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.
Giontella A, Pieramati C, Silvestrelli M, Sarti FM.The Maremmano is an autochthonous Italian horse breed, which probably descended from the native horses of the Etruscans (VI century B.C.); the Studbook was acknowledged in 1980, and it includes 12 368 horses born from that year up to 2015. The aim of this study was to evaluate the effect of the selection program on the genetic variability of the Maremmano population; the analysis was performed using both the 'Endog v 4.8' program available at http://webs.ucm.es/info/prodanim/html/JP_Web.htm and in-house software on official pedigree data. Four Reference Populations were considered, and the mos...
Tan Y, Lam TT, Heberlein-Larson LA, Smole SC, Auguste AJ, Hennigan S, Halpin RA, Fedorova N, Puri V, Stockwell TB, Shilts MH, Andreadis T....Eastern equine encephalitis virus (EEEV) has a high case-fatality rate in horses and humans, and Florida has been hypothesized to be the source of EEEV epidemics for the northeastern United States. To test this hypothesis, we sequenced complete genomes of 433 EEEV strains collected within the United States from 1934 to 2014. Phylogenetic analysis suggested EEEV evolves relatively slowly and that transmission is enzootic in Florida, characterized by higher genetic diversity and long-term local persistence. In contrast, EEEV strains in New York and Massachusetts were characterized by lower genet...
Wormstrand B, Østevik L, Ekman S, Olstad K.Failure of the cartilage canal blood supply leads to ischemic chondronecrosis which causes osteochondrosis, and osteochondral lesions. Osteochondrosis is a disease with a heritable component and usually occurs under aseptic conditions. Because bacteria can bind to growth cartilage and disrupt the blood supply in pigs and chickens, we considered whether this might play a role in development of equine osteochondrosis. The aim of this study was to examine whether bacteria are present in canals in the growth cartilage of foals with septic arthritis/osteomyelitis, and whether this is associated wit...
AbouEl Ela NA, El-Nesr KA, Ahmed HA, Brooks SA.Severe combined immunodeficiency (SCID) is a fatal genetic disorder and one of the common genetic diseases of the Arabian horse. The genetic mutation responsible for this disease is a five base pair deletion (TCTCA) in the DNA-protein kinase catalytic subunit gene. Severe combined immunodeficiency is a recessive autosomal genetic disorder with 25% chance inheritance of the disease among the progeny of carrier parents. It causes complete absence of certain immune cells, like B and T lymphocytes, leaving foals with immunodeficiency and exposing them to early death within 4 to 6 months. This stud...
Morris LHA.The development of techniques to produce equine embryos in vitro is reviewed with specific reference to intracytoplasmic sperm injection (ICSI). Unexplored 50 years ago, this technology has progressed rapidly in the last 20 years to become a commercial reality for the equine breeding industry. Improvements in our understanding of oocyte and embryo competence in the horse have been key factors in overcoming some of the initial problems associated with ICSI. It is now possible to obtain high nuclear maturation and cleavage rates in vitro and the most limiting factor, presently, is the low rate o...
Lupo A, Haenni M, Saras E, Gradin J, Madec JY, Börjesson S.A predominance of the bla/IncHI1 plasmid combination in horses has been reported in Czech-Republic, Denmark, and The Netherlands. To clarify a possible specific plasmid epidemiology of bla in horses in a European perspective, a collection of 74 extended-spectrum beta-lactamase-producing Escherichia coli recovered from diseased horses in France and Sweden during the period 2009-2014 was investigated in respect of their genetic relatedness, plasmid content, and molecular features. Overall, 80% of E. coli isolates from diseased horses harbored bla on large IncHI1 plasmids with plasmid sequence ty...
Gao JF, Zhang XX, Wang XX, Li Q, Li Y, Xu WW, Gao Y, Wang CR.Parascarosis is caused mainly by parasitic infections with Parascaris equorum and Parascaris univalens, the most common ascarid nematodes, in the small intestine of equines. Parascarosis often causes severe illness and even death in foals and yearlings. In this study, we obtained the complete sequence of the P. equorum mitochondrial (mt) genome and compared its organization and structure with that of P. equorum Japan isolate (nearly complete), and the complete mtDNA sequences of P. univalens Switzerland and USA isolates. The complete mtDNA genome of P. equorum China isolate is 13,899 base pair...
