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.
Myćka G, Klecel W, Stefaniuk-Szmukier M, Jaworska J, Musiał AD, Ropka-Molik K.The Polish draft horse (PDH) breed is a result of crossing local mares with imported cold-blooded stallions, such as Belgians, Ardennes, Fjords, and others. A part of the broodmare stock investigated in this study was also imported from various countries, such as Denmark. In this study, we investigate the genetic composition of the PDH by analyzing the whole mitochondrial d-loop variability and comparing it to previously demonstrated whole d-loop sequences of other cold-blooded breeds: Ardennais, Belgian, Breton, Clydesdale, Noriker, Norwegian Fjord, Percheron, and Suffolk. Our results show hi...
Divers TJ, Mongodin EF, Miller CB, Belgrave RL, Gardner RB, Fraser CM, Schutzer SE.Antemortem diagnosis of neuroborreliosis in horses has been hindered by both the low sensitivity of PCR testing for in CSF and the low specificity of serum:CSF ELISA ratios used to determine intrathecal antibody production against the bacterium. PCR testing of the CSF of an adult horse with acute neurologic disease for the flagellin gene was negative. However, we enriched DNA through nucleic acid hybrid capture, followed by next-generation sequencing, and identified in the CSF of the horse, confirming a diagnosis of neuroborreliosis.
Colpitts J, McLoughlin PD, Poissant J.Understanding inbreeding and its impact on fitness and evolutionary potential is fundamental to species conservation and agriculture. Long stretches of homozygous genotypes, known as runs of homozygosity (ROH), result from inbreeding and their number and length can provide useful population-level information on inbreeding characteristics and locations of signatures of selection. However, the utility of ROH for conservation is limited for natural populations where baseline data and genomic tools are lacking. Comparing ROH metrics in recently feral vs. domestic populations of well understood spe...
Ortiz I, Dorado J, Pereira B, Diaz-Jimenez M, Consuegra C, Gosalvez J, Hidalgo M.The objectives of this study were to evaluate the effect of vitrification on the DNA fragmentation rate of equine cumulus cells and to assess its relationship to oocyte in vitro maturation (IVM) after vitrification. Cumulus cells (CC) from 14 mares were recovered from COCs, previously submitted to vitrification (VIT) and IVM. The DNA fragmentation rate of the cumulus cells (CC-DF) was assessed using a chromatin dispersion test. CC-DF rates between vitrified and control COCs were statistically compared by Student's t-test. The rates of CC-DF from control COCs were lower than in vitrified COCs...
Ameni G, Messele Kebede A, Zewude A, Girma Abdulla M, Asfaw R, Gobena MM, Kyalo M, Stomeo F, Gumi B, Sori T.Equine histoplasmosis commonly known as epizootic lymphangitis (EL) is a neglected granulomatous disease of equine that is endemic to Ethiopia. It is caused by variety , a dimorphic fungus that is closely related to variety c The objective of this study was to undertake a phylogenetic analysis of isolated from EL cases of horses in central Ethiopia and evaluate their relationship with isolates in other countries and/or clades using the internal transcribed spacer (ITS) region of rRNA genes. Clinical and mycological examinations, DNA extraction, polymerase chain reaction (PCR), Sanger seque...
Reich P, Falker-Gieske C, Pook T, Tetens J.Genotype imputation is a cost-effective method to generate sequence-level genotypes for a large number of animals. Its application can improve the power of genomic studies, provided that the accuracy of imputation is sufficiently high. The purpose of this study was to develop an optimal strategy for genotype imputation from genotyping array data to sequence level in German warmblood horses, and to investigate the effect of different factors on the accuracy of imputation. Publicly available whole-genome sequence data from 317 horses of 46 breeds was used to conduct the analyses. Results: Depend...
Xu C, Wei Z, Tan F, Liu A, Yu F, Zhao A, Zhang L, Qi M, Zhao W.Cryptosporidium is a protozoan parasite causing diarrhoea in humans and animals. Although Cryptosporidium has been found in domestic horses (farmed or kept at pasture), there has been only one published study of Cryptosporidium infections in Chinese racehorses, which was restricted to a very small geographical area. Objective: To investigate the presence of Cryptosporidium spp. in the faeces of racehorses in China and to perform molecular characterisation of the parasite. Methods: Cross-sectional. Methods: A total of 621 fresh faecal samples were collected for DNA extraction from racehorses at...
