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.
Smith M, Tzipori S.Rotavirus RNA prepared from calf, pig, mouse, deer, foal and dog-adapted human isolates was compared using polyacrylamide gel electrophoresis. Reproducible differences in the RNA migration patterns were found between all isolates. There were 11 clearly resolved segments in the pig, mouse and foal samples. The calf rotavirus RNA and deer rotavirus RNA separated into 9 bands and 10 bands, respectively. The dog-adapted human virus migrated in 12 bands, and this probably results from the complex passage history of the original human rotavirus isolate.
Hatami-Monazah H, Pandit RV.The group of Caspian ponies studied contained some animals with 65 chromosomes and others with 64 chromosomes. The morphology and G-banding pattern of the chromosomes resembled those of Equus caballus and E. przewalskii. The karyogram of animals with 65 chromosomes was identical to that of the cross between E. caballus and E. przewalskii. It is suggested that the Caspian pony is the product of natural hybridization between E. caballus and E. prezwalskii. Low reproductive effeciency of the Caspian pony is suggested as the cause of decline in the population of these animals.
Brown JE, Corstvet RE, Stratton LG.Two experiments incorporating 13 mares were conducted for the purpose of producing and monitoring intrauterine infection with Klebsiella pneumoniae. In the pilot study, the infection was produced with strains of K pneumoniae type 68 and type 10 isolated from the genital tract of stallions with a history of breeding problems. In the principal study, K pneumoniae type 68 was used to produce the infection. Tampons and guarded culture swabs were used to obtain uterine samples in the pilot study. In comparing the efficacies of isolation of K pneumoniae with the tampons and isolation with standard g...
van der Linde-Sipman JS, Goedegebuure SA, Kroneman J.In this article a description is given of the clinical and postmortem findings of a persistent right aortic arch in association with a persistent left ductus arteriosus and a ventricular septal defect in a horse.
Stromberg B.There appears to be an increasing incidence of osteochondrosis in young fast-growing horses in Europe and the USA. The disease is thought to be congenital in type and affects endochondral ossification in growing bones. It can be localised to one joint or may be a generalised condition. The clinical manifestations of the disease lead to a secondary chronic degenerative joint disease in adult animals. There is a genetic predisposition to the condition which is associated with rapid growth and excessive high energy feeding. The careful genetic selection of bloodstock and restricted intake in earl...
Cline LJ, Crowle AJ.Evans Blue dye binds selectively, but with different avidities, to five major antigens in human serum. The anodic mobility of the antigen-dye complexes is greater than that of the antigens alone in crossed immunoelectrophoresis, which is of practical value for identification. We used this characteristic to show that in some human sera there is a population of alpha1-lipoprotein molecules that migrates electrophoretically in the beta-lipoprotein region, where in conventional zone electrophoresis it could be mistaken for beta-lipoprotein. We also demonstrate that horses, unlike rabbits, rarely m...
Greeves PR, Witherington DH.The difficulties that arise in filling out marking certificates for thoroughbreds are described. The description given on the certificate has to be both written and graphic. A general guide to whorl location is given.
Menard L, Marcoux M, Halle G.A case of unilateral front leg lameness with bone changes in the pedal bone suggestive of osteodystrophia fibrosa cystica is reported in an eight year old crossbred gelding. The changes were diagnosed at postmortem examination. The known possible causes are briefly reviewed.
Chen CL, Neilson JT, Kumar MS, Estes KS.Highly purified equine prolactin was prepared from equine pituitary glands (hypophysis) by serial extractions with water at pH 5.5, 0.1 M (NH4)2SO4 at pH 4.0, and 0.25 M (NH4)2SO4 at pH 5.5 to remove other hormones, and then finally with 70% ethanol at pH 9.3 to 10.0 to extract prolactin. Preliminary purification of the extract involved salting out other substances with 0.1% NaCl at pH 9.0. Prolactin was precipitated out by adding three times the volume of 95% ethanol at 4 C. This prolactin preparation had a biological potency of 24 IU/mg. Further purification by isoelectric focusing on a pH g...
Sugo T, Kato H, Iwanaga S, Fujii S.On incubation of purified horse plasma high-molecular-weight kininogen with purified plasma kallikrein, three new peptides, named fragment 1.2, fragment 1 and fragment 2, were released, in addition to the vasopeptide, bradykinin. Fragment 2 contained an extremely high level of histidine, in which eleven residues out of the total 48 residues were characterized. Thus the result proves the existence of the histidine-rich region in horse high-molecular-weight kininogen, which is similar to the region previously identified in bovine high-molecular-weight kininogen. Moreover, we have identified a ne...
