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.
Steinhardt J, Hiremath CB.Many of the stability characteristics of horse ferrihemo-globin (Hb+) in acid solutions, such as pH dependence and susceptibility to stabilization by iron ligands, are shared by human ferrihemoglobin, but striking differences between the two proteins exist. The most noticeable is the much greater rate of denaturation of the human protein at all pH values. Other differences include a shift to higher pH in the equi-librium between native and acid-denatured forms, differ-ences in the temperature at which the temperature effect on the equilibrium-pH curve reverses, a complete absence in human Hb+ ...
Rockey JH.Eight antigenically unique immunoglobulins have been identified in purified equine anti-p-azophenyl-beta-lactoside (Lac) antibody isolated from a single horse. The Fc fragments of the gammaGa-, gammaGb-, gammaGc-, and -gammaA-globulins have been shown to possess unique antigenic determinants. Common gammaG- and gammaA-Fc fragment antigenic determinants, which were absent from the 10Sgamma(1)- and gammaM-globulins, have also been observed. All antibody populations share two antigenically distinct light (B, L) chain variants. The association of anti-Lac antibody with the hapten p-(p-dimethylamin...
Haque RU.A technique for identifying and characterizing staphylococcal hemolysins by first separating them electrophoretically in barbital-buffered agar gel (pH 8.4) at 5 ma/cm for 2 hr and then determining their hemolytic activities by exposing them to human, horse, rabbit, and sheep erythrocytes is described. The alpha-hemolysin produced by a White variant of the Wood 46 strain of Staphylococcus aureus migrated 18 mm towards the cathode, and it lysed horse, rabbit, and sheep erythrocytes, whereas a Clear variant of the Wood 46 strain of S. aureus produced a lysin which migrated similarly to the alpha...
Bornstein S.Two intersex horses were characterized externally by vulva and “enlarged clitoris-hypoplastic penis” and internally by uterus and testicles. Both had a normal female karyotype 64/XX. One of the horses whose body measurements were in accordance with mares of the same breed, showed a distinct stallion behaviour.
Ginther OJ.After the cessation of equine embryo mobility (fixation) on mean Day 16, the embryonic vesicle is rotated or oriented so that the pole with the embryo proper is opposite to the mesometrial attachment. Orientation involves massage of the vesicle by contractions of the turgid uterine horn and greater thickening of the vesicle at the pole with the embryo proper. Thickening of the dorsal endometrium (encroachment) especially on each side of the mesometrial attachment accounts for a guitar-pick shape of the vesicle when viewed in cross section of the uterine horn. On Days 21-40, the allantoic sac e...
Ferrer MS, Canisso IF, Podico G, Ellerbrock RE, Hurley DJ, Palomares R.Different stallions exhibit a high level of variation in the ability of their sperm to survive cryopreservation. A large fraction of stallions show poor post-thaw sperm motility, and their semen is not suitable for commercial freezing. In this study, we hypothesized that the presence of sperm-bound antisperm antibodies (ASAs) was associated with poor cryosurvival of stallion sperm. Our objective was to assess the level of ASA binding to stallion sperm, and determine if it was associated with good or poor sperm cryosurvival. In Experiment 1, cooled shipped semen from 27 stallions was frozen usi...
Lee J, Shin D, Kim H.Thoroughbred horses have been bred exclusively for racing in England for a long time. Additionally, because horse racing is a global sport, a healthy leisure activity for ordinary citizens, and a high-value business, systematic racehorse breeding at the population level is a requirement for continuous industrial development. Therefore, we established genomic evaluation system (using prize money as horse racing traits) to produce spirited, agile, and strong racing horse population. Methods: We used phenotypic data from 25,061 Thoroughbred horses (all registered individuals in Korea) that compet...