Wolny-Koładka K, Lenart-Boroń A.The aim of the study was to determine the antimicrobial resistance profile and the occurrence of extended-spectrum beta-lactamase genes and to analyze the genetic diversity of Escherichia coli strains isolated from the environment of horse riding centers. The study was conducted using E. coli strains isolated from the air, manure, and horse nostril swabs in three horse riding centers differing in the system of horse keeping-stable (OJK Pegaz and KJK Szary) and free-range (SKH Nielepice). Resistance to antibiotics was determined using the disk-diffusion method, and the PCR technique was employe...
Zhao RY, Zhao YP, Li B, Bou G, Zhang XZ, Mongke T, Bao T, Gereliin S, Gereltuuin T, Li C, Bai DY, Dugarjaviin ML.Mammalian coat color is one of the first phenotypic changes resulting from positive selection by humans, and it serves important roles in genetic and evolutionary processes. Among them, horses show a broad variety of coat color patterns, based on which it is difficult to distinguish the real phenotypes, resulting in confused records in horse breed registration. Thus, research in the genetic mechanisms on the development of coat color patterns is significant in horse reproduction and breeding. With the recent establishment of genomics and sequencing technologies, there are significant advances ...
Dahl CD, Wyss C, Zuberbühler K, Bachmann I.One model of signal evolution is based on the notion that behaviours become increasingly detached from their original biological functions to obtain a communicative value. Selection may not always favour the evolution of such transitions, for instance, if signalling is costly due to predators usurping signal production. Here, we collected inertial movement sensing data recorded from multiple locations in free-ranging horses (Equus caballus), which we subjected to a machine learning algorithm to extract kinematic gestalt profiles. This yielded surprisingly rich and multi-layered sets of informa...
Tong KJ, Duchêne DA, Duchêne S, Geoghegan JL, Ho SYW.Phylogenetic analysis of DNA from modern and ancient samples allows the reconstruction of important demographic and evolutionary processes. A critical component of these analyses is the estimation of evolutionary rates, which can be calibrated using information about the ages of the samples. However, the reliability of these rate estimates can be negatively affected by among-lineage rate variation and non-random sampling. Using a simulation study, we compared the performance of three phylogenetic methods for inferring evolutionary rates from time-structured data sets: regression of root-to-tip...
Jenkins C, Jelocnik M, Micallef ML, Galea F, Taylor-Brown A, Bogema DR, Liu M, O'Rourke B, Chicken C, Carrick J, Polkinghorne A.Chlamydia psittaci is an avian pathogen capable of spill-over infections to humans. A parrot C. psittaci strain was recently detected in an equine reproductive loss case associated with a subsequent cluster of human C. psittaci infections. In this study, we screened for C. psittaci in cases of equine reproductive loss reported in regional New South Wales, Australia during the 2016 foaling season. C. psittaci specific-PCR screening of foetal and placental tissue samples from cases of equine abortion (n = 161) and foals with compromised health status (n = 38) revealed C. psittaci positiv...
Kraus M, Physick-Sheard P, Brito LF, Sargolzaei M, Schenkel FS.Admissions of Standardbred racehorses (Std) to the Ontario Veterinary College Teaching Hospital (OVCTH) for treatment of atrial fibrillation (AF) began to increase in the early 1990s. The arrhythmia has been shown to have a modest heritability (h2 ≃ 0.15), with some stallions appearing as sires or sires of mares used in breeding (broodmares) of affected horses more frequently than others. The objective of this study was to determine the marginal genetic contributions of ancestors to cohorts of Std affected with AF and their contemporary control groups, and whether these ancestors contribute ...
Jonsdottir S, Stefansdottir SB, Kristinarson SB, Svansson V, Bjornsson JM, Runarsdottir A, Wagner B, Marti E, Torsteinsdottir S.Insect bite hypersensitivity is an allergic dermatitis of horses caused by bites of Culicoides midges. Sufficient amount of pure, endotoxin-free allergens is a prerequisite for development and monitoring of preventive and therapeutic allergen immunotherapy. Aims of the study were to compare the Culicoides nubeculosus (Cul n) allergens Cul n 3 and Cul n 4, produced in transgenic barley grains with the corresponding E. coli or insect cells expressed proteins for measuring antibody and cytokine responses. Allergen-specific IgG responses were measured by ELISA in sera from twelve horses not expose...
Hollis AR, Starkey MP.MicroRNAs are small noncoding RNAs that play a pivotal role in diverse cellular processes through post-transcriptional regulation of gene expression. The dysregulation of specific microRNAs is associated with disease development and progression. In this review, we summarise how microRNAs modulate gene expression, and explain microRNA nomenclature. We discuss the potential applications of microRNAs in equine disease diagnosis and treatment, in the context of the sum of current knowledge about microRNA expression in normal and diseased equine tissues.
