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.
Wang J, Liu J, Yang J, Wang X, Li Z, Jianlin X, Li X, Xiang Q, Li Y, Liu Z, Luo J, Guan G, Yin H.Equine piroplasmosis, caused by Theileria equi and Babesia caballi, is an economically important tick-borne disease worldwide. In the current study, 242 blood samples were randomly collected from horses in Zhangye city of Gansu province, China. The presence and genetic diversity of piroplasms were evaluated with a nested PCR assay, gene sequencing and phylogenetic analysis. The results showed that seventy-five (31.0%) samples were positive for piroplasms. Sequences analysis showed that seventy-three (30.2%) were positive for T. equi, and seven (2.9%) for B. caballi, five of which (2.1%) were i...
Henkel J, Lafayette C, Brooks SA, Martin K, Patterson-Rosa L, Cook D, Jagannathan V, Leeb T.White spotting phenotypes in horses are highly valued in some breeds. They are quite variable and may range from the common white markings up to completely white horses. EDNRB, KIT, MITF, PAX3 and TRPM1 represent known candidate genes for white spotting phenotypes in horses. For the present study, we investigated an American Paint Horse family segregating a phenotype involving white spotting and blue eyes. Six of eight horses with the white-spotting phenotype were deaf. We obtained whole-genome sequence data from an affected horse and specifically searched for structural variants in the known ...
de Lagarde M, Larrieu C, Praud K, Schouler C, Doublet B, Sallé G, Fairbrother JM, Arsenault J.Although antimicrobial resistance is increasingly common in equine medicine, molecular and epidemiological data remains scarce. Objective: We estimated the prevalence of, and risk factors for, shedding of multidrug resistant (MDR), extended spectrum β-lactamase (ESBL)-producing, and AmpC β-lactamase-producing, or some combination of these in Escherichia coli in horses in France. We characterized ESBL/AmpC isolates for antimicrobial susceptibility and the presence of virulence and ESBL/AmpC-associated resistance genes. Methods: Fecal samples from healthy adult horses at 41 premises were colle...
Lepage SIM, Lee OJ, Koch TG.Mesenchymal stromal cells (MSCs) are the most common cell population studied for therapeutic use in veterinary medicine. MSCs obtained from neonatal sources such as umbilical cord tissue (CT-MSCs) or cord blood (CB-MSCs) are appealing due to the non-invasive nature of procurement and the time allowed for characterization of cells before use. However, it remains unclear as to whether CB- or CT-MSCs have equivalent progenitor and non-progenitor functions. CB-MSCs have been shown to have superior chondrogenic potential to MSCs from other sources, whereas their immunomodulatory capacity does not s...
Cassimeris L, Engiles JB, Galantino-Homer H.Laminitis is often associated with endocrinopathies that cause hyperinsulinemia and is also induced experimentally by hyperinsulinemia, suggesting that insulin initiates laminitis pathogenesis. Hyperinsulinemia is expected to activate pro-growth and anabolic signaling pathways. We hypothesize that chronic over-stimulation of these pathways in lamellar tissue results in endoplasmic reticulum stress, contributing to tissue pathology, as it does in human metabolic diseases. We tested this hypothesis by asking whether lamellar tissue from horses with naturally-occurring endocrinopathic laminitis s...
Gianino GM, Valberg SJ, Perumbakkam S, Henry ML, Gardner K, Penedo C, Finno CJ.Immune-mediated myositis (IMM) in American Quarter Horses (QHs) causes acute muscle atrophy and lymphocytic infiltration of myofibers. Recently, an E321G mutation in a highly conserved region of the myosin heavy chain 1 (MYH1) gene was associated with susceptibility to IMM and nonexertional rhabdomyolysis. Objective: To estimate prevalence of the E321G MYH1 variant in the QH breed and performance subgroups. Methods: Three-hundred seven elite performance QHs and 146 random registered QH controls. Methods: Prospective genetic survey. Elite QHs from barrel racing, cutting, halter, racing, reining...
Kecerova Z, Cizek A, Nyc O, Krutova M.Clostridium difficile has been recovered from the faeces of several animal species as well as horses. Between April 2015 and October 2016, 213 samples of faeces from non-hospitalized (n = 138) and hospitalized horses (n = 75) were investigated and eighteen C. difficile isolates were cultured using an enrichment method. Sixteen C. difficile positive samples were identified from hospitalised horses (p < 0.01). Molecular typing revealed seven ribotypes and sequence types (RT033/ST11 n = 8, 44.4%; RT081/ST9 n = 4, 22.2%; RT009/ST3 n = 2, 11.1%; RT003/ST12 n = 1, 5.6%;...
