Genetics in horses encompasses the study of hereditary traits and the genetic makeup that influences various characteristics and health conditions in equine populations. This field involves the analysis of genes and their functions, inheritance patterns, and the impact of genetic variations on traits such as coat color, performance ability, and susceptibility to diseases. Research in equine genetics employs techniques such as genome mapping, sequencing, and genetic testing to identify specific genes and mutations associated with these traits. This page gathers peer-reviewed research studies and scholarly articles that explore the genetic basis of equine traits, the methodologies used in genetic research, and the implications for breeding, health management, and conservation of horse breeds.
Ghielmetti G, Stevens MJA, Schmitt S, Kittl S, Cernela N, Biggel M, Schulthess B, Keller PM, Schrenzel J, Stephan R.Rhodococcus equi is an intracellular bacterial pathogen that can cause infections in various hosts, including humans and animals. Host-associated virulence plasmids have been identified as key contributors to the pathogenicity of R. equi and potentially play a role in determining the host tropism of the bacteria. The investigation of additional clinical and environmental isolates is likely to provide novel insights into the population structure, infection pathways, and drug resistance of this important pathogen. We combined whole-genome sequencing and antimicrobial-susceptibility testing of 37...
McGlennon AA, Verheyen KL, Newton JR, van Tonder A, Wilson H, Parkhill J, de Brauwere N, Frosth S, Waller AS.Strangles (Streptococcus equi infection) remains endemic in the UK, with ~300 laboratory diagnoses annually. Sub-clinically infected long-term carriers are considered a key driver of endemicity. Analysing genomes of circulating strains could provide valuable transmission insights of this pathogen. Objective: To determine the population structure and diversity of UK S. equi isolates and to model transmission using epidemiological and whole genome sequencing data. Methods: Retrospective cross-sectional epidemiological and genomic surveillance. Methods: A dated phylogenetic tree derived from 511...
Ding W, Gong W, Bou T, Shi L, Lin Y, Shi X, Li Z, Wu H, Dugarjaviin M, Bai D.The core objective of racehorse breeding is to enhance the speed and endurance of the horses. The Grassland-Thoroughbred is an emerging horse breed developed in northern China in recent years, characterized by excellent speed performance, enduring stamina, and strong environmental adaptability. However, research on the genetic characteristics within this breed and the genes associated with athletic performance remains relatively limited. We conducted whole-genome resequencing of Grassland-Thoroughbred F1, F2, F3, and the crossbred population (CY) and obtained a total of 4056.23 Gb of high-qual...
Jia H, Tang L, Fu Y, Xiong Y, Yan L, Shao C, Li K, Zhang D, Hu D.Petrovinema skrjabini (Nematoda: Strongylidae, Cyathostominae) is a parasitic nematode colonizing the cecum and colon of equids. Like other cyathostomins, its larvae (L3) invade the intestinal mucosa, forming encysted nodules that may remain dormant for years. Mass larval emergence triggers larval cyathostominosis-a severe syndrome characterized by hemorrhagic typhlocolitis and diarrhea, with mortality rates exceeding 50%. However, owing to the morphological indistinguishability of cyathostomin and frequent mixed infections in natural settings, species-specific contributions to pathogenesis re...
Zhang Z, Lu Z, Yao X, Li L, Meng J, Wang J, Zeng Y, Ren W.Kazakh mares have drawn significant attention for their outstanding lactation traits. Lactation, a complex physiological activity, is modulated by multiple factors. This study utilized high-throughput sequencing to conduct whole-transcriptome sequencing analysis on the mammary gland tissue of eight Kazakh mares, of which four were pregnant and four were non-pregnant, to systematically reveal the molecular regulatory mechanisms. The results showed differential expression in 2136 mRNAs, 180 lncRNAs, 104 miRNAs, and 1162 circRNAs. Gene ontology functional annotation indicates that these different...
Brodesser DM, Schlangen K, Rodríguez-Rojas A, Kuropka B, Doulidis PG, Brandt S, Pratscher B.Malignant melanoma (MM) affects not only humans but also animals, with gray horses being particularly predisposed to acquiring the disease. Multiomics have greatly advanced the understanding of human MM. In contrasty little is known regarding the pathogenesis of gray-horse melanoma and the unique phenomenon of melanoma "dormancy" in some animals. To help close this gap in knowledge, melanoma tissue and intact skin collected from gray horses were subjected to transcriptome analysis using RNAseq. In the next step, cultured primary tumor cells and normal skin fibroblasts were established from gra...
