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.
Rossdale PD.Diagnosis in veterinary medicine is based upon observations of the manner in which the behavioural patterns differ from those exhibited by normal subjects. The newborn foal adapts to an advanced level of activity within a period which is short relative to many other species, and the behavioural patterns which it exhibits during the period of adaptation are comparatively stereotyped. Because the status of any newborn mammal is affected by its previous experience of foetal development and birth, the behavioural patterns of the mother form an important anamnesis in the life of each individual neo...
Williams MA, Harrison PM.Horse ferritin was fractionated both by starch-gel electrophoresis and by gel filtration on Sephadex G-200. Monomer fractions contained up to 98% of monomer and oligomer fractions up to 76% of oligomers as determined by quantitative electron microscopy. Percentages obtained from electron micrographs correlated well with analytical starch-gel electrophoretograms and ultracentrifuge patterns. Amino acid analyses of monomer- and oligomer-enriched fractions showed no significant differences. Ferritin oligomers did not apparently dissociate on dilution for electron microscopy or on storage. Apoferr...
Turner GA, Taylor DM.The interactions between tetravalent plutonium and horse serum proteins were studied in vitro by electrophoresis on cellulose acetate and by gel filtration. The results show that in horse serum, as in other mammalian sera, the plutonium is associated principally with the transferrin component of the beta1-globulins. The formation of the plutonium-transferrin complex requires the presence of HCO3-, and plutonium is displaced from the complex by excess iron, thus indicating that similar binding sites may be involved in the complexing of iron and plutonium. The plutonium complex is considered to ...
Oliver L, Hartree AS.The cystine-containing peptides of horse growth hormone were isolated and their amino acid sequences determined. Four unique half-cystine residues occur in two peptides, one containing 11 and the other, at the C-terminus of the protein, 15 amino acids. These sequences are compared with published data on growth hormones from other species.
de Laat MA, Spence RJ, Sillence MN, Pollitt CC.Equine laminitis is a disease of the digital epidermal lamellae typified by epidermal cell proliferation and structural collapse. Most commonly the disease is caused by hyperinsulinemia, although the pathogenesis is incompletely understood. Insulin can activate the epidermal growth factor (EGF) system in other species and the present study tested the hypothesis that upregulation of EGF receptor (EGFR) signalling is a key factor in laminitis pathophysiology. First, we examined lamellar tissue from healthy Standardbred horses and those with induced hyperinsulinemia and laminitis for EGFR distrib...
Hendrikse J, van der Holst W, Best AP.Examination of 539 ejaculates of stallions of various breeds showed that approximately 60 per cent of the spermatozoa were completely normal morphologically. Of these morphologically normal spermatozoa, 13 per cent were dead. The total proportion of live spermatozoa was 75 per cent, 32 per cent being obviously abnormal (22 per cent of live and 10 per cent of dead spermatozoa). Separated heads (normal as well as abnormal) were significantly more common among dead spermatozoa. Protoplasmic droplets (both at the neck and at the end of the middle piece) were mainly present in live spermatozoa. As ...
Papkoff H, Murthy HM, Roser JF.The tyrosine residues of equine chorionic gonadotropin have been nitrated with tetranitromethane and the resulting effects on the biological and immunological activities of the hormone studied. All of the tyrosine residues in equine chorionic gonadotropin were found to react with tetranitromethane when a 100-fold molar excess of reagent was used or with an 8.6 molar excess in the presence of 5 M guanidine hydrochloride. Complete nitration abolished the biological activities and decreased the immunological activity of the hormone. The nitration of one tyrosine residue resulted in the loss of 70...
Church S.Three Quarter Horse stallions and 5 of their 11 tested progeny were diagnosed as affected with the inherited autosomal dominant defect hyperkalaemic periodic paralysis in Victoria in 1992. The diagnoses were based on the appearance of clinical signs and associated increased plasma potassium concentrations in response to oral potassium loading. All affected horses were descendants of the American Quarter Horse Impressive. Indirect evidence indicates that at least 3 other affected Quarter Horse stallions have stood or are standing at stud in Australia. The clinical details of the affected horses...