Lode A, Bernhardt A, Kroonen K, Springer M, Briest A, Gelinsky M.The application of bone graft substitutes with osteoinductive properties is of high importance for the repair of large bone defects. COLLOSS E, a protein lyophilizate extracted from equine long bones, exhibits an osteoinductive potential which has been proven in several studies. In this work, a mechanically stable, but biodegradable support for COLLOSS E has been developed aiming at a bone graft substitute that retains shape and size when coming in contact with body fluids. Mineralization of collagen type I, isolated from horse tendon, resulted in a stable collagen hydroxyapatite nanocomposite...
Curcio Bda R, Pereira GR, Antunes LI, Boff AN, dos Santos FC, Lucas T, Nogueira CE, Corcini CD, Liu I, Deschamps JC.In vitro fertilization (IVF) procedures are limited by the inability to mature equine oocytes on in vitro methods. Objective: The aim of this study was to evaluate structural integrity of equine oocytes subjected to vitrification with a synthetic polymer (PVA). Methods: The effect of eGH and its relationship with IGF-I on in vitro maturation (IVM) were evaluated. Compact cumulus oocytes complexes (n=122) were cultured in TCM-199 with eGH, IGF-I or eGH+IGF-I for 30h at 38.5C in air with 5 % CO2. Oocytes were fixed after IVM or subjected to the vitrification protocol. Cryopreserved oocytes were ...
Frazer GS, Bucci DM.The aims of this project were to document the protein profile of equine seminal plasma and determine the variability between stallions in the relative composition of proteins in the ejaculate. A single ejaculate was obtained from 14 stallions of varying breed and age. The gel fraction was removed by an in-line filter. The semen was centrifuged and the supernatant seminal plasma aspirated without disturbing the sperm pellet. The seminal plasma was recentrifuged and stored in cryovials at -70 degrees C. Samples were thawed, recentrifuged, assayed for protein concentration (BCA protein assay), di...
Heap RB, Hamon MH, Allen WR.Aromatase distribution in membranes of preimplantation horse and donkey conceptuses was compared by measuring the incorporation of [3H]androstenedione into oestrone and oestradiol-17 beta. In the donkey conceptus, aromatase activity was similar in all the tissues examined (yolk sac, chorionic girdle and allantochorion), whereas in the horse it was generally lower and showed the relationship chorionic girdle greater than yolk sac greater than allantochorion. A higher proportion of labelled precursor was incorporated into oestradiol-17 beta by extra-embryonic tissues of the donkey compared with ...
Pellegrini A, von Fellenberg R.Pre-alpha 2-elastase inhibitor of horse plasma has recently been isolated in our laboratory. In this article we demonstrate that the inhibitor is a composite structure built of alpha 1-proteinase inhibitor and alpha 1-beta 1-glycoprotein. The compound inhibitor is biologically active, although it has previously been shown that its enzyme specificity is different from that of free alpha 1-proteinase inhibitor. Our observations are based on immunochemical cross-reactions between pre-alpha 1-elastase inhibitor and antibodies to alpha 2-beta 1-glycoprotein as well as antibodies to alpha 1-proteina...
Miszczak F, Pronost S, Vabret A.Equine arteritis virus (EAV) is the causative agent of equine viral arteritis, a disease observed only in equids. EAV is the prototype of the family Arteriviridæ within the order Nidovirales. EAV is an enveloped, positive-sense, single-stranded RNA virus with a considerable variation in the genome as observed in other RNA viruses. During natural infections, EAV may cause abortion and persistent subclinical infections in stallions which can shed the virus in the semen for years, or even lifetime. Chronically infected stallions represent the natural reservoir of the virus. They ensure the persi...
Dai CM, Zhang XY, Zhang RR, Shao YM, Shen RX.To develop a novel vaccine candidate of Equine infectious anemia virus(EIAV). Methods: env genes of EIAV Chinese donkey leukocyte attenuated strain (EIAV DLV) and its parental virus strain (EIAV LN) were expressed using the BAC-To-BAC system, and Env proteins were confirmed by SDS-PAGE and Western blot. BALB/c mice were immunized with recombinant vaccinia viruses containing env genes of EIAV alone or boosted with Env proteins expressed by recombinant baculovirus. Both protective humoral and cellular immune responses were detected. Results: Recombinant baculovirus could express complete Env pro...