Scupham AJ.Many viruses mutate rapidly to adapt to host defenses, and for some of these viruses, the result is long-term infection in individual hosts. The work described here examines the infection and long-term maintenance of a newly identified virus, equine parvovirus-hepatitis (EqPV-H), in an individual horse. This description is possible because of a hypervariable region in the capsid gene; sequence variants were tracked by high-throughput sequencing of serum samples taken over a 16-year period. The data support the hypothesis that EqPV-H infection resulted in a sequence variant bottleneck. The cont...
Cortez JV, Hardwicke K, Méndez-Calderón CE, Grupen CG.The asynchrony of cytoplasmic and nuclear maturation in cumulus-oocyte complexes (COCs) due to prematurely declining concentrations of cyclic adenosine monophosphate (cAMP) has been shown to result in reduced oocyte developmental competence. The objective of this study was to evaluate the effect of pre-IVM treatment with cAMP modulators for different durations on the developmental potential of equine oocytes used for cloned embryo production. Collected COCs were transferred to cryovials filled with transport medium at 20-22 °C. Within the cryovials, the COCs were either untreated (Control) fo...
While the centromeric function is conserved and epigenetically specified by CENP-A, centromeric DNA, typically composed of satellite repeats, is highly divergent and rapidly evolving. In the species of the genus Equus (horses, asses and zebras), also known as equids, the numerous centromeres devoid of satellite repeats enabled us to carry out molecular analysis of centromeric chromatin establishing a unique model system for mammalian centromere biology. In this review, after a brief description of the rapid evolution of equids, we outline one of our most relevant initial discoveries: the posit...
Tian Y, Su Y, Jiang X, Su L, Zhang B, Lv F.The zoonotic pathogen subspecies (SEZ) frequently colonizes equines harmlessly but can occasionally cause disease or cross species barriers. Currently, growing evidence suggests SEZ can lead to severe clinical manifestations in horses and other animals, posing a threat to human and companion animal health. In this study, we sequenced the complete genome of the SEZ strain HT321, a novel sequence type 420 isolated from a donkey with a respiratory infection in China. Subsequently, we conducted comparative genomics, core genome single nucleotide polymorphisms (cgSNP), phylogenetic analysis multi...
Avila F, Esdaile E, Bellone RR. Standardbreds, a breed of horses used in harness racing at either the trot or the pace, established a closed studbook in 1973. Concerns about genetic diversity within the breed led the United States Trotting Association (USTA) to establish a limit of mares bred per stallion (i.e., a studbook cap) in 2009. Here, we aimed to evaluate the impact of the breeding restrictions on genetic diversity between and among subpopulations. : Sixteen short tandem repeats (STRs) were analyzed across a dataset of 176,424 Standardbreds foaled in the United States between 1998 and 2021. We examined allelic richn...
Furukawa R, Tozaki T, Kawate K, Kikuchi M, Ishige T, Takahashi Y, Fukui E, Kakoi H.Gene doping, which entails the administration of transgenes, poses a serious threat to the integrity of equine sports and also raises both ethical and regulatory concerns. Current methods used for the detection of such doping often necessitate the extraction of DNA from plasma, which can be time-consuming and labour-intensive. To overcome this limitation, we developed a direct chamber digital PCR (cdPCR) method that enables transgene detection in equine plasma without the need for DNA purification. Using the equine erythropoietin (EPO) transgene as a model, we validated the assay by analysing ...
Ryan CA, Berry DP, Bugno-Poniewierska M, Burke MK, Raudsepp T, Egan S, Doyle JL.Autosomal trisomy, a genetic disorder characterized by the presence of an extra autosome, is a rare but important chromosomal abnormality in horses, often associated with infertility, developmental abnormalities, and reduced life expectancy. This study represents the largest population-level screening for autosomal trisomy in horses; the analysis used single nucleotide polymorphism (SNP) panel genotype intensity data from 17,078 horses, 6601 of which were juveniles (i.e., ≤12 months of age) when genotyped. Using methodologies adapted from similar screening studies in cattle, the only aneuplo...
Ablondi M, Eriksson S, Mikko S.Fragile foal syndrome (FFS) is a disease caused by a recessive lethal missense mutation in the PLOD1 gene located on ECA2. Despite its harmful effect, a relatively high frequency of FFS carriers was observed in Warmblood breeds spanning from 7.4% in a random sample of Swedish Warmblood breed to 17% in the Hanoverian and Danish Warmblood, indicating potential heterozygous advantage. Balancing selection can be further studied based on haplotype blocks and via detection of heterozygosity-rich region (ROHet) around the target of selection. In this study we evaluated the presence of haplotype block...