Mackowski M, Wodas L, Brooks SA, Cieslak J.Although only a few specific pigmentation types are allowed within the Hucul horse registry, accurate determination of particular coat colors can be uncertain due to the presence of variation in color shades and segregation of multiple dun dilution variants. Herein, we genotyped the previously identified polymorphisms within two coat color loci TBX3 (T-box 3) and ASIP (Agouti Signaling Protein) in 462 Hucul individuals and compared the genotype predicted phenotypes with observed pigmentation types provided in the Polish Horse Breeders Association database. We identified disagreement between th...
Hill EW, McGivney BA, Rooney MF, Katz LM, Parnell A, MacHugh DE.Race distance aptitude in Thoroughbred horses is highly heritable and is influenced largely by variation at the myostatin gene (MSTN). Objective: In addition to MSTN, we hypothesised that other modifying loci contribute to best race distance. Methods: Using 3006 Thoroughbreds, including 835 'elite' horses, which were >3 years old, had race records and were sampled from Europe/Middle-East, Australia/New Zealand, North America and South Africa, we performed genome-wide association (GWA) tests and separately developed a genomic prediction algorithm to comprehensively catalogue additive geneti...
Kim SW, Jo A, Im J, Lee HE, Kim HS.A microRNA (miRNA) is a small non-coding RNA (ncRNA) approximately 20 nucleotides long and it affects gene expression through mRNA cleavage or translational repression. Horses (Equus caballus) have been domesticated and bred to enhance their speed for racing. It has been studied extensively with genetic diversity, origins and evolution. We examined expression patterns of miR-221-3p and its target gene CDKN1C in various horse tissues. We used bioinformatic tools to examine target gene, seed region and evolutionary conservation of miR-221-3p. The expression patterns of miR-221-3p and its target ...
The Journal of heredityDecember 28, 2018
Volume 110, Issue 2 173-182 doi: 10.1093/jhered/esy061
Sadeghi R, Moradi-Shahrbabak M, Miraei Ashtiani SR, Schlamp F, Cosgrove EJ, Antczak DF.The principal aims of this study were to explore genetic diversity and genome-wide selection signatures in Persian Arabian horses and to determine genetic relationship of Persian Arabians with other Iranian horse breeds. We evaluated 71 horses from 8 matrilineal strains tracing to 47 mares from the mid to late 19th century, using the equine 670k single nucleotide polymorphism (SNP) BeadChip. Mean observed and expected heterozygosity were (0.43) and (0.45), respectively, average inbreeding measures (inbreeding estimates based on runs of homozygosity and pedigree information) were low, indicatin...
Mura E, Edwards J, Kittelmann S, Kaerger K, Voigt K, Mrázek J, Moniello G, Fliegerova K.Anaerobic fungi are potent fibre degrading microbes in the equine hindgut, yet our understanding of their diversity and community structure is limited to date. In this preliminary work, using a clone library approach we studied the diversity of anaerobic fungi along six segments of the horse hindgut: caecum, right ventral colon (RVC), left ventral colon (LVC), left dorsal colon (LDC), right dorsal colon (RDC) and rectum. Of the 647 ITS1 clones, 61.7 % were assigned to genus level groups that are so far without any cultured representatives, and 38.0 % were assigned to the cultivated genera Ne...
Kumar R, Sarkhel SP, Kumar S, Batra K, Sethi K, Jain S, Kumar S, Tripathi BN.Six Trypanosoma evansi isolates were collected from ponies (PH1 and PK6), camel (CB2), donkeys (DJ3 and DH4) and cattle (CK5) from different States of Northern India (Haryana, Rajasthan, Uttar Pradesh and Gujarat) for molecular characterization based on 18S rRNA gene. The 18S rRNA gene (2251 bp) of different isolates was amplified, cloned and custom sequenced separately. Based on sequence and phylogenetic analysis of all six isolates, collected from different hosts as well as geographical areas, were having high identity among Indian T. evansi strains (99.7%) and with other strains of T. eva...
