% of all the Lusitano founder mares and 14 haplotypes (51.9%) being rare variants found only once in the sampling. Four main haplotype clusters were present in the Lusitano breed. The comparison of these sequences with other equine haplotypes shows that they fall in groups shared with other horse breeds. These data support the hypothesis of multiple dome...