Herkenhoff ME.MicroRNAs (miRNAs) are molecules that regulate gene expression by targeting the 3' untranslated region (UTR) of mRNAs. They are essential in numerous biological processes like growth, metabolism, and muscle development. miRNA research has become crucial in livestock breeding, offering solutions for improving animal health and productivity. This review focuses on miRNAs' roles in equine performance, reproduction, and disease, highlighting key findings and future applications in these areas. It discusses the use of circulating miRNAs (ci-miRNA) as biomarkers for athletic performance, particularl...
Hisaeda K, LE NAT, Kadekaru S, Ono T, Hiasa Y, Ohzawa E, Hata A, Kutara K, Sugimoto K, Une Y, Iwata E, Kunieda T, Zhang C, Kitagawa H.We evaluated metabolic abnormalities in six neonatal Noma foals (Nos. 54-57, 62, and 66) that died shortly after birth, using laboratory tests, pathological examinations, serum amino acid (AA) analyses, gas chromatography/mass spectrometry (GC/MS), and genetic analyses. Nonspecific clinical symptoms, such as poor suckling and weakness, were commonly observed at birth. Sepsis caused by various bacterial infections was detected in foal Nos. 54, 62, and 66, while a heart malformation was identified in foal No. 57. Laboratory tests showed high aspartate transaminase, lactate dehydrogenase, and cre...
Barandalla M, Colleoni S, Perota A, Galli C, Lazzari G.The introduction of ovum pick-up, Intracytoplasmic Sperm Injection (ICSI) and in vitro embryo production in equine reproduction offers significant advantages, including overcoming infertility, high blastocyst yields, embryo cryopreservation, and preimplantation genetic testing (PGT) by collecting few cells extruded spontaneously during embryo growth using a mouth pipette. PGT enables embryo selection before transfer and is particularly useful in breeds with a preference for specific offspring genders, coat color, and detecting genetic diseases. Here, we present the first large-scale validation...
Wang X, Shen Y, Ren H, Yi M, Bou G.Genomic imprinting is critical for mammalian development, but its regulation varies across species. The insulin-like growth factor 2 receptor (IGF2R), which is a maternally expressed imprinted gene critical for cell proliferation and differentiation, as well as embryonic and placental development, is classically regulated by differentially methylated regions (DMRs) and lncRNA- in mice. However, studies on this in equus are scarce, especially in terms of mechanistic studies. In the present study, heart, liver, spleen, lung, kidney, brain, and muscle samples were obtained from horses, donkeys, a...
Everts RE, Caron R, Foster G, McLoone K, Martin K, Brooks SA, Lafayette C.The roan coat color is described as the dispersion of white hairs within an otherwise solid background color coat. This phenotype is primarily expressed on the body of the horse, with the head and legs exhibiting few to no white hairs. Previous studies mapped the locus for roan to the KIT region and observed linked variants in a small number of breeds. However, utilizing those linked markers to determine the roan genotype in other breeds has seen limited success. In this communication we identify a second roan allele (RN2) which, in conjunction with a previously observed roan allele (RN1) disc...
Mojsiejczuk L, Whitlock F, Chen H, Magill C, Aranday-Cortes E, Bone J, Tong L, Da Silva Filipe A, Bryant N, Newton JR, Chambers TM, Reedy SE....Influenza A viruses (IAVs) are prime examples of emerging viruses in humans and animals. IAV circulation in domestic animals poses a pandemic risk as it provides new opportunities for zoonotic infections. The recent emergence of H5N1 IAV in cows and subsequent spread over multiple states within the USA, together with reports of spillover infections in humans, cats and mice highlight this issue. The horse is a domestic animal in which an avian-origin IAV lineage has been circulating for >60 years. In 2018/19, a Florida Clade 1 (FC1) virus triggered one of the largest epizootics recorded in the ...
Fakhar-I-Adil M, Angel-Velez D, Araftpoor E, Amin QA, Hedia M, Bühler M, Gevaert K, Menten B, Van Soom A, Chuva de Sousa Lopes SM, Stoop D, De Roo C....In vitro maturation (IVM) of oocytes retrieved from ovum pick-up (OPU) or ovarian tissue (OT) is a standard approach for patients with specific conditions where prior hormonal stimulation is contraindicated. However, the developmental competence of oocytes matured in vitro is still inferior to that of oocytes matured in vivo. Capacitation IVM (CAPA-IVM) includes an extra step of pre-maturation culture (PMC) with c-type natriuretic peptide (CNP) as a meiotic arrestor to better synchronize cytoplasmic and nuclear maturity in oocytes by allowing the cytoplasm additional time to acquire essential ...
