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.
Hornstra H, Pearson T, Georgia S, Liguori A, Dale J, Price E, O'Neill M, Deshazer D, Muhammad G, Saqib M, Naureen A, Keim P.We collected epidemiologic and molecular data from Burkholderia mallei isolates from equines in Punjab, Pakistan from 1999 through 2007. We show that recent outbreaks are genetically distinct from available whole genome sequences and that these genotypes are persistent and ubiquitous in Punjab, probably due to human-mediated movement of equines.
Watts EJ, Rose MT.Horses are more prone to complications in the wound healing process than other species, and problems such as chronic inflammation, delayed epithelialization, poor wound contraction, and exuberant granulation tissue are commonly seen, particularly in wounds on the distal limbs. In comparison, wounds of the oral mucosa heal rapidly in a scarless fashion with a high degree of wound contraction. The effect of platelet-derived growth factor BB (PDGF), insulin-like growth factor (IGF)-1, and transforming growth factor beta1 (TGFbeta1) on the contraction of a fibroblast-populated collagen matrix (FPC...
Schuh EM, Friedman MS, Carrade DD, Li J, Heeke D, Oyserman SM, Galuppo LD, Lara DJ, Walker NJ, Ferraro GL, Owens SD, Borjesson DL.OBJECTIVE-To optimize the isolation and culture of mesenchymal stem cells (MSCs) from umbilical-cord blood (UCB), identify variables that predicted successful MSC isolation, and determine whether shipping, processing, and cryopreservation altered MSC viability, recovery rates, and expansion kinetics. SAMPLE POPULATION-UCB samples from 79 Thoroughbred and Quarter Horse mares. PROCEDURES-UCB samples were processed to reduce volume and remove RBCs. Nucleated cells (NCs) were cryopreserved or grown in various culture conditions to optimize MSC monolayer expansion and proliferation. Donor and UCB-s...
Horin P, Sabakova K, Futas J, Vychodilova L, Necesankova M.In previous work, we found significant associations of horse polymorphic microsatellite and immunity-related (IR) gene markers with Rhodococcus equi infection of foals. Here, a statistically significant association between a single nucleotide polymorphism (SNP) within the interleukin 7 receptor-encoding gene (IL7R) with high R. equi burden in transtracheal aspirates was found (Fisher's F = 0.043, odds ratio: 8.00, 95% confidence interval: 1.127-56.795). Further positional and/or functional candidate genes investigated TLR2, IL13, IL17A, IL28R, TACE/ADAM 17 and GBP1, were not associated with in...
Suagee JK, Corl BA, Crisman MV, Wearn JG, McCutcheon LJ, Geor RJ.The lipogenic capacities of equine liver and adipose tissue explants were investigated in vitro. Preference for glucose or acetate as the primary carbon source for de novo fatty acid synthesis was determined using (14)C labeled substrates. Additional aims included determining the relative contribution of NADPH generating pathways to reducing equivalent generation and comparing the lipogenic activity of two adipose depots, mesenteric and subcutaneous harvested from the crest region of the neck. Mesenteric adipose tissue had greater lipogenic activity than subcutaneous adipose tissue, and liver ...
Minervini F, Lacalandra GM, Filannino A, Nicassio M, Visconti A, Dell'Aquila ME.The purpose of this study was to assess the natural exposure of male horses (Equus caballus) to the mycotoxin zearalenone (ZEA) by using the ELISA test and to evaluate the effects of in vitro exposure of sperm cells to mycotoxin-containing urine extracts on sperm chromatin structure stability. Because of their occurrence in urine samples, ZEA and its derivatives were tested by sperm chromatin structure assay (SCSA) at natural levels detected by ELISA. Thirty-eight urine extracts of Italian (n = 11) and northeastern European (n = 27) horses were tested on frozen-thawed spermatozoa to evaluate t...
Sairanen J, Nivola K, Katila T, Virtala AM, Ojala M.The Finnish mating records of Standardbred trotters (SB; n = 33 679) and Finnhorses (FH; n = 32 731) were analysed to study the effect of the level of inbreeding on foaling rates and to estimate the heritability of foaling rate. A linear mixed model was assumed, with the outcome of the foaling (foal or no foal) as the trait of the study. A restricted maximum likelihood-based method was used to calculate the estimates of the variance components. Predictions of breeding values and estimates of fixed effects were also calculated. The average level of inbreeding was 9.9% in the SB and 3.6% in the ...
