Genomics in horses involves the study and analysis of the horse genome to understand genetic variations and their implications for equine health, performance, and breeding. This field encompasses the identification and mapping of genes associated with specific traits, diseases, and conditions in horses. Techniques such as whole-genome sequencing and genome-wide association studies (GWAS) are employed to explore genetic diversity and inheritance patterns among different horse breeds. Genomics provides insights into hereditary disorders, informs selective breeding practices, and aids in the development of personalized veterinary care. This page compiles peer-reviewed research studies and scholarly articles that explore the applications, methodologies, and findings of genomic research in equine science.
Worthing KA, Abraham S, Pang S, Coombs GW, Saputra S, Jordan D, Wong HS, Abraham RJ, Trott DJ, Norris JM.This study aimed to determine the frequency and molecular epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) from Australian animals and whether animal-derived MRSA was similar to that from Australian veterinarians. A total of 1,080 clinical coagulase positive Staphylococcus isolates from Australian animals were collected during 2013. Sixteen (4%) of 360 S. aureus isolates were MRSA. Most MRSA came from companion animals, while none came from livestock. MRSA isolates were characterized using whole genome sequencing. ST22-IV (EMRSA-15) was the most common clone in dogs and cats....
Plumlee Q, Meason-Smith C, Dieterly A, Gomez G, Porter BF, Rodrigues Hoffmann A.Many previously unrecognized fungi are emerging as potential pathogens. One such group is dematiaceous fungi of the Chaetomiaceae family (phylum Ascomycota, class Sordariomycetes). These fungi are rare causes of opportunistic, neurotropic phaeohyphomycosis in humans but are not known to cause similar infections in animals. The aims of this study were to investigate equine hyphal mycotic encephalitis, characterize key histopathologic features, and classify causative organisms with molecular diagnostic techniques. Seven cases were evaluated by histopathology. Panfungal PCR targeting the ribosoma...
Bailly-Chouriberry L, Baudoin F, Cormant F, Glavieux Y, Loup B, Garcia P, Popot MA, Bonnaire Y.The improvement of doping control is an ongoing race. Techniques to fight doping are usually based on the direct detection of drugs or their metabolites by analytical methods such as chromatography hyphenated to mass spectrometry after ad hoc sample preparation. Nowadays, omic methods constitute an attractive development and advances have been achieved particularly by application of molecular biology tools for detection of anabolic androgenic steroids (AAS), erythropoiesis-stimulating agent (ESA), or to control human growth hormone misuses. These interesting results across different animal spe...
Charbonneau ARL, Forman OP, Cain AK, Newland G, Robinson C, Boursnell M, Parkhill J, Leigh JA, Maskell DJ, Waller AS.Utilising next generation sequencing to interrogate saturated bacterial mutant libraries provides unprecedented information for the assignment of genome-wide gene essentiality. Exposure of saturated mutant libraries to specific conditions and subsequent sequencing can be exploited to uncover gene essentiality relevant to the condition. Here we present a barcoded transposon directed insertion-site sequencing (TraDIS) system to define an essential gene list for Streptococcus equi subsp. equi, the causative agent of strangles in horses, for the first time. The gene essentiality data for this grou...
Almarzook S, Reissmann M, Arends D, Brockmann GA.Although Arabian horses have been bred in strains for centuries and pedigrees have been recorded in studbooks, to date, little is known about the genetic diversity within and between these strains. In this study, we tested if the three main strains of Syrian Arabian horses descend from three founders as suggested by the studbook. We examined 48 horses representing Saglawi (n = 18), Kahlawi (n = 16) and Hamdani (n = 14) strains using the Equine SNP70K BeadChip. For comparison, an additional 24 Arabian horses from the USA and three Przewalski's horses as an out group were added. Observed h...
