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.
Loy RG, Swan SM.Progesterone in oil solution injected into mares intramuscularly in midcycle blocked estrus and ovulation at levels of 100 mg. per day or higher. Fifty milligrams per day prevented estrus but not ovulation. The interval from end of treatment to estrus appeared to depend upon dosage, and the effects on subsequent cyclic patterns were confounded by season of the year. Neither 50 nor 100 mg. per day stopped estrus or blocked ovulation when treatment was started on day 1 of estrus. Injection of 100 mg. per day of progesterone in oil delayed postpartum estrus and ovulation, but 50 mg. per day did n...
Weir RC, Porter RR.A study of the chemical structure of the horse immunoglobulins IgG and IgA(T) has shown that the amino acid contents of the peptide chains are very similar. These globulins differ most markedly in the products of papain digestion. IgG gives 3.5s products, whereas IgA(T) gives a 5s fraction and smaller components. This difference appears to be associated with the presence of an additional easily reducible disulphide bond in the Fd fragment of the heavy chain. There is two to three times as much carbohydrate in IgA(T) as in IgG. In both, this is in the heavy chain and in IgA(T) more than half is...
Darlington RW, James C.Darlington, R. W. (St. Jude Children's Research Hospital, Memphis, Tenn.), and C. James. Biological and morphological aspects of the growth of equine abortion virus. J. Bacteriol. 92:250-257. 1966.-The growth of equine abortion virus (EAV) was studied by bioassay and electron microscopy in L-cell monolayer and suspension cultures, and in HeLa and BHK 21/13 cell monolayers. Results of virus assay (plaque-forming units) indicated that production of cell-associated virus (CAV) began at 6 to 9 hr after infection in all of the cell strains used. Virus release occurred 1 to 2 hr later. By 15 to 20 h...
Kalmykov NP.The first data on polymorphism and preadaptation of the Pleistocene horses in the mountains surrounding Lake Baikal are presented. It has been shown that disregard of intraspecific polymorphism leads to unreasonable ignoring of their diversity, phylogenetically false constructions, and incorrect interpretation of natural environment.
Huricha , Kawai M, Ninomiya S.In this study, we investigated suckling behavior and the distance between a foal and its mare as indicators of foal growth in Hokkaido native horses (HKD) during the first 40 days of life. Direct observations were made of 22 mare and foal pairs from two consecutive days 1 and 2, 5 and 6, 10 and 11, 20 and 21, 30 and 31, and 40 and 41 after birth by focal animal sampling for 3 h per day. Suckling behavior was continuously recorded, along with the terminator. The distance between the foal and its mare was determined using the instantaneous sampling method (1 min), and the percentage was calc...
Baracca A, Bucchi L, Ghelli A, Lenaz G.A method to prepare coupled submitochondrial particles from horse platelets is described. The method allowed us to study the protonophoric activities of both complex I and complex V following the fluorescence quenching of the monoamine 9-amino-6-chloro-2 methoxyacridine (ACMA), a probe highly sensitive to the generation of a transmembrane delta pH. We carried out a kinetic analysis of each enzyme complex studying the proton translocation and the electron transfer activities of complex I as well as the proton translocation and the ATP hydrolytic activities of complex V. A micromethod to prepare...
Jung H, Lee G, Kim J, Lee JW, Yoon M.The endocrine system is critical to the maintenance of testicular function. The homeostasis of sex hormone levels is orchestrated by positive and negative feedback systems controlled by the hypothalamic-pituitary-gonadal axis. This study investigated the long-term effects of hemicastration on testicular size and function in stallions. Four Thoroughbred stallions, 4-6 years of age, were included in this study. Several parameters, including testicular weight and volume, plasma testosterone concentrations, VASA-positive germ cell populations and cross-sectional areas of the seminiferous tubules ...
Aggarwal N, Holmes MA.Despite the importance of IgG Fc receptors in the regulation of various immunological mechanisms, these receptors have not been well characterised in the domesticated animals including equines. This paper describes the production of two monoclonal antibodies (CVS 59 and CVS 61) that recognise equine IgG Fc receptors. Fusions were conducted using BALB/c mice hyperimmunised with equine peripheral blood mononuclear cells. Hybridoma supernatants were screened on the basis of their ability to inhibit the rosetting of equine antibody coated sheep erythrocytes with equine peripheral blood mononuclear...
Baker JM, Stidworthy M, Gull T, Novak J, Miller JM, Antczak DF.Serological and cellular assays and molecular techniques were used to define features of the major histocompatibility complex (MHC) of the donkey With this information in hand, immune recognition of MHC determinants within and between donkeys and horses was compared. An antibody-mediated, complement-dependent, microcytotoxicity assay using a variety of antisera to donkey histocompatibility antigens, including those induced as a result of intraspecies or interspecies pregnancy in horse mares and jenny donkeys, delineated five donkey leukocyte antigen (DoLA) specificities. Antisera raised across...