Silvia PJ, Fitzgerald BP.An attenuated ovulatory rise in circulating concentrations of LH is characteristically associated with the first seasonal reproductive cycle of horse mares. Unlike ovulations (OV) of subsequent estrous cycles, the first OV of the breeding season (OV1) is not preceded by elevated concentrations of progesterone (PROG). Hence, the ability of pretreatment with PROG to abolish attenuation of LH-secretion associated with OV1 was investigated. Ten nonpregnant anestrous mares were randomly divided into 2 groups; control (C) and treated (T). Per individual, when diameter of the largest follicle was con...
Kadivar A, Rashidzadeh H, Davoodian N, Nazari H, Dehghani Tafti R, Heidari Khoei H, Seidi Samani H, Modaresi J, Ahmadi E.Accurate diagnosis of foetal sex in pregnant mare is helpful for many breeders, both for private or commercial purposes. In this study, in order to pre-natal foetal sexing in equine, we used TaqMan duplex real-time PCR to detect the specific regions of SRY and TSPY genes on extracted cell-free foetal DNA from maternal blood. Peripheral blood samples from 50 pregnant Arabian mares with singleton foetuses were collected. Cell-free foetal DNA was extracted from maternal plasma, and duplex real-time PCR assays were performed with TaqMan probes and primers. Amplification of glyceraldehyde-3-phospha...
Fukushima JG, Cascone O, Santomé JA, Biscoglio de Jimenez Bonino MJ.Reactivity of histidine residues in equine growth hormone to ethoxyformic anhydride was studied. The existence of two kinetically different sets was demonstrated: one of them including only the slow reacting histidine 169 (k = 0.164 min-1) and the other containing fast reacting histidines 19 and 21 (k = 0.892 min-1). A correlation between the decrease in the capacity to compete with 125I-labeled hormone for rat liver binding sites and the degree of ethoxyformylation of the fast group was found. Circular dichroism studies indicated no significant conformational changes in the protein with all t...
Parés-Casanova PM.Morphological integration and modularity are concepts that refer to the covariation level between the components of a structure. Morphological modules are independent subsets of highly correlated traits. The horse skull has been studied as a whole functional structure for decades, but the integrative approach towards quantitative examination of modules is scarce. We report here the first evaluation of cranial modularity in the horse at basal level. For this, we studied the modularity hypothesis for splanchnocranium and basicranium modules in the horse, two phenotipic regions under local influe...
Stock KF, Hoeschele I, Distl O.Simulated horse data were used to compare multivariate estimation of genetic parameters and prediction of breeding values (BV) for categorical, continuous and molecular genetic data using linear animal models via residual maximum likelihood (REML) and best linear unbiased prediction (BLUP) and mixed linear-threshold animal models via Gibbs sampling (GS). Simulation included additive genetic values, residuals and fixed effects for one continuous trait, liabilities of four binary traits, and quantitative trait locus (QTL) effects and genetic markers with different recombination rates and polymor...
Pellegrini A, Zweifel HR, von Fellenberg R.Several publications have described in the past properties of partly purified horse alpha 2-macroglobulin (alpha 2M) which are strikingly different from the human alpha 2M. Horse alpha 2M was therefore isolated to purity by classical procedures, i.e. affinity chromatography, ion exchange chromatography and gel filtration, and its properties are compared with those of its human counterpart. The molecular weight of the native protein and its subunits, the isoelectrofocusing pattern and the change in electrophoretic mobility caused by interaction with protease were similar to those of human alpha...
Ciosek J, Kimes A, Vinardell T, Miller DC, Antczak DF, Brooks S.Valued for their temperament, beauty, athletic ability, and exhibition in the show ring, Arabian horses are an important component of the horse industry. Juvenile idiopathic epilepsy (JIE), a seizure disorder, is most often reported in Arabian foals from birth to 6 months of age. Affected foals exhibit tonic-clonic seizures lasting as long as 5 min and risking secondary complications like temporary blindness and disorientation. Some foals outgrow this condition, while others die or suffer lifelong complications if not treated. Previous work suggested a strong genetic component to JIE and propo...