Schoster A, Staempfli HR, Guardabassi LG, Jalali M, Weese JS.Diarrhea in foals affects up to 60% of foals during the first six months of life. The effect of diarrhea on the fecal bacterial microbiota in foals has not been investigated. Little is known on the fecal bacterial microbial richness and diversity of foals at a young age. The objective was to compare the fecal bacterial microbiota of healthy foals to foals with diarrhea at two and four weeks of life. Methods: Fecal samples were collected from foals (n = 20) at 1-14 (T1) and 15-28 (T2) days of age and analyzed using high throughput sequencing. Differences in relative abundance of bacterial tax...
Parkinson NJ, Buechner-Maxwell VA, Witonsky SG, Pleasant RS, Werre SR, Ahmed SA.The innate immune response to lipopolysaccharide contributes substantially to the morbidity and mortality of gram-negative sepsis. Horses and humans share an exquisite sensitivity to lipopolysaccharide and thus the horse may provide valuable comparative insights into this aspect of the inflammatory response. MicroRNAs, small non-coding RNA molecules acting as post-transcriptional regulators of gene expression, have key roles in toll-like receptor signaling regulation but have not been studied in this context in horses. The central hypothesis of this study was that lipopolysaccharide induces di...
Goldansaz SA, Guo AC, Sajed T, Steele MA, Plastow GS, Wishart DS.Metabolomics uses advanced analytical chemistry techniques to comprehensively measure large numbers of small molecule metabolites in cells, tissues and biofluids. The ability to rapidly detect and quantify hundreds or even thousands of metabolites within a single sample is helping scientists paint a far more complete picture of system-wide metabolism and biology. Metabolomics is also allowing researchers to focus on measuring the end-products of complex, hard-to-decipher genetic, epigenetic and environmental interactions. As a result, metabolomics has become an increasingly popular "omics" app...
Perez de Souza L, Naake T, Tohge T, Fernie AR.The grand challenge currently facing metabolomics is the expansion of the coverage of the metabolome from a minor percentage of the metabolic complement of the cell toward the level of coverage afforded by other post-genomic technologies such as transcriptomics and proteomics. In plants, this problem is exacerbated by the sheer diversity of chemicals that constitute the metabolome, with the number of metabolites in the plant kingdom generally considered to be in excess of 200 000. In this review, we focus on web resources that can be exploited in order to improve analyte and ultimately metabol...
Tallmadge RL, Miller SC, Parry SA, Felippe MJB.The value of prophylactic neonatal vaccination is challenged by the interference of passively transferred maternal antibodies and immune competence at birth. Taken our previous studies on equine B cell ontogeny, we hypothesized that the equine neonate generates a diverse immunoglobulin repertoire in response to vaccination, independently of circulating maternal antibodies. In this study, equine neonates were vaccinated with 3 doses of keyhole limpet hemocyanin (KLH) or equine influenza vaccine, and humoral immune responses were assessed using antigen-specific serum antibodies and B cell Ig var...
Neuditschko M, Raadsma HW, Khatkar MS, Jonas E, Steinig EJ, Flury C, Signer-Hasler H, Frischknecht M, von Niederhäusern R, Leeb T, Rieder S.Evaluating the genetic contribution of individuals to population structure is essential to select informative individuals for genome sequencing, genotype imputation and to ascertain complex population structures. Existing methods for the selection of informative individuals for genomic imputation solely focus on the identification of key ancestors, which can lead to a loss of phasing accuracy of the reference population. Currently many methods are independently applied to investigate complex population structures. Based on the Eigenvalue Decomposition (EVD) of a genomic relationship matrix we ...
Mirajkar NS, Kelley MR, Gebhart CJ.Reported herein is the draft genome sequence of equine-origin Lawsonia intracellularis strain E40504, an obligate intracellular bacterium and the etiological agent of equine proliferative enteropathy. The 1.69-Mb draft genome sequence includes 1,380 protein-coding genes and 49 RNA genes, and it lacks a genomic island reported in swine-origin L. intracellularis strain PHE/MN1-00.
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...
