Species comparison in horses involves examining the physiological, anatomical, and behavioral differences and similarities between horses and other animal species. This area of study can provide insights into the evolutionary adaptations and ecological roles of horses. Researchers often focus on aspects such as digestive systems, locomotion, sensory capabilities, and social structures to understand how horses have evolved to meet their environmental and survival needs. Comparative studies may also explore genetic differences and similarities, contributing to a broader understanding of species evolution and adaptation. This page aggregates peer-reviewed research and scholarly articles that analyze various aspects of species comparison involving horses, highlighting significant findings and methodologies used in the field.
Khittoo G, Vermette L, Nappert G, Lariviere N.In mammalian species studied previously, pepsinogen consisted of biochemically different groups of isozymogens. By use of gel filtration chromatography and electrophoresis, we isolated a predominant pepsinogen from the gastric mucosa of a horse. Peptide mapping with V8 protease revealed differences with its porcine homologue. However, porcine and equine pepsinogens, when activated to pepsin, had a similar pattern of activity when hemoglobin was used as substrate. Those results suggest that differences must exist in the primary structure of the pepsinogens of the 2 species.
McFarlane JR, Czekala NM, Papkoff H.Six samples of pregnant zebra (z) serum from the first and second trimesters of pregnancy were analyzed by RIA and shown to have chorionic gonadotropin levels comparable to that of the mare (0.9-5.3 micrograms/ml); first trimester levels in most cases were higher than second trimester levels. A pool of the sera (10 ml) was fractionated by methods previously employed for the purification of equine (e) and donkey (d) chorionic gonadotropin to achieve a concentration of the zebra chorionic gonadotropin (zCG). A yield of 1.0 mg of glycoprotein was obtained. HPLC analysis of the material indicated ...
Miksík I, Deyl Z.Skin and aorta collagen specimens of Wistar rats, white mice, beagle dogs, cats, horses, and human necropsies of different ages were examined with respect to the content of glycated products. The data presented show that (a) glycation and accumulation of the chromophore(s) are comparable in collagen samples from different species of comparable age; (b) glycation and pigmented accumulation increase markedly during the first 5-10 years of age; (c) the extent of glycation is different in different tissues (in particular, glycation of aortal collagen is about twice that of skin collagen); and (d) ...
Schuberth HJ, Hadam M, Leibold W.The determination of differentiation and transplantation antigens will be of growing importance in immune diagnosis for individual animals as well as for breeding purposes in populations. Differentiation antigens characterize subsets of cell populations and indicate their functional capacity while transplantation antigens represent markers of individuals of a species. Occurrence and significance of these antigenic systems are briefly reviewed.
Takehana K, Masty J, Abe M, Yamaguchi M.The ultrastructure and histochemistry of the duodenal glands of the pony (Equus caballus) was examined in four horses. Unlike that of most species except for the rabbit, the submucous glands of the horse contain two distinct cell types, serous and mucous. These cells are described.
Stankov B, Cozzi B, Lucini V, Fumagalli P, Scaglione F, Fraschini F.Melatonin receptors were characterized in the brains of three mammals (rabbit, horse and sheep) by an in vitro binding technique, using 2-[125I]iodomelatonin as labelled ligand. Although binding sites for melatonin have been described recently in several vertebrate species (including the sheep), the rabbit and the horse have not been the subject of investigation so far. Apart from characterization, the present report describes receptor distribution in a number of brain regions, thus allowing for direct interspecies comparison under the same methodological conditions. 2-[125I]iodomelatonin labe...
Karsai F, Szaniszló F, Pethes G.The levels of the two primary bile acids, cholic acid (CA) and chenodeoxycholic acid (CDCA), were determined by radioimmunoassay in cattle, horse, pig and dog serum. The mean serum cholic acid (SCA) and deoxycholic acid (SCDCA) levels of cows varied with their reproductive status, being 7.8 (+/- 3.3) and 1.5 (+/- 1.0) mumol/l in dry cows, 17.8 (+/- 6.9) and 2.3 (+/- 1.0) mumol/l in freshly calved dams, and 15.8 (+/- 5.7) and 2.3 (+/- 0.8) mumol/l, respectively, in lactating cows. The SCA level found in the immediate prepartal period and also on the day of calving corresponded to those found du...