Donovan K, Torres J, Zhu D, Herrington WG, Staplin N.Genome-wide association studies (GWAS) of disease progression are vulnerable to collider bias caused by selection of participants with disease at study entry. This bias introduces spurious associations between disease progression and genetic variants that are truly only associated with disease incidence. Methods of statistical adjustment to reduce this bias have been published, but rely on assumptions regarding the genetic correlation of disease incidence and disease progression which are likely to be violated in many human diseases. MR-Horse is a recently published Bayesian method to estimate...
Ding W, Gong W, Bou T, Shi L, Lin Y, Shi X, Li Z, Wu H, Dugarjaviin M, Bai D, Zhao Y.Speed and endurance are the primary goals in racehorse breeding. The Grassland-Thoroughbred is a newly developed breed in northern China that combines speed, endurance, and environmental adaptability. However, current research on the genetic background of this breed and the genes associated with athletic performance remains limited. We conducted whole-genome resequencing on Mongolian (MG), Thoroughbred (TB), Xilingol (XL), and Grassland-Thoroughbred (CY) horses, generating 3813.74 Gb of clean data after quality control. The number of transitions was significantly higher than that of transversi...
Faulk C.Sequencing a genome by students has now become practical as we demonstrated with our recent publication of the Przewalski's horse (Equus ferus przewalskii) genome. In this review, I describe my experience teaching genome assembly in the classroom. In my course, students sequenced, assembled, and published a high-quality genome for Przewalski's horse using Oxford Nanopore long-read sequencing with only $4000 of materials. Along with the genome, we assembled the mitochondrial genome, sequence variants, predicted gene annotations, and DNA methylation levels. Our genome statistics far exceeded the...
Ding W, Gong W, Bou T, Shi L, Lin Y, Shi X, Li Z, Wu H, Dugarjaviin M, Bai D.Copy number variation (CNV) is an important source of genetic variation. However, studies utilizing whole-genome sequencing to investigate CNVs in horse populations and their effects on traits remain relatively limited. This study aims to address the lack of research on the impact of copy number variation (CNV) on racing performance in horse populations, providing new insights for locally bred racing breeds. We analyzed 60 offspring derived from the crossbreeding of Thoroughbred horses and Xilingol horses. These horses were temporarily named "Grassland-Thoroughbred" and were divided into two g...
Asti V, Summer A, Ablondi M, Sartori C, Giontella A, Pilastro V, Mecocci S, Cappelli K, Mancin E, Oian A, Mantovani R, Capomaccio S, Sabbioni A.Horses have undergone extensive natural and artificial selection, shaping the diversity of breeds observed today. Native Italian breeds present unique traits influenced by natural selection, such as adaptation to harsh climates, or hoof strength, but face challenges due to population declines and the reduction of their original breeding purpose. This study focuses on five local Italian breeds: Bardigiano, Haflinger, Maremmano, Murgese, and Italian Heavy Draught Horse, to understand how selection has shaped their populations. A total of 1620 individuals were genotyped with a medium-density SNP ...
Science (New York, N.Y.)May 15, 2025
Volume 388, Issue 6748 748-755 doi: 10.1126/science.adr2355
Climate affects habitat, food availability, and the movement and sustainability of all life. In this work, we apply Indigenous and Western scientific methods, including genomics and isotope profiling, on fossils from across Beringia to explore the effect of climate change on horses. We find that Late Pleistocene horses from Alaska and northern Yukon are related to populations from Eurasia and crossed the Bering land bridge multiple times during the last glacial interval. We also find deeply divergent lineages north and south of the American ice sheets that genetically influenced populations ac...
Barsi B, Oláh J, Posta J.The Hungarian Coldblood horse was developed in the 1920s by crossing local mares with draft horses imported from Belgium and France, and was approved as an official horse breed in 1954. The aim of the study was to analyze the quality of the pedigree, generation interval, gene origin, and inbreeding. The pedigree information was received from the Hungarian Coldblood Horse Breeding Association. The studbook data of the registered animals up to 2023 were evaluated. Two reference populations were chosen: horses having offspring in 1989 and 2023. The final database contained 21,699 horses. Pedigree...