Kaaden OR, Truyen U.There is a continuous change in viral epidemics with respect to clinical symptoms, their duration or disappearance and the emergence of new diseases. This can be observed both in human and animal diseases. This evolution of virus diseases is mainly related to three factors: etiological agent, host and environment. As far as genetic alterations of the virus are concerned, two major mechanisms are involved: 1) mutations such as recombination and reassortment; 2) selection for resistance or susceptibility. The epidemiology of newly emerged virus diseases in man and animals, such as AIDS and hemor...
Raengsakulrach B, Staczek J.Equine cytomegalovirus (ECMV) contains a linear, double-stranded DNA genome composed of a 146-kbp unique region flanked by a pair of 18-kbp direct repeat (DR) sequences at the termini. Cycloheximide, actinomycin D, and phosphonoacetic acid were applied to infected cell cultures to divide viral transcription into immediate-early (IE), early, and late phases. Eight IE transcripts were identified and mapped to two regions (I and II) of the viral genome. Two of these IE RNAs (13.0 and 5.5 kb in size) were transcribed from region I, which is located within the DR regions; these IE genes are diploid...
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 ...
Davicco MJ, Coxam V, Faulconnier Y, Dubroeucq H, Martin-Rosset W, Barlet JP.The present study was undertaken to assess GH secretory profiles in 12 light-breed foals and their dams during forty days after delivery, and the possible influence of GRF and TRH on plasma GH concentrations in these newborn foals. GH secretory pattern was pulsatile in one day- as well as in forty days-old foals. The number of secretory spikes (10 per 24 h) did not vary between days 1 and 40. In the same times, GH secretion did not show any circadian rhythm either in foals or in their dams. Mean daily plasma concentrations (measured through blood samples collected every 20 min for 24 h) were l...
Walencik-Łata A, Kozłowska B, Mietelski JW, Szufa K, Freire FD, Souza SO.This study aimed at assessing the incorporation of radionuclides in animals in the proximity of the uranium mine in Caetité, Brazil. In 2014, samples of bovine and equine teeth and skull bones were collected and their contents of natural and artificial isotopes were assessed using nuclear spectrometry techniques. Gamma ray emission from Ra and K isotopes was determined using high-purity germanium (HPGe) spectrometry, Sr radioactivity was measured with liquid scintillation, and U, Th, Po and Pu radioactivity was assessed with alpha-spectrometry. Prior to the measurements, sample dissolutions a...
Drummond WH, Sanchez IR, Kosch PC, Webb AI.Adult ponies develop pulmonary hypertension at altitude (Bisgard, Orr and Will 1975), but the neonatal response to acute hypoxaemia is unknown. Seven foals aged five days were instrumented with a systemic and a Swan-Ganz pulmonary artery catheter while anesthetised and intubated. Cardiac index, pulmonary (PAP) and systemic (SAP) vascular pressures were measured as the foals breathed gas mixtures with FI02 of 8 to 94 per cent. Because foramen ovale or ductus arteriosus shunts might have altered thermodilution cardiac index measurements in the stressed foals, the ratio, PAP/SAP was calculated to...
Greenaway EC, Cunningham FM, Goode NT.Phorbol esters, which activate protein kinase C (PKC), stimulate equine eosinophil superoxide production and adherence. After showing that superoxide production could be inhibited by the nonselective PKC inhibitors, staurosporine and bisindolymaleimide I, the PKC isotypes in equine eosinophils were characterized, because evidence suggests that individual isotypes may play distinct roles in regulating eosinophil function. Western blots demonstrated that equine eosinophils expressed PKC alpha, beta, delta, epsilon, iota, and zeta. However, unlike the equine neutrophil, the majority of the PKC wa...