Sonali , Giri SK, Unnati , Nayan V, Legha RA, Pal Y, Bhardwaj A.India has well documented horse and pony breeds; however, the population is well diversified in different geographical regions. The Myostatin gene is one of the most profoundly studied genetic components for the detection of SNP's for the performance analysis in horses. In the present study, the MSTN exon 2 partial cds were amplified, sequenced and characterized in about 60 samples of eight different breeds of Indian horses. The results indicated the transition of Thymine to Cytosine (T>C) as single nucleotide polymorphisms in the partial sequence of exon 2 of the MSTN gene at two different...
Hu R, Yao R, Li L, Xu Y, Lei B, Tang G, Liang H, Lei Y, Li C, Li X, Liu K, Wang L, Zhang Y, Wang Y, Cui Y, Dai J, Ni W, Zhou P, Yu B, Hu S.With the rapid development of high-throughput sequencing technology, the amount of metagenomic data (including both 16S and whole-genome sequencing data) in public repositories is increasing exponentially. However, owing to the large and decentralized nature of the data, it is still difficult for users to mine, compare, and analyze the data. The animal metagenome database (AnimalMetagenome DB) integrates metagenomic sequencing data with host information, making it easier for users to find data of interest. The AnimalMetagenome DB is designed to contain all public metagenomic data from animals,...
Pawlina-Tyszko K, Semik-Gurgul E, Ząbek T, Witkowski M.Horses are of great importance in recreation, livestock production, as working animals in poorly developed countries, and for equine-assisted therapy. Equine sarcoids belong to the most commonly diagnosed tumors in this species. They may cause discomfort, pain, and can lead to the permanent impairment of motor function. The molecular bases of their formation are still under investigation. Our previous studies revealed altered microRNA (miRNA) expression and DNA methylation levels in sarcoid tumors. Abnormal patterns of methylation may be responsible for changes in gene expression levels, inclu...
Budachetri K, Lin M, Yan Q, Chien RC, Hostnik LD, Haanen G, Leclère M, Waybright W, Baird JD, Arroyo LG, Rikihisa Y.Potomac horse fever (PHF) is an acute and potentially fatal enterotyphlocolitis of horses with clinical signs that include anorexia, fever, diarrhea, and laminitis. Its incidence is increasing despite a commercially available vaccine. PHF is caused by Neorickettsia risticii, and the recently rediscovered and classified . PHF diagnosis is currently accomplished using serology or nested PCR. However, both methods cannot distinguish the two species that cause PHF. Further, the current real-time PCR test fails to detect Thus, in this study, two species-specific real-time PCR assays based on a...
Hernández-Quiroz F, Murugesan S, Flores-Rivas C, Piña-Escobedo A, Juárez-Hernández JI, García-Espitia M, Chávez-Carbajal A, Nirmalkar K....Horses are non-ruminant, herbivorous mammals, been used through history for various purposes, with a gut microbiota from cecum to the colon, possessing remarkable fermentative capacity. We studied the fecal microbiota of Azteca, Criollo, Frisian, Iberian, Pinto, Quarter and Spanish horse breeds living in Mexico by next-generation DNA sequencing of 16S rRNA gene libraries. Dominant phyla Firmicutes, Bacteroidetes, Proteobacteria, Spirochaetes, Fibrobacteres, Actinobacteria and Verrucomicrobia have different relative abundances among breeds, with contrasted alpha and beta diversities as well. He...
Contreras MJ, Arias ME, Silva M, Cabrera P, Felmer R.Cryopreservation of stallion semen is less efficient than other species such as bovine. This is mainly because of the greater susceptibility of stallion sperm to the freezing damage that generates oxidative stress and plasma membrane injury, resulting in DNA fragmentation and cell death. These data suggest the need to develop new strategies of sperm cryopreservation that can improve the efficiency of this technique in stallions by reducing or preventing membrane damage and cell death. The present study aimed to evaluate the effect of adding membrane stabilizers to the freezing medium and asses...
El-Gameel SM, Al-Mokaddem AK, Salaeh NMK, Attia MM.Equine gastrointestinal tract is infected with () which is highly pathogenic parasite for its harmful effect on cranial mesenteric artery during its migration. So, this study was applied for identification of in donkeys ultramorphologically and molecularly. In addition to, detection of the pathological effect of larval stage of on the mesenteric arterial system using histopathology and immunohistochemistry. During the period from September to December; 2019, 60 male and 20 female donkeys at the Giza Zoo was postmortem examined. adults and larvae were collected from the large intestine and ...