Rapacz-Leonard A, Leonard M, Chmielewska-Krzesińska M, Paździor-Czapula K, Janowski T.Major histocompatibility protein class I (MHC-I) is believed to be expressed in the horse allantochorion only in limited areas at limited times. However, its expression has only been investigated in early pregnancy with non-quantitative techniques that cannot reliably detect small amounts of protein. To quantify the relative expression of MHC-I in the allantochorion and endometrium during days 90-240 of pregnancy (PREG), parturition with physiological delivery of fetal membranes (PHYS), and parturition with retention of these membranes (FMR). Also, to visualize protein expression and determine...
Perry S, Larhammar M, Vieillard J, Nagaraja C, Hilscher MM, Tafreshiha A, Rofo F, Caixeta FV, Kullander K.Neuronal networks within the spinal cord, collectively known as the central pattern generator (CPG), coordinate rhythmic movements underlying locomotion. The transcription factor doublesex and mab-3-related transcription factor 3 (DMRT3) is involved in the differentiation of the dorsal interneuron 6 class of spinal cord interneurons. In horses, a non-sense mutation in the gene has major effects on gaiting ability, whereas mice lacking the gene display impaired locomotor activity. Although the gene is necessary for normal spinal network formation and function in mice, a direct role for -deri...
Shang S, Zhang M, Zhao Y, Dang W, Hua P, Zhang S, Wang Z.Due to the thriving development of the modern horse industry and the occurrence of horse related crimes, the demand for methods of individual horse identification, parentage tests and other genetic analyses is increasing. Previous methods had disadvantages that decreased the accuracy of the results, lacked the inclusion of all commonly used short tandem repeats (STR) or increased the experimental cost and time. Objective: We aimed to develop a novel 13-plex STR typing system to resolve the above issues. Methods: Experimental study. Methods: Twelve autosomal and most commonly used di-nucleotide...
Dini P, Daels P, Loux SC, Esteller-Vico A, Carossino M, Scoggin KE, Ball BA.The human chromosome 14 microRNA cluster (C14MC) is a conserved microRNA (miRNA) cluster across eutherian mammals, reported to play an important role in placental development. However, the expression kinetics and function of this cluster in the mammalian placenta are poorly understood. Here, we evaluated the expression kinetics of the equine C24MC, ortholog to the human C14MC, in the chorioallantoic membrane during the course of gestation. Results: We demonstrated that C24MC-associated miRNAs presented a higher expression level during early stages of pregnancy, followed by a decline later in g...
Senokuchi A, Ishikawa S, Tozaki T, Takasu M, Kakoi H, Misumi K, Hobo S.In order to promote conservation of the traditional Tokara horse in its remaining three breeding areas in Japan (Nakanoshima, Kaimondake, and Iriki), we genotyped 123 horses using 31 microsatellite markers and determined their genetic diversity. On average, the number of alleles (N), observed heterozygosity (H), expected heterozygosity (H), and inbreeding coefficient (F) among all horses were 3.0, 0.424, 0.481, and 0.108, respectively. Compared with other endangered horse breeds, we found that, even though the size of the Tokara horse population has recently increased, the N, H, and H of Tokar...
Douet C, Reigner F, Barrière P, Blard T, Deleuze S, Goudet G.Most wild donkey breeds are severely threatened by poaching for meat, habitat loss, and competition with livestock for food resources. Moreover, due to the mechanization in agriculture and in transport, most domestic donkey breeds are at risk of extinction. Considering the importance of biodiversity and preservation of genetic resources, the creation of genetic banks for endangered donkey breeds is urgently needed. Cryopreservation of immature jennies oocytes would be an efficient tool to allow storage of female genetics. The aim of the present study was to establish conditions for immature do...
Ghezelsoflou H, Hamidi P, Gharahveysi S.The Iranian Turkoman horse is considered one of the major categories of Iranian native horses. The aim of this research was to study the genetic and nongenetic factors affecting body conformation traits in Iranian Turkoman horses. For this, measurements were performed on body conformation traits of 121 horses. To study the effect of nongenetic factors, the Lsmeans procedure was used. Variance components and heritability were estimated by restricted maximum likelihood method (REML) and AI-REML convergence algorithm. The standard deviation was estimated to be 7.04 cm for croup depth and 2.08 cm ...
Soni Y, Talluri TR, Kumar A, Ravi SK, Mehta JS, Tripathi BN.Traditionally Glycerol (Gly) is being used as major cryoprotectant and its toxicity could be a reason for the variation on stallion sperm freezability and fertility. In an effort to minimize Gly toxicity alternative cryoprotective agents like Di-methyl Formamide (DMF) have been investigated. The effect of the cryoprotectant and dose of cryoprotective agent varies from breed to breed and also from stallion to stallion within the same breed. Considering these factors a study was designed to study the effects of Gly and DMF at different concentrations and combinations on the plasma membrane, acro...