Science (New York, N.Y.)April 30, 2017
Volume 356, Issue 6336 442-445 doi: 10.1126/science.aam5298
Librado P, Gamba C, Gaunitz C, Der Sarkissian C, Pruvost M, Albrechtsen A, Fages A, Khan N, Schubert M, Jagannathan V, Serres-Armero A, Kuderna LFK....The genomic changes underlying both early and late stages of horse domestication remain largely unknown. We examined the genomes of 14 early domestic horses from the Bronze and Iron Ages, dating to between ~4.1 and 2.3 thousand years before present. We find early domestication selection patterns supporting the neural crest hypothesis, which provides a unified developmental origin for common domestic traits. Within the past 2.3 thousand years, horses lost genetic diversity and archaic DNA tracts introgressed from a now-extinct lineage. They accumulated deleterious mutations later than expected ...
The Journal of heredityApril 30, 2017
Volume 108, Issue 5 505-514 doi: 10.1093/jhered/esx039
Druml T, Grilz-Seger G, Neuditschko M, Neuhauser B, Brem G.Genetic analyses of coat colors are frequently restricted to subjectively categorized phenotype information. The aim of this study was to develop a method to numerically quantify the variability of leopard complex (LP) spotting phenotypes introducing tools from image analysis. Generalized Procrustes analysis eliminates systematic errors due to imaging process. The binarization of normalized images and the application of principal component analysis (PCA) on the derived pixel matrices, transform pixel information into numerical data space. We applied these methods on 90 images to ascertain the ...
The Journal of heredityApril 27, 2017
Volume 108, Issue 4 361-368 doi: 10.1093/jhered/esx025
Al Abri MA, König von Borstel U, Strecker V, Brooks SA.Horse breeders rely heavily on pedigrees for identification of ancestry in breeding stock. Inaccurate pedigrees may erroneously assign individuals to false lineages or breed memberships resulting in wrong estimates of inbreeding and coancestry. Moreover, discrepancies in pedigree records can lead breeders seeking to limit inbreeding into making misguided breeding decisions. Genome-wide SNPs provide a quantitative tool to aid in the resolution of lineage assignments and the calculation of genomic measures of relatedness. The aim of this project was to pilot a comparison between pedigree and gen...
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...
Yoon SH, Kim J, Shin D, Cho S, Kwak W, Lee HK, Park KD, Kim H.The Korean native horse (Jeju horse) is one of the most important animals in Korean historical, cultural, and economical viewpoints. In the early 1980s, the Jeju horse was close to extinction. The aim of this study is to explore the phylogenomics of Korean native horse focusing on spatio-temporal dynamics. We determined complete mitochondrial genome sequences for the first Korean native (n = 6) and additional Mongolian (n = 2) horses. Those sequences were analyzed together with 143 published ones using Bayesian coalescent approach as well as three different phylogenetic analysis method...
Loux SC, Scoggin KE, Bruemmer JE, Canisso IF, Troedsson MH, Squires EL, Ball BA.MicroRNAs (miRNAs) are small, non-coding RNAs which are produced throughout the body. Individual tissues tend to have a specific expression profile and excrete many of these miRNAs into circulation. These circulating miRNAs may be diagnostically valuable biomarkers for assessing the presence of disease while minimizing invasive testing. In women, numerous circulating miRNAs have been identified which change significantly during pregnancy-related complications (e.g. chorioamnionitis, eclampsia, recurrent pregnancy loss); however, no prior work has been done in this area in the horse. To identif...
Singha H, Malik P, Saini S, Khurana SK, Elschner MC, Mertens K, Barth SA, Tripathi BN, Singh RK.Burkholderia mallei is a Gram-negative coccobacillus which causes glanders-a fatal disease of equines that may occasionally be transmitted to humans. Several cases of outbreaks have been reported from India since 2006. This paper presents draft genome sequences of two B. mallei strains isolated from equines affected by glanders in India.
Lewis SL, Holl HM, Streeter C, Posbergh C, Schanbacher BJ, Place NJ, Mallicote MF, Long MT, Brooks SA.Equine obesity can cause life-threatening secondary chronic conditions, similar to those in humans and other animal species. Equine metabolic syndrome (EMS), primarily characterized by hyperinsulinemia, is often present in obese horses and ponies. Due to clinical similarities to conditions such as pituitary pars intermedia dysfunction (formerly equine Cushing's disease), conclusive diagnosis of EMS often proves challenging. Aside from changes in diet and exercise, few targeted treatments are available for EMS, emphasizing the need for early identification of at-risk individuals to enable imple...