Cheung HW, Wong KS, Lin VYC, Farrington AF, Bond AJ, Wan TSM, Ho ENM.The concern about gene doping has remained high in horseracing and other equestrian competitions. Our laboratory has previously developed a duplex quantitative polymerase chain reaction (qPCR) assay capable of detecting in equine blood the human erythropoietin (hEPO) transgene and equine tubulin α 4a (TUBA4A) gene as an internal control the latter providing quality control over DNA extraction and qPCR. This study aimed to optimize the method for routine testing of regulatory samples. The use of an automated DNA extraction system has increased the sample throughput, consistency of DNA extracti...
Zandi MB, Salek Ardestani S, Vahedi SM, Mahboudi H, Mahboudi F, Meskoob A.Dareshouri, Arabian, and Akhal-Teke are 3 Middle Eastern horse breeds that have been selected for endurance and adaptation to harsh climates. Deciphering the genetic characteristics of these horses by tracing selection footprints and copy number of variations will be helpful in improving our understanding of equine breeds' development and adaptation. For this purpose, we sequenced the whole genome of 4 Dareshouri horses using Illumina Hiseq panels and compared them with publicly available whole-genome sequences of Arabian (n = 3) and Akhal-Teke (n = 3) horses. Three tests of FLK, hapFLK, and p...
Lv K, Zhang Y, Yang Y, Liu Z, Deng L.Equine piroplasmosis (EP) is a type of blood protozoan disease caused by tick-borne parasites, (), () and . While many studies have been conducted on EP diagnosis, diagnostic methods exhibiting high sensitivity and specificity remain lacking. Therefore, nested PCR (nPCR) and duplex real-time fluorescence quantitative PCR (qPCR) that can simultaneously detect both and causing agents were established and compared. The two techniques were used to analyze 36 horse blood samples for EP. This set of samples was also detected by a multinested PCR (mnPCR) targeting the gene of and the gene of ....
Xu Y, Zhang X, Peng P, Liu Y, Yu M, Xie L.Equine copivirus (EqCoPV) is a newly discovered parvovirus that infects equines. Currently, it is unclear whether this virus is prevalent in China. In the present study, serum samples were collected from equines in China and were processed for EqCoPV DNA detection by PCR. The results demonstrated that EqCoPV was circulating among the sampled equines, with a low detection rate of 0.94%. The genome sequence of one Chinese EqCoPV strain, UH26, was determined and used for genetic and phylogenetic analysis. The results demonstrated that UH26 has a close genetic relationship to EqCoPV strains from t...
Hu Y, Jia Q, Liu J, Sun W, Bao Z, Che C, Wu G, Fan B, Jarhen , Ran D.Equid alphaherpesvirus 1 (EHV-1) is prevalent in China, and causes notable economic damage to the equine industry. However, there is no information regarding the molecular characteristics and pathogenicity of the Chinese strains. Therefore, an EHV-1 strain, named YM2019, was isolated from the lung tissue of an aborted horse fetus in Xinjiang, China, and its genome and pathogenicity were analyzed. The full genome of the isolate was 150,267 base pairs in length, with 56.7% G + C content. Genetic and phylogenetic analysis showed that strain YM2019 (GenBank: MT063054) belonged to the ORF30 N75...
Cai D, Zhu S, Gong M, Zhang N, Wen J, Liang Q, Sun W, Shao X, Guo Y, Cai Y, Zheng Z, Zhang W, Hu S, Wang X, Tian H, Li Y, Liu W, Yang M, Yang J, Wu D....The exceptionally rich fossil record available for the equid family has provided textbook examples of macroevolutionary changes. Horses, asses, and zebras represent three extant subgenera of lineage, while the subgenus is another remarkable lineage ranging from North America to Ethiopia in the Pleistocene. We sequenced 26 archaeological specimens from Northern China in the Holocene that could be assigned morphologically and genetically to , a species representative of . We present the first high-quality complete genome of the lineage, which was sequenced to 13.4× depth of coverage. Radioc...