Doud MB, Ashenberg O, Bloom JD.Evolution drives changes in a protein's sequence over time. The extent to which these changes in sequence lead to shifts in the underlying preference for each amino acid at each site is an important question with implications for comparative sequence-analysis methods, such as molecular phylogenetics. To quantify the extent that site-specific amino acid preferences shift during evolution, we performed deep mutational scanning on two homologs of human influenza nucleoprotein with 94% amino acid identity. We found that only a modest fraction of sites exhibited shifts in amino acid preferences tha...
Pelkonen S, Lindahl SB, Suomala P, Karhukorpi J, Vuorinen S, Koivula I, Väisänen T, Pentikäinen J, Autio T, Tuuminen T.Streptococcus equi subspecies zooepidemicus (S. zooepidemicus) is a zoonotic pathogen for persons in contact with horses. In horses, S. zooepidemicus is an opportunistic pathogen, but human infections associated with S. zooepidemicus are often severe. Within 6 months in 2011, 3 unrelated cases of severe, disseminated S. zooepidemicus infection occurred in men working with horses in eastern Finland. To clarify the pathogen's epidemiology, we describe the clinical features of the infection in 3 patients and compare the S. zooepidemicus isolates from the human cases with S. zooepidemicus isolates...
Galli C, Lagutina I, Crotti G, Colleoni S, Turini P, Ponderato N, Duchi R, Lazzari G.Several animal species, including sheep, mice, cattle, goats, rabbits, cats, pigs and, more recently, mules have been reproduced by somatic cell cloning, with the offspring being a genetic copy of the animal donor of the nuclear material used for transfer into an enucleated oocyte. Here we use this technology to clone an adult horse and show that it is possible to establish a viable, full-term pregnancy in which the surrogate mother is also the nuclear donor. The cloned offspring is therefore genetically identical to the mare who carried it, challenging the idea that maternal immunological rec...
Librado P, Der Sarkissian C, Ermini L, Schubert M, Jónsson H, Albrechtsen A, Fumagalli M, Yang MA, Gamba C, Seguin-Orlando A, Mortensen CD....Yakutia, Sakha Republic, in the Siberian Far East, represents one of the coldest places on Earth, with winter record temperatures dropping below -70 °C. Nevertheless, Yakutian horses survive all year round in the open air due to striking phenotypic adaptations, including compact body conformations, extremely hairy winter coats, and acute seasonal differences in metabolic activities. The evolutionary origins of Yakutian horses and the genetic basis of their adaptations remain, however, contentious. Here, we present the complete genomes of nine present-day Yakutian horses and two ancient specim...
Peregrine AS, Molento MB, Kaplan RM, Nielsen MK.Parascaris equorum and cyathostomins are currently considered the most important parasites of horses and have traditionally been controlled with anthelmintics belonging to three drug classes: benzimidazoles, the tetrahydropyrimidine pyrantel, and macrocyclic lactones. Unfortunately, resistance to benzimidazoles, and to a lesser extent pyrantel, is widespread in cyathostomins around the world. Furthermore, resistance to macrocyclic lactones appears to be in the early stages of development in cyathostomins in multiple locations. In contrast, P. equorum populations have remained susceptible to th...
Arrigo NC, Adams AP, Weaver SC.The eastern equine encephalitis (EEE) complex consists of four distinct genetic lineages: one that circulates in North America (NA EEEV) and the Caribbean and three that circulate in Central and South America (SA EEEV). Differences in their geographic, pathogenic, and epidemiologic profiles prompted evaluation of their genetic diversity and evolutionary histories. The structural polyprotein open reading frames of all available SA EEEV and recent NA EEEV isolates were sequenced and used in evolutionary and phylogenetic analyses. The nucleotide substitution rate per year for SA EEEV (1.2 x 10(-4...
Telford EA, Watson MS, Aird HC, Perry J, Davison AJ.The complete DNA sequence of equine herpesvirus 2 (EHV-2) strain 86/67 was determined. The genome is 184,427 bp in size and has a base composition of 57.5% G + C. Unusually for a herpesvirus, about a third of the sequence distributed in several large blocks appears not to encode proteins. The 79 open reading frames that were identified as probably polypeptide-coding are predicted to encode 77 distinct proteins. Amino acid sequence comparisons confirmed that EHV-2 is a gamma-herpesvirus that is genetically collinear with herpesvirus saimiri (HVS; a gamma 2-herpesvirus) and Epstein-Barr virus (E...
