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.
Matthews AG.Three major antiprotease components in equine serum were identified and characterised. These were the acidic prealbumin Pr, the homologue of human alpha-1 antitrypsin and 2 protease binding proteins, the acidic prealbumin Xc and alpha-2 macroglobulin, both capable of inhibiting the proteolytic activity of trypsin, but with only limited inhibitory effect on its esterolytic activity. The possible role of these serum antiproteases in the onset of chronic obstructive pulmonary disease (COPD), analogous to the hereditary dysproteinaemia of alpha-1 antitrypsin in man, was investigated. There was no ...
McDonald TL, Burger D.Initial separation and concentration of Clq from fresh, normal equine serum was accomplished by precipitation in 0.02 M acetate buffer, pH 5.5, at 4 degrees for 24 h. The re-dissolved precipitate was clarified by centrifugation at 80,000 g for 1 h and then dialysed against Tris-HCl buffer (0.05 M, pH 8.0) containing 10-3 M EDTA. The clarified dialysate remained biologically active at 5 degrees for at least 4 weeks. Biological activity of equine Clq was determined by assay of its ability to agglutinate sensitized sheep erythrocytes (EA). Following ammonium sulphate fractionation, Sepharose 4B g...
Magnuson NS, Perryman LE.The effect of adenosine on the mitogenic response of peripheral blood lymphocytes (PBL) and on the nucleotide pools of erythrocytes from normal horses, horses heterozygous for the combined immunodeficiency (CID) trait (carriers), and foals with CID was studied. When PBL from normal, carrier, and CID horses were stimulated by phytohemagglutinin (PHA), concanavalin A, or pokeweed mitogen, [3H]thymidine uptake was inhibited by adenosine (0.1 microM) to 1.0 mM) in a dose-dependent manner. Adenosine (100 microM) mediated inhibition of [3H]thymidine uptake was prevented in both normal and carrier ho...
Science (New York, N.Y.)June 22, 1979
Volume 204, Issue 4399 1317-1319 doi: 10.1126/science.451540
Bailey E, Stormont C, Suzuki Y, Trommershausen Smith A.A system of equine lymphocyte alloantigens designated ELA, is identified, and it is shown that the locus or loci controlling these markers must be closely linked to the locus controlling markers in the A system of horse blood groups. Among 29 offspring in two stallion families there was evidence for one recombinant. Lod scores for linkage between the A and ELA loci in the two families were 3.61 and 3.33, respectively, for theta equal to 0.
Shupe JL, Leone NC, Olson AE, Gardner EJ.Investigation of hereditary multiple exostoses in horses under controlled research conditions for 10 years and epidemiologic studies that have spanned up to five generations of human families contain notable similarities. The present study demonstrated that a single dominant autosomal gene is responsible for hereditary multiple exostoses in horses and man. Affected individuals transmit this trait to approximately 50% of their progeny, whereas nonaffected individuals do not transmit the condition to their offspring. The tumors in affected horses are most often present at birth. They tend to be ...
van Nie CJ, van der Kamp JS.A case of tricuspid atresia in a premature foal associated with large atrial septal and ventricular septal defects is reported. This anomaly is compared with other cases in horses as reported in the literature. As tricuspid atresia in horses is usually not diagnosed so that relatively few cases have been reported, a classification similar to that of human anomalies is not possible. It is suggested that the present malformation is due to abnormal development of the atrioventricular canal. The factors involved in the pathogenesis of this abnormal development are obscure.
Liberatori J, Morisio Guidetti L, Conti A.By double diffusion in agarose gel, in well defined experimental conditions, cross reactions were observed between porcine beta-lactoglobulins and anti-bovine beta-lactoglobulin antisera. The immunological reactivity between these beta-lactoglobulins from a monogastric and the ruminant anti beta-lactoglobulin antiserum thus implies a certain degree of similarity between the monomeric beta-lactoglobulins examined and the dimeric of the ruminants. With the same antisera it also proved possible to demonstrate the presence of beta-lactoglobulins in the mammary secretions of another monogastric, na...
Leid RW.The investigation of the mast cell-basophil products has progressed from studies directed solely at implicating histamine or serotonin in allergic diseases to molecular definitions of pathways to target cell activation and mediator release. In addition, within the last several years the detection and molecular characterization of the many other mediators of immediate hypersensitivity have begun. This area should continue to prove a fruitful arena in the future. Identification of the physiologic importance of these mediators in the heaves syndrome or other potential equine allergic syndromes ma...
Ryder OA, Hansen SK.A (G + C)-rich density satellite DNA (rho = 1.713 gm/cc) has been purified from splenic DNA of Przewalski's horse, Equus przewalskii, by successive equilibrium density gradient centrifugations. The purified satellite, which may comprise as much as 29% of the total DNA, renatures rapidly; however, analyses of native, single-stranded, and reassociated molecules by analytical ultracentrifugation and melting properties suggest that some sequence heterogeniety exists in the 1.713 gm/cc satellite. Complementary RNA (cRNA) transcribed from satellite DNA has been utilized for in situ hybridization stu...
Cox JE, Edwards GB, Neal PA.The authors analyse data collected over 23 years from 500 cryptorchid horses. They show that left- and right-sided abdominal cases occur with approximately equal frequency in ponies. Approximately half the right-sided unilateral abdominal cases have the epididymal tail descended while only 20 per cent of the left-sided cases do. These findings are briefly discussed. From their analysis of inguinal cryptorchidism the authors conclude that it is a relatively more complex phenomenon with incidence changing with age as well as breed. Right-sided retention predominates in young ponies, probably bei...