Birdwhistell KE, Hurley DJ, Heins B, Peroni JF.Allogeneic solid organ transplantation is currently the only treatment option for end stage organ disease. The shortage of available donor organs has driven efforts to utilize xenogeneic organs for transplantation. In vitro methods for evaluating immune-compatibility are a quick and low cost means of screening novel tissue products prior to more involved, expensive, and invasive live animal studies. Recently, a new analog of the DNA base thymidine, 5-ethynyl-2'-deoxyuridine (EdU), was developed. It may be used in a fast, efficient and specific means of evaluating cell proliferation via flow cy...
Voss SJ, McGuinness DH, Weir W, Sutton DGM.The role of the equine gastrointestinal microbiota in the pathogenesis of equine glandular gastric disease (EGGD) is poorly understood. To investigate whether the glandular gastric microbiota is altered in horses with EGGD. Prospective longitudinal study. Five Thoroughbred racehorses from one training center underwent gastroscopy as part of poor performance investigation. Samples were taken from EGGD lesions and adjacent normal mucosa using sheathed transendoscopic cytology brushes and frozen at -80°C. DNA was extracted for 16S rRNA sequencing, and sequences compared against a database to gen...
Suchan T, Chauvey L, Poullet M, Tonasso-Calvière L, Schiavinato S, Clavel P, Clavel B, Lepetz S, Seguin-Orlando A, Orlando L.Ancient DNA preservation in subfossil specimens provides a unique opportunity to retrieve genetic information from the past. As ancient DNA extracts are generally dominated by molecules originating from environmental microbes, capture techniques are often used to economically retrieve orthologous sequence data at the population scale. Post-mortem DNA damage, especially the deamination of cytosine residues into uracils, also considerably inflates sequence error rates unless ancient DNA extracts are treated with the USER enzymatic mix prior to library construction. While both approaches have rec...
Peckle M, Santos H, Pires M, Silva C, Costa R, Vitari G, Camilo T, Meireles N, Paulino P, Massard C.Experimental studies have demonstrated that () transmits to horses. However, the degree and dynamics of this protozoan infection in the vector's organism have not been fully elucidated. Therefore, this study aimed to evaluate the infection rate and parasitic load of in , the infection dynamics in this arthropod during experimental infestation in a horse chronically infected with , and to evaluate the trans-stadial and intrastadial transmission competence of by . The experimental infestation period of on the horse was 33 days, but males were found on the animal up to 60 days post-infestat...
Cohen ND, Flores-Ahlschewde P, Gonzales GM, Kahn SK, da Silveira BP, Bray JM, King EE, Blair CC, Bordin AI.Diagnostic accuracy of real-time, quantitative PCR (qPCR) assays to quantify virulent Rhodococcus equi using rectal swab samples has not been systematically evaluated. Objective: To evaluate the accuracy of qPCR of rectal swab samples to differentiate foals with pneumonia from healthy foals of similar age from the same environment. Methods: One hundred privately owned foals born in 2021 from 2 farms in New York. Methods: An incident case-control study design was used. Rectal swabs were collected from all foals diagnosed with R. equi pneumonia at 2 horse-breeding farms (n = 47). Eligible pneu...
Maniego J, Pesko B, Habershon-Butcher J, Hincks P, Taylor P, Tozaki T, Ohnuma A, Stewart G, Proudman C, Ryder E.Gene editing and subsequent cloning techniques offer great potential not only in genetic disease correction in domestic animals but also in livestock production by enhancement of desirable traits. The existence of the technology, however, leaves it open to potential misuse in performance-led sports such as horseracing and other equestrian events. Recent advances in equine gene editing, regarding the generation of gene-edited embryos using CRISPR/Cas9 technology and somatic cell nuclear transfer, have highlighted the need to develop tools to detect potential prohibited use of the technology. On...
Criscione A, Mastrangelo S, D'Alessandro E, Tumino S, Di Gerlando R, Zumbo A, Marletta D, Bordonaro S.Purosangue Orientale Siciliano, Sanfratellano and Siciliano represent the Sicilian equine genetic resource. This study aimed to investigate the genetic diversity, population structure and the pattern of autozygosity of Sicilian horse populations using genome-wide single-nucleotide polymorphism (SNP) data generated with the Illumina Equine SNP70 array. The genotyping data of 17 European and Middle East populations were also included in the study. The patterns of genetic differentiation, model-based clustering and Neighbour-Net showed the expected positioning of Sicilian populations within the w...