Ropka-Molik K, Stefaniuk-Szmukier M, Żukowski K, Piórkowska K, Gurgul A, Bugno-Poniewierska M.Arabian horses are believed to be one of the oldest and most influential horse breeds in the world. Blood is the main tissue involved in maintaining body homeostasis, and it is considered a marker of the processes taking place in the other tissues. Thus, the aim of our study was to identify the genetic basis of changes occurring in the blood of Arabian horses subjected to a training regimen and to compare the global gene expression profiles between different training periods (T: after a slow canter phase that is considered a conditioning phase, T: after an intense gallop phase, and T: at the e...
Bauer A, Hiemesch T, Jagannathan V, Neuditschko M, Bachmann I, Rieder S, Mikko S, Penedo MC, Tarasova N, Vitková M, Sirtori N, Roccabianca P, Leeb T....Naked foal syndrome (NFS) is a genodermatosis in the Akhal-Teke horse breed. We provide the first scientific description of this phenotype. Affected horses have almost no hair and show a mild ichthyosis. So far, all known NFS affected horses died between a few weeks and 3 yr of age. It is not clear whether a specific pathology caused the premature deaths. NFS is inherited as a monogenic autosomal recessive trait. We mapped the disease causing genetic variant to two segments on chromosomes 7 and 27 in the equine genome. Whole genome sequencing of two affected horses, two obligate carriers, and...
Viļuma A, Mikko S, Hahn D, Skow L, Andersson G, Bergström TF.The mammalian Major Histocompatibility Complex (MHC) region contains several gene families characterized by highly polymorphic loci with extensive nucleotide diversity, copy number variation of paralogous genes, and long repetitive sequences. This structural complexity has made it difficult to construct a reliable reference sequence of the horse MHC region. In this study, we used long-read single molecule, real-time (SMRT) sequencing technology from Pacific Biosciences (PacBio) to sequence eight Bacterial Artificial Chromosome (BAC) clones spanning the horse MHC class II region. The final asse...
Murungi EK, Kariithi HM.The apicomplexan parasite Sarcocystis neurona causes equine protozoal myeloencephalitis (EPM), a degenerative neurological disease of horses. Due to its host range expansion, S. neurona is an emerging threat that requires close monitoring. In apicomplexans, protein kinases (PKs) have been implicated in a myriad of critical functions, such as host cell invasion, cell cycle progression and host immune response evasion. Here, we used various bioinformatics methods to define the kinome of S. neurona and phylogenetic relatedness of its PKs to other apicomplexans. We identified 97 putative PKs clust...
Gim JA, Kim HS.MicroRNAs (miRNAs) are single-stranded, small RNAs (21-23 nucleotides) that function in gene silencing and translational inhibition via the RNA interference mechanism. Most miRNAs originate from host genomic regions, such as intergenic regions, introns, exons, and transposable elements (TEs). Here, we focused on the palindromic structure of medium reiteration frequencies (MERs), which are similar to precursor miRNAs. Five MER consensus sequences (MER5A1, MER53, MER81, MER91C, and MER117) were matched with paralogous transcripts predicted to be precursor miRNAs in the horse genome (equCab2) and...
Steinbusch MM, Fang Y, Milner PI, Clegg PD, Young DA, Welting TJ, Peffers MJ.The development of effective treatments for the age-related disease osteoarthritis and the ability to predict disease progression has been hampered by the lack of biomarkers able to demonstrate the course of the disease. Profiling the expression patterns of small nucleolar RNAs (snoRNAs) in joint ageing and OA may provide diagnostic biomarkers and therapeutic targets. This study determined expression patterns of snoRNAs in joint ageing and OA and examined them as potential biomarkers. Using SnoRNASeq and real-time quantitative PCR (qRT-PCR) we demonstrate snoRNA expression levels in murine age...