Sharp DC, Garcia MC, Ginther OJ.Luteinizing hormone (LH) was quantified in pony mares during artificially induced sexual maturation. Ovarian follicular development was also assessed by rectal palpation of the ovaries. With the exception of large periovulatory LH concentrations in two mares that ovulated, LH concentrations were not significantly different in mares undergoing sexual maturation and thus having marked follicular development when compared with mares that were not undergoing sexual maturation and thus did not have marked follicular development. These results indicate a dissociation in time between the onset of fol...
Eriksson H, Augustinsson KB.A plausible mechanism of action of horse serum butyrylcholinesterase is proposed. It includes substrate activation at the level of deacylation. The rate constant for the acylation of the enzyme appears to be much greater than the rate constant for the deacylation, at low substate concentrations. At higher substrate concentrations the rate constants become more similar. No interaction between the four subunits in binding of inhibitors or in the catalysis was observed. There is one esteratic and one anionic site per subunit apparent from labelling studies with [32P]diisopropylfluorophosphate and...
Perryman LE, Buening GM, McGuire TC, Torbeck RL, Poppie MJ, Sale GE.Six young horses with combined immunodeficiency were given liver cells intravenously or intraperitoneally and thymuses subcutaneously from equine fetuses ranging from 68 to 110 days of gestational age. Three of four horses given cells from fetuses over 90 days of age developed lesions compatible with graft versus host reactions. One horse given cells from an 80-day fetus developed mitogen-responsive lymphocytes, synthesized immunoglobulins of the four major equine classes, and survived to 11.5 months of age. The sixth foal receiving cells from a 68-day fetus showed no discernable effects from ...
Corradin G, Chiller JM.Murine T-lymphocyte specificity was determined in a system of antigen driven in vitro T-cell proliferation using cytochrome c molecules from different species, their derived peptides and reconstituted hybrid proteins. It was observed that primed T cells could discriminate between peptide fragments which differed from each other at a single amino acid residue. These conclusions were substantiated by the pattern of cross-reactivity noted in the response of closely related cytochrome c proteins as well as when artificial hybrid molecules reconstituted by the covalent linkage of peptide fragments ...
Smyth GB.An abnormal cryptorchid testicle removed from the abdominal cavity of a 4 year old Thoroughbred stallion is described. The abnormal organ conforms to the requirements of Willis (1960) for a teratoma. The difference between these tumours in man and horses is discussed.
Bowling AT.Preliminary evidence for the fifth autosomal linkage group in the horse, comprised of the loci for a red cell alloantigen (U) and serum protease inhibitor (Pi), was demonstrated by means of paternal half-sib groups in thoroughbred, standardbred and Arabian breeds. Recombination frequency in males was estimated to be 0.125 +/- 0.019.
Bull TE, Lindman B, Einarsson R, Zeppezauer M.The binding of Au(CN)2- and Pt(CN)4-2- ions to the coenzyme binding site of horse liver alcohol dehydrogenase (alcohol : NAD+ oxidoreductase EC 1.1.1.1) has been studied by 35C1 nuclear magnetic relaxation. Longitudinal relaxation rates were analyzed in terms of a simple model and binding constants for Au(CN)2-, Pt(CN)4-2- and C1- were estimated. From a comparison between transverse and longitudinal relaxation rates the correlation time and the quadrupole coupling constant of bound chloride ion were obtained. The quadrupole coupling constant estimated from a simple electrostatic model for chlo...
Affleck KJ, Conboy HS, Fitzgerald BP.Eleven anoestrous mares were assigned randomly to Group A (intact, n = 6) or Group B (ovariectomized in January, n = 5). Jugular blood samples were collected during February to April. Ovarian activity was assessed by ultrasound and ovulation was confirmed by progesterone analysis. Intact mares ovulated between 2 and 28 April. Mean diameter of the largest follicle was less than 20 mm on 17 or 18 March (Period 3), but increased to 29 mm by 31 March or 1 April (Period 4). During Periods 1 and 2 (14 or 15 February and 3 or 4 March) mean luteinizing hormone (LH) concentrations were similar in both ...
Moyaert H, Haesebrouck F, Dewulf J, Ducatelle R, Pasmans F.Faecal samples of sixty-six 3-day- to 6-month-old foals were screened for Helicobacter equorum DNA by means of a PCR amplifying a 1074 bp fragment of the 23S rRNA gene with primers specific for this enterohepatic Helicobacter species. H. equorum DNA was demonstrated in faeces from 28.6% of the less than 1-month-old foals, while 67.8% of foals from 1 to 6 months of age tested positive. In a previous study, H. equorum was demonstrated in faeces of 0.8-7.9% of adult horses. These results indicate that the prevalence of H. equorum in horses differs with the age of the investigated horse population...
SAXENA BB, McSHAN WH, MEYER RK.Fresh horse-pituitary glands were extracted with 40% ethanol and the gonadotropins were recovered by increasing the alcohol concentration to 85% followed by drying with acetone. This preparation was further extracted with water at pH 5, and the extract was adjusted to pH 7 and lyophilized. The follicle-stimulating hormone in the pH-5-souluble fraction was purified by zone electrophoresis and resolved into six components by starch-gel electrophoresis. One of these components contained follicle-stimulating hormone which was recovered in the elution cell and the contaminating starch was separated...
Bovell DL, Riggs CM, Sidlow G, Troester S, MacLaren W, Yip W, Ko WH.Fluid secretion by sweat glands in response to heat and exercise is underpinned by increases in intracellular calcium. In horses, this is primarily via β2-adrenoceptors, but studies in equine sweat gland cell lines have indicated a possible role for purinergic agonists. Knowledge of equine sweating stimulus-secretion mechanisms in intact glands from healthy animals would allow future comparison to determine whether these mechanisms are affected in equine anhidrosis. Objective: To determine whether purinergic agonists can induce changes in intracellular calcium in intact, freshly isolated equi...