Yamanouchi K, Hirasawa K, Hondo E, Hasegawa T, Ikeda A, Sugawara Y, Matsuyama S, Miyazawa K, Sawasaki T, Tojo H, Tachi C, Takahashi M.The expression of inhibin alpha-subunit mRNA in equine fetal gonads during pregnancy (Days 90 to 300) was examined by means of Northern blot analysis. In all samples examined, a single species of transcript was detected at the size of 1.5 kb. A digoxigenin-labeled antisense cRNA probe specific to equine inhibin alpha-subunit was synthesized and in situ hybridization analysis to locate the inhibin alpha-subunit mRNA positive cells was performed using frozen tissue sections of equine fetal ovary (day 150 of pregnancy) and equine fetal testis (day 180 of pregnancy). In the fetal ovary, positive c...
Mukaiya R, Kimura T, Ochiai K, Wada R, Umemura T.Equine herpesvirus-1 (EHV-1) infection was demonstrated in the lung tissue of seven aborted fetuses by immunohistochemical labelling and polymerase chain reaction. The placentas of the fetuses were also examined by non-isotopic in-situ hybridization for the EHV-1 glycoprotein B (gB) gene. Positive hybridization signals were observed in the cytoplasm of trophoblasts, especially in microcotyledons, of all seven placentas, and in villous epithelium of the allantochorion of six placentas. Despite the presence of EHV-1 RNA, EHV-1 antigens were not detected in placentas by immunohistochemical examin...
Han H, Mao C, Chen N, Lan X, Chen H, Lei C, Dang R.Kit gene is a genetic determinant of horse white coat color which has been a highly valued trait in horses for at least 2,000 years. Single nucleotide polymorphisms (SNPs) in Kit are of importance due to their strong associations with melanoblast survival during embryonic development. In this study, a mutation analysis of all 21 Kit exons in 14 Chinese domestic horse breeds revealed six SNPs (g.91214T>G, g.143245T>G, g.164297C>T, g.170189C>T, g.171356C>G, and g.171471G>A), which located in 5'-UTR region, intron 6, exon 15, exon 20, intron 20, and exon 21 of the equine Kit gene, respectively. S...
Capshaw EL, Thompson DL, Kulinski KM, Johnson CA, French DD.Fourteen foals between 4 and 4.5 mo of age were used to determine the effects of 12 mo of daily treatment with equine somatotropin (eST) on growth, metabolic, and hormonal characteristics. The foals were paired by sex, type, and lineage, and one of each pair was administered eST daily at 20 microg/kg of BW. Body weights, body measurements, and assessments of glucose tolerance and feedback effects on endogenous somatotropin (ST) secretion were made routinely. Treatment with eST did not alter (P > 0.10) BW, height at withers, length of body, widths of chest and rump, heart girth, length of he...
Drbalova J, Musilova P, Kubickova S, Sebestova H, Vahala J, Rubes J.The T cell receptor (TCR) genes (TRA, TRB, TRD and TRG) reside in 3 different chromosomal regions. During the maturation of T lymphocytes, the TCR genes are rearranged by site-specific recombination, a process that also predisposes T cells to aberrant rearrangements. Illegitimate recombination between the TCR genes occurs at a low level in healthy individuals, but this frequency may correlate with the risk of lymphoma. The aim of this work was to investigate interlocus recombination in equids. Illegitimate rearrangements were studied in peripheral blood lymphocytes by FISH with painting and BA...
Wang Y, Zhang XY, Wei LL, Wu DL, Wang XJ, Xiang WH, Shen RX, Shao YM.To evaluate the relationship between the transcriptional level of IFN-gamma mRNA in peripheral blood mononuclear cells (PBMC) and immune protective response driven by inoculated horses with donkey leukocyte attenuated vaccine of EIAV(DLV), and to elucidate the immune mechanism of DLV. Methods: A real-time PCR method was established for quantitative detection of IFN-gamma mRNA level from horse PBMCs. Twelve horses were divided into vaccination group, healthy control group, challenging control group and EIAV natural infection group. The transcriptional level and distribution of IFN-gamma mRNA in...