Sedykh SE, Purvinish LV, Monogarov AS, Burkova EE, Grigor'eva AE, Bulgakov DV, Dmitrenok PS, Vlassov VV, Ryabchikova EI, Nevinsky GA.Exosomes are 40-100 nm nanovesicles containing RNA and different proteins. Exosomes containing proteins, lipids, mRNAs, and microRNAs are important in intracellular communication and immune function. Exosomes from different sources are usually obtained by combination of centrifugation and ultracentrifugation and according to published data can contain from a few dozens to thousands of different proteins. Crude exosome preparations from milk of eighteen horses were obtained for the first time using several standard centrifugations. Exosome preparations were additionally purified by FPLC gel fi...
Pawlina K, Gurgul A, Szmatoła T, Koch C, Mählmann K, Witkowski M, Bugno-Poniewierska M.Equine sarcoids are the most common neoplasms occurring in horses. Despite frequent occurrence, they are still not well described at the molecular level. Thus, in the present study, we performed a comprehensive comparative analysis of sarcoid miRNAome profile to identify aberrantly expressed microRNAs, along with their structural variants, potentially useful as biomarkers and, in a wider perspective, broaden the knowledge about this tumor and underlying mechanisms. To this end, we conducted next generation sequencing and as a result we identified both known and potentially novel miRNAs. Differ...
Maniego J, Pesko B, Habershon-Butcher J, Huggett J, Taylor P, Scarth J, Ryder E.Throughout the history of horse racing, doping techniques to suppress or enhance performance have expanded to match the technology available. The next frontier in doping, both in the equine and human sports areas, is predicted to be genetic manipulation; either by prohibited use of genome editing, or gene therapy via transgenes. By using massively-parallel sequencing via a two-step PCR method we can screen for multiple doping targets at once in pooled primer sets. This method has the advantages of high scalability through combinational indexing, and the use of reference standards with altered ...
Moyo NA, Marchi E, Steinbach F.Dendritic cells (DC) are the main immune mediators inducing primary immune responses. DC generated from monocytes (MoDC) are a model system to study the biology of DC in vitro, as they represent inflammatory DC in vivo. Previous studies on the generation of MoDC in horses indicated that there was no distinct difference between immature and mature DC and that the expression profile was distinctly different from humans, where CD206 is expressed on immature MoDC whereas CD83 is expressed on mature MoDC. Here we describe the kinetics of equine MoDC differentiation and activation, analysing both ph...
Liu L, Zhang Y, Ma H, Cao H, Liu W.Horse Milk has important quantitative characteristics and high economic value. However, the DNA methylation regulators involved in horse milk traits have not been clarified. To explore the important role of genome-wide DNA methylation in regulating equine milk yield, this study systematically investigated the genome-wide DNA methylation profiles of Kazakh horse blood by comparing a high-production group (HP, average daily milk yield of 7.5 kg) and low-production group (LP, average daily milk yield of 3.2 kg) using deep whole-genome bisulfite sequencing. First, both groups showed similar prop...
Mittelholzer C, Stadejek T, Johansson I, Baule C, Ciabatti I, Hannant D, Paton D, Autorino GL, Nowotny N, Belák S.To determine a conclusive phylogeny, equine arteritis viruses from Italy, Austria, Hungary, Sweden, South Africa and other parts of the world were analysed by reverse-transcription polymerase chain reaction amplification and direct sequencing. The nucleotide sequences corresponding to the variable part of the large glycoprotein GP5, specified by open reading frame 5, were compared and added to a previously published phylogenetic tree in which a clear division between 'European' and 'American' type viruses had been established. Adding the sequences determined in this study and new sequences ret...
Lindgren G, Naboulsi R, Frey R, Solé M.Equine skin diseases are common, causing increased costs and reduced welfare of affected horses.Genetic testing, if available, can complement early detection, disease diagnosis, and clinical treatment and offers horse breeders the possibility to rule out carrier status. The mechanisms of complex disease can be investigated by using the latest state-of-the-art genomic technologies. Genome-based strategies may also serve as an efficient and cost-effective strategy for the management of the disease severity levels, with particular interest in complex traits such as insect bite hypersensitivity, c...