Azab W, Tsujimura K, Kato K, Arii J, Morimoto T, Kawaguchi Y, Tohya Y, Matsumura T, Akashi H.Equine herpesvirus 4 (EHV-4) is an important equine pathogen that causes respiratory tract disease among horses worldwide. A thymidine kinase (TK)-deletion mutant has been generated by using bacterial artificial chromosome (BAC) technology to investigate the role of TK in pathogenesis. Deletion of TK had virtually no effect on the growth characteristics of WA79DeltaTK in cell culture when compared to the parent virus. Also, virus titers and plaque formation were unaffected in the absence of the TK gene. The sensitivity of EHV-4 to inhibition by acyclovir (ACV) and ganciclovir (GCV) was studied...
Covaleda L, Fuller FJ, Payne SL.Equine infectious anemia virus (EIAV) infection is distinctive in that it causes a rapid onset of clinical disease relative to other retroviruses. In order to understand the interaction dynamics between EIAV and the host immune response, we explored the effects of EIAV and its S2 protein in the regulation of the cytokine and chemokine response in macrophages. EIAV infection markedly altered the expression pattern of a variety of pro-inflammatory cytokines and chemokines monitored in the study. Comparative studies in the cytokine response between EIAV(17) and EIAV(17DeltaS2) infection revealed ...
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...
The Journal of heredityNovember 27, 2009
Volume 101, Issue 2 133-143 doi: 10.1093/jhered/esp101
Gonzales E, Hamrick JL, Smouse PE, Trapnell DW, Peakall R.We examined spatial genetic structure (SGS) in Enterolobium cyclocarpum (the Guanacaste tree), a dominant tree of Central American dry forests in 4 sites in Guanacaste Province, Costa Rica. In disturbed dry forest sites (e.g., pastures), E. cyclocarpum is primarily dispersed by cattle and horses, whose movements are restricted by pasture boundaries. The study sites varied in tree densities and disturbance. Allozyme analyses of adult trees demonstrated significant levels of SGS in 3 of 4 sites. SGS was primarily due to clusters of young adults located along seasonal streams, rocky areas, and in...
Nieto JE, MacDonald MH, Braim AE, Aleman M.Horses are exquisitely sensitive to bacterial endotoxin and endotoxaemia is common in colic cases. In this study, gene expression of inflammatory cytokines was characterised in the blood of healthy horses following i.v. administration of lipopolysaccharide (LPS). Six horses received an LPS infusion and 6 controls received an equivalent volume of saline. Gene expression of genes encoding interleukin (IL)-1alpha, IL-1beta, IL-6, IL-8, and tumour necrosis factor-alpha (TNF-alpha) was quantified by real-time PCR. Gene expression of all inflammatory cytokines was upregulated following administratio...
Gläser KE, Sun Q, Wells MT, Nixon AJ.No large scale equine microarray is available commercially to allow genomic and transcriptional profiling of the majority of genes that would define the genetic basis of equine disease. Objective: To generate a whole transcript target labelled GeneChip to interrogate the equine transcriptome and validate chip performance using RNA samples derived from organs, articular cells and normal cartilage. Methods: Equine mRNA and selected equine gene sequences derived from perfect cross-hybridisation of equine RNA on human microarray GeneChips, were used to design a custom equine gene microarray. Seque...
The Journal of heredityNovember 25, 2009
Volume 101, Issue 2 240-245 doi: 10.1093/jhered/esp090
Dobosz M, Bocci C, Bonuglia M, Grasso C, Merigioli S, Russo A, De Iuliis P.Microsatellites have been used for parentage testing and individual identification in forensic science because they are highly polymorphic and show abundant sequences dispersed throughout most eukaryotic nuclear genomes. At present, genetic testing based on DNA technology is used for most domesticated animals, including horses, to confirm identity, to determine parentage, and to validate registration certificates. But if genetic data of one of the putative parents are missing, verifying a genealogy could be questionable. The aim of this paper is to illustrate a new approach to analyze complex ...
Lira J, Linderholm A, Olaria C, Brandström Durling M, Gilbert MT, Ellegren H, Willerslev E, Lidén K, Arsuaga JL, Götherström A.Multiple geographical regions have been proposed for the domestication of Equus caballus. It has been suggested, based on zooarchaeological and genetic analyses that wild horses from the Iberian Peninsula were involved in the process, and the overrepresentation of mitochondrial D1 cluster in modern Iberian horses supports this suggestion. To test this hypothesis, we analysed mitochondrial DNA from 22 ancient Iberian horse remains belonging to the Neolithic, the Bronze Age and the Middle Ages, against previously published sequences. Only the medieval Iberian sequence appeared in the D1 group. N...