Lee SK, Choi J, Yoon J, Jung J, Park JY, Park J, Kim Y, Park JY, Park D.Equine adenovirus 1 (EAdV-1) can cause upper respiratory disease in horses and has been reported worldwide. In this study, and for the first time in Korea, the prevalence of EAdV-1 in equine nasal swabs was investigated using a PCR to identify potential risk factors and examine the genetic diversity of its DNA sequences by a comparison with foreign strains. Nasal swabs collected from 359 horses reared at Korea Racing Authority facilities were tested using an EAdV-1 hexon-specific PCR and the associations between EAdV-1 infection and sex, age, region, breed, and activity were analyzed. Five sam...
Henkel J, Lafayette C, Brooks SA, Martin K, Patterson-Rosa L, Cook D, Jagannathan V, Leeb T.White spotting phenotypes in horses are highly valued in some breeds. They are quite variable and may range from the common white markings up to completely white horses. EDNRB, KIT, MITF, PAX3 and TRPM1 represent known candidate genes for white spotting phenotypes in horses. For the present study, we investigated an American Paint Horse family segregating a phenotype involving white spotting and blue eyes. Six of eight horses with the white-spotting phenotype were deaf. We obtained whole-genome sequence data from an affected horse and specifically searched for structural variants in the known ...
López-Fernández C, Crespo F, Arroyo F, Fernández JL, Arana P, Johnston SD, Gosálvez J.The mixed success of equine artificial insemination programs using chilled and frozen-thawed semen is most likely associated with the variable response of the sperm cell to the preservation process and the fact that stallions are not selected on the basis of reproductive performance. We propose that the traditional indicators of sperm viability do not fully account for male factor infertility in the stallion and that knowledge of sperm DNA damage in the original semen sample and during semen processing may provide a more informed explanation of an individual stallion's reproductive potential. ...
Schneberger D, Caldwell S, Suri SS, Singh B.Toll-like receptor 9 (TLR9) has been found to be the main receptor to respond to bacterial DNA in a wide variety of species. Recent work has shown that TLR9 is expressed in a diverse set of cells within the lung. However, much of this data has been centered on human and mouse cell culture lines or primary cultures and very little is known of TLR9 expression in intact lung, especially that of the horse. Here we show that TLR9 is expressed in the lungs of horses in a wide variety of cells. In particular, we note expression in pulmonary intravascular macrophages (PIMs), alveolar macrophages, bron...
Kovac M, Litvin YA, Aliev RO, Zakirova EY, Rutland CS, Kiyasov AP, Rizvanov AA.This clinical study describes the intralesional application of the plasmid DNA encoding two therapeutic species-specific growth factors: vascular endothelial growth factor (VEGF164) and fibroblast growth factor 2 (FGF2) in seven horses to restore naturally occurring injuries of the superficial digital flexor tendon (SDFT) (tendinitis) and in three horses with suspensory ligament branch desmitis. Following application all horses were able to commence a more rapid exercise program in comparison to standardized exercise programs. Clinical observation and ultrasonic imaging was used to evaluate th...
Wen B, Rikihisa Y, Fuerst PA, Chaichanasiriwithaya W.Ehrlichia risticii is the causative agent of Potomac horse fever. Variations among the major antigens of different local E. risticii strains have been detected previously. To further assess genetic variability in this species or species complex, the sequences of the 16S rRNA genes of several isolates obtained from sick horses diagnosed as having Potomac horse fever were determined. The sequences of six isolates obtained from Ohio and three isolates obtained from Kentucky were amplified by PCR. Three groups of sequences were identified. The sequences of five of the Ohio isolates were identical ...
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...
Minke JM, Fischer L, Baudu P, Guigal PM, Sindle T, Mumford JA, Audonnet JC.In this study, experimental canarypox virus (ALVAC) and plasmid DNA recombinant vaccines expressing the gB, gC and gD glycoproteins of EHV-1 were assessed for their ability to protect conventional ponies against a respiratory challenge with EHV-1. In addition, potential means of enhancing serological responses in horses to ALVAC and DNA vaccination were explored. These included co-administration of the antigen with conventional adjuvants, complexation with DMRIE-DOPE and co-expression of the antigen along with equine GM-CSF. Groups of EHV primed ponies were vaccinated twice intra-muscularly wi...