Ortved KF, Begum L, Stefanovski D, Nixon AJ.Following joint trauma, a posttraumatic inflammatory cascade drives degeneration of the joint. We aimed to assess whether transduction of chondrocytes with AAV5 overexpressing the immunomodulatory cytokine IL-10 would have protective effects in pellet cultures stimulated with IL-1β. Chondrocytes were isolated from 3 healthy horses and were transduced with AAV5-IL-10 at a dose of 1 x 105vg/cell. Chondrocyte pellets were formed by centrifugation and were stimulated with IL-1β starting 48 hours following transduction. After 2, 6 and 14 days in culture, supernatants were collected for cytokine a...
Fischer CD, Wachoski-Dark GL, Grant DM, Bramer SA, Klein C.Interferon epsilon (IFNE) is type I interferon which stands out through its unusual expression profile and differing regulation compared to classic type I interferons such as interferon alpha and interferon beta. Unlike other type I interferons, the expression of IFNE is not stimulated through exposure to viral agents. Expression of IFNE is most abundant in mouse and human endometrium where it is constitutively expressed in luminal and glandular epithelial cells and expression levels are up-regulated with estrogen exposure. The aim of the current study was to determine whether a cycle or pregn...
Baird A, Lindsay T, Everett A, Iyemere V, Paterson YZ, McClellan A, Henson FMD, Guest DJ.Bone fractures occur in horses following traumatic and non-traumatic (bone overloading) events. They can be difficult to treat due to the need for the horse to bear weight on all legs during the healing period. Regenerative medicine to improve fracture union and recovery could significantly improve horse welfare. Equine induced pluripotent stem cells (iPSCs) have previously been derived. Here we show that equine iPSCs cultured for 21 days in osteogenic induction media on an OsteoAssay surface upregulate the expression of osteoblast associated genes and proteins, including , , , , and We al...
Science (New York, N.Y.)May 9, 2018
Volume 360, Issue 6396 eaar7711 doi: 10.1126/science.aar7711
de Barros Damgaard P, Martiniano R, Kamm J, Moreno-Mayar JV, Kroonen G, Peyrot M, Barjamovic G, Rasmussen S, Zacho C, Baimukhanov N, Zaibert V....The Yamnaya expansions from the western steppe into Europe and Asia during the Early Bronze Age (~3000 BCE) are believed to have brought with them Indo-European languages and possibly horse husbandry. We analyzed 74 ancient whole-genome sequences from across Inner Asia and Anatolia and show that the Botai people associated with the earliest horse husbandry derived from a hunter-gatherer population deeply diverged from the Yamnaya. Our results also suggest distinct migrations bringing West Eurasian ancestry into South Asia before and after, but not at the time of, Yamnaya culture. We find no ev...
López-Correa RD, Peñagaricano F, Rovere G, Urioste JI.The aim of this study was to estimate the genetic parameters of performance in a 750-km, 15-day ride in Criollo horses. Heritability (h2 ) and maternal lineage effects (mt2 ) were obtained for rank, a relative placing measure of performance. Additive genetic and maternal lineage (rmt) correlations among five medium-to-high intensity phase ranks (pRK) and final rank (RK) were also estimated. Individual records from 1,236 Criollo horses from 1979 to 2012 were used. A multivariate threshold animal model was applied to the pRK and RK. Heritability was moderate to low (0.156-0.275). Estimates of mt...
Rink BE, Kuhl J, Esteves CL, French HM, Watson E, Aurich C, Donadeu FX.Mesenchymal stem or stromal cells (MSCs) play key roles in tissue homeostasis. In the cyclic equine endometrium, this may be regulated by changes in serum concentrations of sex steroid hormones. This study was designed to investigate the changes in endometrial expression of MSC markers during reproductive cycles in mares and the influence of sex steroid hormones on endometrial MSC proliferation in vitro. Endometrial biopsies were collected from pony mares at different reproductive stages (estrus; day 5 and 13 after ovulation; seasonal anestrus; 20 h and 7days post-partum; n = 5 per stag...