The Journal of heredityNovember 25, 2009
Volume 101, Issue 2 246-250 doi: 10.1093/jhered/esp091
Mittmann EH, Lampe V, Mömke S, Zeitz A, Distl O.The availability of a high-quality draft sequence of the horse makes known the physical location of microsatellites. The aim of the present study was to establish a highly polymorphic minimal screening set of microsatellite markers for horses (MSSH) annotated on the horse genome assembly EquCab2.0. We have used the previously reported linkage and radiation hybrid maps and have extended these marker sets by filling in gaps as noted from annotation on the horse sequence. This MSSH covers all autosomes and the X chromosome with 322 evenly spaced microsatellites whose positions were determined on ...
Yi J, Heinecke J, Tan H, Ford PC, Richter-Addo GB.It is now well-established that mammalian heme proteins are reactive with various nitrogen oxide species and that these reactions may play significant roles in mammalian physiology. For example, the ferrous heme protein myoglobin (Mb) has been shown to reduce nitrite (NO(2)(-)) to nitric oxide (NO) under hypoxic conditions. We demonstrate here that the distal pocket histidine residue (His64) of horse heart metMb(III) (i.e., ferric Mb(III)) has marked effects on the mode of nitrite ion coordination to the iron center. X-ray crystal structures were determined for the mutant proteins metMb(III) H...
Woodward AD, Holcombe SJ, Steibel JP, Staniar WB, Colvin C, Trottier NL.To test the hypothesis that AA transporter transcripts are present in the large intestine and similarly expressed along the intestinal tract, mRNA abundance of candidate AA transporter genes solute carrier (SLC) family 7, member 9 (SLC7A9), SLC7A1, SLC7A8, and SLC43A1 encoding for b(0,+)-type AA transporter (b(0,+)AT), cationic AA transporter-1 (CAT-1), L-type AA transporter-2 (LAT-2), and L-type AA transporter-3 (LAT-3), respectively, was determined in small and large intestinal segments of the horse. Mucosa was collected from the equine small (jejunum and ileum) and large intestine (cecum, l...
Gauci PJ, Wu JQ, Rayner GA, Barabé ND, Nagata LP, Proll DF.DNA vaccines encoding different portions of the structural proteins of western equine encephalitis virus were tested for the efficacy of their protection in a 100% lethal mouse model of the virus. The 6K-E1 structural protein encoded by the DNA vaccine conferred complete protection against challenge with the homologous strain and limited protection against challenge with a heterologous strain.
Rieder S.Colour phenotypes may have played a major role during early domestication events and initial selection among domestic animal species. As coat colours mostly follow a relatively simple mode of Mendelian inheritance, they have been among the first traits to be systematically analysed at the molecular level. As a result of the number of genetic tools developed during the past decade, horse coat colour tests have been designed and are now commercially available for some of the basic phenotypes. These tests enable breeders to verify segregation within particular pedigrees, to select specific colour...
Magdesian KG, Williams DC, Aleman M, Lecouteur RA, Madigan JE.To evaluate deafness in American Paint Horses by phenotype, clinical findings, brainstem auditory-evoked responses (BAERs), and endothelin B receptor (EDNBR) genotype. Methods: Case series and case-control studies. Methods: 14 deaf American Paint Horses, 20 suspected-deaf American Paint Horses, and 13 nondeaf American Paint Horses and Pintos. Methods: Horses were categorized on the basis of coat color pattern and eye color. Testing for the EDNBR gene mutation (associated with overo lethal white foal syndrome) and BAERs was performed. Additional clinical findings were obtained from medical reco...
Kakoi H, Tozaki T, Nagata S, Gawahara H, Kijima-Suda I.In order to develop a genotyping method that can be used in the registration procedure for Thoroughbreds, we developed a method for simultaneously genotyping multiple coat colour genes on the basis of single nucleotide polymorphism typing by using the SNaPshot(TM) technique. This method enabled precise and reasonable detection of causal mutations; it was effective for genotyping of MC1R, ASIP, and SLC45A2 at the Extension (E), Agouti (A), Cream dilution (C) loci, and the possibility of identification of rare variants of MC1R, EDNRB and KIT at the E, Overo (O) and Sabino 1 (SB1) loci, respectiv...