Condò SG, Coletta M, Cicchetti R, Argentin G, Guerrieri P, Marini S, el-Sherbini S, Giardina B.The equilibrium O2-binding properties of the hybrid haemoglobin (Hb) present in vivo in erythrocytes from mule and of its parent Hbs from horse and donkey were compared with special reference to the effect of heterotropic ligands such as Cl-, D-glycerate 2,3-bisphosphate (DPG) and inositol hexakisphosphate. All these Hbs display a decreased effect by polyphosphates, confirming that what has been observed for horse Hb [Giardina, Brix, Clementi, Scatena, Nicoletti, Cicchetti, Argentin & Condò (1990) Biochem. J. 266, 897-900] is common to other equine species, at least from a qualitative sta...
Hermeyer K, Seehusen F, Gehlen H, Peters M, Wohlsein P.Cutaneous malignant lymphomas are rare in horses and comprise predominantly T-cell-rich B-cell lymphomas. They are characterized by multiple tumour nodules affecting predominantly female horses with a survival rate of months to years. At the final stage, metastases to regional lymph nodes occur, whereas widespread organ involvement is rarely reported. In this case report, a cutaneous T-cell-rich B-cell lymphoma in a 7-year-old standardbred gelding with metastases is described. Clinically, multiple cutaneous and subcutaneous nodules, enlarged superficial lymph nodes, rapid weight loss, and vent...
Andrianov AM, Akhrem AA.Using the earlier suggested method the calculation of the backbone conformations of horse heart cytochrome c in oxidized (ferricytochrome c) and reduced (ferrocytochrome c) states has been performed by the two-dimensional nuclear Overhauser effect spectroscopy data. For both protein forms the secondary structure elements have been revealed and the conformations of the irregular polypeptide chain segments have been analysed. The similarity of the secondary structures of ferri- and ferrocytochrome c in solution was established from the comparison of their conformations. Small differences between...
Vandeplassche M, Henry M, Coryn M.Oestrogen and progesterone concentrations in blood and follicular fluid and blood levels of LH were determined in 426 mares at different stages of the oestrous cycle. Mature follicles occur at all stages of the cycle; they ovulate readily in early metoestrus, occasionally in late metoestrus and very rarely in dioestrus. Maturation of a mid-cycle follicle is associated with intermediate levels of LH, which are less than those found during oestrus. This lower level of LH together with a high level of progesterone are probably responsible for the failure of ovulation and regression of most of the...
Yamanouchi K, Yoshida S, Hasegawa T, Ikeda A, Chang KT, Matsuyama S, Nishihara M, Miyazawa K, Takahashi M.cDNA encoding equine inhibin alpha-subunit precursor protein was isolated from an equine ovarian cDNA library. For screening, the DNA probe was amplified by the RT-PCR using primers designed based on the rat inhibin alpha-subunit cDNA sequence. Out of 1.2 x 10(5) plaques screened, 19 positive clones were isolated, and one of these clones (Eq-alpha-11) contained a complete open reading frame encoding 367 amino acids. The similarity of the deduced amino acid sequences of both equine inhibin alpha-subunit precursor protein and the mature protein were greater than 80% to those of other six mammali...
Ross MW, Stephens PR, Reimer JM.A 9-year-old pregnant Standardbred broodmare was evaluated for signs of mild abdominal pain, failure to defecate, and mild abdominal distention. Rectal examination revealed the leading edge of a small colon intussusception, and peritoneal fluid analysis indicated suppurative peritonitis. Surgical management, including reduction of the intussusception and small colon resection with end-to-end anastomosis, resulted in successful outcome (1-year follow-up evaluation). Postoperative complications including dehiscence of the ventral midline surgical incision and simple obstruction at the anastomosi...
Bugno-Poniewierska M, Dardzińska A, Pawlina K, Słota E.A normal course of meiosis and the associated course of spermatogenesis in males are very significant from the viewpoint of animal breeding, in particular animal reproduction. This takes on special significance when studying late-maturing animals such as horses. The aim of the study was to analyse meiotic cells, with particular consideration of synaptonemal complexes obtained from the testes of young stallions and cryptorchids, based on observations of the X-Y bivalent. The analysis was performed in successive stages of meiotic division using the FISH technique. The greatest diversity and most...