Nilson JH, Bokar JA, Clay CM, Farmerie TA, Fenstermaker RA, Hamernik DL, Keri RA.Expression of the glycoprotein hormone alpha-subunit gene occurs in the pituitary of all mammals but in placenta of only primates and horses. In humans, two different elements, termed upstream regulatory element (URE) and cAMP response element (CRE), are required for placenta-specific expression of the alpha-subunit gene. The URE binds a protein unique to placenta whereas the CRE binds a ubiquitous protein. Comparative analysis of the promoter-regulatory region of the alpha-subunit gene from a number of mammals indicates that a functional URE has been retained and suggests the potential for pl...
Steger DJ, Altschmied J, Büscher M, Mellon PL.Primate and equine species are thought to be unique among mammals in synthesizing placental gonadotropin glycoprotein hormones. Human chorionic gonadotropin (CG) and equine pregnant mare's serum gonadotropin (PMSG) are produced in placenta by the specific activation of a glycoprotein hormone alpha-subunit gene and a corresponding beta-subunit gene. The evolutionary mechanisms for the apparently independent acquisition of tissue specificity were investigated by cloning the 5' flanking region of the equine alpha-subunit gene and comparing the DNA elements and trans-acting factors involved in pla...
Washizu T, Tomoda I, Kaneko JJ.The fractionation of serum bile acids was performed in the dog, cow, horse, and human by high performance liquid chromatography equipped with an immobilized 3 alpha-hydroxysteroid dehydrogenase (3 alpha-HSD) column. There were significant differences in the bile acid compositions, conjugation patterns and quantities of each bile acid among these animals. Cholic acid was the major primary bile acid in the dog and cow, which constituted 62.9% and 83.5%, respectively, whereas chenodeoxycholic acid was the major acid in the horse and human, which constituted 68.4% and 46.3%, respectively. Taurine ...
Penhallow RC, Mason AB, Woodworth RC.1. Human, bovine and equine transferrins have been characterized with respect to mol. wt, and behavior on urea-polyacrylamide gels, and isoelectric focussing gels. 2. As shown by SDS-polyacrylamide gel electrophoresis human transferrin has one major polypeptide whereas both bovine and equine transferrins have two polypeptides. 3. The transferrins show multiple banded patterns on urea-polyacrylamide and isoelectric focussing gels, particularly when iron saturated. The various forms are not resolved by neuraminidase treatment.
Ferlazzo AM, Vinci R, Panzera M, Ferlazzo A, Calatroni A.1. The measured values of acid glycosaminoglycan (GAG) concentration in plasma or in serum show significant differences between trained and untrained horses and among sedentary horses and other animal species (cattle, rabbit, sheep). 2. Diurnal variations in serum GAG levels are reported (cattle), and changes in plasma GAG concentrations after road transport (horses) and in late pregnancy (mares, cows), while sex, age and breed do not affect them.
Hässig M, Casal M, Von Beust B, Nussbaumer M, Rüsch P.In human cancer treatment, CEA (carcino embryonic antigen) testing is a routine procedure, even though the test is of low sensitivity (40%) and low specificity (70%). Since tests with polyclonal antibodies render no reproducible results with animal sera, the applicability of a recently available monoclonal CEA test designed for human sera was evaluated. We were able to show that the latter test was of supplemental diagnostic value when testing animal sera. The upper normal limit for dogs is 1.65 ng/ml, for cats 2.81 ng/ml, for cows 2.85 ng/ml, for sheep 2.85 ng/ml and for horses 1.61 ng/ml.
Stewart F, Maher JK.The number of genes encoding the common alpha-subunit and hormone-specific beta-subunits of the equine gonadotrophins (FSH, LH and CG) were investigated in the horse (Equus caballus), donkey (E. asinus) and 2 horse x donkey hybrids (the mule and hinny). The Southern technique, involving restriction enzyme digestion, blotting and DNA hybridization to 32P-labelled DNA probes was used to estimate the copy number for each gene and to assess the extent to which equids resemble primates, the only other animals that secrete a CG during pregnancy. These methods indicated that, in common with mammals, ...