Manna G, Cersini A, Nardini R, Bartolomé Del Pino LE, Antognetti V, Zini M, Conti R, Lorenzetti R, Veneziano V, Autorino GL, Scicluna MT.Babesia caballi and Theileria equi are tick-borne pathogens causing equine piroplasmosis infecting the Equidae family in which they cause significant sanitary and economic losses. Furthermore, equine piroplasmosis is included in the World Animal Health Organization (OIE) notifiable diseases list with possible movement restrictions for positive horses. Thirty-nine EDTA and whole-blood samples collected during 2013 and 2014 from symptomatic and asymptomatic horses of Central-Southern Italy were included in the present study either because of their strongly positive results in Real Time (RT) PCRs...
Park MJ, Lee J, Byeon JS, Jeong DU, Gu NY, Cho IS, Cha SH.Mesenchymal stem cells (MSCs) are useful candidates for tissue engineering and cell therapy fields. We optimize culture conditions of equine adipose tissue-derived MSCs (eAD-MSCs) for treatment of horse fractures. To investigate enhancing properties of three-dimensional (3D) culture system in eAD-MSCs, we performed various sized spheroid formation and determined changes in gene expression levels to obtain different sized spheroid for cell therapy. eAD-MSCs were successfully isolated from horse tailhead. Using hanging drop method, spheroid formation was generated for three days. Quantitative re...
Sallé G, Kornaś S, Basiaga M.Equine strongyles are a major health issue. Large strongyles can cause death of horses while cyathostomins (small strongyles) have shown increased resistance to anthelmintics worldwide. Description of strongyle communities have accumulated but little is known about the diversity of these communities and underpinning environmental factors. Strongyles were recovered after ivermectin treatment from 48 horses located in six premises in Poland. Correlation between previously published species fecundity and the observed relative abundance and prevalence were estimated. Significance of horse sex was ...
Forni D, Cagliani R, Pontremoli C, Pozzoli U, Vertemara J, De Gioia L, Clerici M, Sironi M.Hepatitis C virus (HCV) belongs to the genus and is genetically heterogeneous, with seven major genotypes further divided into several recognized subtypes. HCV origin was previously dated in a range between ∼200 and 1000 years ago. Hepaciviruses have been identified in several domestic and wild mammals, the largest viral diversity being observed in bats and rodents. The closest relatives of HCV were found in horses/donkeys (equine hepaciviruses, EHV). However, the origin of HCV as a human pathogen is still an unsolved puzzle. Using a selection-informed evolutionary model, we show that the c...
Mammalian centromeres are associated with highly repetitive DNA (satellite DNA), which has so far hindered molecular analysis of this chromatin domain. Centromeres are epigenetically specified, and binding of the CENPA protein is their main determinant. In previous work, we described the first example of a natural satellite-free centromere on Chromosome 11. Here, we investigated the satellite-free centromeres of by using ChIP-seq with anti-CENPA antibodies. We identified an extraordinarily high number of centromeres lacking satellite DNA (16 of 31). All of them lay in LINE- and AT-rich regio...
Gehlen H, Bildheim LM.An effect of aging on cardiac morphology and function has been shown in humans. In horses, cardiac wall motion analysis using two-dimensional speckle tracking (2D-ST) has not yet been reported. Our study included 57 horses of different warmblood breeds between 3 and 30 years old. Age had a significant influence on left ventricular free wall (LVFW) systolic strain rate ( ≤ 0.05) and early diastolic relaxation ( ≤ 0.01). In the interventricular septum (IVS), systolic ( ≤ 0.01) and late diastolic ( ≤ 0.05) contraction velocities also increased with age. In our study, 2D-ST revealed import...
Read JE, Cabrera-Sharp V, Kitscha P, Cartwright JE, King PJ, Fowkes RC, de Mestre AM.Equine chorionic gonadotrophin (eCG) is a placental glycoprotein critical for early equine pregnancy and used therapeutically in a number of species to support reproductive activity. The factors in trophoblast that transcriptionally regulate eCGβ-subunit (), the gene which confers the hormones specificity for the receptor, are not known. The aim of this study was to determine if glial cells missing 1 regulates promoter activity. Here, studies of the proximal promoter identified four binding sites for glial cells missing 1 (GCM1) and western blot analysis confirmed GCM1 was expressed in equi...
Saey V, Tang J, Ducatelle R, Croubels S, De Baere S, Schauvliege S, van Loon G, Chiers K.Friesian horses are known for their high inbreeding rate resulting in several genetic diseases such as hydrocephaly and dwarfism. This last decade, several studies focused on two other presumed hereditary traits in Friesian horses: megaoesophagus and aortic rupture. The pathogenesis of these diseases remains obscure but an important role of collagen has been hypothesized. The purpose of this study was to examine possible breed-related differences in collagen catabolism. Urinary specimens from Friesian (n = 17, median age 10 years old) and Warmblood horses (n = 17, median age 10 years...