McGahern AM, Edwards CJ, Bower MA, Heffernan A, Park SD, Brophy PO, Bradley DG, MacHugh DE, Hill EW.Equine mitochondrial DNA sequence variation was investigated in three indigenous Irish horse populations (Irish Draught Horse, Kerry Bog Pony and Connemara Pony) and, for context, in 69 other horse populations. There was no evidence of Irish Draught Horse or Connemara Pony sequence clustering, although the majority of Irish Draught Horse sequences (47%) were assigned to haplogroup D. Conversely, 31% of the Kerry Bog Pony sequences were assigned to the rare haplogroup E. In addition to the extant population analyses, ancient DNA sequences were generated from three out of four Irish archaeologic...
Hübert PH, Birkenmaier S, Rziha HJ, Osterrieder N.The equine herpesvirus type-1 modified live-vaccine strain RacH (256th passage on porcine embryonic kidney cells) was investigated by restriction-enzyme analysis and compared to representative plaque isolates of the 12th passage (RacL11, RacL22) and 185th passage (RacM24, RacM36). The restriction patterns of all Rac plaque isolates differed compared with reference strain Ab4. The left UL terminus was shortened by 0.1 kbp and a missing BamHI site led to the fusion of the f and t fragments. In some Rac derivatives, losses of restriction sites without deletions were observed: 1. One BamHI site lo...
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...
Bellone RR, Forsyth G, Leeb T, Archer S, Sigurdsson S, Imsland F, Mauceli E, Engensteiner M, Bailey E, Sandmeyer L, Grahn B, Lindblad-Toh K, Wade CM.Leopard Complex spotting occurs in several breeds of horses and is caused by an incompletely dominant allele (LP). Homozygosity for LP is also associated with congenital stationary night blindness (CSNB) in Appaloosa horses. Previously, LP was mapped to a 6 cm region on ECA1 containing the candidate gene TRPM1 (Transient Receptor Potential Cation Channel, Subfamily M, Member 1) and decreased expression of this gene, measured by qRT-PCR, was identified as the likely cause of both spotting and ocular phenotypes. This study describes investigations for a mutation causing or associated with the Le...
Rodríguez-Lázaro D, Lewis DA, Ocampo-Sosa AA, Fogarty U, Makrai L, Navas J, Scortti M, Hernández M, Vázquez-Boland JA.We developed a novel quantitative real-time PCR (Q-PCR) method for the soil actinomycete Rhodococcus equi, an important horse pathogen and emerging human pathogen. Species-specific quantification was achieved by targeting the chromosomal monocopy gene choE, universally conserved in R. equi. The choE Q-PCR included an internal amplification control (IAC) for identification of false negatives. A second Q-PCR targeted the virulence plasmid gene vapA, carried by most horse isolates but infrequently found in isolates from other sources. The choE-IAC and vapA assays were 100% sensitive and specific ...
Borchers K, Wolfinger U, Ludwig H.Equine herpesvirus type 4 (EHV-4) is a major respiratory pathogen of horses. Unlike most other members of the Alphaherpesvirinae, EHV-4 was regarded as non-neurotropic. Here, neural and lymphoid tissues of 17 horses have been analysed post-mortem. EHV-4 DNA was detected in 11 cases (65%) by PCR, exclusively in the trigeminal ganglia. In order to define the transcriptional activity, RNA preparations of 10 EHV-4 DNA-positive ganglia were investigated by nested RT-PCR. EHV-4-specific transcripts derived from genes 63 [herpes simplex virus type 1 (HSV-1) ICPO gene homologue] and 64 (HSV-1 ICP4 gen...
Peckle M, Pires MS, Dos Santos TM, Roier EC, da Silva CB, Vilela JA, Santos HA, Massard CL.The aim of this study was to detect Theileria equi (Laveran 1901) DNA in horses and ticks using real-time PCR and to list the factors associated with infection in animals located in the Seropedica and Petropolis municipalities of the state of Rio de Janeiro. We tested blood samples from 314 horses and samples from 300 ticks, including 191 Amblyomma cajennense, 104 Dermacentor nitens, and 5 Ixodida larvae. Factors inherent to the horse, the ownership, and animal management were obtained from an epidemiological questionnaire and were evaluated in association with the presence of T. equi DNA in t...
Penedo MC, Millon LV, Bernoco D, Bailey E, Binns M, Cholewinski G, Ellis N, Flynn J, Gralak B, Guthrie A, Hasegawa T, Lindgren G, Lyons LA, Røed KH....A comprehensive male linkage map was generated by adding 359 new, informative microsatellites to the International Equine Gene Map half-sibling reference families and by combining genotype data from three independent mapping resources: a full sibling family created at the Animal Health Trust in Newmarket, United Kingdom, eight half-sibling families from Sweden and two half-sibling families from the University of California, Davis. Because the combined data were derived primarily from half-sibling families, only autosomal markers were analyzed. The map was constructed from a total of 766 marker...
