Molecular biology in horses involves the study of molecular processes and genetic mechanisms that underpin equine physiology and health. This field encompasses the analysis of DNA, RNA, proteins, and other biomolecules to understand gene expression, genetic variation, and cellular functions in horses. Techniques such as genomic sequencing, gene expression profiling, and molecular diagnostics are employed to explore topics like hereditary diseases, performance traits, and immune responses in equines. This page assembles peer-reviewed research studies and scholarly articles that investigate the molecular biology of horses, focusing on genetic research, molecular techniques, and their applications in equine science.
Holmes EC, Ellis SA.We carried out an analysis of partial sequences from expressed major histocompatibility complex (MHC) class I genes isolated from a range of equid species and more distantly related members of the mammalian order Perissodactyla. Phylogenetic analysis revealed a minimum of six groups, five of which contained genes and alleles that are found in equid species and one group specific to the rhinoceros. Four of the groups contained only one, or very few sequences, indicating the presence of relatively nonpolymorphic loci, while another group contained the majority of the equid sequences identified. ...
Scocchi M, Bontempo D, Boscolo S, Tomasinsig L, Giulotto E, Zanetti M.Cathelicidins are precursors of defense peptides of the innate immunity and are widespread in mammals. Their structure comprises a conserved prepropiece and an antimicrobial domain that is structurally varied both intra- and inter-species. We investigated the complexity of the cathelicidin family in horse by a reverse transcription-PCR-based cloning strategy of myeloid mRNA and by Southern and Western analyses. Three novel cathelicidin sequences were deduced from bone marrow mRNA and designated equine cathelicidins eCATH-1, eCATH-2 and eCATH-3. Putative antimicrobial domains of 26, 27 and 40 r...
Borchers K, Wolfinger U, Ludwig H.Equine herpesvirus type 4 (EHV-4) is a major respiratory pathogen of horses. Unlike most other members of the Alphaherpesvirinae, EHV-4 was regarded as non-neurotropic. Here, neural and lymphoid tissues of 17 horses have been analysed post-mortem. EHV-4 DNA was detected in 11 cases (65%) by PCR, exclusively in the trigeminal ganglia. In order to define the transcriptional activity, RNA preparations of 10 EHV-4 DNA-positive ganglia were investigated by nested RT-PCR. EHV-4-specific transcripts derived from genes 63 [herpes simplex virus type 1 (HSV-1) ICPO gene homologue] and 64 (HSV-1 ICP4 gen...
Boerboom D, Kerban A, Sirois J.Estradiol biosynthesis is a key biochemical trait of developing follicles. To study its regulation in equine follicles, the objectives of this study were to clone and determine the structure of equine cytochrome P450 aromatase (P450AROM), and characterize the regulation of P450AROM and P450 17alpha-hydroxylase/C17-20 lyase (P45017alpha) messenger RNAs (mRNAs) in vivo in equine preovulatory follicles isolated during hCG-induced ovulation. Two distinct P450AROM complementary DNAs (cDNAs) were isolated from an equine preovulatory follicle cDNA library. One clone was 2682 bp in length and included...
Clegg PD, Carter SD.A study was performed to identify the activation status of the gelatinase MMPs, MMP-2 and -9, in both normal and diseased equine articular tissues. In addition, the production and activation status of equine MMP-2 and -9 by equine articular cells and tissues in response to increasing IL-1beta concentrations was assessed. The study was performed to test the hypothesis that activation of MMPs is a fundamental step in the pathogenesis of joint diseases; and that this activation is mediated by the cytokine IL-1. Using purified equine MMP-2 and -9, the molecular weights of the zymogen and activated...
Ehlers B, Borchers K, Grund C, Frölich K, Ludwig H, Buhk HJ.A consensus primer PCR approach was used to (i) investigate the presence of herpesviruses in wild and zoo equids (zebra, wild ass, tapir) and to (ii) study the genetic relationship of the herpesvirus of pigeons (columbid herpesvirus 1) to other herpesvirus species. The PCR assay, based on degenerate primers targeting highly conserved regions of the DNA polymerase gene of herpesviruses, was modified by using a mixture of degenerate and deoxyinosine-substituted primers. The applicability of the modification was validated by amplification of published DNA polymerase genes of 16 herpesvirus specie...