Riley SC, Gibson AH, Leask R, Mauchline DJ, Pedersen HG, Watson ED.Extensive tissue remodelling is required in equine ovaries for follicle growth and development and also migration of the follicle to the ovulatory fossa, where ovulation occurs. The mechanisms for these processes are largely unexplored. Matrix metalloproteinases (MMPs) and their endogenous tissue inhibitors (TIMPs) are important for control of breakdown of extracellular matrix during tissue remodelling. The aims of this study were to determine the pattern and sites of secretion of the gelatinases MMP-2 and -9 and TIMPs into follicular fluid during follicle development in mare ovaries. The pred...
Spaas JH, Chiers K, Bussche L, Burvenich C, Van de Walle GR.The mammary gland is a highly regenerative organ that can undergo multiple cycles of proliferation, lactation, and involution. Based on the facts that (i) mammary stem/progenitor cells (MaSC) are proposed to be the driving forces behind mammary growth and function and (ii) variation exists between mammalian species with regard to physiological and pathological functioning of this organ, we believe that studying MaSC from different mammals is of great comparative interest. Over the years, important data has been gathered on MaSC of men and mice, although knowledge on MaSC in other mammals remai...
Crossett B, Allen WR, Stewart F.Large quantities of an unusual 19 kDa protein (p19) are secreted into the lumen of the uterus of the mare (Equus caballus) during the oestrous cycle and early pregnancy. p19 associates strongly with the acellular capsule that surrounds the young horse conceptus and is believed to be important in maintaining pregnancy. Here we report the complete cDNA sequence encoding p19, its expression patterns in horse tissues and a Southern blot analysis of the gene in horse DNA. The predicted amino acid sequence of the p19 cDNA demonstrated a signal peptide of 18 residues and a mature protein of 162 resid...
Ricard A.Recently, a mutation was discovered in the DMRT3 gene that controls pacing in horses. The mutant allele A is fixed in the American Standardbred trotter breed, while in the French trotter breed, the frequency of the wild-type allele C is still 24%. This study aimed at measuring the effect of DMRT3 genotypes on the performance of French trotters and explaining why the polymorphism still occurs in this breed. Using a mixed animal model, genetic parameters and environmental effects on performance traits were estimated from data on 173 176 French trotter races. The effect of the DMRT3 gene was then...
Li J, Zhu Y, Mi J, Zhao Y, Holyoak GR, Yi Z, Wu R, Wang Z, Zeng S.Endometrial and vaginal microbiomes are critical in the study of endometritis, which is an important cause of infertility in donkeys. Our objective was to investigate the difference of the endometrial and vaginal microbiomes between healthy donkey jennies (group C) and jennies with endometritis (group E). Endometrial and vaginal swab samples were collected, and the 16 s rRNA gene amplicon high-throughput sequencing technique was applied to identify the microbial composition in the samples. A similar microbial composition pattern was found between endometrial and vaginal samples, which indica...
Blott SC, Swinburne JE, Sibbons C, Fox-Clipsham LY, Helwegen M, Hillyer L, Parkin TD, Newton JR, Vaudin M.Thoroughbred racehorses are subject to non-traumatic distal limb bone fractures that occur during racing and exercise. Susceptibility to fracture may be due to underlying disturbances in bone metabolism which have a genetic cause. Fracture risk has been shown to be heritable in several species but this study is the first genetic analysis of fracture risk in the horse. Results: Fracture cases (n = 269) were horses that sustained catastrophic distal limb fractures while racing on UK racecourses, necessitating euthanasia. Control horses (n = 253) were over 4 years of age, were racing during the s...
Blackhall WJ, Kuzmina T, von Samson-Himmelstjerna G.Resistance to benzimidazoles (BZ) in the gastrointestinal nematodes of livestock is characterised by the presence of specific polymorphisms in the β-tubulin isotype 1 protein, a component of microtubules. The most prevalent polymorphism associated with resistance in nematodes infecting cattle, sheep, and goats is found at codon 200, with minor occurrences of polymorphisms at codons 167 and 198. In the cyathostomins that infect horses, however, a polymorphism at codon 167 appears to be more common than the codon 200 polymorphism. In the present study, a focussed analysis of PCR-amplified β-tu...