Raudsepp T, Chowdhary BP.A pilot study comparing horse and donkey karyotypes on a molecular basis was initiated using the chromosomal microdissection approach. All equine meta- and submetacentric chromosomes, viz. ECA1 to ECA13 and the X and Y chromosomes, were microdissected. The DNA was PCR amplified, non-radioactively labelled and used as probes on equine metaphase chromosomes to confirm their origin. Once tested, the paints were used as probes on donkey metaphase chromosomes to detect homologous chromosomal segments between the two species. The results not only detected conservation of whole chromosome and/or arm ...
Kurowski PB, Traub-Dargatz JL, Morley PS, Gentry-Weeks CR.To use real-time polymerase chain reaction (PCR) technology to develop a highly sensitive and specific diagnostic assay for the detection of Salmonella spp in fecal specimens. Methods: 299 fecal specimens from cattle, horses, and dogs. Methods: Enrichment of fecal specimens was followed by genomic DNA extraction by use of commercially available isolation kits. Real-time PCR assay was performed to target a Salmonella spp-specific DNA segment. Results of real-time PCR assay were compared with bacterial culture results to determine relative sensitivity and specificity. Results: Use of the spaQ pr...
Graves KT, Henney PJ, Ennis RB.Laminin 5 is a heterotrimeric basement membrane protein integral to the structure and function of the dermal-epidermal junction. It consists of three glycoprotein subunits: the alpha3, beta3 and gamma2 chains, which are encoded by the LAMA3, LAMB3 and LAMC2 genes respectively. A mutation in any of these genes results in the condition known as hereditary junctional epidermolysis bullosa (JEB). A 6589-bp deletion spanning exons 24-27 was found in the LAMA3 gene in American Saddlebred foals born with the skin-blistering condition epitheliogenesis imperfecta. The deletion confirms that this autoso...
Tozaki T, Ohnuma A, Takasu M, Kikuchi M, Kakoi H, Hirota KI, Kusano K, Nagata SI.Indiscriminate genetic manipulation to improve athletic ability is a major threat to human sports and the horseracing industry, in which methods involving gene-doping, such as transgenesis, should be prohibited to ensure fairness. Therefore, development of methods to detect indiscriminate genetic manipulation are urgently needed. Here, we developed a highly sensitive method to detect horse erythropoietin () transgenes using droplet digital PCR (ddPCR). We designed two TaqMan probe/primer sets, and the transgene was cloned into a plasmid for use as a model. We extracted the spiked transgene f...
The Bering Land Bridge (BLB) last connected Eurasia and North America during the Late Pleistocene. Although the BLB would have enabled transfers of terrestrial biota in both directions, it also acted as an ecological filter whose permeability varied considerably over time. Here we explore the possible impacts of this ecological corridor on genetic diversity within, and connectivity among, populations of a once wide-ranging group, the caballine horses (Equus spp.). Using a panel of 187 mitochondrial and eight nuclear genomes recovered from present-day and extinct caballine horses sampled acros...
Brama PA, Tekoppele JM, Bank RA, Karssenberg D, Barneveld A, van Weeren PR.The aim of this study was to evaluate topographical differences in the biochemical composition of the extracellular matrix of articular cartilage of the normal equine fetlock joint. Water content, DNA content, glycosaminoglycan (GAG) content and a number of characteristics of the collagen network (total collagen content, levels of hydroxylysine- (Hyl) and the crosslink hydroxylysylpyridinoline, (HP) of articular cartilage in the proximal 1st phalanx (P1), distal 3rd metacarpal bone (MC), and proximal sesamoid bones (PSB) were determined in the left and right fetlock joint of 6 mature horses (a...
Yalamanchili RR, Raengsakulrach B, O'Callaghan DJ.We have previously reported the sequence of the equine herpesvirus one genomic termini that are homologous to the genomic termini of other herpesviruses. In this paper, we present the nucleotide sequence adjacent to the left terminus sequence (map units 0.0087 to 0.0237). This sequence codes for two open reading frames (ORF) which are homologous to ORF2 and ORF3 of the varicella-zoster virus genome and are located at colinear positions. The L region sequence presented here also contains a segment that is involved in the generation of the genome of EHV-1 DI particles through recombination with ...