Laughlin AM, Welsh TH, Love CC, Varner DD, Parrish AR, Forrest DW, Ing NH.In vitro culture systems are valuable tools for investigating reproductive mechanisms in the testis. Here, we report the use of the precision-cut in vitro system using equine testicular slices. Testes were collected from immature light breed stallions (n=3) and cut into slices (mean slice weight= 13.85 ± 0.20 mg; mean slice thickness=515.00 ± 2.33 μm) using the precision-cut tissue-slicing method. Four tissue slices were placed on a grid floating on medium in individual vials. After a 1-h preincubation, they were exposed to medium containing ovine luteinizing hormone (oLH) at concentrations...
Science (New York, N.Y.)November 7, 2009
Volume 326, Issue 5954 865-867 doi: 10.1126/science.1178158
Wade CM, Giulotto E, Sigurdsson S, Zoli M, Gnerre S, Imsland F, Lear TL, Adelson DL, Bailey E, Bellone RR, Blöcker H, Distl O, Edgar RC, Garber M....We report a high-quality draft sequence of the genome of the horse (Equus caballus). The genome is relatively repetitive but has little segmental duplication. Chromosomes appear to have undergone few historical rearrangements: 53% of equine chromosomes show conserved synteny to a single human chromosome. Equine chromosome 11 is shown to have an evolutionary new centromere devoid of centromeric satellite DNA, suggesting that centromeric function may arise before satellite repeat accumulation. Linkage disequilibrium, showing the influences of early domestication of large herds of female horses, ...
Gericota B, Aleman M, Kozikowski TA, Pesavento P, Bollen AW, Madigan JE, Higgins RJ.A 4-year-old Dutch warmblood mare was presented with a 10-month history of ataxia and proprioceptive deficits. Computed tomography defined a large, non-contrast enhancing mass in the left cerebral hemisphere. Necropsy examination revealed a tumour that effaced much of the piriform and temporal lobes. Microscopically the lesion was classified as a grade IV glioblastoma with an oligodendroglial component (GBM-O). The tumour was composed of highly pleomorphic cells organized in different patterns within a fibrillary stroma. There were multiple foci of necrosis. At the periphery of the tumour neop...
Brosnahan MM, Damiani A, van de Walle G, Erb H, Perkins GA, Osterrieder N.Available vaccines fail to induce lasting and protective immunity to equine herpesvirus 1 (EHV-1) associated diseases. RNA interference is a novel approach showing promise for therapeutic use in outbreak situations. This study examined the effect of small interfering RNA (siRNA) on clinical signs as well as the presence of live virus and viral DNA in nasal secretions and peripheral blood mononuclear cells (PBMCs) in horses experimentally infected with EHV-1. siRNA targeting two EHV-1 genes (glycoprotein B and the origin binding protein) was administered 12h before and 12h after intranasal infe...
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...
Riggs LM, Krunkosky TM, Noschka E, Boozer LA, Moore JN, Robertson TP, Peroni JF.To compare characteristics and enzymatic products of leukocytes detected in the skin and laminar tissues of horses administered black walnut heartwood extract (BWHE) and horses administered purified lipopolysaccharide (LPS). Methods: 25 healthy 5- to 15-year-old horses. Methods: Horses were randomly assigned to receive LPS (20 ng of O55:B5 Escherichia coli endotoxin/kg; n = 5) IV or 6 L of BWHE (10) or water (control group; 10) via nasogastric intubation. Horses were euthanatized 12 hours after treatment or at onset of Obel grade 1 lameness. Laminar tissue samples and skin samples from the mid...
Oliveira Filho JP, Badial PR, Cunha PHJ, Cruz TF, Araújo JP, Divers TJ, Winand NJ, Borges AS.Equine serum or plasma iron concentration drops quickly during inflammation. Accumulation of iron inside macrophages and reduction of the intestinal absorption of this element cause hypoferremia during systemic inflammatory processes. These mechanisms are mediated by hepcidin, a 25 amino acids peptide synthesized mainly in the liver in response to iron stores and inflammation. Hepcidin is an important peptide for systemic iron homeostasis and also has antibacterial and antifungal activities. Hepcidin up-regulation is particularly useful during acute inflammation, especially before adaptive imm...
Hermans WA, Kersjes AW, van der Mey GJ, Dik KJ.A breeding experiment was carried out in a group of Shetland ponies in order to investigate the heredity of congenital lateral patellar (sub)luxation. A breeding herd was established and consisted of stallions and mares acquired at different times. Some were free from, and others were affected by lateral patellar (sub)luxation in either one or both femoropatellar joints. Over a period of 20 years, 49 foals were born from different mating combinations. Some offspring were free from the defect and others showed the abnormality. Though the number of foals bred during the experiment is rather smal...