Na W, Yeom M, Yuk H, Moon H, Kang B, Song D.This study provides information regarding vaccine research and the epidemiology of influenza virus in neglected hosts (horses and dogs). Equine influenza virus (EIV) causes a highly contagious disease in horses and other equids, and outbreaks have occurred worldwide. EIV has resulted in costly damage to the horse industry and has the ability of cross the host species barrier from horses to dogs. Canine influenza is a virus of equine or avian origin and infects companion animals that live in close contact with humans; this results in possible exposure to the seasonal epizootic influenza virus. ...
Olofsson KM, Hjertner B, Fossum C, Press CM, Lindberg R.Inflammatory bowel disease (IBD) in horses is an idiopathic disorder, encompassing different types of chronic intestinal inflammation. The pathogenesis of the disease remains to be established, but it has been suggested that an imbalance between regulatory T cells (Tregs) and T helper 17 (Th17)-associated cytokines and altered toll-like receptor 4 (TLR4) expression is associated with intestinal inflammation in other species. The aim of the present study was to quantify Tregs in rectal biopsies from horses affected with IBD by immunohistochemistry and to evaluate expression of genes encoding in...
Coultous RM, McDonald M, Raftery AG, Shiels BR, Sutton DGM, Weir W.Theileria equi, one of the primary pathogens causing equine piroplasmosis, has previously been sub-classified into a number of clades on the basis of 18S SSU rRNA gene sequence diversity. This partitioning of the parasite population has potential implications for host immunity, treatment and vaccine development. To detect and identify different clade genotypes among and within individual equine blood samples, a novel PCR-based technique was designed and optimized. Theileria equi has only recently been described in The Gambia, and the developed genotyping technique was used to analyse blood sam...
The Journal of nutritionJune 15, 2006
Volume 136, Issue 7 Suppl 2094S-2098S doi: 10.1093/jn/136.7.2094S
Treiber KH, Kronfeld DS, Geor RJ.Insulin is a major regulatory hormone in glucose and fat metabolism, vascular function, inflammation, tissue remodeling, and the somatotropic axis of growth. Insulin resistance alters insulin signaling by decreasing insulin action in certain resistant pathways while increasing insulin signaling in other unaffected pathways via compensatory hyperinsulinemia. In humans, altered insulin signaling is implicated in reduced glucose availability to insulin-sensitive cells, vasoconstriction and endothelial damage, and inflammatory response. Although no direct evidence exists for insulin's role in thes...
Köhne M, Kuhlmann M, Tönißen A, Martinsson G, Sieme H.Endometritis is a major cause for impaired fertility in mares. The objectives of this study were to collect information on diagnostic and treatment practices performed by veterinarians and to investigate possible effects of professional experience, caseload, and geographical location on the practitioners' management of endometritis cases. For this purpose, equine practitioners ( = 680) were asked to fill out an online survey (34 questions). The online survey yielded 117 responses by veterinarians practicing in all parts of Germany. Most respondents came from Lower Saxony and managed <20 mares ...
Albertsdóttir E, Eriksson S, Sigurdsson Á, Árnason T.Genetic evaluation of Icelandic horses is currently based on results from breeding field tests where riding ability and conformation of the horses are evaluated over the course of 1-2 days. Only a small part of registered horses attend these field tests, and it can be assumed that these are not a random sample of the population. In this study, the trait test status was introduced, describing whether a horse was assessed in a breeding field test. This trait was analysed to find out whether it has a genetic variation and how it correlates genetically to other traits in the breeding goal. Breedin...
Tessier L, Côté O, Bienzle D.Severe equine asthma is a chronic inflammatory disease of the lung in horses similar to low-Th2 late-onset asthma in humans. This study aimed to determine the utility of RNA-Seq to call gene sequence variants, and to identify sequence variants of potential relevance to the pathogenesis of asthma. Methods: RNA-Seq data were generated from endobronchial biopsies collected from six asthmatic and seven non-asthmatic horses before and after challenge (26 samples total). Sequences were aligned to the equine genome with Spliced Transcripts Alignment to Reference software. Read preparation for sequenc...
Ablondi M, Eriksson S, Tetu S, Sabbioni A, Viklund Å, Mikko S.The equestrian sport horse Swedish Warmblood (SWB) originates from versatile cavalry horses. Most modern SWB breeders have specialized their breeding either towards show jumping or dressage disciplines. The aim of this study was to explore the genomic structure of SWB horses to evaluate the presence of genomic subpopulations, and to search for signatures of selection in subgroups of SWB with high or low breeding values (EBVs) for show jumping. We analyzed high density genotype information from 380 SWB horses born in the period 2010-2011, and used Principal Coordinates Analysis and Discriminant...