Patterson SD, Bell K, Shaw DC.1. The donkey postalbumin protein has been shown to be the equivalent of human alpha 1 B-glycoprotein by protein immunoblotting and N-terminal amino acid sequence. 2. The horse A1B system (already identified as the homologue of human alpha 1 B-glycoprotein) and the donkey alpha 1 B-glycoprotein were characterized further for terminal sialic acid content, isoelectric point, amino acid composition and affinity for the dye-ligand, Cibacron Blue F3GA (known to bind human alpha 1 B-glycoprotein). 3. Two new alleles in the horse A1B system were found, bringing the total number of alleles to five. No...
Kydd JH, Butcher GW, Antczak DF, Allen WR.The expression of class I Major Histocompatibility Complex (MHC) molecules by early trophoblast of intraspecific horse and donkey, interspecific mule and extraspecific donkey-in-horse conceptuses was determined using a rat monoclonal antibody (MAC 291) in a peroxidase anti-peroxidase immunohistochemical technique. Most non-invasive allantochorion of horse, donkey and mule conceptuses did not express class I MHC molecules at any stage of gestation except in small isolated patches of pseudostratified trophoblast lying adjacent to the openings of endometrial glands. In contrast, MHC class I molec...
Nielsen AH, Gotfredsen P, Nielsen PB, Hyttel P, Poulsen K.1. Species specific problems complicating the measurement of prorenin and renin concentrations were studied in bovine, hog and horse plasma. 2. In contrast to horse renin, bovine and hog renin reacted with rat angiotensinogen, allowing measurement of the plasma renin concentration in cattle and hog with rat angiotensinogen as exogenous substrate. 3. Trypsin treatment of plasma in order to activate prorenin generated an interfering angiotensin I immunoreactive material in all three species, most extensively in horse plasma. 4. This material could be removed in bovine and hog plasma by a cation-...
Fowden AL, Mundy L, Ousey JC, McGladdery A, Silver M.Glycogen and glucose 6-phosphatase levels were measured in a variety of tissues from fetal, newborn and adult pregnant mares. Hepatic and renal glucose 6-phosphatase activities increased with increasing gestational age and rose further in the 24 h after birth to values similar to those observed in maternal tissues. The glycogen content of fetal liver and skeletal muscle also increased in late gestation, whereas that of fetal lung and cardiac muscle decreased toward term. No significant change in renal glycogen content with fetal age was observed. The values of hepatic glycogen and glucose 6-ph...
McFarlane JR, Cabrera CM, Coulson SA, Papkoff H.The rhinoceros is an endangered species related to the horse family. Little is known of its reproductive endocrinology. The objectives of this study were to partially purify rhinoceros pituitary hormones, determine which assays could be used for their assessment, and to ascertain whether rhinoceros LH possesses the intrinsic FSH activity of equine LH. A single pituitary each from a White (1.3 g) and a Black (1.2 g) Rhinoceros was homogenized and extracted (pH 9.5), then subjected to pH and salt fractionation, and ion-exchange chromatography (DEAE and Sephadex SP-C50) to yield partially purifie...
Ledwozyw A, Kadziołka A, Jabłonka S, Tusińska E, Herbut M.The aim of this study was to investigate the platelet factor 3 activity in platelet-rich plasma of horse, cattle, sheep and pig, by the use of chromogenic tripeptide substrate H-D-Phenylalanyl-Pipecolyl-Arginyl-p-nitroanilide. Among species examined the highest activity of this factor was stated in pig, the lowest one in sheep. Chromogenic substrate test was 10 times more sensitive that Stypven clotting time test. Thus, the use of chromogenic tripeptide substrate is fully valuable in platelet factor 3 activity estimation in domestic animals.