Weitkamp LR, Allen PZ.Ancient origin of the equine vitamin D binding protein (Gc) polymorphism is suggested by the finding of two alleles, Gc(F) and Gc(S), in each of three equine subgenera, Equus, Asinus and Hippotigris. The equine Gc and albumin loci are closely linked (lod score = 6). Although no recombinants were observed, the data are not inconsistent with a map distance similar to the 2 centimorgans reported for the human albumin/Gc linkage relationship. Gametic association between the Gc(F) and Alb(F) alleles appears probable in the American Standardbred horse, perhaps as a result of population structure. Si...
Speirs VC, Wrigley R.Degenerative arthritis of the coxofemoral joints in the Norwegian Dole horse characterised by lameness, erosion of the joint cartilages, deposition of new bone at the attachments of the joint capsules and the teres ligaments, stretching and rupture of the teres ligaments and eventually luxation has been described and is considered to be due to hip dysplasia and to be inherited (Haakenstad, 1953). More recently there have been 2 reports of unilateral degenerative arthritis and subluxation in young horses (Jogi and Norberg, 1962; Davidson, 1967). In the last 8 years there have been 12,051 equine...
Parker GA, Novilla NM, Brown AC, Flor WJ, Stedham MA.A granular cell tumour (myoblastoma) occurred in the lung of an aged mare. Multiple greyish-white neoplastic nodules of various sizes almost replaced one lung. Histologically, the neoplasm consisted of small clumps of granular cells in a stroma composed of thick bands of collagen and numerous capillaries. The globoid or stellate neoplastic cells were characterized by a large number of eosinophilic, PAS-positive, diastase-resistant cytoplasmic granules. Ultrastructurally, the granules were of two types: (a) homogeneous, electron-dense granules and (b) multimorphous granules that resembled cell ...
Asquith RL, Sharp DC.Double monsters are structurally related to monozygotic twins and the reported frequency of these abnormalities in the equine species is low. Symmetrical, double development in both the cephalic region and caudal trunk was demonstrated along with a common undeveloped cervical mass. Anomalies found in the separate genito-urinary systems added another variant to this case.
Ahlswede L.Future competition horses may suffer from health impairments due to complex or partial genetic components as well as to management faults in respects to keeping, feeding and health prophylaxis against infectious diseases. This health risks exist during the whole rearing period: from late pregnancy till far beyond weaning. Health impairments reduce trade value and practical use, and interfere with aspects of animal protection. In the field of breeding permission, first in stallions, applied research ist needed. For horse farms a praxis-oriented comprehensive advisory service should be establish...
Kozawa Y, Mishima H, Sakae T.During the evolution of the Equoidea, the histological structures of the teeth have become more complex as the molars have become hypsodont in form. The straight Hunter-Schreger bands of Hiracotherium have evolved into a more complex pattern in Equus. The enamel prisms changed from an arched form (about 5μm in diameter) with an alternating pattern in Hiracotherium to an oval form (about 2 μm width) arranged in straight rows in Equus. In Equus the rows of prisms are separated by interprismatic sheets. This pattern may have increased the architectural strength of the enamel, and is related to ...
Hollyer JA, McGuinness E, Bowers LC, Didier ES, Giudice C, Perl DP, Fogarty U.A case of encephalitis of unknown origin in the horse was investigated. Postmortem examination findings revealed a nonsuppurative granulomatous meningoencephalitis in the right hemisphere of the cerebral cortex. Testing for West Nile virus, equine herpes virus, equine infectious anemia, , , and were negative. The horse had a titer for , and sections from the affected area of the brain tested positive for the organism using both polymerase chain reaction (PCR) and immunohistochemistry. Amplicons generated using PCR were sequenced, and genotype II was identified. This is the first case of gen...
Schmid A, Schmid H.In this paper, the metabolism of xenobiotics in the horse, including differences to other species, is discussed. The most important metabolic reactions of phase I (oxidation, reduction and hydrolysis of substrates), as well as of phase II (conjugation of substrates with glucuronic acid, sulphuric acid, acetic acid, alkyl groups, amino acids, amino acid derivatives, glutathione etc.), are discussed and enzymes involved in the metabolic reactions are considered.
Gulevsky AK, Grischenko VI, Tereschenko OS, Shchenyavcky IJ.The experimental data presented in the work testify to the cytostatic activity of 1-10 kD polypeptide fractions from brains of the hibernating ground squirrel and the Yakut horse towards Ehrlich ascitic carcinoma (EAC) cells. The experiments on the investigation of the inhibiting influence of 1-10 kD fractions from tissues of the hibernating and cold-adapted animals on protein-synthesizing system of EAC cells allow us to conclude that the cytostatic effect of the fractions is effected at the genetic level in the tumor cells.
Stewart-Scott IA, Pearce PD, Burkin DJ.Sex chromosome abnormalities have been detected in a further five mares with clinical histories of small ovaries and absent or irregular oestrous cycles. Three mares had 63,XO karyotypes (X monosomy) and two were sex chromosome mosaics with karyotypes of 63,XO/64,XY and 63,XO/64,XX/64,XY respectively. A sex chromosome abnormality (X monosomy) has also been found in a filly where it was suspected because of her short stature.