Liu XX, Pan JF, Zhao QJ, He XH, Pu YB, Han JL, Ma YH, Jiang L.The X chromosome shows a special interaction between demographic factors and genetic variation, and the analysis of X-linked genomic variation can therefore provide insights into the unique effects of demography and selection on the horse genome that cannot be readily detected by autosomal markers. Debao (DB) ponies have experienced intense selective pressure for the development of their small stature (<106 cm at adult height). To identify selective sweeps on the X chromosome of the DB pony, we performed a genome-wide scan of three Chinese horse breeds using an Equine SNP70 BeadChip. Using Yi...
Perelygin AA, Lear TL, Zharkikh AA, Brinton MA.Mammalian 2'-5' oligoadenylate (2-5A) synthetases are important mediators of the antiviral activity of interferons. Both human and mouse 2-5A synthetase gene families encode four forms of enzymes: small, medium, large and ubiquitin-like. In this study, the structures of four equine OAS genes were determined using DNA sequences derived from fifteen cDNA and four BAC clones. Composition of the equine OAS gene family is more similar to that of the human OAS family than the mouse Oas family. Two OAS-containing bovine BAC clones were identified in GenBank. Both equine and bovine BAC clones were phy...
Han H, Dong H, Chen Q, Gao Y, Li J, Li W, Dang R, Lei C.Testes produce sperm, and investigations into gene expression in the testes will enhance the understanding of the roles of testicular genes in male reproduction. Cryptorchidism, the failure of one or both testes to descend into the scrotal sac, is a common congenital malformation in horses. The major clinical consequence of this abnormality is impaired fertility. The aim of this study was to analyze the expression patterns of testicular genes and to identify the differentially expressed genes (DEGs) in testes between cryptorchid and normal horses. In this study, the gene expression patterns in...
Thaker SR, Dutta SK, Adhya SL, Mattingly-Napier BL.A gene bank of Ehrlichia risticii was constructed in plasmid vector pUC13. Five clones representing discrete regions of the E. risticii genome were tested for their ability to hybridize specifically to E. risticii DNA. None of the clones cross-hybridized with Ehrlichia equi DNA, whereas four of these clones cross-hybridized with Ehrlichia canis and Ehrlichia sennetsu DNAs. However, one clone carrying a 1-kilobase HindIII fragment of E. risticii DNA failed to cross-react with the genomes of E. sennetsu, E. canis, and E. equi in dot blot hybridization assays. The sensitivity of this probe for th...
Schurink A, Ducro BJ, Bastiaansen JW, Frankena K, van Arendonk JA.Insect bite hypersensitivity (IBH) is the most common allergic disease present in horses worldwide. It has been shown that IBH is under genetic control, but the knowledge of associated genes is limited. We conducted a genome-wide association study to identify and quantify genomic regions contributing to IBH in the Dutch Shetland pony population. A total of 97 cases and 91 controls were selected and matched on withers height, coat colour and pedigree to minimise the population stratification. A blood sample was collected from participating Shetland pony mares, their IBH phenotype was scored and...
Mosher CM, Court MH.Pharmacogenomics is the study of the impact of genetic variation on drug effects, with the ultimate goal of achieving "personalised medicine". Since the completion of the Human Genome Project, great strides have been made towards the goal of personalised dosing of drugs in people, as exemplified by the development of gene-guided dosing of the anticoagulant drug, warfarin. Although the pharmacogenomics of domestic animals is still at an early stage of development, there is great potential for advances in the coming years as the direct result of complete genome sequences currently being derived ...
Reich P, Möller S, Stock KF, Nolte W, von Depka Prondzinski M, Reents R, Kalm E, Kühn C, Thaller G, Falker-Gieske C, Tetens J.Body conformation, including withers height, is a major selection criterion in horse breeding and is associated with other important traits, such as health and performance. However, little is known about the genomic background of equine conformation. Therefore, the aim of this study was to use imputed sequence-level genotypes from up to 4891 German Warmblood horses to identify genomic regions associated with withers height and linear conformation traits. Furthermore, the traits were genetically characterised and putative causal variants for withers height were detected. Results: A genome-wide ...