Fayrer-Hosken RA, Caudle AB, Shur BD.beta 1, 4-Galactosyltransferase (GalTase) is localized to the plasma membrane of mouse sperm, in which it mediates the binding of sperm to glycoconjugate residues in the egg zona pellucida. In this study, the presence of subcellular distribution of sperm GalTase were determined in two other mammalian species that yield sufficient sperm for subcellular fractionation. Equine and bovine semen were collected, and the plasma membranes (PM), outer acrosomal membranes (OAM), and inner acrosomal membranes (IAM) were sequentially removed. The purities of the isolated membrane preparations were determin...
Magno M.This review considers the similarities and difference between several animal species to determine which are most appropriate for studies of the human bronchial circulation in health and disease. The subgross anatomy of the sheep, cow, pig and horse appear to be similar to that of humans. These species have a major bronchial artery with a consistent location. In humans and other species, there is evidence of anastomoses between the bronchial and coronary circulations. The bronchial circulation provides nutrient supply to the neural structures of all species. The bronchial arteries themselves ar...
Wakuri H, Sakuma Y, Mutoh K, Watanabe S.In 6 equine specimens of both sexes, the morphological features of the cleavage lines of the skin over the entire body were examined using a metal probe with a sharp conical point. Wounds were produced on the skin with the probe and painted with Chinese white or Indian ink. The direction of running of the cleavage lines was determined from their relationship to the long axis of each region or area of the physical structure. The cleavage lines of the head and face revealed a fixed pattern in all specimens. They were similar to those of equine fetuses of 6 to 7 months of age. A transverse patter...
Monteiro-Riviere NA, Bristol DG, Manning TO, Rogers RA, Riviere JE.Studies in dermatology, cutaneous pharmacology, and toxicology utilize skin from different animal species and body sites. However, regional differences exist in topical chemical percutaneous absorption studies in man and in animal. The objective of this study was to compare epidermal thickness and number of cell layers across species and body sites using both formalin-fixed paraffin and frozen sections. Cutaneous blood flow determined by laser Doppler velocimetry (LDV) was compared to histologic data. Six animals of each of the following species were used: monkeys, pigs, dogs, cats, cows, hors...
Fenstermaker RA, Farmerie TA, Clay CM, Hamernik DL, Nilson JH.Expression of the glycoprotein hormone alpha-subunit gene occurs in the pituitaries of all mammals and in the placentas of primates and horses. In humans, tandem cAMP response elements (CREs), located in the proximal promoter-regulatory region of the alpha-subunit gene, act together with an adjacent upstream regulatory element to confer placenta-specific expression. Here, we report that the alpha-subunit genes of Old World Monkeys contain a single functional CRE. This suggests that tandem CREs are unique to higher primates and humans and are not absolutely required for placenta-specific expres...
Sobel JH, Thibodeau CA, Kolks MA, Canfield RE.Immunochemical studies of equine fibrinogen were conducted to characterize the structural basis for the immunologic cross-reactivity observed between human and equine A alpha chains when employing an antiserum to the 26K, human cyanogen bromide (CNBr) fragment, A alpha 241-476 (CNBr VIII). A 38K, equine CNBr fragment that reacts with this antiserum was isolated from CNBr-digested equine fibrinogen by Sephadex G-100 gel filtration. It was further purified by sequential hydrophobic chromatography on phenyl-Sepharose CL-4B, followed by reversed-phased (C-8) high-performance liquid chromatography ...
McKellar QA, Nolan AM, Galbraith EA.Blood collected from calves, sheep, goats, pigs, dogs, horses, ponies and donkeys, was allowed to clot under standard conditions. Thromboxane B2 generated during the clotting process was measured by radioimmunoassay in serum harvested from each sample. Highly significant differences were found between species and also between genera within a species. Highest concentrations of thromboxane B2 were detected in the dog samples (887.7 +/- 123.7 ng/ml) and lowest concentrations in samples from sheep (2.7 +/- 0.2 ng/ml). The amount of thromboxane produced per unit number of circulating platelets or p...