Minelli A, Allegrucci C, Mezzasoma I, Ronquist G, Lluis C, Franco R.Membrane vesicles of horse seminal plasma present at their surface a highly specific serine-type protease, dipeptidyl peptidase IV/CD26, a surface antigen known to characterize human prostasomes. Horse sperm cells expressed at their surface A(1) adenosine receptors (A(1)AR) and ecto-adenosine deaminase (ecto-ADA), both detected by immunoblot analysis, whereas CD26 was visualized at the equatorial segment by immunofluorescence microscopy. In addition to CD26, horse membrane vesicles showed ecto-ADA. The fusion process between horse sperm cells and vesicles was evidenced by confocal microscopy, ...
Hung GC, Gasser RB, Beveridge I, Chilton NB.The first and second internal transcribed spacer sequences of 28 morphologically-defined species of horse strongyle were characterized, and specific oligonucleotide primers were designed for some species based on the nucleotide differences. Utilizing these primers, a PCR approach was developed for the specific amplification of ribosomal DNA of Strongylus vulgaris, Cyathostomum catinatum, Cylicocyclus nassatus, Cylicostephanus longibursatus or Cylicostephanus goldi. The method allowed the species-specific amplification of parasite DNA derived from faecal samples and/or copro-cultures, demonstra...
Bashiruddin JB, Cammà C, Rebêlo E.Babesia equi and Babesia caballi are tick-borne haemoparasites that may cause babesiosis of Equidae. In southern Europe B. equi is enzootic and infections may occur asymptomatically and more frequently than those due to B. caballi. Complement fixation test (CFT) is the official serological test for the diagnosis of equine babesiosis, but it has low sensitivity during early and latent stages of the disease. With the aim of developing more sensitive and rapid direct diagnostic alternatives, PCR systems that amplified DNA targets of 664 or 659 bp regions of the 16S rRNA genes were designed and de...
Julliand V, de Vaux A, Millet L, Fonty G.Detection and quantification of cellulolytic bacteria with oligonucleotide probes showed that Ruminococcus flavefaciens was the predominant species in the pony and donkey cecum. Fibrobacter succinogenes and Ruminococcus albus were present at low levels. Four isolates, morphologically resembling R. flavefaciens, differed from ruminal strains by their carbohydrate utilization and their end products of cellobiose fermentation.
Oxburgh L, Hagström A.In this paper we describe the development of a nested RT-PCR assay for the rapid diagnosis and characterisation of influenza virus directly from clinical specimens. Viral RNA is extracted from nasal swabs by the guanidine thiocyanate extraction method, and subsequently reverse transcribed. The complementary DNA is then used as template in a nested PCR reaction. Primers designed for use in this assay are specific for three templates; (1) the nucleoprotein (NP) gene, (2) the haemagglutinin gene of the H7N7 equine influenza virus (A1), and (3) the haemagglutinin gene of the H3N8 equine influenza ...
Kim KI, Yang YH, Lee SS, Park C, Ma R, Bouzat JL, Lewin HA.Historical records suggest that horses inhabiting the island of Cheju in Korea are descendants of Mongolian horses introduced in 1276. Other studies, however, suggest that horses may have been present on the island prior to the Mongolian introduction. To determine the origin of the Cheju horses we used a phylogenetic analysis of sequences of the mitochondrial DNA (mtDNA) D-loop region, including tRNA Pro and parts of tRNA thr and tRNA Phe sequences (1102-bp excluding the tandem repeat region). Maximum parsimony and neighbor-joining trees were constructed using sequences determined for seven Ch...
Morozova-Roche LA, Jones JA, Noppe W, Dobson CM.The refolding of equine lysozyme from guanidinium chloride has been studied using hydrogen exchange pulse labelling in conjunction with NMR spectroscopy and stopped flow optical methods. The stopped flow optical experiments indicate that extensive hydrophobic collapse occurs rapidly after the initiation of refolding. Pulse labelling experiments monitoring nearly 50 sites within the protein have enabled the subsequent formation of native-like structure to be followed in considerable detail. They reveal that an intermediate having persistent structure within three of the four helices of the alph...