Clark RJ, Valderrama XP, Furlan MA, Chedrese PJ.We report the equine (Equs equs) and elk (Cervus elaphus) pituitary pre-prolactin (PRL) cDNA cloning, and their nucleotide and deduced amino acid sequences. Pre-PRL cDNA was obtained by RNA ligation mediated-rapid amplification of cDNA ends (RLM-RACE) and polymerase chain reaction (PCR). The elk pre-PRL cDNA exhibits two polymorphisms at positions 96 and 672, which are silent since they encode for the same amino acids, proline and isoleucine, respectively. We found no polymorphisms in the equine pre-PRL cDNA. The deduced amino acid sequence of the equine pre-PRL is 99% identical to the previou...
Alexander SL, Irvine CH, Shand N, Turner J.Removal of opioid inhibition of GnRH neurones is thought to be a critical event in generating the ovulatory surge in some species. In the present study, a nonsurgical technique was used to collect pituitary venous blood samples from eight mares every 0.5-1.0 min for 1 h before and after administration of the opioid receptor antagonist naloxone (0.2 mg kg(-1), i.v.), to investigate whether opioid inhibition is also important in mares. Jugular blood samples were taken at 10-15 min intervals. Mares were studied 0, 1 or 2 days before ovulation. Naloxone administration increased mean rates of GnRH ...
Schembri MA, Major DA, Suttie JJ, Maxwell WM, Evans G.To investigate cryopreservation-induced capacitation-like changes in equine spermatozoa frozen in three different media using chlortetracycline (CTC) fluorescence staining analysis. Methods: Semen collected from three stallions was diluted in one of three centrifugation media and, after centrifugation and removal of supernatant, extended in corresponding freezing media containing additional egg yolk, glycerol, lactose and Equex paste. The semen was frozen in 5 mL straws and the spermatozoa assessed for motility and membrane quality after thawing. Results: Following centrifugation, spermatozoa ...
Coutinho da Silva MA, Seidel GE, Squires EL, Graham JK, Carnevale EM.Objectives were to determine the effects of extracellular Ca(2+) and milk proteins on intracellular Ca(2+) concentrations in stallion sperm; and to determine the effects of single caseins on sperm binding to the zona pellucida (ZP). In Experiment I, sperm were incubated in media containing 2 or 4mM Ca(2+) and intracellular Ca(2+) concentration was determined after ionomycin treatment and long-term incubation (3h). Extracellular Ca(2+) concentrations (2 compared with 4mM) did not affect baseline intracellular Ca(2+) concentration of sperm. However, incubating sperm in a medium containing 4 comp...
Wilson RB, Haffner JC.Right atrioventricular atresia with a ventricular septal defect, a rare congenital cardiac anomaly of either animals or man, was diagnosed in a one week old Arabian foal. The foal had been weak and cyanotic since birth, sometimes becoming dyspneic when stressed. Necropsy revealed a dilated and hypertrophied left ventricle with the right ventricle being small. The right atrioventricular valve was absent. The right and left ventricles communicated via a septal defect which was located immediately adjacent to the aortic valve.
Bell K, Arthur H, Breen M.Eleven apparent mutations of the equine plasma transferrin and esterase gene (10 in TF and one in ES) were found in an analysis of approximately 240,000 thoroughbred horses. Eight of the transferrin mutations produced variants not previously recognized in horses. In the two remaining transferrin mutations and the esterase mutation, reduced plasma concentrations of the proteins were demonstrated by immunological techniques and together with the family data indicated the existence of 'null' alleles.
Brom-de-Luna JG, Canesin HS, Wright G, Hinrichs K.Nuclear transfer using somatic cells from frozen semen (FzSC) would allow cloning of animals for which no other genetic material is available. Horses are one of the few species for which cloning is commercially feasible; despite this, there is no information available on the culture of equine FzSC. After preliminary trials on equine FzSC, recovered by density-gradient centrifugation, resulted in no growth, we hypothesized that sperm in the culture system negatively affected cell proliferation. Therefore, we evaluated culture of FzSC isolated using fluorescence-assisted cell sorting. In Exp. 1,...
León B, González G, Nicoli A, Rojas A, Pizio AD, Ramirez-Carvajal L, Jimenez C.Venezuelan Equine Encephalitis virus (VEEV) is an arboviral pathogen in tropical America that causes lethal encephalitis in horses and humans. VEEV is classified into six subtypes (I to VI). Subtype I viruses are divided into epizootic (IAB and IC) and endemic strains (ID and IE) that can produce outbreaks or sporadic diseases, respectively. The objective of this study was to reconstruct the phylogeny and the molecular clock of sequences of VEEV subtype I complex and identify mutations within sequences belonging to epizootic or enzootic subtypes focusing on a sequence isolated from a mare in C...