Gmel AI, Mikko S, Ricard A, Velie BD, Gerber V, Hamilton NA, Neuditschko M.The Franches-Montagnes (FM) is the last native horse breed of Switzerland, established at the end of the 19th century by cross-breeding local mares with Anglo-Norman stallions. We collected high-density SNP genotype data (Axiom™ 670 K Equine genotyping array) from 522 FM horses, including 44 old-type horses (OF), 514 European Warmblood horses (WB) from Sweden and Switzerland (including a stallion used for cross-breeding in 1990), 136 purebred Arabians (AR), 32 Shagya Arabians (SA), and 64 Thoroughbred (TB) horses, as introgressed WB stallions showed TB origin in their pedigrees. The aim of ...
Sigurðardóttir H, Ablondi M, Kristjansson T, Lindgren G, Eriksson S.The Icelandic horse and Exmoor pony are ancient, native breeds, adapted to harsh environmental conditions and they have both undergone severe historic bottlenecks. However, in modern days, the selection pressures on these breeds differ substantially. The aim of this study was to assess genetic diversity in both breeds through expected (HE) and observed heterozygosity (HO) and effective population size (Ne). Furthermore, we aimed to identify runs of homozygosity (ROH) to estimate and compare genomic inbreeding and signatures of selection in the breeds. Results: HO was estimated at 0.34 and 0.33...
Hain-Saunders NMR, Knight DR, Bruce M, Byrne D, Riley TV.Clostridioides difficile poses an ongoing threat as a cause of gastrointestinal disease in humans and animals. Traditionally considered a human healthcare-related disease, increases in community-associated C. difficile infection (CDI) and growing evidence of inter-species transmission suggest a wider perspective is required for CDI control. In horses, C. difficile is a major cause of diarrhoea and life-threatening colitis. This study aimed to better understand the epidemiology of CDI in Australian horses and provide insights into the relationships between horse, human and environmental strains...
Triant DA, Walsh AT, Hartley GA, Petry B, Stegemiller MR, Nelson BM, McKendrick MM, Fuller EP, Cockett NE, Koltes JE, McKay SD, Green JA, Murdoch BM....Current genome sequencing technologies have made it possible to generate highly contiguous genome assemblies for non-model animal species. Despite advances in genome assembly methods, there is still room for improvement in the delineation of specific gene features in the genomes. Here we present genome visualization and annotation tools to support seven livestock species (bovine, chicken, goat, horse, pig, sheep, and water buffalo), available in a new resource called AgAnimalGenomes. In addition to supporting the manual refinement of gene models, these browsers provide visualization tracks for...
Pfeffer M, Burck G, Meyer H.Five case reports on cowpox virus infections in cats, humans, and for the first time in a horse are presented. It becomes obvious that in most cases the diagnosis cowpox is suspected rather late, although fast and reliable diagnostic tools such as pathohistological examination and polymerase chain reaction are available. The threat of a zoonotic transmission mainly through cats is gaining importance. Although wild rodents have been claimed to be the reservoir and source for cowpox viruses in cats, very little is known about the epidemiology of cowpox virus. Based on the different genome organi...
Criscione A, Moltisanti V, Chies L, Marletta D, Bordonaro S.Salernitano (SAL) is an ancient Italian horse breed developed over the course of the ages together with Napoletano and, during the 20th century, by crossing with Thoroughbred horse lines. Excellent in hurdle jumping, this breed is currently facing a concrete risk of extinction due to the lack of appropriate management strategies. This research is the first SAL genetic characterization that aims to set up the basic knowledge for a conservation plan. A representative sample of 61 SALs was analyzed by means of a set of 16 microsatellites markers (short tandem repeats (STRs)). The sequence of hype...