Sharma AK, Paramasivam M, Srinivasan A, Yadav MP, Singh TP.Lactoferrin is a monomeric glycoprotein with a molecular mass of approximately 80 kDa. The three-dimensional structure of mare diferric lactoferrin (mlf) has been determined at 2.6 A resolution. The protein crystallizes in the space group P 212121with a=85.2 A, b=99.5 A, c=103.1 A with a solvent content of 55 % (v/v). The structure was solved by the molecular replacement method using human diferric lactoferrin as the model. The structure has been refined using XPLOR to a final R -factor of 0.194 for all data in the 15-2.6 A resolution range. The amino acid sequence of mlf was determined using ...
Borchers K, Frölich K, Ludwig H.In blood samples of seven captive equid species from four German zoos EHV-1 specific antibodies were detected in 76% and EHV-4 specific antibodies in 73% of the 55 animals, whereas 93% were tested positive for EHV-2 and EHV-5, respectively. In only one blood sample from a Przewalski's wild horse EHV-4 DNA was amplified by PCR. From seven Przewalski's wild horses EHV-2, and from another one EHV-5 was isolated by cocultivation. The identity of the virus isolates was verified by PCR and restriction enzyme digestion.
Behrendt-Adam CY, Adams MH, Simpson KS, McDowell KJ.A positive-feedback loop between luteal oxytocin and uterine prostaglandin F2 alpha (PGF) is a major signal for luteolysis in ruminants. Likewise, uterine PGF causes luteolysis in mares, but the involvement of oxytocin in this process is unclear. We wanted: 1) to determine if the oxytocin-neurophysin I (OT-NP I) gene is transcribed into mRNA in the endometrium of mares; and, if so, 2) to analyze relative changes in abundance of endometrial OT-NP I mRNA throughout the estrous cycle and during early stages of pregnancy. Endometrial biopsies were obtained from nonbred mares during estrus, and 5, ...
Scocco P, Menghi G, Ceccarelli P, Pedini V.This study was aimed at characterizing the glycoconjugates produced by the horse sublingual gland and, in particular, at discriminating between the sialoderivatives by means of differential oxidation and saponification combined with lectin histochemistry and enzymatic degradation. The results showed a predominance of sialoglycoconjugates with beta-galactose as acceptor sugar in the salivary mucins produced by the sublingual gland. Besides being the most represented terminal residue, sialic acid was also expressed in a great variety of derivatives distinguishable on the basis of acceptor sugars...
Hess S, Gulati R, Peluso JJ.The present studies showed that sequential treatment with equine CG (eCG) and hCG not only induced an increase in ovarian weight, but also caused an estimated 4.6-fold increase in the number of ovarian surface epithelial cells. In addition, eCG-hCG treatment increased ovarian hepatocyte growth factor (HGF) messenger RNA levels. These studies also demonstrated that rat primary ovarian surface epithelial cells as well as a cell line derived from rat ovarian surface epithelium (i.e. ROSE-179 cells) do not express the LH (hCG) receptor. Both of these cells express c-Met, the receptor for HGF. To a...
Chopineau M, Martinat N, Pourchet C, Stewart F, Combarnous Y, Guillou F.Although donkey luteinizing hormone exhibits a very high degree of amino acid sequence identity with horse LH, its FSH activity in non-equine species is tenfold lower. The coding regions of the common zebra (Equus burchelli) glycoprotein hormone alpha-subunit and LH beta-subunit transcripts were cloned by reverse transcription-PCR from pituitary gland RNA to investigate more precisely the structure-function relationships of this gonadotrophin family. Zebra LH was then expressed in COS-7 cells and its LH and FSH activities were assessed in a rat Leydig cell bioassay (for LH) and in a cell line ...
Whatmore AM, King SJ, Doherty NC, Sturgeon D, Chanter N, Dowson CG.Although often considered a strict human pathogen, Streptococcus pneumoniae has been reported to infect and cause pneumonia in horses, although the pathology appears restricted compared to that of human infections. Here we report on the molecular characterization of a group of S. pneumoniae isolates obtained from horses in England and Ireland. Despite being obtained from geographically distinct locations, the isolates were found to represent a tight clonal group, virtually identical to each other but genetically distinguishable from more than 120 divergent isolates of human S. pneumoniae. A co...