Asmundsson T, Gunnarsson E, Johannesson T.Blood samples were taken from 18 healthy horses (Group A), 15 horses clinically diagnosed to have "haysickness" ("farmer's lung") (Group B), 10 closely related horses (Group C) and 14 inbred horses (Group D). Precipitins in sera were measured by double gel diffusion test against Micropolyspora faeni, Thermoactinomyces vulgaris, Aspergillus fumigatus, Alternaria, Penicillium and Rhizopus species. In Group A, all the horses were precipitin negative except one with a faint reaction to Rhizopus species. In Group B all had precipitin against M faeni. One horse also had precipitins against Rhizopus ...
Kniazev SP, Nikitin SV.The study of the association between the coat-color variants and the blood-group system D antigens in the populations of two related trotter breeds (Orlov Trotter and Russian Trotter) showed the presence of three associations between these characters in the Orlov Trotter breed. In the populations of Russian trotters, these associations were not detected. Possible reasons for the formation and maintenance of these associations and the role of the selection for coat color in the differentiation of breeds by the frequencies of some system D antigens are discussed.
Nation PN, Klavano GG.This account describes two neonatal foals affected with osteopetrosis. One of these foals, a full term Peruvian Paso, was born alive, was bright and alert but was unable to stand and was euthanized at two days of age. The second foal, an Appaloosa, was also born alive at full term and was blind, weak, uncoordinated and unable to stand. Postmortem examination of both foals revealed generalized osteopetrosis and brachygnathia inferior. The osteopetrosis was characterized by failure of bone remodelling resulting in spicules of mineralized and nonmineralized cartilage covered by osteoid occupying ...
Wu H, Bi X, Cao F, Zhu C, Liu H, Song J, Ma L, Ma L, Zhang Y, Zhao D, Liu H, Xu X, Zhang S.A proliferation inducing ligand (APRIL) is a member of the TNF superfamily. It shares two receptors with B-cell activating factor (BAFF), B-cell maturation antigen (BCMA), and transmembrane activator and CAML interactor (TACI). Herein, the equine APRIL was identified from equine adipose-derived stem cell (ASC), and the protein expression of APRIL and its related molecules were detected during the adipogenic differentiation of equine ASC in vitro. The equine APRIL gene was located on chromosome 11, spans 1852 base pairs (bp). Its open reading frame covers 753 bp, encoding a 250-amino acid prot...
Sairam MR, Yarney TA, Bhargavi GN, Sanford LM.A membrane preparation from the testis of maturing Dorset-Leicester-Suffolk sheep, capable of discriminating pituitary LH (lutropin) from placental gonadotropins human choriogonadotropin (hCG) and equine choriogonadotropin is described. Maximum binding of 125I-oLH (ovine lutropin) to the testicular receptors occurred at 4 degrees C in a rapid manner, attaining equilibrium in 12-16 h. Under such optimal conditions, only unlabeled ovine LH or the structurally identical bovine LH effectively competed for receptor occupation. Other highly purified pituitary LH preparations from rat and human pitui...
Castagnasso EE, Kienast ME, García PP, Giovambattista G.Recently, the use of DNA markers has provided a more accurate method of identifying individuals and verifying parentage. In this report, we describe foal assignment in a farm bred jumping horses (Silla argentino). Ten mares were freely served by two stallions, resulting in nine foals. Weaning occurred without registration of the mare of each offspring, resulting in a failure to identify either the mare or the sire of each foal. Animals were typed using 12 microsatellite systems and four biochemical polymorphisms in order to determine the paternity/maternity of each foal. We used the CERVUS pro...
Schlichtherle C.This paper describes the importance of fumonisins for human beings and animals and shows data for the occurence in food. Corn-based food samples (n = 299) purchased in the area of munich were analyzed for fumonisin content using an enzyme immunoassay.Fumonisins are mycotoxins produced byFusarium species, especially byFusarium moniliforme andFusarium proliferatum. Occurrence of fumonisins in corn and in cornbased foods and feeds has been reported from almost all over the world. In several animal species different diseases are traced back to fumonisin toxicosis. Fumonisin levels of 5-10 ppm inho...
Douglas RH, Garcia MC, Ginther OJ.Luteolysis, determined by corpus luteum weight and progesterone concentration in jugular blood, occurred in uterine-intact and in hysterectomized mares after injection of prostaglandin F2alpha or of an antiserum against an equine pituitary fraction. Results indicated that luteolytic effects of exogenous prostaglandin F2alpha and inhibition of the endogenous luteotrophic activity of the hypophysis (pituitary gland) by antiserum did not involve the uterus.