Bowling AT, Millon L, Hughes JP.Chromosomal abnormality was detectable in 98 of 180 mares aged 3 years or over with gonadal dysgenesis. The most common abnormality was X monosomy (63,X). The second most common abnormality was a karyotype indistinguishable by G- or C-banding from that of a male horse (64,XY). Two mares demonstrated structural abnormality of one X chromosome [64,X,del(Xp)] which has not previously been reported in horses. One of these foaled a filly with the same karyotype as her dam. Blood typing confirmed parentage of the foal. This is the only example in our experience of fertility in a mare with gonadal dy...
Cook RF, Cook SJ, Bolin PS, Howe LJ, Zhou W, Montelaro RC, Issel CJ.In the context of DNA vaccines the native equine infectious anemia virus (EIAV)-envelope gene has proven to be an extremely weak immunogen in horses probably because the RNA transcripts are poorly expressed owing to an unusual codon-usage bias, the possession of multiple RNA splice sites and potential adenosine-rich RNA instability elements. To overcome these problems a synthetic version of sequences encoding the EIAV surface unit (SU) envelope glycoprotein was produced (SYNSU) in which the codon-usage bias was modified to conform to that of highly expressed horse and human genes. In transfect...
Perkins JD, Windley Z, Dixon PM, Smith M, Barakzai SZ.To evaluate the use of sinoscopy for detection and treatment of ventral conchal sinus (VCS) and/or rostral maxillary sinus (RMS) disease in horses. Methods: Case series Methods: Horses (n=60) with suspected paranasal sinus disease. Methods: Horses were evaluated by sinoscopy through a conchofrontal sinus (CFS) portal with ventral conchal bulla (VCB) fenestration. Other endoscopic sinus approaches and adjunctive diagnostic tests; oral examination, computed tomography, radiography, scintigraphy and endoscopic examination of the upper portion of the respiratory tract were used in some horses. Res...
Wang Y, Mao Q, Chang H, Wu Y, Pan S, Li Y, Zhang Y.Integrins can function as receptors for foot-and-mouth disease virus (FMDV) in epithelium. Horses are believed to be insusceptible to this disease, but the mechanism of resistance remains unclear. To detect whether FMDV can use integrin to attach to equine epithelial, we compared the utilities of αvβ3 and αvβ6 between bovine and equine kidney epithelial cells (KECs). Equine KECs showed almost equal efficiency to those of bovine. Further, the integrin αv, β3, and β6 subunits from bovine and equine were cloned and vectors were transfected into SW480 cells and COS-1 cells alone or together...
Hatzel JN, Bouma GJ, Cleys ER, Bemis LT, Ehrhart EJ, McCue PM.Early pregnancy factor has been identified as a 10-kDa extracellular homolog of heat shock protein 10 (Hsp10). Hsp10 has been detected during early pregnancy in serum of mice, sheep, pigs, horses, cows, and humans by the rosette inhibition test. Hsp10 has also been associated with several neoplastic and autoimmune diseases. The goal of the present study was to determine if Hsp10 could be detected in the early equine embryo through the use of immunohistochemistry and quantitative real-time PCR. Additionally, analysis of systemically harvested peripheral blood mononuclear cells (PBMCs) from both...
Szczerba-Turek A, Siemionek J, Ras A, Bancerz-Kisiel A, Platt-Samoraj A, Lipczynska-Ilczuk K, Szweda W.Equine sarcoids are the most common neoplasms in horses. Bovine papilloma- virus type 1 (BPV-1) is the main viral type identified in equine sarcoids in Europe. Objective: The aim of the present study was to genetically evaluate BPV types based on DNA analyses of the CDS of the L1 gene. The presence of BPV DNA was confirmed by Degenerate Oligonucleotide-Primed Polymerase Chain Reaction (DOP PCR) with FAP59/FAP64 consensus primers. Results: The DNA was detected in 21/40 (52.5%) of clinically diagnosed sarcoids. More than half of 14 isolates (66.7%) shared 100% homology with BPV-1 Deltapapillomav...