Ishida N, Katayama Y, Sato F, Hasegawa T, Mukoyama H.The entire cDNA sequences were determined by reverse transcription-polymerase chain reaction (RT-PCR) and rapid amplification of cDNA ends (RACE) techniques for equine copper/zinc superoxide dismutase (Cu/Zn-SOD) and manganese superoxide dismutase (Mn-SOD) through the use of total RNA extracted from the testis of an adult Thoroughbred. The results revealed a protein coding region for equine Cu/Zn-SOD with bases totaling 465 bp, accompanied by an estimated 154 residues of amino acids. As for equine Mn-SOD, its coding region contained a total of 669 bp and an estimated 222 residues of amino acid...
Simpson KS, Adams MH, Behrendt-Adam CY, Baker CB, McDowell KJ.For development to proceed normally, the appropriate genes must be expressed in the correct tissues and in the correct time frame. Knowledge of gene expression during development provides information about the changes taking place within the conceptus as well as possible reasons for pregnancy failure. However, little is known about gene expression during development in the equine conceptus. In this study, we examined differences in gene expression between day 12 and day 15 equine conceptuses by suppression subtractive hybridization. This technique was used to isolate transcripts that are more ...
Sugawara Y, Yamanouchi K, Naito K, Tachi C, Tojo H, Sawasaki T.A cDNA clone encoding equine follistatin was isolated from an equine ovarian cDNA library. Out of 1.2 x 10(5) independent clones screened, one positive clone was isolated and its cDNA sequence determined. The isolated clone, named EQ-FS-1, contained a complete open reading frame encoding 344 amino acid residues. The similarity of its deduced amino acid sequence to these of other mammalian species was greater than 95%. Although its expression level varied among the tissues examined, follistatin mRNA was detected in the equine uteroplacental tissues, follicles and corpora lutea by Northern blot ...
Martínez-Torrecuadrada JL, Langeveld JP, Venteo A, Sanz A, Dalsgaard K, Hamilton WD, Meloen RH, Casal JI.African horse sickness virus (AHSV) causes a fatal disease in horses. The virus capsid is composed of a double protein layer, the outermost of which is formed by two proteins: VP2 and VP5. VP2 is known to determine the serotype of the virus and to contain the neutralizing epitopes. The biological function of VP5, the other component of the capsid, is unknown. In this report, AHSV VP5, expressed in insect cells alone or together with VP2, was able to induce AHSV-specific neutralizing antibodies. Moreover, two VP5-specific monoclonal antibodies (MAbs) that were able to neutralize the virus in a ...
Sharma AK, Rajashankar KR, Yadav MP, Singh TP.The structure of mare apolactoferrin (MALT) has been determined at 3. 8 A resolution by the molecular-replacement method, using the structure of mare diferric lactoferrin (MDLT) as the search model. The MDLT structure contains two iron-binding sites: one in the N-terminal lobe, lying between domains N1 and N2, and one in the C-terminal lobe between domains C1 and C2. Both lobes have a closed structure. MALT was crystallized using the microdialysis method with 10%(v/v) ethanol in 0.01 M Tris-HCl. The structure has been refined to a final R factor of 0.20 for all data to 3.8 A resolution. Compar...
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...
Wilson SM, Gallagher M, Rakhit S, Remsbury AL, Ko WH.Uridine triphosphate (UTP) evoked inhibition of adrenaline-evoked cAMP accumulation in cultured equine epithelial cells (EC50, 1.8 +/- 0.2 microM) and this effect was mimicked by 5-Br-UTP (EC50, 6.6 +/- 1.8 microM) and uridine diphosphate (UDP; EC50, 96 +/- 26 microM). This inhibitory action of UTP was abolished by pre-treating cells with pertussis toxin (10 ng ml-1, 24 h). UTP (EC50, 2.3 +/- 0.3 microM) and 5-Br-UTP (EC50, 29.4 +/- 9.4 microM) also increased intracellular free calcium ([Ca2+]i) whilst UDP did not; the two effects are thus differentially sensitive to these pyrimidine nucleotid...