Miller JR, Blake JW, Tobin T.An electron capturing derivative of apomorphine was prepared by incubating the drug with heptafluorobutyric anhydride (HFBA), triethylamine and heat. Mass spectral analysis suggests that HFBA reacts with both phenolic hydroxyl groups on apomorphine to give a derivative detectable at low picogram levels. This method is sufficiently sensitive for pharmacokinetic studies in the horse and is likely applicable to other dopaminergic analogues of apomorphine.
Watanabe K, Sohara T, Takeda M, Ueno K, Suzumura N, Rokurouda Y, Rokurouda I, Yamamoto S.Each of five genetic variants of horse serum transferrin (Tf), D, F, H, O, and R, was separated into two bands by polyacrylamide gel isoelectric focusing (PAGIEF). The more acidic band, termed component a, was more abundant than the other one, termed component b, in all variants. Components a and b of TFO variant were immunologically indistinguishable from each other by double immunodiffusion test. Determination of the content ratio of component a to component b in each variant revealed that the variants were classified into two groups: one group (D, F, and H) had a relatively high ratio withi...
Helms CM, Allen PZ.Immunodiffusion analysis of papain digestion products, heavy and light chains of horse IgG-globulins with several rabbit and anti-horse IgG sera, have permitted the demonstration of five antigenic specificities (Fc1, Fc2, L, Lsp and Fabsp) associated with these equine antigens. Reactivity with anti-Fc1 is shown by both F′c and Fc fragments, while anti-Fc2 reactivity is shown only by Fc fragment.
Absorption of anti-Fab serum with L chain Fc fragment provides a reagent (anti-Fabsp) which precipitates only with Fab fragment, IgG-globulin or reduced and alkylated IgG. Upon exposure to deterge...
von Lepel J.A central control system for German Thoroughbred horses is described. Autumn examination of mares and stallions enables them to be classified according to breeding potential. The results of 25 years of study are reported.
Patterson Rosa L, Troop TW, Martin K, Vierra M, Foster G, Lundquist E, Brooks SA, Lafayette C.Hereditary Equine Regional Dermal Asthenia (HERDA) is an autosomal recessive condition present in the American Quarter Horse and other related breeds. Resulting from a mutation in the peptidyl-prolyl cis-trans isomerase B (PPIB) gene, HERDA is homologous to Ehlers-Danlos syndrome in humans. Characterized by fragile, hyperelastic, skin, HERDA affected horses often present first with slow-healing wounds usually on the dorsum, and resulting in atrophic scars, seromas, and ulcers. As there is no treatment for the condition affected horses are typically reported to be unrideable, and if persisten...
Woolford L, Staniek G, Blunden AS.Pleuropulmonary blastoma (PPB) is a rare biphasic tumor of children formed by mixed epithelial-and-mesenchymal elements. In this article, the authors report a pulmonary mass in an equine fetus with characteristics of PPB. A soft multicystic broad-based pleural mass was identified in the right caudal lung lobe. The mass comprised solid areas of loose mesenchyme, fenestrated by small ducts or large cystic areas lined by cuboidal epithelium. Mesenchymal elements had moderate anisocytosis, anisokaryosis, and cellular pleomorphism and were immunoreactive for vimentin. Epithelial cells lining ducts ...
Camici G, Manao G, Cappugi G, Ramponi G.We have predicted the secondary structure of horse muscle acylphosphatase by the statistical method of Chou and Fasman. In addition, we have studied the circular dichroism spectra of the enzyme, obtaining values for comparison to the predicted results. Discrepancies were found for the alpha-helix content estimated by the two methods.
Ihrke PJ, Wong A, Stannard AA, Vivrette SL.The fungal flora of the hair and underlying skin from 2 sites was examined qualitatively in 20 horses free of skin or ocular disease. Fungi were isolated from both the hair and the underlying skin of all 20 horses. Twenty-two genera regarded commonly as saprophytes were identified and an additional 2 fungi resembled the perfect state of the cutaneous pathogenic genera Microsporum and Trichophyton. Cladosporium spp, Penicillium spp, and Rhizopus spp were the most frequently isolated saprophytes. In general, similar fungi were isolated from the hair and underlying skin, and differences were not ...
Aranguren-Méndez J, Gómez M, Jordana J.The hierarchical population structure of five, native-Spanish donkey breeds (Andaluza, Catalana, Mallorquina, Encartaciones and Zamorano-Leonesa) has been studied using F-statistics. In addition, nine Moroccan asses and 24 Merens breed horses were included in the analysis. Data came from 15 DNA microsatellites. The analysis shows that Spanish donkeys are substructured at both hierarchical levels studied, among breeds and within breeds (between subpopulations). In the whole population, the deficit of heterozygotes was estimated to be about 21%. The fixation indices corresponding to differences ...