Prakoso D, Dark MJ, Barbet AF, Salemi M, Barr KL, Liu JJ, Wenzlow N, Waltzek TB, Long MT.West Nile virus (WNV), a small, positive sense, single stranded RNA virus continues to encroach into new locales with emergence of new viral variants. Neurological disease in the equine can be moderate to severe in the face of low to undetectable virus loads. Physical methods of virus enrichment may increase sensitivity of virus detection and enhance analysis of viral diversity, especially for deep sequencing studies. However, the use of these techniques is limited mainly to non-neural tissues. We investigated the hypothesis that elimination of equine brain RNA enhances viral detection without...
Senju N, Tozaki T, Kakoi H, Matsuyama R, Nakamura K, Takasu M.The Miyako and Yonaguni horses are native horses in Okinawa. Here, we evaluated their genetic relationship using microsatellite data and Kiso horses, which have four subpopulations, as a reference population for evaluating this relationship. Microsatellite data from 35 Miyako, 78 Yonaguni, and 172 Kiso horses were evaluated using the STRUCTURE software for analyzing multilocus genotype data to investigate the population structures and their underlying relationship. The results of the STRUCTURE analysis were stable when ΔK was 2, suggesting that the Okinawan horses are different from the Kiso ...
Wise LN, Kappmeyer LS, Knowles DP, White SN.The equine parasite Theilera equi continues to curtail global equine commerce due primarily to its ability to persist indefinitely in the immunocompetent horse. Details regarding the parasite life cycle, pathogenesis and mechanism of persistence remain unclear. The recently discovered T. haneyi is also capable of persistence in the horse, creating a potential reservoir for additional infections. These two divergent parasites share a unique gene family that expresses surface merozoite antigens, or equi merozoite antigens (EMAs). The EMA family was maintained in number and size in both parasites...
Kakoi H, Kikuchi M, Tozaki T, Hirota KI, Nagata SI.The integrity of thoroughbreds is maintained under strict regulation involving DNA parentage testing, which is robust in a population with high genetic variability. The genetic variability of the thoroughbred population is possibly fluctuating because of selective breeding that has focused on adaptations for racing performance. To monitor genetic variability within the population and the effectiveness of short tandem repeat (STR) parentage testing, we investigated allele frequencies and the exclusion probability (PE) of 16-17 loci of a parentage panel in the Japanese thoroughbred population ov...
Norton EM, Schultz NE, Rendahl AK, Mcfarlane D, Geor RJ, Mickelson JR, McCue ME.Equine metabolic syndrome (EMS) is a complex clinical disorder with both environmental and genetic factors contributing to EMS phenotypes. Estimates of heritability determine the proportion of variation in a trait that is attributable to genetics. Objective: To provide heritability estimates for nine metabolic traits associated with EMS in two high-risk breeds. Methods: Retrospective cohort study. Methods: High-density single-nucleotide polymorphism (SNP) genotype data was used to estimate the heritability (h ) of nine metabolic traits relevant to EMS in a cohort of 264 Welsh ponies and 286 M...
Manso TC, Groenner-Penna M, Minozzo JC, Antunes BC, Ippolito GC, Molina F, Felicori LF.Horse serum antibodies have been used for greater than a century for the treatment and prophylaxis of infectious diseases and envenomations. Little is known, however, about the immunogenetic diversity that produces horse serum antibodies. Here, we employed next-generation sequencing for a first-in-kind comprehensive analysis of the equine B-cell repertoire. Nearly 45,000 and 30,000 clonotypes were obtained for the heavy-chain (IGH) and lambda light-chain (IGL) loci, respectively. We observed skewed use of the common subgroups IGHV2 (92.49%) and IGLV8 (82.50%), consistent with previous reports,...
Brosnahan MM, Al Abri MA, Brooks SA, Antczak DF, Osterrieder N.Equine herpesvirus type 1 (EHV-1)-induced myeloencephalopathy (EHM) is a neurologic disease of horses that represents one outcome of infection. The neurologic form of disease occurs in a subset of infected horses when virus-induced endothelial cell damage triggers vasculitis and subsequent ischemic insult to the central nervous system. EHM causes considerable animal suffering and economic loss for the horse industry. Virus polymorphisms have been previously associated with disease outcome but cannot fully explain why only some horses develop EHM. This study investigated the role of host geneti...