Kingma SE, Thibault ME, Betteridge KJ, Schlaf M, Gartley CJ, Chenier TS.Poor survival of cryopreservation by equine expanded blastocysts may involve low penetration of the embryonic capsule by cryoprotective agents (CPAs). This study characterized the permeation and accumulation rates of the CPAs ethylene glycol (EG) and glycerol (GLY) across isolated capsule in vitro, using a dual-chambered Valia-Chien permeation apparatus. Pieces of Days 14 to 18 ± 1 capsules separated media in the "donor" chamber containing either 1.5 M EG (n = 6), 0.74 M EG (n = 5), 0.87 M GLY (n = 7), or 0.15 M NaCl (saline, SAL) (n = 6), from the "recipient" chamber. Concentrations of CPA, ...
Thomas PG, Ball BA.To facilitate the study of interactions between equine spermatozoa and homologous oviduct epithelial cells, we developed an assay to count labelled spermatozoa bound to oviduct epithelial cell (OEC) monolayers and used the assay to compare the binding ability of spermatozoa from different stallions. Washed spermatozoa from three stallions were incubated with the fluorochrome Hoechst 33342 (5 micrograms/ml) for 1 min. Spermatozoa were then layered over confluent monolayers of oviduct epithelial cells in 2 cm2 culture wells. Coculture treatments comprised five concentrations of spermatozoa (10(5...
Monet-Kuntz C, Guillou F, Fontaine I, Combarnous Y.Using a suspension of seminiferous tubule cells, we had previously shown that equine FSH is superactive in the male rat, i.e. that it exhibits a higher biological potency than expected from its binding activity. In this work we investigated equine FSH superactivity in rat, pig and sheep, by comparing in each species the equine FSH with the homologous FSH, both for their binding activities (in a radioreceptor assay using a testicular membrane fraction) and for their in vitro biological potencies (in a plasminogen activator assay using a Sertoli cell-enriched population cultured on plastic). In ...
Southwood LL, Lindermann J, Zarucco L, Driessen B, Olander H, Habecker P, Birks EK, Frisbie DD.Growth factors (GF) are important for maintenance and repair of intestinal mucosal structure and function, but there have been no studies investigating growth factor (GF) or growth factor receptor (GF-R) mRNA expression in the intestine of horses with large colon volvulus (LCV). Objective: (1) To determine mRNA expression for epidermal growth factor (EGF), EGF receptor (EGF-R), insulin-like growth factor-I (IGF), IGF receptor (IGF-R), vascular endothelial growth factor (VEGF) and VEGF receptor (VEGF-R) in the intestine of horses with an LCV compared to normal intestine. (2) To measure the corr...
Sellon DC, Russell KE, Monroe VL, Walker KM.Seven ponies were infected with the virulent wild-type Wyoming strain of equine infectious anaemia virus (EIAV). Infection status was monitored by serum reverse transcriptase activity, rectal temperature, and complete blood count. Preinfection serum and serum obtained during the initial febrile episode following infection were assayed for interleukin 6 (IL-6) activity. Postinfection IL-6 activity was significantly increased as compared to preinfection values. The magnitude of increase in IL-6 was positively correlated with reverse transcriptase activity (an indirect measure of viraemia) but wa...
Dhar AK, Thompson MS, Paradis MR, Alcivar-Warren A.To determine the complementary DNA (cDNA) sequence of interleukin-1 receptor antagonist (IL-1ra) in horses and compare messenger RNA (mRNA) expression of IL-1ra among horses of various breeds. Methods: Blood samples from neonatal and adult horses examined for a variety of diseases. Methods: A polymerase chain reaction procedure was used to amplify a 220 base pair (bp) portion of the genomic DNA. The upstream and downstream regions of the cDNA sequence were determined by means of 5' and 3' rapid amplification of cDNA ends (RACE) procedures. Northern blot hybridization was used to examine steady...