Warmuth V, Eriksson A, Bower MA, Barker G, Barrett E, Hanks BK, Li S, Lomitashvili D, Ochir-Goryaeva M, Sizonov GV, Soyonov V, Manica A.Despite decades of research across multiple disciplines, the early history of horse domestication remains poorly understood. On the basis of current evidence from archaeology, mitochondrial DNA, and Y-chromosomal sequencing, a number of different domestication scenarios have been proposed, ranging from the spread of domestic horses out of a restricted primary area of domestication to the domestication of numerous distinct wild horse populations. In this paper, we reconstruct both the population genetic structure of the extinct wild progenitor of domestic horses, Equus ferus, and the origin and...
Metzger J, Schrimpf R, Philipp U, Distl O.Body size is an important characteristic for horses of various breeds and essential for the classification of ponies concerning the limit value of 148 cm (58.27 inches) height at the withers. Genome-wide association analyses revealed the highest associated quantitative trait locus for height at the withers on horse chromosome (ECA) 3 upstream of the candidate gene LCORL. Using 214 Hanoverian horses genotyped on the Illumina equine SNP50 BeadChip and 42 different horse breeds across all size ranges, we confirmed the highly associated single nucleotide polymorphism BIEC2-808543 (-log(10)P = ...
Liu X, Zhang Y, Li Y, Pan J, Wang D, Chen W, Zheng Z, He X, Zhao Q, Pu Y, Guan W, Han J, Orlando L, Ma Y, Jiang L.High altitude represents some of the most extreme environments worldwide. The genetic changes underlying adaptation to such environments have been recently identified in multiple animals but remain unknown in horses. Here, we sequence the complete genome of 138 domestic horses encompassing a whole altitudinal range across China to uncover the genetic basis for adaptation to high-altitude hypoxia. Our genome data set includes 65 lowland animals across ten Chinese native breeds, 61 horses living at least 3,300 m above sea level across seven locations along Qinghai-Tibetan Plateau, as well as 7...
Fernandes KA, Kittelmann S, Rogers CW, Gee EK, Bolwell CF, Bermingham EN, Thomas DG.The effects of abrupt dietary transition on the faecal microbiota of forage-fed horses over a 3-week period were investigated. Yearling Thoroughbred fillies reared as a cohort were exclusively fed on either an ensiled conserved forage-grain diet ("Group A"; n = 6) or pasture ("Group B"; n = 6) for three weeks prior to the study. After the Day 0 faecal samples were collected, horses of Group A were abruptly transitioned to pasture. Both groups continued to graze similar pasture for three weeks, with faecal samples collected at 4-day intervals. DNA was isolated from the faeces and microbial 16S ...
Guo Y, Wang M, Kawaoka Y, Gorman O, Ito T, Saito T, Webster RG.In March 1989 a severe outbreak of respiratory disease occurred in horses in the Jilin and Heilongjiang provinces of Northeast China that caused up to 20% mortality in some herds. An influenza virus of the H3N8 subtype was isolated from the infected animals and was antigenically and molecularly distinguishable from the equine 2 (H3N8) viruses currently circulating in the world. The reference strain A/Equine/Jilin/1/89 (H3N8) was most closely related to avian H3N8 influenza viruses. Sequence comparisons of the entire hemagglutinin (HA), nucleoprotein (NP), neuraminidase (NA), matrix (M), and NS...
Puffer BA, Watkins SC, Montelaro RC.We have identified an interaction between the equine infectious anemia virus (EIAV) late assembly domain and the cellular AP-2 clathrin-associated adapter protein complex. A YXXL motif within the EIAV Gag late assembly domain was previously characterized as a sequence critical for release of assembling virions. We now show that this YXXL sequence interacts in vitro with the AP-50 subunit of the AP-2 complex, while the functionally interchangeable late assembly domains carried by the Rous sarcoma virus p2b protein and human immunodeficiency virus type 1 p6 protein, which utilize PPPY and PTAPP ...
Couetil L, Cardwell JM, Leguillette R, Mazan M, Richard E, Bienzle D, Bullone M, Gerber V, Ivester K, Lavoie JP, Martin J, Moran G, Niedźwiedź A....The 2019 Havemeyer Workshop brought together researchers and clinicians to discuss the latest information on Equine Asthma and provide future research directions. Current clinical and molecular asthma phenotypes and endotypes in humans were discussed and compared to asthma phenotypes in horses. The role of infectious and non-infectious causes of equine asthma, genetic factors and proposed disease pathophysiology were reviewed. Diagnostic limitations were evident by the limited number of tests and biomarkers available to field practitioners. The participants emphasized the need for more accessi...