Pilling A, Davison AJ, Telford EA, Meredith DM.Glycoprotein 45 is a major envelope glycoprotein of equine herpesvirus type 1. The gene encoding this protein is located between map units 0.615 and 0.636 on the virus genome and evidence has suggested that it is encoded by gene 52, one of four genes within this region. Using PCR we have amplified gene 52 and subsequently cloned it into a mammalian expression vector under the control of the human cytomegalovirus immediate early gene promoter. The gene was expressed in COS-7 cells and its product was detected by immunofluorescence and Western blotting. The results indicate that glycoprotein 45 ...
Ballagi-Pordány A, Klingeborn B, Flensburg J, Belák S.Primers and probes were selected from the gene encoding glycoprotein 13 (gp 13) of equine herpesvirus 1 (EHV-1). The polymerase chain reaction (PCR) was run on infected and noninfected cultured cells and on 63 specimens from 29 aborted equine fetuses. The results were evaluated by electrophoresis and dot-blot hybridization using an oligonucleotide probe labeled with biotin. In the infected samples electrophoresis showed a PCR product of about 280 base pairs. The dot-blot hybridization confirmed that this product contained EHV-1 DNA sequences. PCR took 4 h and hybridization another 14 h; the re...
Moe KK, Yano T, Kuwano A, Sasaki S, Misawa N.Equine canker is a chronic pododermatitis of the hoof in horses. Although spirochetes are detectable histopathologically in the lesions, the precise etiology remains unclear. This study reports the 16S rRNA gene sequencing of randomly selected clones based on PCR with Treponema-specific primers, using the canker lesions from two horses and healthy frog and sole from a horse. A total of 114 clones were obtained from the lesions, but no clones were detected in the healthy hoof tissues. The clones from the canker lesions examined were grouped into 19 operational taxonomic units, such as treponema...
Chowdhary BP, Raudsepp T.The map of the horse genome has undergone unprecedented expansion during the past six years. Beginning from a modest collection of approximately 300 mapped markers scattered on the 31 pairs of autosomes and the X chromosome in 2001, today the horse genome is among the best-mapped in domestic animals. Presently, high-resolution linearly ordered gene maps are available for all autosomes as well as the X and the Y chromosome. The approximately 4350 mapped markers distributed over the approximately 2.68 Gbp long equine genome provide on average 1 marker every 620 kb. Among the most remarkable deve...
Briski O, Salamone DF.During the past 2 decades, intracytoplasmic sperm injection (ICSI) has become a routine technique for clinical applications in humans. The widespread use among domestic species, however, has been limited to horses. In horses, ICSI is used to reproduce elite individuals and, as well as in humans, to mitigate or even circumvent reproductive barriers. Failures in superovulation and conventional in vitro fertilization (IVF) have been the main reason for the use of this technology in horses. In pigs, ICSI has been successfully used to produce transgenic animals. A series of factors have resulted in...
Dobrinsky JR.The development of embryo freezing technologies revolutionized cattle breeding. Since then, advancements in cryobiology, cell biology, and domestic animal embryology have enabled the development of embryo preservation methodologies for our other domestic animal species, including sheep and goats. Recently, technologies have been developed to cryopreserve pig embryos, notorious for their extreme sensitivity to cooling; horse embryo cryopreservation is in its infancy. While cryopreservation can enhance the utilization of in vitro embryo production technologies, cryosurvival of in vitro-produced ...
Aleman M.Muscle disorders are a common cause of disability in horses. For many years, clinical manifestations such as muscle pain, exercise intolerance, weakness, and stiffness were believed to be caused by a single syndrome. However, in the past years a broad spectrum of muscle disorders have been recognized including glycogen and polysaccharide storage myopathies, malignant hyperthermia, mitochondrial myopathy, hyperkalemic periodic paralysis and others. For some, a specific mutation has been identified. Recognition of the myopathic clinical phenotype and thorough clinical, electrodiagnostic, and his...
Bagge J, Berg LC, Janes J, MacLeod JN.Bone marrow (BM)- and adipose tissue (AT)-derived mesenchymal stromal cells (MSCs) have shown potential as cell-based therapies for cartilage and bone injuries and are used increasingly in human and veterinary practice to facilitate the treatment of orthopedic conditions. However, human and rodent studies have documented a sharp decline in chondrogenic and osteogenic differentiation potential with increasing donor age, which may be problematic for the important demographic of older orthopedic patients. The aim of this study was to identify the effect of donor age on the chondrogenic and osteog...