Yu MF, Ewaskiewicz JI, Adda S, Bailey K, Harris V, Sosnoski D, Tomasic M, Wilson J, Kotlikoff MI.We report adenovirus-mediated gene transfer into airway smooth muscle cells in cultured cells and organ-cultured tracheal segments. Incubation of cultured rat tracheal myocytes with virus (5 x 10(8) pfu/ml) for 6 h resulted in beta-galactosidase expression in 94.8 +/- 2.5% of cells (n = 4). Following incubation of thin (less than 200 microns diameter) equine trachealis muscle segments with virus in organ culture (5 x 10(8)-5 x 10(10) pfu/ml) the average expression of the Lac Z gene was approximately 19 +/- 10% (n = 9). Expression was markedly improved, however, in segments from neonatal rats (...
Troyer D, Howard D, Leipold HW, Smith JE.Southern blot analysis of equine DNA's digested with the restriction endonuclease Hinfl hybridized with a 32 PdCTP labeled human VNTR probe revealed a highly polymorphic pattern of restriction fragments upon autoradiography. The horses were unrelated individuals of the quarter horse breed. This heterologous probe can thus be used in the equine species for individual identification and pedigree analysis.
Di Bello C, Vita C, Gozzini L.A strategy based on complexation-assisted condensation of large synthetic protein fragments and mitochondria-mediated stereospecific heme insertion has been utilized to assemble a functional molecule corresponding to native horse heart holocytochrome c. This original approach offers the unique opportunity of selective modifications both in the C-terminal and in the N-terminal regions of the apoprotein and may represent an useful alternative to site-directed mutagenesis, particularly when D-amino acids, chemically and/or isotopically modified or other unnatural amino acids have to be introduced...
Sletten K, Johnson KH, Westermark P.The primary structure of amyloid fibril protein AA of a burro has been determined by Edman degradation. The 80 amino acid residue long protein shows strong resemblance to that of other mammalian AA-proteins and differs from equine protein AA at 5 positions: Burro/horse positions 20 (Q/N), 44 (R,Q, K/K,Q), 59 (G,L/G,A), 61 (Q/E) and 65 (N/R).
Gargiulo AM, Pedini V, Ceccarelli P, Lorvik S.In the present work, gustatory glands (von Ebner's glands) of the horse tongue were examined by means of five peroxidase-conjugated lectins (PNA, DBA, SBA, UEA I, WGA), with and without prior sialidase digestion, in order to investigate the presence and distribution of carbohydrate residues in secretory cells and duct cells. The most intense staining of secretory cells was observed with PNA after pre-treatment with neuraminidase. This indicates that the terminal trisaccharide sequence sialic acid- (alpha 2-->3, 6) galactosyl (beta 1-->3) N-acetylgalactosamine is the most frequent oligosa...
Walasek OF, Margoliash E.Donkey cytochrome c was shown to differ from horse cytochrome c by having a serine in position 47 rather than a threonine. The rest of the amino acid sequences are identical. Mules and hinnies, both males and females, carry equal amounts of horse and donkey cytochromes c. The same ratio is found in hinnies in preparations from heart tissue and from skeletal muscle. These results demonstrate that cytochrome c is transmitted in horse-donkey crosses as a simple Mendelian character which is neither sex-linked nor shows dominance. The cytochrome c gene is therefore located in the nuclear genome, as...
Papkoff H, Farmer SW, Cole HH.The gonadotropin (PMEG) in pregnant mare endometrial cups was purified and compared to pregnant mare serum gonadotropin (PMSG). Purification methodology applicable to PMSG was employed. In vivo and in vitro assays for FSH and LH were used to evaluate PMEG preparations. In all cases, lower activities (11-54%) were observed with PMEG compared to PMSG. Antiserum raised in rabbits against PMSG cross-reacts fully with PMEG in agar double diffusion tests. The amino acid composition of PMEG is similar to PMSG, but amino terminal group analyses show PMEG preparations to be more heterogeneous than PMSG...