Smith PJ, Gum GG, Whitley RD, Samuelson DA, Brooks DE, Garcia-Sanchez GA.Tonometric and tonographic techniques were evaluated in the normal pony and compared to other species. Applanation tonometry was utilised to calculate the ocular ridigity of the normal equine eye. The mean intraocular pressure for the pony eye was established as 23.5 mm Hg (sd +/- 4.5). Comparing the non-anaesthetised and anaesthetised pony eye (xylazine-ketamine and glycerol guaiacolate) no significant change in intraocular pressure occurred (P < 0.49). Mean aqueous outflow facility was 0.88 microliter/min/mm Hg (sd +/- 0.65) which is significantly higher (P < 0.01) than the canine and ...
Prosser CG, McLaren RD.Ligand blotting analysis of serum from the horse using radiolabelled IGF-I revealed a protein at 96 kDa which was not present in serum from goat, cow, sheep, deer or donkey. These latter species all displayed five labelled bands in the range 24 to 41 kDa. Conversely, these were only weakly labelled in serum from the horse. Size exclusion chromatography of horse serum pre-incubated with radiolabelled IGF-I revealed reduced binding in the 130-kDa peak compared with goat plasma, and ligand blotting analysis indicated the 96-kDa protein was present in this peak. The 96-kDa protein from horse serum...
Bugno M, Slota E, Witarski W, Gerber V, Klukowska-Roetzler J.The results obtained in the present study enabled the physical map of the donkey genome to be extended with markers associated with recurrent airway obstruction (RAO), a major performance-limiting disease of Equidae. The equine BAC clone containing the IL4R and CLCA1 genes were localized to EAS 14q13 and EAS 6q15 respectlivy by fluorescent in situ hybridization. Identification of their locus confirmed the distribution of syntenic regions between the domestic horse and the domestic donkey within the chromosomes analysed.
Wertz PW, Colton SW, Downing DT.The acylglucosylceramides were isolated from the polar lipids of horse epidermis and examined to determine whether the component omega-hydroxyacids are straight chained as in the corresponding lipids from pig epidermis or branched as in horse sebum. The hydroxyacids from horse epidermis were found to be almost entirely straight chained compounds. The results indicate that sebaceous glands, although derived from epidermal cells, have evolved independent pathways of lipid metabolism.
Allen WRT, Stansfield F, Wilsher S.The placenta and fetal gonads of 12 pregnant plains zebra (Equus quagga), estimated to be between 81 and 239 days of gestation, were examined. The diffuse, microcotyledonary zebra placenta appeared, developmentally, to be 3-4 weeks behind its counterpart in horse pregnancy and this, together with the presence of small and long-lived endometrial cups, low levels of zebra chorionic gonadotrophin in maternal serum and few accessory corpora lutea in the maternal ovaries during the first half of gestation, made zebra pregnancy more similar to donkey than horse pregnancy. Zebra fetal gonads enlarged...
Feofilov AV, Bardukov NV, Glazko VI.Using ISSR-PCR marker data, comparative analysis of the gene pools of Altaic and trotting horse breeds was carried out. Horse groups of different origin demonstrated differences in amplification spectra of DNA fragments flanked by inverted repeats of four microsatellites. Combinations of certain DNA fragments present in these profiles reproducibly distinguished genomes of the Altaic breed from the trotting breeds. Genetic differentiation between some trotting breeds, based on Nei genetic distance values, was found to be comparable to that between the groups of horses of Altaic breed from two d...
Cobb MA, Schutt WA, Hermanson JW.The horse provides an interesting model for study of the structure and function of the mammalian diaphragm. Multiple regions of diaphragm from seven adult horses were prepared for histochemistry, immunocytochemistry, myosin heavy chain electrophoresis, and native myosin electrophoresis. Two additional adults were dissected to demonstrate myofiber and central tendon morphology and stained for acetylcholinesterase to demonstrate motor endplates. All regions of the adult diaphragm were histochemically characterized by a preponderance of type I fibers with some type IIa fibers. Type IIb fibers wer...
Bugno M, Klukowka-Rötzler J, Słota E, Witarski W, Gerber V, Leeb T.The physical localization of the epidermal growth factor receptor (EGFR) gene was performed on donkey chromosomes. Bacterial artificial chromosome DNA containing the equine EGFR gene was used to map this gene by fluorescent in situ hybridization on donkey metaphase chromosomes. The gene was mapped on donkey 1q21.1 region.