Kostenko SA, Ermakova OV, Sushko SN, Fyedorova EV, Dzhus PP, Baschlykova LA, Kurylenko YF, Raskosha OV, Savin AO, Shaforost AS.We used cytogenetic analysis in the studies of the biological effects of a radiation factor of natural and artificial origin (under conditions ofthe 30-km exclusion zone ofthe Chernobyl experimental landfills in Ukraine, Belarus and Russia). The studies have been performed on various types of mammals: domestic animals--cows, pigs, horses and rodents--root voles, the Af mouse line, and yellow necked field mouse, bank voles. We found significant changes in the level of MN and chromosomal aberrations in the animals that were exposed to the conditions of chronic low-dose radiation for a long time ...
Bailey E, Lear TL.We compared pools of DNA from 10 Thoroughbred horses and 10 Arabian horses for the presence of randomly amplified polymorphic DNA (RAPD) markers which might be useful in distinguishing between the breeds. Using 212 decamer oligonucleotides and our polymerase chain reaction (PCR) conditions, 173 of the primers produced scoreable bands. The number of bands ranged from 0 to 9 with an average of 3.6. In family studies using 11 arbitrarily selected primers, five of the 11 primers produced polymorphic bands which exhibited Mendelian inheritance as dominant markers. When comparing the pooled DNA from...
Holl HM, Armstrong C, Galantino-Homer H, Brooks SA.Laminitis results in impaired tissue integrity and Inflammation of the epidermal and dermal lamellae connecting the hoof capsule to the underlying distal phalanx and causes loss-of-use, poor quality of life and euthanasia in horses. Historically, studies to better understand the etiology of laminitis by documenting changes in gene expression were hampered by the paucity of gene annotation specific to hoof tissues. Next-generation sequencing enables improvements to annotation by incorporating equine- and hoof-specific transcripts. Here we characterize the hoof lamellar tissue transcriptome of n...
Poyato-Bonilla J, Anaya-Calvo G, Molina A, Valera M, Moreno-Millán M, Dorado J, Demyda-Peyrás S.Chromosomal abnormalities are a major cause of infertility and reproductive problems in equids. Nowadays, their detection is rising due to the use of new diagnostic tools based on molecular markers instead of karyotyping. Reports of this kind of genetic aberrations in domestic donkeys (Equus asinus) are extremely scarce, despite their importance in human activities. In the present study, we analysed the implementation of a short-tandem-repeat (STR)-based molecular method initially developed for horses, as a diagnostic tool to detect chromosomal abnormalities in donkeys. The frequency of five X...
Lambertini C, Bombardi C, Zannoni A, Bernardini C, Dondi F, Morini M, Rinnovati R, Spadari A, Romagnoli N.Proteinase activated receptor 4 (PAR) in the gastrointestinal tract is involved in the regulation of inflammation and pain pathways. The aim of the present study was to evaluate the distribution and expression of PAR in the jejunum of healthy horses and in the pathologic tracts from horses undergoing surgery for herniation of the small intestine through the epiploic foramen. Eight healthy horses (Group H) and eight horses with epiploic hernia (Group EH) were included; the jejunum samples were collected at the slaughter or intraoperatively after enterectomy, respectively. To evaluate PAR expres...
Brinsko SP, Ball BA.The equine oviduct is the site of fertilisation and location of embryonic development during the first 5 or 6 days. It therefore has an important influence on mare fertility. Although histopathological changes have been described previously, there is limited information regarding lymphocyte subtypes present in the mucosa of the normal equine oviduct. Objective: To characterise the distribution of CD3+, CD4+, CD8+ and B lymphocytes in the equine oviduct from inseminated mares during oestrus and dioestrus, and from noninseminated mares during the immediate post ovulatory period. Methods: Oviduct...
Gläser KE, Davies ME, Jeffcott LB.This study was designed to examine a new role for cysteine proteinases in the process of endochondral ossification. Objective: The aim of the present study was to investigate the presence and distribution of cathepsin B and cathepsin L in equine articular cartilage during development. Methods: Full-depth cartilage samples from a total of 40 horses (age range: 4 month fetuses to 2 years) were examined and enzymes detected by immunocytochemical localisation. Results: Observations on the presence of cathepsins B and L revealed significant age-related differences, resulting in clear division of th...
Dumasia MC.The in vivo phase I biotransformation of 17 alpha-methyltestosterone in the horse leads to the formation of a complex mixture of regio- and stereoisomeric C(20)O(2), C(20)O(3) and C(20)O(4) metabolites, excreted in urine as glucuronide and sulphate phase II conjugates. The major pathways of in vivo metabolism are the reduction of the A-ring (di- and tetrahydro), epimerisation at C-17 and oxidations mainly at C-6 and C-16. Some phase I metabolites have been identified previously by positive ion electron ionisation capillary gas chromatography/mass spectrometry (GC/EI + MS) mainly from the chara...