Tharasanit T, Colenbrander B, Stout TA.Oocyte cryopreservation is a potentially valuable technique for salvaging the germ-line when a valuable mare dies, but facilities for in vitro embryo production or oocyte transfer are not immediately available. This study examined the influence of maturation stage and freezing technique on the cryopreservability of equine oocytes. Cumulus oocyte complexes were frozen at the immature stage (GV) or after maturation in vitro for 30 hr (MII), using either conventional slow freezing (CF) or open pulled straw vitrification (OPS); cryoprotectant-exposed and untreated nonfrozen oocytes served as contr...
Grund CH, Lechman ER, Issel CJ, Montelaro RC, Rushlow KE.In this study we used immune sera from equine infectious anaemia virus (EIAV)-infected horses which uniquely display broad reactivity with different lentivirus capsid proteins (CA) to characterize the cross-reactive determinants of lentivirus CA proteins. In particular, the role of the major homology region (MHR) of lentivirus CA proteins in this serological cross-reactivity was evaluated using both equine immune serum and murine monoclonal antibodies (MAbs) directed against the MHR segment of different lentiviruses. The results of our studies indicate that about 80% of sera from long-term exp...
The centromere is the chromosomal locus essential for proper chromosome segregation. While the centromeric function is well conserved and epigenetically specified, centromeric DNA sequences are typically composed of satellite DNA and represent the most rapidly evolving sequences in eukaryotic genomes. The presence of satellite sequences at centromeres hampered the comprehensive molecular analysis of these enigmatic loci. The discovery of functional centromeres completely devoid of satellite repetitions and fixed in some animal and plant species represented a turning point in centromere biology...
Holt C, Jenness R.Skim-milk samples from rat, rabbit, pig, sheep, goat, horse and man were analysed for lactose, casein and the total and ultrafilterable concentrations of the main salts. Results are compared with data for the cow. The ultrafiltrate concentrations of Ca and Mg were positively correlated with that of citrate and the colloidal concentrations of Ca, Mg and citrate were positively correlated with that of Pi, suggesting that common, general, principles determine the partition of salts in milks. Casein concentration in the skim-milks was inversely related to that of lactose in accordance with a recen...
Han H, Randhawa IAS, MacHugh DE, McGivney BA, Katz LM, Dugarjaviin M, Hill EW.Thousands of years of natural and artificial selection since the domestication of the horse has shaped the distinctive genomes of Chinese Mongolian horse populations. Consequently, genomic signatures of selection can provide insights into the human-mediated selection history of specific traits and evolutionary adaptation to diverse environments. Here, we used genome-wide SNPs from five distinct Chinese Mongolian horse populations to identify genomic regions under selection for the population-specific traits, gait, black coat colour, and hoof quality. Other global breeds were used to identify r...
Sadeghi R, Moradi-Shahrbabak M, Miraei Ashtiani SR, Miller DC, Antczak DF.Previous research on the equine major histocompatibility complex (MHC) demonstrated strong correlations between haplotypes defined by polymorphic intra-MHC microsatellites and haplotypes defined using classical serology. Here, we estimated MHC diversity in a sample of 124 Arabian horses from an endangered strain native to Iran (Persian Asil Arabians), using a validated 10-marker microsatellite panel. In a group of 66 horses related as parent-offspring pairs or half-sibling groups, we defined 51 MHC haplotypes, 49 of which were new. In 47 of the remaining 58 unrelated horses, we could assign on...
Blythe LL, Hultgren BD, Craig AM, Appell LH, Lassen ED, Mattson DE, Duffield D.A clinical, viral, hematologic , and genetic study was conducted over a 4-year period on a family of Appaloosas with high incidence of clinical ataxia and pathologic features of equine degenerative myeloencephalopathy. Marginal to deficient serum vitamin E (alpha-tocopherol) and blood selenium values were the only other consistent antemortem abnormalities in the affected horses. Members of this family were all descendants of a clinically normal mare and were raised in 3 separate environments with variable quality of feed. All horses had access to pasture grasses. Normal chromosomal karyotypes ...