Biswas B, Mukherjee D, Mattingly-Napier BL, Dutta SK.Genomic amplification by the polymerase chain reaction (PCR) was used to identify a unique genomic sequence of Ehrlichia risticii directly in DNA isolated from peripheral-blood buffy coat cells of E. risticii-infected horses (Potomac horse fever) and from infected cell cultures. A specific primer pair, selected from a cloned, species-specific, 1-kb DNA fragment of the E. risticii genome as a template, was used for the amplification of the target DNA of 247 bp. The optimal number of 40 PCR cycles, determined by analyzing an amplification profile obtained with a constant Taq polymerase concentra...
Gulati BR, Singha H, Singh BK, Virmani N, Kumar S, Singh RK.Japanese encephalitis (JE) is an important vector-borne viral disease of humans and horses in Asia. JE outbreaks occur regularly amongst humans in certain parts of India and sporadic cases occur among horses. In this study, JE seroprevalence and evidence of JE virus (JEV) infection among horses in Haryana (India) is described. Antibodies against JEV were detected in 67 out of 637 (10.5%) horses screened between 2006 and 2010. Two foals exhibiting neurological signs were positive for JEV RNA by RT-PCR; JEV was isolated from the serum of one of the foals collected on the second day of illness. T...
Ochala J, Finno CJ, Valberg SJ.Myosinopathies are defined as a group of muscle disorders characterized by mutations in genes encoding myosin heavy chains. Their exact molecular and cellular mechanisms remain unclear. In the present study, we have focused our attention on a -related E321G amino acid substitution within the head region of the type IIx skeletal myosin heavy chain, associated with clinical signs of atrophy, inflammation and/or profound rhabdomyolysis, known as equine myosin heavy chain myopathy. We performed Mant-ATP chase experiments together with force measurements on isolated IIx myofibres from control horse...
Payne SL, La Celle K, Pei XF, Qi XM, Shao H, Steagall WK, Perry S, Fuller F.The Wyoming strain of equine infectious anaemia virus (EIAV) is a highly virulent field strain that replicates to high titre in vitro only in primary equine monocyte-derived macrophages. In contrast, Wyoming-derived fibroblast-adapted EIAV strains (Malmquist virus) replicate in primary foetal equine kidney and equine dermis cells as well as in the cell lines FEA and Cf2Th. Wyoming and Malmquist viruses differ extensively both in long terminal repeat (LTR) and envelope region sequences. We have compared the promoter activities of the Wyoming LTR with those of LTRs derived from fibroblast-adapte...
Shang S, Yu Y, Zhao Y, Dang W, Zhang J, Qin X, Irwin DM, Wang Q, Liu F, Wang Z, Zhang S, Wang Z.Through domestication and human selection, horses have acquired various coat colors, including seven phenotypes: black, brown, dark bay, bay, chestnut, white, and gray. Here we determined the genotypes for melanocortin-1 receptor (MC1R) and agouti signaling protein (ASIP) in 709 horses from 15 breeds. We found that the EEEE genotype frequency at MC1R decreased from dark to light colors (black = 64.5%, brown = 67.5%, dark bay = 47.0%, bay = 16.5%, and chestnut = 0.0%), whereas the AAAA genotype frequency at ASIP increased as coat color lightened (black = 0.0%, brown = 22.9%, dark bay = 69.2%, a...
Rosa M, Cardozo LM, da Silva Pereira J, Brooks DE, Martins AL, Florido PS, Stussi JS.The conjunctival fungal flora of 32 adult horses with normal eyes (n = 64) from the State of Rio de Janeiro in Brazil was identified in the fall of 2000 using horses of different breeds, both genders and aged 5-19 years old. The culture samples were taken from the conjunctival sac of both eyes with a sterile cotton swab wetted with saline solution, seeded in Sabouraud's dextrose agar with chloramphenicol, and incubated for 5 days at an average temperature of 25 degrees C. The number of fungal colonies per eye varied between 0 and 250 colony forming units (CFUs). There were often differences in...
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 ...