Bhuyan AK, Udgaonkar JB.The unfolding kinetics of horse cytochrome c in the oxidized state has been studied at 10, 22, and 34 degreesC as a function of guanidine hydrochloride (GdnHCl) concentration. Rapid (millisecond) measurements of far-UV circular dichroism (CD) as well as fluorescence quenching due to tryptophan to heme excitation energy transfer have been used to monitor the unfolding process. At 10 degreesC, the decrease in far-UV CD signal that accompanies unfolding occurs in two phases. The unobservable burst phase is complete within 4 ms, while the slower phase occurs over tens to hundreds of milliseconds. ...
Koho NM, Hyyppä S, Pösö AR.Monocarboxylate transporters (MCT) facilitate the transport of lactate across membranes. In red blood cells (RBC) the transport activity varies interindividually due to differences in the amount of an ancillary protein CD147. Similar variations in muscles could have a great influence on lactate accumulation during exercise. Objective: To study the expression of MCT isoforms and CD147 in the middle gluteal muscle. Methods: Venous blood and muscle biopsy samples were taken from 14 Standardbred horses. Lactate transport activity in RBC and the amounts of MCT1, 2, 4 and CD147 were measured. Result...
Brosnahan MM, Erb HN, Perkins GA, Divers TJ, Borges AS, Osterrieder N.Research in humans has demonstrated that high serum iron (sFe) concentration can predispose to infection, and many infections subsequently result in alterations of host sFe. A decrease in sFe concentration is an early and sensitive indicator of systemic inflammation caused by tissue necrosis, bacterial infections, or endotoxemia in horses. Serum iron parameters in acute equine herpesvirus type 1 (EHV-1) infection have not been evaluated previously. Objective: To document the sFe response to EHV-1 infection and to determine whether or not significant differences in sFe concentration exist betwe...
Power MM, Gustavsson I, Switoński M, Plöen L.Synaptonemal complex analysis by electron microscopy of a trisomy 28 in a male horse demonstrated a trivalent or a bivalent plus a univalent in primary spermatocytes. Two of the chromosomes making up the trivalent were, most often, completely paired with each other and only partially paired or associated with the third one. Half of the spermatocytes analysed demonstrated heterologous pairing or association between the free axis of the trivalent and the sex bivalent. The pairings remained, to a large extent, into diakinesis-metaphase I. In most pachytene cells one autosomal bivalent showed prox...
Proops L, Burden F, Osthaus B.Donkeys and mules are frequently kept as companion animals for horses and ponies, with these different equids often being considered a homogenous group. However, the extent to which domestic equids form inter-specific bonds and display similar social behaviour when living in a mixed herd has not previously been studied. Here we compare the social organization of these three (sub)species when housed together, providing the first systematic analysis of how genetic hybridization is expressed in the social behaviour of mules. A group of 16 mules, donkeys and ponies was observed for 70h and preferr...
Basrur PK, Kanagawa H, Gilman JP.Cytogenetic and histological studies have been carried out on an intersex horse which was clinically diagnosed as a cryptorchid. The horse had the general conformation of a stallion but the external genitalia included a well developed vulva and a penis. The right testis which was descended was devoid of germ cells and the left "gonad" located in the cavum vaginale contained neither testicular nor ovarian tissue. The male duct system on both sides were relatively well developed despite the absence of a testis on the left side. Chromosome analysis on cultured cells from the descended testis reve...
Leathwick DM, Sauermann CW, Geurden T, Nielsen MK.A previously described model for the dynamics of the parasitic stages of Parascaris spp. was modified to include eggs outside the host and the genetics of anthelmintic resistance before being used to address questions regarding the development of resistance. Three broad questions were addressed; i) How sustainable is the current common practice of treating foals monthly for their first year of life (i.e. 12 treatments/year)? ii) Does the timing of treatments have an effect on resistance development? (i.e. do certain treatments select for resistance more strongly than others?), and iii) How sus...
Taylor SD, Leib SR, Wu W, Nelson R, Carpenter S, Mealey RH.Using the equine infectious anemia virus (EIAV) lentivirus model system, we previously demonstrated protective effects of broadly neutralizing immune plasma in young horses (foals) with severe combined immunodeficiency (SCID). However, in vivo selection of a neutralization-resistant envelope variant occurred. Here, we determined the protective effects of purified immunoglobulin with more potent broadly neutralizing activity. Overall, protection correlated with the breadth and potency of neutralizing activity in vitro. Four of five SCID foals were completely protected against homologous challen...