Pintore MD, Cantile C.A full-term male foal born in a farm holidays in Maremma (Tuscany, Italy) was euthanized shortly after birth due to the presence of several malformations. The rostral maxilla and the nasal septum were deviated to the right (wry nose), and a severe cervico-thoracic scoliosis and anus atresia were evident. Necropsy revealed ileum atresia and agenesis of the right kidney. The brain showed an incomplete separation of the hemispheres of the rostral third of the forebrain and the olfactory bulbs and tracts were absent (olfactory aplasia). A diagnosis of semilobar holoprosencephaly (HPE) was achieved...
Schaefer RJ, Cullen J, Manfredi J, McCue M.A gene's response to an environment is tightly bound to the underlying genetic variation present in an individual's genome and varies greatly depending on the tissue it is being expressed in. Gene co-expression networks provide a mechanism to understand and interpret the collective transcriptional responses of genes. Here, we use the Camoco co-expression network framework to characterize the transcriptional landscape of adipose and gluteal muscle tissue in 83 domestic horses (Equus caballus) representing 5 different breeds. In each tissue, gene expression profiles, capturing transcriptional re...
Browne NS, Scarratt WK, Robertson J.A 10-year-old Andalusian mare was presented for evaluation of weight loss, increasing periods of recumbency, and swelling of the lower limbs. Radiographs revealed severe palisading to solid periosteal new bone formation in numerous locations. Necropsy revealed a metastatic malignant adenocarcinoma of ovarian origin with secondary hypertrophic osteopathy. Une jument d’Andalousie âgée de 10 ans a été présentée pour évaluation à la suite d’une perte de poids, de périodes croissantes de décubitus et d’enflure dans les membres inférieurs. Les radiographies ont révélé des lésio...
Trolldenier H, Klarmann D, Krabisch P, Rohde J, Steiner A, Verspohl J.368 streptococcal strains from udder secretions of cattle (Sc. agalactiae, Sc. dysgalactiae, Sc. uberis) and 191 streptococcal isolates from horse specimens (Sc. equi ssp. zooepidemicus, Sc. equi ssp. equi) originating from different agricultural regions in Germany (Lower Saxony, in particular the region of Weser-Ems, Bavaria, Altmark) were investigated for their sensitivity to 4 beta-lactam antibiotics (benzylpenicillin, ampicillin, oxacillin, cefotaxime). Two different test methods were applied: the agar diffusion test for determination of the diameter of the zone of inhibition and the E-tes...
Reubel GH, Studdert MJ.We report the first nucleotide sequence data on equine adenovirus 2 (EAdV2) which corroborate on the molecular level that EAdV2 is distinct from equine adenovirus 1 (EAdV1). Based on sequence homology with Eadv1 the hexon gene of Eadv2 was identified. HindIII restriction fragments containing the hexon and eight other viral genes were cloned into the plasmid pUC19 and the nucleotide sequence of the hexon and the 23K proteinase genes completely determined. Amino acid (aa) comparison of sequence fragments with published adenovirus (AdV) proteins identified the genes for the E1B/19K, IVa2, DNA pol...
Dordas-Perpinyà M, Pintart C, Terris H, Normandin L, Bruyas JF.Two cloned mares, produced from the same sample of skin fibroblasts, were bred during four breeding seasons from their second year of age, as embryo donors, in exactly the same conditions, using the same stallions for both cloned mares. The aim of this study was to test the embryo donor potential of cloned mares and to compare the results obtained from two cloned mares of the same mare with other embryo donor mares (n = 31-39 per breeding season) at the same stud. For both cloned mares, 19 embryos were recovered by 43 collection attempts (44%) (7/22 for one; 12/21 for the other), 16 (84%) pr...