Osawa Y, Higashiyama T, Nakamura T.NADPH-cytochrome c (P-450) reductases from human placental aromatase II and from horse placental microsomes were solubilized and purified to show a single band of 83,000 daltons in SDS-polyacrylamide gel electrophoresis. Rabbits were immunized with purified human placental aromatase II NADPHcytochrome c (P-450) reductase. The resulting antibodies (Reduc-Ab) were used to examine the species specificity of estrogen biosynthesis and the reductase activity in humans, baboons, horses and rats. Rcduc-Ab suppressed androstenedione aromatase activity in human, baboon and horse placental microsomes wit...
Desantis S, Accogli G, Crovace A, Francioso EG, Crovace AM.The use of bone marrow-derived mesenchymal stem cells (MSCs) for clinical and experimental studies is increasing, but full characterization of MSCs in veterinary species is hindered by the variability in species-specific cell surface marker expression and antibody cross reactivity. Recent studies demonstrated that the glycans in the glycocalyx of MSCs are promising candidates as cell biomarkers. In the present study, we analyzed the glycocalyx of canine MSCs (cMSCs), ovine MSCs (oMSCs), and equine MSCs (eMSCs) using a cell microarray procedure in which MSCs were spotted on microarray slides an...
Fenu G, Melis A, Pinna MS, Loi MC, Calderisi G, Cogoni D. (SWEs), despite their pivotal ecological role due to their participation in hydrogeological processes and their richness in biodiversity, seem to be often overlooked by the scientific community. In this study, the vascular plant diversity in some representative SWEs, that host a peculiar assemblage of plant and animal species, was investigated in relation to the disturbance effects of a wild horse population. A total of 50 plots, equally distributed in small and large SWEs, were surveyed and a level of disturbance was attributed to each plot. We found greater species richness in small and und...
Putt W, Whitehouse DB.This paper reports genetic variation at the prealbumin (Pr), postalbumin (Pa) and transferrin (Tf) loci in Equus przewalskii found using thin layer isoelectric focusing and an amphoteric separator. The method resolves all three loci plus serum esterase (Es) on a single gel, and typing of all four loci is readily achieved. In addition to the esterase alleles previously reported by Fisher & Scott (1979), five alleles were found at the Pr locus, three at the Pa locus and six at the Tf locus. Analysis of several mating types confirms inheritance is autosomal and codominant for all four loci.
Vollmerhaus B, Roos H, Gerhards H, Knospe C.The canine teeth of the horse developed phylogenically from the simple, pointed, short-rooted tooth form of the leaf eating, in pairs living, Eocene horse Hyracotherium and served up to the Oligocene as a means of defense (self preservation). In the Miocene the living conditions of the Merychippus changed and they took to eating grass and adopted as a new behavior the life in a herd. The canine teeth possibly played an important role in fights for social ranking; they changed from a crown form to knife-like shape. In the Pliohippus the canine tooth usually remained in male horses and since the...
Bessent C, Ginther OJ.The caracteristics of early intrauterine mobility of the conceptus were compared between ponies (n = 9) and donkeys (n = 9). The extensive mobility of the early conceptus, previously reported for ponies and horses, was found in donkeys as well. There were no significant differences between donkeys and ponies in the characteristics or patterns of mobility. However, the mean day of fixation was approximately one day later (P<0.05) in donkeys (Day 15.6 +/- 0.3) than in ponies (Day 14.7 +/- 0.2).
Schelling C, Hagger C, Pieńkowska A, Siegfried JP, Stranzinger G.A population of Baudet du Poitou donkeys was genetically characterized using microsatellites. The results were used to verify the pedigrees and to estimate the genetic variability. It could be confirmed that a equine parentage test kit works well for donkeys and that by using 13 microsatellites more than 99% of wrong pedigree informations would be detected. The genetic variability was comparable to a representative group of Baudet du Poitou donkeys in France.