Larson EM, Babasyan S, Wagner B.Human IgE-binding monocytes are identified as allergic disease mediators, but it is unknown whether IgE-binding monocytes promote or prevent an allergic response. We identified IgE-binding monocytes in equine peripheral blood as IgE+/MHCIIhigh/CD14low cells that bind IgE through an FcεRI αɣ variant. IgE-binding monocytes were analyzed monthly in Culicoides hypersensitive horses and nonallergic horses living together with natural exposure to Culicoides midges. The phenotype and frequency of IgE-binding monocytes remained consistent in all horses regardless of Culicoides exposure. All horses ...
Taylor SE, Clegg PD.Mesenchymal stromal cells (MSC) are derived from adult mesenchymal tissues and have the ability to undergo differentiation into bone, cartilage, and fat, and have therefore attracted great interest in regenerative medicine. Many isolation and culture methods have been described, making comparison between laboratories and quality-control protocols difficult. A uniform protocol to characterize equine MSC has recently been proposed, aiming to introduce consistency across the equine stem cell research field. This article reviews the published techniques for collection and propagation of equine MSC...
Kisiday JD, Goodrich LR, McIlwraith CW, Frisbie DD.To compare the mesenchymal stem cell (MSC) yield and chondrogenic and osteogenic differentiation from 5- and 50-mL bone marrow aspirates from horses. Methods: Six 2- to 5-year-old mixed-breed horses. Procedures-2 sequential 5-mL aspirates were drawn from 1 ilium or sternebra. A single 50-mL aspirate was drawn from the contralateral ilium, and 2 sequential 50-mL aspirates were drawn from a second sternebra. The MSC yield was determined through the culture expansion process. Chondrogenesis and osteogenesis were evaluated by means of conventional laboratory methods. Results: The second of the 2 s...
Knych HK, Baden RW, Gretler SR, McKemie DS.Despite their widespread popularity as sport and companion animals and published and anecdotal reports of vast difference in drug disposition and pharmacokinetics between individuals, studies describing equine drug metabolism are limited. It has been theorized that similar to humans, members of the CYP2D family in horses may be polymorphic in nature leading to differences in metabolism of substrates. This study aims to build on the limited current knowledge regarding P450 mediated metabolism in horses by describing the metabolism of the polymorphic CYP2D6 probe drug codeine in vitro. Codeine, ...
Hung GC, Chilton NB, Beveridge I, Gasser RB.In order to maximise the positional homology in the primary sequence alignment of the second internal transcribed spacer for 30 species of equine strongyloid nematodes, the secondary structures of the precursor ribosomal RNA were predicted using an approach combining an energy minimisation method and comparative sequence analysis. The results indicated that a common secondary structure model of the second internal transcribed spacer of these nematodes was maintained despite significant interspecific differences (2-56%) in primary sequences. The secondary structure model was then used to refine...
Lassaline M, Cranford TL, Latimer CA, Bellone RR.To describe the prevalence of LSCC in Haflinger horses and to analyze affected horses' pedigrees investigating the genetic mode of inheritance. Methods: Fifteen horses met inclusion criterion of (i) being of the Haflinger breed, as confirmed by North American Haflinger Registry pedigree and (ii) being diagnosed with LSCC, as confirmed by clinical examination by a veterinary ophthalmologist or by histopathology. Pedigrees could not be obtained for four additional horses diagnosed with LSCC that had been identified as Haflingers. Methods: Retrospective medical record review of all 19 horses was ...
Aurich C, Schneider J.In the equine species, sex determination of the conceptus is of growing interest for the breeding industry. In horses, the sex ratio of the offspring depends on changes in body condition of the mother at conception and under natural conditions may thus markedly deviate from an expected 1:1 ratio. Insemination with sex-sorted spermatozoa allows a pronounced shift of the sex ratio but at present pregnancy rates are low and vary considerably under field conditions. In equine embryo transfer programmes, sex determination in embryos before transfer via genetic methods is a promising approach with h...
Richer CL, Power MM, Klunder LR, McFeely RA, Kent MG.The following decisions concerning the banded karyotype of the horse (Equus caballus) were made at the second International conference for Standardization of Domestic Animal Karyotypes, held at Jouy-en Josas, France, 22nd-26th May 1989: (1) numbering of the chromosomes was modified to correspond to an arrangement into only two groups (the non-acrocentrics and the acrocentrics) within which the autosomes are placed according to length alone; (2) a more compact karyotype arrangement was adopted: chromosomes 1 to 5 on the first row, 6 to 10 on the second, 11 to 13, and, at the far right, X and Y ...