Satterlee JD, Moench S.Proton hyperfine resonance assignments for cytochromes c from several species are currently being successfully pursued by several laboratories. These efforts focus mostly on the ferrous forms. In contrast to that work, we have pursued assignments of the proton hyperfine shifted resonances for horse and tuna ferricytochromes c. Our results indicate that assignments are nearly identical in those two proteins. Using the pre-steady state nuclear Overhauser effect, several additional assignments have been made for the tuna protein, whereas for the horse protein, the following protons have been assi...
Montagna P, Liguori R, Monari L, Strong PN, Riva R, Di Stasi V, Gandini G, Cipone M.To describe a case of equine muscular dystrophy with myotonia. Methods: A 5-year-old horse presented with hypertrophy and delayed relaxation of the muscles of the hindlimbs from age 2 months. Testicular atrophy developed from 2 years of age. Action and percussion myotonia was associated with weakness in these muscles, and EMG showed diffuse myotonic discharges and myopathic features. Biopsy of the gluteal muscle showed adipose and connective tissue infiltration, marked variation in muscle fibre size, and moth-eaten, ring and whorled fibres. Results: Injection of apamin, a peptide blocker of ca...
Trachsel DS, Calloe K, Mykkänen AK, Raistakka P, Anttila M, Fredholm M, Tala M, Lamminpää K, Klaerke DA, Buhl R.Exercise-associated sudden deaths (EASDs) are deaths occurring unexpectedly during or immediately after exercise. Sudden cardiac death (SCD) is one cause of EASD. Cardiac arrhythmias caused by genetic variants have been linked to SCD in humans. We hypothesize that genetic variants may be associated with SCD in animals, including horses. Genetic variants are transmitted to offspring and their frequency might increase within a family. Therefore, the frequency of such variants might increase with the inbreeding factor. Higher inbreeding could have a negative impact on racing performance. Pedigree...
Caij AB, Tignon M.In January 2010, the United Kingdom notified cases of equine infectious anaemia (EIA) in two horses introduced from Belgium. The animals came from one assembly centre in Romania and had transited through Belgium with 16 other horses. Nine of them, bought by a Belgian horse breeder, were investigated in Belgium and revealed one additional EIA-positive animal. Afterwards, the Belgian Federal Agency for the Safety of the Food Chain (FASFC) organized a serological EIA survey of the horses introduced into Belgium from Romania between 2007 and 2009. Among the 95 horses identified, six additional ser...
Blatter M, Haase B, Gerber V, Poncet PA, Leeb T, Rieder S, Henke D, Janett F, Burger D.In April 2008 a Franches-Montagnes colt was born with an unusual coat colour phenotype which had never been observed in that population before. The foal showed extended white markings on body and legs, a white head and blue eyes. As both parents have an unremarkable bay coat colour phenotype, a de novo mutation was expected in the offspring and a candidate gene approach revealed a spontaneous mutation in the microphthalmia associated transcription factor gene (MITF). A detailed clinical examination in 2010 indicated an impaired hearing capacity. As in the American Paint Horse large white facia...
Choi Y, Yoon M.Androstenone is the first mammalian steroidal pheromone to be identified. Pheromones are chemicals that animals use to communicate within a species. Pheromone detections are related to vomeronasal organ (VNO) and olfactory epithelium (OE) in mammals. Olfactory Receptor Family 7 Subfamily D Member 4 (OR7D4) is an odorant receptor that responds to androstenone. Several studies indicated that spray with androstenone changes behaviors of the boar and dogs. However, the expression of OR7D4 in VNO and OE was not reported in mammals except human. Thus, the main objectives of this study were to invest...
Meng S, Zhang Y, Lv S, Zhang Z, Liu X, Jiang L.With their enormous muscle mass and athletic ability, horses are well-positioned as model organisms for understanding muscle metabolism. There are two different types of horse breeds-Guanzhong (GZ) horses, an athletic breed with a larger body height (~148.7 cm), and the Ningqiang pony (NQ) horses, a lower height breed generally used for ornamental purposes-both inhabited in the same region of China with obvious differences in muscle content. The main objective of this study was to evaluate the breed-specific mechanisms controlling muscle metabolism. In this study, we observed muscle glycogen, ...
Bedford SJ, Kurokawa M, Hinrichs K, Fissore RA.In oocytes from all mammalian species studied to date, fertilization by a spermatozoon induces intracellular calcium ([Ca(2+)](i)) oscillations that are crucial for appropriate oocyte activation and embryonic development. Such patterns are species-specific and have not yet been elucidated in horses; it is also not known whether equine oocytes respond with transient [Ca(2+)](i) oscillations when fertilized or treated with parthenogenetic agents. Therefore, the aims of this study were: (i) to characterize the activity of equine sperm extracts microinjected into mouse oocytes; (ii) to ascertain i...