Lazary S, Gerber H, Glatt PA, Straub R.The distribution of equine leucocyte antigens (ELA) in horses affected by equine sarcoid tumours was determined and compared with unaffected controls. ELA-haplotype W3,B1 occurred more frequently in affected riding horses of Irish, Swiss and French background. The combined data for the three breeds resulted in a chi 2 value of 20.35 (P less than 0.0005 after correction). Simultaneously, ELA-specificity W11 was more frequently found in horses of Irish background, while W5 was found in Swiss and French horses with sarcoids. The combined data for haplotype W3,B1 and/or W5 specificity demonstrated...
Carnevale EM, Catandi GD, Fresa K.Numerous similarities in reproductive aging have been documented between the mare and woman. Aging is associated with a decline in fertility. In mares and women, oocyte transfer procedures were initially used to establish that oocyte donor age is associated with oocyte quality. Age-associated differences in oocytes include altered morphology, gene expression, and developmental potential. Reactive oxygen species and mitochondrial dysfunction are thought to be important contributors to loss of oocyte quality. In the woman, aneuploidy is a primary consideration with maternal aging. Although misal...
Ivens PA, Matthews D, Webb K, Newton JR, Steward K, Waller AS, Robinson C, Slater JD.Strangles is the most commonly diagnosed and important infectious disease of horses worldwide. Very little is known about the temporo-spatial and molecular epidemiology of strangles. The disease is not notifiable in the UK and there are few published data on the geographical locations of outbreaks. Objective: To investigate whether typing of a surface protein (SeM) of Streptococcus equi ssp. equi (S. equi), the causative agent of strangles, is a useful epidemiological tool. Methods: The variable region of the SeM gene was amplified from 145 isolates of S. equi by PCR and sequenced. Different S...
Bjørnstad G, Røed KH.Assignment tests have been utilized to investigate population classification, measure genetic diversity and to solve forensic questions. Using microsatellite data from 26 loci genotyped in eight horse breeds we examined how population differentiation, number of scored loci, number of scored animals per breed and loci variability affected individual assignment precision applying log likelihood methods. We found that both genetic differentiation and number of scored loci were highly important for recognizing the breed of origin. When comparing two and two breeds, a proportion of 95% of the most ...
Barrey E, Jayr L, Mucher E, Gospodnetic S, Joly F, Benech P, Alibert O, Gidrol X, Mata X, Vaiman A, Guérin G.Recurrent exertional rhabdomyolysis (RER) is frequently observed in race horses like trotters. Some predisposing genetic factors have been described in epidemiological studies. However, the exact aetiology is still unknown. A calcium homeostasis disruption was suspected in previous experimental studies, and we suggested that a transcriptome analysis of RER muscles would be a possible way to investigate the pathway disorder. The purpose of this study was to compare the gene expression profile of RER vs. control muscles in the French Trotter to determine any metabolic or structural disruption. T...
Andersson L, Sandberg K.In the present study an extensive amount of data, comprising more than 30,000 offspring in total, was analyzed to evaluate the influence of age and sex on the recombination frequency in the K-PGD segment of the equine linkage group (LG) I and the influence of age, breed and sex on recombination in the Al-Es segment of LG II. A highly significant sex difference is reported for both segments. Male and female recombination values in the K-PGD segment were estimated at 25.8 +/- 0.8 and 33.3 +/- 2.5%, respectively. Similarly, recombination was less frequent in the male (36.6 +/- 0.7%) than in the f...
Love CC, Kenney RM.The relationship between fertility and susceptibility of sperm DNA to denaturation was determined in a group of 84 actively breeding, clinically fertile stallions. Susceptibility of DNA to denaturation was determined using the sperm chromatin structure assay (SCSA). The SCSA measures, mean of alpha-t (mean alpha t), standard deviation of alpha-t (SD alpha t), and the COMP of alpha-t (cells outside the main population)] were significantly correlated with the percentage seasonal pregnancy rate (SPR; mean alpha t, r = -0.24, P < or = 0.05; % COMP alpha t, r = -0.27, P < or = 0.05); percentage pre...
Hanot P, Herrel A, Guintard C, Cornette R.Organisms are organized into suites of anatomical structures that typically covary when developmentally or functionally related, and this morphological integration plays a determinant role in evolutionary processes. Artificial selection on domestic species causes strong morphological changes over short time spans, frequently resulting in a wide and exaggerated phenotypic diversity. This raises the question of whether integration constrains the morphological diversification of domestic species and how natural and artificial selection may impact integration patterns. Here, we study the morpholog...