Lindgren G, Backström N, Swinburne J, Hellborg L, Einarsson A, Sandberg K, Cothran G, Vilà C, Binns M, Ellegren H.Genetic studies using mitochondrial DNA (mtDNA) have identified extensive matrilinear diversity among domestic horses. Here, we show that this high degree of polymorphism is not matched by a corresponding patrilinear diversity of the male-specific Y chromosome. In fact, a screening for single-nucleotide polymorphisms (SNPs) in 14.3 kb of noncoding Y chromosome sequence among 52 male horses of 15 different breeds did not identify a single segregation site. These observations are consistent with a strong sex-bias in the domestication process, with few stallions contributing genetically to the do...
Goodrich LR, Hidaka C, Robbins PD, Evans CH, Nixon AJ.Gene therapy with insulin-like growth factor-1 (IGF-1) increases matrix production and enhances chondrocyte proliferation and survival in vitro. The purpose of this study was to determine whether arthroscopically-grafted chondrocytes genetically modified by an adenovirus vector encoding equine IGF-1 (AdIGF-1) would have a beneficial effect on cartilage healing in an equine femoropatellar joint model. A total of 16 horses underwent arthroscopic repair of a single 15 mm cartilage defect in each femoropatellar joint. One joint received 2 x 10(7) AdIGF-1 modified chondrocytes and the contralateral...
Carbone L, Nergadze SG, Magnani E, Misceo D, Francesca Cardone M, Roberto R, Bertoni L, Attolini C, Francesca Piras M, de Jong P, Raudsepp T....Centromere repositioning (CR) is a recently discovered biological phenomenon consisting of the emergence of a new centromere along a chromosome and the inactivation of the old one. After a CR, the primary constriction and the centromeric function are localized in a new position while the order of physical markers on the chromosome remains unchanged. These events profoundly affect chromosomal architecture. Since horses, asses, and zebras, whose evolutionary divergence is relatively recent, show remarkable morphological similarity and capacity to interbreed despite their chromosomes differing co...
Asanovich KM, Bakken JS, Madigan JE, Aguero-Rosenfeld M, Wormser GP, Dumler JS.The agent of human granulocytic ehrlichiosis (HGE), Ehrlichia phagocytophila, and Ehrlichia equi are very similar. HGE is of variable severity. Genetic and antigenic differences among 3 human isolates (Webster, Spooner, and NY-8) and 1 horse isolate (MRK) were evaluated. The 16S rRNA gene sequences were identical in all human isolates. By use of 5 homologous antisera from these 3 humans and 1 horse and an additional 5 antisera in heterologous reactions, the immunodominant antigens of each isolate were noted to differ in molecular size: 43 kDa in the Webster (Wisconsin) isolate, 46 kDa in the S...
Gu J, Orr N, Park SD, Katz LM, Sulimova G, MacHugh DE, Hill EW.Thoroughbred horses have been selected for exceptional racing performance resulting in system-wide structural and functional adaptations contributing to elite athletic phenotypes. Because selection has been recent and intense in a closed population that stems from a small number of founder animals Thoroughbreds represent a unique population within which to identify genomic contributions to exercise-related traits. Employing a population genetics-based hitchhiking mapping approach we performed a genome scan using 394 autosomal and X chromosome microsatellite loci and identified positively selec...
Pezzanite LM, Fortier LA, Antczak DF, Cassano JM, Brosnahan MM, Miller D, Schnabel LV.This study tested the hypothesis that Major Histocompatibility Complex (MHC) incompatible equine mesenchymal stromal cells (MSCs) would induce cytotoxic antibodies to donor MHC antigens in recipient horses after intradermal injection. No studies to date have explored recipient antibody responses to allogeneic donor MSC transplantation in the horse. This information is critical because the horse is a valuable species for assessing the safety and efficacy of MSC treatment prior to human clinical application. Methods: Six MHC heterozygote horses were identified as non-ELA-A2 haplotype by microsat...
Turton JF, Baklan H, Siu LK, Kaufmann ME, Pitt TL.A multiplex PCR using targets within the serotype-specific region of the capsular polysaccharide synthesis gene cluster of serotypes K1, K2 and K5 was evaluated using the 77 reference serotype strains of Klebsiella, and a panel of clinical isolates subjected previously to conventional serotyping. The PCR was highly specific for these serotypes, which are those most associated with virulence in humans and horses. PCR confirmed that isolates of the K5 serotype had cross-reacted with antiserum for other serotypes, particularly for K7. K5 isolates received by our laboratory were almost exclusively...