Agnieszka N, Joanna K, Wojciech W, Adam O.The aim of this study was determine the viability and developmental competence of equine oocytes after IVM and vitrification using the Rapid-I method, as part of an effort to develop an effective equine oocyte vitrification protocol. Equine oocytes were collected by scraping ovarian follicles of slaughtered mares. A total of 1052 ovaries were used in this study, from which 3135 oocytes were obtained. Of the 2853 oocytes retrieved, 2557 underwent in vitro maturation for approximately 36 h. After in vitro culture, 1202 oocytes (47%) had a first polar body. To evaluate the toxicity of the solu...
Valenzuela OA, Couturier-Tarrade A, Choi YH, Aubrière MC, Ritthaler J, Chavatte-Palmer P, Hinrichs K.Assisted reproductive technologies (ARTs) such as intracytoplasmic sperm injection (ICSI), in vitro embryo culture and embryo transfer (ET) may be associated with alterations in fetal and placental development. In horses, ET has been used for decades. More recently, in vitro embryo production by ICSI and in vitro culture, followed by embryo transfer (ICSI-C) has become an accepted method for clinical foal production. However, no information is available on the effects of ICSI-C or even of standard ET itself on placental and neonatal parameters in horses. We therefore evaluated placental and ne...
Gmel AI, Gmel G, von Niederhäusern R, Weishaupt MA, Neuditschko M.Gait quality, that is, the way horses move according to functional and aesthetic principles, englobes many traits that are scored by experts during breeding competitions. The experts can score a trait on a subjective valuating (SV) scale or on a linear profiling (LP) scale representing the biological extremes of the population. However, the reliability of the appraisal of gait quality traits has not been extensively evaluated. In this study, seven breed experts appraised the walk and trot quality of 24 Franches-Montagnes stallions presented in hand on a sand track. Inter-rater reliabilities of...
Neuhauser S, Dörfel S, Handler J.Preservation of epididymal spermatozoa is important to save genetic material of endangered species and breeds, or in case of unexpected injury, which will end the breeding career of valuable sires. Seminal plasma (SP) influences sperm quality in a dose-dependent manner and its addition to preserved semen immediately before insemination may be beneficial for sperm fertility. Increased plasma membrane stability of epididymal spermatozoa reduces freezing injury of cells, and the addition of SP after freezing and thawing might have activating and protecting effects on spermatozoa within the female...
Alpoim-Moreira J, Szóstek-Mioduchowska A, Słyszewska M, Rebordão MR, Skarzynski DJ, Ferreira-Dias G.Endometrosis negatively affects endometrial function and fertility in mares, due to excessive deposition of type I (COL1) and type III (COL3) collagens. The pro-fibrotic transforming growth factor (TGF-β1) induces myofibroblast differentiation, characterized by α-smooth muscle actin (α-SMA) expression, and collagen synthesis. In humans, fibrosis has been linked to epigenetic mechanisms. To the best of our knowledge, this has not been described in mare endometrium. Therefore, this study aimed to investigate the in vitro epigenetic regulation in TGF-β1-treated mare endometrial fibroblasts an...
Koban E, Denizci M, Aslan O, Aktoprakligil D, Aksu S, Bower M, Balcioglu BK, Ozdemir Bahadir A, Bilgin R, Erdag B, Bagis H, Arat S.The horse has been a food source, but more importantly, it has been a means for transport. Its domestication was one of the crucial steps in the history of human civilization. Despite the archaeological and molecular studies carried out on the history of horse domestication, which would contribute to conservation of the breeds, the details of the domestication of horses still remain to be resolved. We employed 21 microsatellite loci and mitochondrial control region partial sequences to analyse genetic variability within and among four Anatolian native horse breeds, Ayvacık Pony, Malakan Horse...
Wong PL, Nickel LS, Bowling AT, Steffey EP.Serum samples of 20 horses were evaluated for antibodies against RBC after homologous blood transfusion. Transfusion-associated antibodies against RBC were detected in 10 horses. Antibodies recognizing horse blood group antigens Aa, Ae, Db, and Dc were identified. Antibodies against Aa were found in all samples from Aa-negative horses that were transfused with Aa-positive RBC. Antibodies against Aa persisted for at least 1 year after transfusion. Antibodies against Ae were detected in 7 of 8 horses transfused with Ae-positive RBC. Initial appearance and persistence of antibodies against Ae dif...