Dierks C, Mömke S, Drögemüller C, Leeb T, Chowdhary BP, Distl O.In this study, we present a comprehensive 5000-rad radiation hybrid map of a 40-cM region on equine chromosome 4 (ECA4) that contains quantitative trait loci for equine osteochondrosis. We mapped 29 gene-associated sequence tagged site markers using primers designed from equine expressed sequence tags or BAC clones in the ECA4q12-q22 region. Three blocks of conserved synteny, showing two chromosomal breakpoints, were identified in the segment of ECA4q12-q22. Markers from other segments of HSA7q mapped to ECA13p and ECA4p, and a region of HSA7p was homologous to ECA13p. Therefore, we have impro...
Soghigian J, Andreadis TG, Molaei G.Eastern Equine Encephalitis (EEE) (Togaviridae, Alphavirus) is a highly pathogenic mosquito-borne arbovirus that circulates in an enzootic cycle involving Culiseta melanura mosquitoes and wild Passeriformes birds in freshwater swamp habitats. Recently, the northeastern United States has experienced an intensification of virus activity with increased human involvement and northward expansion into new regions. In addition to its principal role in enzootic transmission of EEE virus among avian hosts, recent studies on the blood-feeding behavior of Cs. melanura throughout its geographic range sugg...
Powell BB, Horvath KC, Gilliam TL, Sibille KT, Keil A, Miller-Cushon EK, Wickens CL, Brooks SA.The startle response can be defined as a reflexive reaction to the sudden appearance of a novel stimulus that influences the survival and resilience of animals. In domesticated species, the behavioral component of the startle response can, in some cases, cause serious injury to the animal or human handlers if inappropriately expressed. Here, we describe a longitudinal study in a population of stock-type horses that quantified behavioral startle responses elicited by the presentation of a sudden novel object (rapidly opening umbrella). The study was performed in weanling foals across four conse...
Gu W, Bertone AL.To create high-quality sequence data for the generation of an equine gene expression microarray and evaluate array performance by use of lipopolysaccharide (LPS) exposure of synoviocytes. Methods: Public nucleotide sequence database from Equus caballus and synoviocytes from clinically normal adult horses. Methods: Computer procurement of equine gene sequences, probe design, and manufacture of an oligomicroarray were performed. Array performance was evaluated by use of patterns for equine synoviocytes in response to LPS. Results: Starting with 18,924 equine gene sequences, 3,098 equine 3' seque...
Vidale P, Piras FM, Nergadze SG, Bertoni L, Verini-Supplizi A, Adelson D, Guérin G, Giulotto E.We mapped six genes (EIF4G3, HSP90, RBBP6, IL8, TERT, and TERC) on the chromosomes of Equus caballus, Equus asinus, Equus grevyi, and Equus burchelli by fluorescence in situ hybridization. Our results add six type I markers to the cytogenetic map of these species and provide new information on the comparative genomics of the genus Equus.
Bright LA, Mujahid N, Nanduri B, McCarthy FM, Costa LR, Burgess SC, Swiderski CE.The equine genome sequence enables the use of high-throughput genomic technologies in equine research, but accurate identification of expressed gene products and interpreting their biological relevance require additional structural and functional genome annotation. Here, we employ the equine genome sequence to identify predicted and known proteins using proteomics and model these proteins into biological pathways, identifying 582 proteins in normal cell-free equine bronchoalveolar lavage fluid (BALF). We improved structural and functional annotation by directly confirming the in vivo expressio...
Snyman J, Koekemoer O, van Schalkwyk A, Jansen van Vuren P, Snyman L, Williams J, Venter M.Equine encephalosis virus (EEV) is a neglected virus endemic to South Africa and is considered to generally result in mild disease in equines. Specimens were analyzed from live horses that presented with undefined neurological, febrile, or respiratory signs, or sudden and unexpected death. Between 2010 and 2017, 111 of 1523 (7.3%) horse samples tested positive for EEV using a nested real-time reverse transcriptase polymerase chain reaction (rRT-PCR). Clinical signs were reported in 106 (7.2%) EEV positive and 1360 negative horses and included pyrexia (77/106, 72.6%), icterus (20/106, 18.9%) an...