Treiber KH, Kronfeld DS, Hess TM, Byrd BM, Splan RK, Staniar WB.To evaluate genetic and metabolic predispositions and nutritional risk factors for development of pasture-associated laminitis in ponies. Methods: Observational cohort study. Methods: 160 ponies. Methods: A previous diagnosis of laminitis was used to differentiate 54 ponies (PL group) from 106 nonlaminitic ponies (NL group). Pedigree analysis was used to determine a mode of inheritance for ponies with a previous diagnosis of laminitis. In early March, ponies were weighed and scored for body condition and basal venous blood samples were obtained. Plasma was analyzed for glucose, insulin, trigly...
Lichtenfels JR, Kharchenko VA, Dvojnos GM.The Equidae (the horse, Equus caballus, the ass, Equus asinus, zebras and their hybrids) are hosts to a great variety of nematode parasites, some of which can cause significant morbidity or mortality if individual hosts are untreated. Worldwide the nematode parasites of horses belong to 7 suborders, 12 families, 29 genera and 83 species. The great majority (19 of 29 genera and 64 of 83 species) are members of the family Strongylidae, which includes the most common and pathogenic nematode parasites of horses. Only the Strongylidae are included in this treatise. The Strongylidae (common name str...
Brunberg E, Andersson L, Cothran G, Sandberg K, Mikko S, Lindgren G.The Silver coat color, also called Silver dapple, in the horse is characterized by dilution of the black pigment in the hair. This phenotype shows an autosomal dominant inheritance. The effect of the mutation is most visible in the long hairs of the mane and tail, which are diluted to a mixture of white and gray hairs. Herein we describe the identification of the responsible gene and a missense mutation associated with the Silver phenotype. Results: Segregation data on the Silver locus (Z) were obtained within one half-sib family that consisted of a heterozygous Silver colored stallion with 34...
Alberti A, Zobba R, Chessa B, Addis MF, Sparagano O, Pinna Parpaglia ML, C뻝u T, Pintori G, Pittau M.The presence of Anaplasma phagocytophilum, a tick-transmitted zoonotic pathogen, was investigated in Sardinia using a molecular approach. Phylogenetic analysis revealed that Sardinian strains are genetically distinct from the two lineages previously described in Europe and are closely related to strains isolated in different areas of the United States.
Pérez DR, Damberger FF, Wüthrich K.The NMR structure of the horse (Equus caballus) cellular prion protein at 25 degrees C exhibits the typical PrP(C) [cellular form of prion protein (PrP)] global architecture, but in contrast to most other mammalian PrP(C)s, it contains a well-structured loop connecting the beta2 strand with the alpha2 helix. Comparison with designed variants of the mouse prion protein resulted in the identification of a single amino acid exchange within the loop, D167S, which correlates with the high structural order of this loop in the solution structure at 25 degrees C and is unique to the PrP sequences of e...
Lafont R, Dinan L.Ecdysteroids are widely used as inducers for gene-switch systems based on insect ecdysteroid receptors and genes of interest placed under the control of ecdysteroid-response elements. We review here these systems, which are currently mainly used in vitro with cultured cells in order to analyse the role of a wide array of genes, but which are expected to represent the basis for future gene therapy strategies. Such developments raise several questions, which are addressed in detail. First, the metabolic fate of ecdysteroids in mammals, including humans, is only poorly known, and the rapid catabo...
Schraiber JG, Evans SN, Slatkin M.The advent of accessible ancient DNA technology now allows the direct ascertainment of allele frequencies in ancestral populations, thereby enabling the use of allele frequency time series to detect and estimate natural selection. Such direct observations of allele frequency dynamics are expected to be more powerful than inferences made using patterns of linked neutral variation obtained from modern individuals. We developed a Bayesian method to make use of allele frequency time series data and infer the parameters of general diploid selection, along with allele age, in nonequilibrium populati...
Vidal MA, Kilroy GE, Johnson JR, Lopez MJ, Moore RM, Gimble JM.To characterize equine bone marrow (BM)-derived mesenchymal stem cell (MSC) growth characteristics and frequency as well as their adipogenic and osteogenic differentiation potential. Methods: In vitro experimental study. Methods: Foals (n=3, age range, 17-51 days) and young horses (n=5, age range, 9 months to 5 years). Methods: Equine MSCs were harvested and isolated from sternal BM aspirates and grown up to passage 10 to determine cell-doubling (CD) characteristics. Limit dilution assays were performed on primary and passaged MSCs to determine the frequency of colony-forming units with a fibr...