Meier H.Both a mandate of the Bernese Government (1705) and statements in the Georgica Helvetica of 1706 prove that Swiss horse breeding was lucrative and of good quality at that time. However, the political turmoil at the transition from the 18th to 19th century and excessive sales to France and Italy led to a severe drop in quantity as well in quality. The exhibition of horses in Aarau in 1865 showed a wretched state of the material. In the same year, Rudolf Zangger wrote a guide for the discussion of horse breeding in Switzerland. In the following year (1866), Johann Jakob Rychner published a repor...
Guèrand M, Mahla R, Lagneaux D, Amigues Y, Palmer E, Bézard J.Paternity analysis was performed on the DNA of 21 equine embryos collected nonsurgically 10 days after ovulation from known mares, but involving 3 possible sires. After extraction, the DNA of each embryo was typed by radioactive PCR amplification using 10 characterised microsatellites; HMS 1, 2, 5, 6, 7 and 8 (Guérin et al. 1994) and HTG 3, 4, 6 and 10 (Marklund et al. 1994). The 21 dams and 3 sires were genotyped using DNA extracted from blood and amplified by PCR. After electrophoresis and autoradiography of the PCR products of the embryo and parents, the alleles of the embryo were compared...
Huhtinen M, Peippo J, Bredbacka P.Embryo biopsy has been used to detect inherited disorders and to improve the phenotype by analyzing of linkages between marker loci and the desired characteristics. Unfortunately, early procedures required the removal of a large portion (one-half) of the embryo for analysis, and the transfer of bisected equine embryos has not been particularly successful. Recent discovery of the polymerase chain reaction (PCR) has made possible the detection of specific DNA sequences from only a few cells. We investigated whether the removal of a small biopsy would allow for successful PCR and normal embryonic...
Evenson DP, Jost LK, Varner DD.Data from the sperm chromatin structure assay (SCSA), a flow cytometric measurement of susceptibility of sperm nuclear DNA to denaturation, show strong correlation with the fertility potential of bulls, boars, men and stallions. Previous studies showed a strong relationship between stallion spermatozoa with denatured DNA and the presence of DNA strand breaks. In the present study, the relationship between stallion sperm DNA denaturation and the redox status of -SH groups on the cysteine residues of sperm nuclear protamines that are thought to stabilize chromatin was investigated. Semen samples...
Bouchard PR, Fortna CH, Rowland PH, Lewis RM.Granular cell tumor (GCT) is a morphologic designation for tumors of varied histogenesis. Most GCTs in human beings are derived from Schwann cells, and rat meningeal GCTs are believed to originate in the neural crest. Three equine pulmonary GCTs from aged horses were studied immunohistochemically with primary antibodies directed against vimentin, cytokeratins (AE1/AE3), S-100, Leu 7, desmin, and neuron-specific enolase (NSE) using a steptavidin-biotin procedure. All three tumors stained similarly with strong and diffuse staining of neoplastic cells for vimentin and S-100 and negative staining ...
Mobarak MS, Ryan MF.Light, scanning, and transmission electron microscopy were employed to provide further data on the putative origins of the immunogenic secretory-excretory product (ESP) of Strongylus vulgaris (Looss 1900). The sharply delineated but superficial attachment to the equine caecum by the mouth leaves behind an oval area devoid of epithelial cells. Attachment does not extend deeply enough to reach the muscularis mucosa layer of the equine intestine. The progressive digestion of the ingested plug of tissue (epithelial cells, blood cells and mucous) was visualized. The coelomocytes, floating cells and...
Cheng HW, Chik TK, Weir J, Chan BP.Damage to the hyaline cartilage of the joint surface and osteochondral fractures are key factors leading to the development of osteoarthritis in racehorses, representing a significant cause of racehorse retirement. To tissue-engineer an osteochondral unit that is suitable for joint repair, incorporation of a zone of calcified cartilage should be considered so as to mimic itscounterpart. To date, equine mesenchymal stem cells (eMSCs) have been reported to have multilineage differentiation potential. Yet the generation of a zone of calcified cartilage using eMSCs has not been reported. This work...