Finno CJ, Aleman M, Higgins RJ, Madigan JE, Bannasch DL.Genome-wide association (GWA) studies are widely used to investigate the genetic etiology of diseases in domestic animals. In the horse, GWA studies using 40-50,000 single nucleotide polymorphisms (SNPs) in sample sizes of 30-40 individuals, consisting of only 6-14 affected horses, have led to the discovery of genetic mutations for simple monogenic traits. Equine neuroaxonal dystrophy is a common inherited neurological disorder characterized by symmetric ataxia. A case-control GWA study was performed using genotypes from 42,819 SNP marker loci distributed across the genome in 99 clinically phe...
Metzger J, Tonda R, Beltran S, Agueda L, Gut M, Distl O.Domestication has shaped the horse and lead to a group of many different types. Some have been under strong human selection while others developed in close relationship with nature. The aim of our study was to perform next generation sequencing of breed and non-breed horses to provide an insight into genetic influences on selective forces. Results: Whole genome sequencing of five horses of four different populations revealed 10,193,421 single nucleotide polymorphisms (SNPs) and 1,361,948 insertion/deletion polymorphisms (indels). In comparison to horse variant databases and previous reports, w...
Traversa D, Giangaspero A, Iorio R, Otranto D, Paoletti B, Gasser RB.Habronema microstoma and Habronema muscae (Spirurida: Habronematidae) are parasitic nematodes which infect the stomach and/or skin of equids. The accurate diagnosis of gastric habronemosis is central to studying its epidemiology, but data on its distribution and prevalence are lacking, mainly due to the limitations of clinical and coprological diagnosis in live horses. To overcome this constraint, a two-step, semi-nested PCR-based assay was validated (utilizing genetic markers in the nuclear ribosomal DNA) for the specific amplification of H. microstoma or H. muscae DNA from the faeces from ho...
Dürig N, Jude R, Holl H, Brooks SA, Lafayette C, Jagannathan V, Leeb T.White spotting phenotypes in horses can range in severity from the common white markings up to completely white horses. EDNRB, KIT, MITF, PAX3 and TRPM1 represent known candidate genes for such phenotypes in horses. For the present study, we re-investigated a large horse family segregating a variable white spotting phenotype, for which conventional Sanger sequencing of the candidate genes' individual exons had failed to reveal the causative variant. We obtained whole genome sequence data from an affected horse and specifically searched for structural variants in the known candidate genes. This...
Perryman LE.Severe combined immunodeficiency (SCID) is an inherited disorder of humans, mice, horses, and dogs, in which affected individuals are incapable of generating antigen-specific immune responses. It occurs when lymphocyte precursors fail to differentiate into mature lymphocytes because of mutations within recombinase-activating genes 1 and 2 or within the genes encoding deoxyribonucleic acid (DNA)-dependent protein kinase (DNA-PK). It also occurs when differentiated lymphocytes are incapable of completing signal transduction pathways because of defects in cell surface receptors for interleukins (...
Hung GC, Gasser RB, Beveridge I, Chilton NB.The first and second internal transcribed spacer sequences of 28 morphologically-defined species of horse strongyle were characterized, and specific oligonucleotide primers were designed for some species based on the nucleotide differences. Utilizing these primers, a PCR approach was developed for the specific amplification of ribosomal DNA of Strongylus vulgaris, Cyathostomum catinatum, Cylicocyclus nassatus, Cylicostephanus longibursatus or Cylicostephanus goldi. The method allowed the species-specific amplification of parasite DNA derived from faecal samples and/or copro-cultures, demonstra...
Shimizu A, Kawano J, Yamamoto C, Kakutani O, Anzai T, Kamada M.Pulsed-field gel electrophoresis (PFGE) was used to determine genetic relationships among 15 methicillin-resistant Staphylococcus aureus (MRSA) isolates from mares with metritis and from a stallion with dermatitis in Hokkaido. All the 15 isolates showed phage pattern 6/47/54/75, coagulase type IV, and enterotoxin type A. The restriction endonuclease SmaI cut their genomic DNAs into 15 or 16 fragments ranging in size from 8 to 630 kb. Fourteen of the 15 isolates showed the same PFGE pattern, whereas the remaining one appeared to be closely related. The 9 human MRSA isolates showing the same phe...