White SH, Warren LK, Li C, Wohlgemuth SE.We tested the hypothesis that, similar to humans and rodents, exercise training would enhance mitochondrial (Mt) biogenesis and function in skeletal muscle of young horses. Twenty-four Quarter Horse yearlings were randomly assigned to either submaximal exercise training or no forced exercise (untrained). Biopsies were collected from the gluteus medius and triceps brachii before and after 9 wk of treatment. Citrate synthase activity was lower (P < 0.0001) and cytochrome c oxidase activity per Mt unit was higher (P < 0.0001) in gluteus compared to triceps, but neither changed over ...
Morgenthaler C, Diribarne M, Capitan A, Legendre R, Saintilan R, Gilles M, Esquerré D, Juras R, Khanshour A, Schibler L, Cothran G.Curly horses present a variety of curl phenotypes that are associated with various degrees of curliness of coat, mane, tail and ear hairs. Their origin is still a matter of debate and several genetic hypotheses have been formulated to explain the diversity in phenotype, including the combination of autosomal dominant and recessive alleles. Our purpose was to map the autosomal dominant curly hair locus and identify the causal variant using genome-wide association study (GWAS) and whole-genome sequencing approaches. Results: A GWAS was performed using a Bayesian sparse linear mixed model, based ...
Jäderkvist Fegraeus K, Velie BD, Axelsson J, Ang R, Hamilton NA, Andersson L, Meadows JRS, Lindgren G.The Swedish-Norwegian Coldblooded trotter and the heavier North-Swedish draught horse both descend from the North-Swedish horse, but the Coldblooded trotters have been selected for racing performance while the North-Swedish draught horse is mainly used for agricultural and forestry work. By comparing the genomes of Coldblooded trotters, North-Swedish draught horses and Standardbreds for a large number of single-nucleotide polymorphisms (SNPs), the aim of the study was to identify genetic regions that may be under selection for racing performance. We hypothesized that the selection for racing p...
Stadejek T, Bj Rklund H, Bascu Ana CR, Ciabatti IM, Scicluna MT, Amaddeo D, McCollum WH, Autorino GL, Timoney PJ, Paton DJ, Klingeborn B, Bel K S.Equine arteritis viruses (EAV) from Europe and America were compared by phylogenetic analysis of 43 isolates obtained over four decades. An additional 22 virus sequences were retrieved from GenBank. Fragments of the glycoprotein G(L) and the replicase genes were amplified by RT-PCR, prior to sequencing and construction of phylogenetic trees. The trees revealed many distinctive lineages, consistent with prolonged diversification within geographically separated host populations. Two large groups and five subgroups were distinguished. Group I consisted mainly of viruses from North America, whilst...
Rourke KM, Coe S, Kohn CW, Rosol TJ, Mendoza FJ, Toribio RE.Epithelial calcium transport occurs by paracellular and transcellular mechanisms. Transcellular transport in intestinal and renal epithelia involves several transport proteins, including transient receptor potential vanilloid member 5 (TRPV5), member 6 (TRPV6), calbindin D9k (CB9), calbindin D28k (CB28), sodium calcium exchanger 1 (NCX1), plasma membrane calcium ATPase 1 (PMCA1), and the vitamin D receptor (VDR). We are interested in the horse because of its unique calcium physiology (high blood calcium, high intestinal calcium absorption, high renal excretion of calcium, low vitamin D concent...
Bordin AI, Liu M, Nerren JR, Buntain SL, Brake CN, Kogut MH, Cohen ND.Rhodococcus equi is an intracellular bacterium that causes pneumonia in foals and immunocompromised adult horses. Evidence exists that foals become infected with R. equi early in life, a period when innate immune responses are critically important for protection against infection. Neutrophils are innate immune cells that play a key role in defense against this bacterium. Enhancing neutrophil function during early life could thus help to protect foals against R. equi infection. The objective of our study was to determine whether in vitro incubation with the TLR9 agonist CpG 2142 would enhance d...
Tallmadge RL, McLaughlin K, Secor E, Ruano D, Matychak MB, Flaminio MJ.Many features of the equine immune system develop during fetal life, yet the naïve or immature immune state of the neonate renders the foal uniquely susceptible to particular pathogens. RT-PCR and immunohistochemical experiments investigated the progressive expression of developmental B cell markers and immunoglobulins in lymphoid tissues from equine fetus, pre-suckle neonate, foal, and adult horses. Serum IgM, IgG isotype, and IgA concentrations were also quantified in pre-suckle foals and adult horses. The expression of essential B cell genes suggests active development and gene recombinati...