Hughes K, Scott VHL, Blanck M, Barnett TP, Spanner Kristiansen J, Foote AK.Hemangiosarcoma is an uncommon tumor in horses. We characterized 3 cases of equine renal hemangiosarcoma, focusing on clinical and pathologic features, and describe occurrence of the epithelioid variant of hemangiosarcoma in one of these cases. Nuclear expression of phosphorylated STAT3 (pSTAT3) was assessed to analyze potential inappropriate STAT3 activation as a component of tumor pathogenesis. Clinical signs in the 3 horses included insidious weight loss, followed in one case by serosanguineous nasal discharge and terminal epistaxis, and nonspecific signs of abdominal pain. Two of the heman...
Budnitskaya P, Gapanhuk E, Henriques OB.The kininogenase activity of trypsin, plasmin, plasma kallikrein and heated Bothrops venom was compared, using fresh, heated and heat-acid-denatured horse plasma as source of kininogen. The venom kininogenase was found to have the highest activity on fresh horse plasma, followed by plasmin and trypsin which were equally active, and plasma kallikrein which was half as active as plasmin on these substrates. Plasmin and trypsin released more kinin from heat-treated than from fresh plasma whereas kallikrein released half as much as it liberates from fresh plasma. On heat-aciddenatured plasma equal...
Nakamura K, Tozaki T, Kakoi H, Owada S, Takasu M.Kiso horse is a breed of Japanese native horses. In this study, to clarify coat color gene variation in Kiso horses, we used SNaPshot™ genotyping to evaluate variation in MC1R, ASIP, and MATP genes at the Extension (E), Agouti (A), and Cream dilution (C) loci. The coat color of 149 horses was documented. The coat color of 140, 3, and 6 horses was bay, chestnut, and buckskin, respectively. Furthermore, the frequency of alleles E, e, A, a, C, and Cr was 0.80, 0.20, 0.86, 0.14, 0.98, and 0.02, respectively. Current status of coat color genes in Kiso horses was clarified, and this information wi...
von Fellenberg R, Zweifel HR, Grünig G, Pellegrini A.Horse seminal plasma does not possess a proteinase inhibitor corresponding to human HUSI-I (human seminal plasma inhibitor). Instead a protein complex of high relative molecular mass (Mr) containing proteinase inhibitory activity was detected, which was called horse seminal plasma protein complex or HSPC. The compound had a broad enzyme-inhibiting spectrum. Its Mr was estimated to be 800 000 and it was composed of 7 different polypeptides with Mr values ranging from 11 000 to 30 000. Its carbohydrate content was between 3.5% and 5%. Despite the high molecular mass, the complex was soluble in d...
Turner GA, Taylor DM.The interactions between tetravalent plutonium and horse serum proteins were studied in vitro by electrophoresis on cellulose acetate and by gel filtration. The results show that in horse serum, as in other mammalian sera, the plutonium is associated principally with the transferrin component of the beta1-globulins. The formation of the plutonium-transferrin complex requires the presence of HCO3-, and plutonium is displaced from the complex by excess iron, thus indicating that similar binding sites may be involved in the complexing of iron and plutonium. The plutonium complex is considered to ...
Carsana A, Furia A, Gallo A, Beintema JJ, Libonati M.1. Extensively glycosylated ribonucleases, like the enzymes from pig and horse pancreas, show a much higher activity on double-stranded RNAs than similarly charged, carbohydrate-free RNAases under stranded assay conditions (relatively high salt concentrations). Glycosylated pig and horse pancreas RNAases also show a larger destabilizing effect on double-stranded poly[d(A-T)] X poly[d(A-T)], than that displayed by bovine RNAase A under these conditions. Both activities show a similar dependence on the ionic strength of the medium. 2. A partial enzymic removal of the heterosaccharide side chains...
Brandon CI, Vandenplas M, Dookwah H, Linden J, Murray TF.The aim of the current study was to clone the equine adenosine A(2A) receptor gene and to establish a heterologous expression system to ascertain its pharmacologic profile via radioligand binding and functional assays. An eA(2A)-R expression construct was generated by ligation of the eA(2A) cDNA into the pcDNA3.1 expression vector, and stably transfected into human embryonic kidney cells (HEK). Binding assays identified those clones expressing the eA(2A)-R, and equilibrium saturation isotherm experiments were utilized to determine dissociation constants (K(D)), and receptor densities (B(max)) ...