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.
Collins MD, Rodriguez Jovita M, Lawson PA, Falsen E, Foster G.Two strains of an unknown Gram-positive, catalase-negative, facultatively anaerobic coccus originating from the reproductive tract of horses were characterized by phenotypic and molecular taxonomic methods. Comparative 16S rRNA gene sequencing studies demonstrated that the two strains constitute a new subline within the lactic-acid group of bacteria, close to, but distinct from, Abiotrophia defectiva, Globicatella sanguinis and close relatives. The unknown bacterium was readily distinguished from other described Gram-positive, catalase-negative cocci by biochemical tests and electrophoretic an...
Caetano AR, Lyons LA, Laughlin TF, O'Brien SJ, Murray JD, Bowling AT.Comparative anchor tagged sequences (CATS) from human Chromosome 5 (HSA5) were used as PCR primers to produce molecular markers for synteny mapping in the horse. Primer sets for 21 genes yielded eight horse-specific markers, which were mapped with the UC Davis horse-mouse somatic cell hybrid panel into two synteny groups: UCD14 and UCD21. These data, in conjunction with earlier human chromosome painting studies of the horse karyotype and synteny mapping of horse microsatellite markers physically mapped by FISH, confirm the assignment of UCD21 to ECA21 and suggest that UCD14 is located on ECA14...
Brault AC, Powers AM, Chavez CL, Lopez RN, Cachón MF, Gutierrez LF, Kang W, Tesh RB, Shope RE, Weaver SC.Eastern equine encephalitis virus (EEEV), the sole species in the EEE antigenic complex, is divided into North and South American antigenic varieties based on hemagglutination inhibition tests. Here we describe serologic and phylogenetic analyses of representatives of these varieties, spanning the entire temporal and geographic range available. Nucleotide sequencing and phylogenetic analyses revealed additional genetic diversity within the South American variety; 3 major South/Central American lineages were identified including one represented by a single isolate from eastern Brazil, and 2 lin...
Lichtenstein DL, Craigo JK, Leroux C, Rushlow KE, Cook RF, Cook SJ, Issel CJ, Montelaro RC.The long terminal repeat (LTR) is reported to be one of the most variable portions of the equine infectious anemia virus (EIAV) genome. To date, however, no information is available on the effects of observed sequence variations on viral replication properties, despite a widespread assumption of the biological importance of EIAV LTR variation. EIAV LTR sequence variability is confined mostly to a small portion of the enhancer within the U3 segment of the LTR. Analysis of published EIAV LTR sequences revealed six different types of LTR based on the pattern of putative transcription factor motif...
Marr KA, Lees P, Cunningham FM.Adherence to vascular endothelium and extracellular matrix proteins is a pre-requisite for neutrophil accumulation at sites of inflammation. In this study, equine neutrophil adherence to fibronectin and autologous serum-coated plastic in response to PAF, hrIL-8, hrC5a and PMA has been measured. In addition, the mechanisms involved have been investigated using monoclonal antibodies (MoAbs) against the beta2 integrin CD18. PAF and hrC5a caused similar, concentration dependent, increases in adherence to fibronectin- and serum-coated plastic (maximum responses 19 +/- 4% and 19 +/- 3% for PAF and 1...
Auvray P, Sourdaine P, Moslemi S, Séralini GE, Sonnet P, Enguehard C, Guillon J, Dallemagne P, Bureau R, Rault S.In this study, we describe the synthesis of a new family of indolizinone derivatives designed to fit an extrahydrophobic pocket within the active site of aromatase and to strongly inhibit human aromatase. This could help improve the specificity of the inhibitors. Equine aromatase, very well characterized biochemically, is used as a comparative model. Indeed, in a previous comparison between both human and equine aromatases, we described the importance of the interaction between the inhibitor and this pocket for the indane derivative MR 20814. MR 20492 and MR 20494 are more potent inhibitors of...
Ikadai H, Xuan X, Igarashi I, Tanaka S, Kanemaru T, Nagasawa H, Fujisaki K, Suzuki N, Mikami T.A cDNA expression library prepared from Babesia caballi merozoite mRNA was screened with a monoclonal antibody BC11D against the rhoptry protein of B. caballi merozoite. A cDNA encoding a 48-kDa protein of B. caballi was cloned and designated BC48. The complete nucleotide sequence of the BC48 gene had 1,828 bp and was shown to contain no intron. Southern blotting analysis indicated that the BC48 gene contained more than two copies in the B. caballi genome. Computer analysis suggested that this sequence contained an open reading frame of 1,374 bp with a coding capacity of approximately 52 kDa. ...
Dubey JP, Mattson DE, Speer CA, Baker RJ, Mulrooney DM, Tornquist SJ, Hamir AN, Gerros TC.An isolate of Sarcocystis neurona (SN6) was obtained from the spinal cord of a horse from Oregon with neurologic signs. The parasite was isolated in cultures of bovine monocytes and equine spleen cells. The parasite divided by endopolygeny and completed at least one asexual cycle in cell cultures in three days. Two gamma interferon knockout mice inoculated with cell culture-derived merozoites became ill 35 d later and S. neurona schizonts and merozoites were found in encephalitic lesions. The parasite in tissue sections of mice reacted with S. neurona-specific antibodies and S. neurona was rei...
Yokoyama S, Radlwimmer FB.To elucidate the molecular mechanisms of red-green color vision in mammals, we have cloned and sequenced the red and green opsin cDNAs of cat (Felis catus), horse (Equus caballus), gray squirrel (Sciurus carolinensis), white-tailed deer (Odocoileus virginianus), and guinea pig (Cavia porcellus). These opsins were expressed in COS1 cells and reconstituted with 11-cis-retinal. The purified visual pigments of the cat, horse, squirrel, deer, and guinea pig have lambdamax values at 553, 545, 532, 531, and 516 nm, respectively, which are precise to within +/-1 nm. We also regenerated the "true" red ...
Akiba M, Sameshima T, Anzai T, Wada R, Nakazawa M.Most Salmonella choleraesuis subsp. choleraesuis serovar Abortusequi strains of equine origin harbor a 95kb plasmid, pSA95. Results of PCR and Southern blot analysis suggest that pSA95 contains spv genes. A pSA95-cured strain of S. Abortusequi was 48 times less virulent to mice than its parental strain. Virulence was restored by reintroduction of pSA95. These results provide clear evidence that pSA95 confers virulence on S. Abortusequi in mice. This is the first report describing a virulence plasmid of S. Abortusequi.
Birch HL, Bailey JV, Bailey AJ, Goodship AE.Specific tendons show a high incidence of partial central core rupture which is preceded by degeneration. In the performance horse, the superficial digital flexor tendon (SDFT) is most often affected. We have described previously the molecular changes that are associated with degeneration in the central core region of the equine SDFT. The pathophysiological mechanism leading to change in synthetic activity of central zone cells in degenerated tendons is not known. In this study, we test the hypothesis that ageing results in matrix composition changes within the central zone of the SDFT. Extrac...
Zhang W, Auyong DB, Oaks JL, McGuire TC.Two defined cytotoxic T lymphocyte (CTL) epitopes from equine infectious anemia virus (EIAV)-infected horses, equine leukocyte alloantigen (ELA)-A5.1-restricted epitope 18a, and ELA-A9-restricted epitope 28b-1 were evaluated for conservation among three wild-type EIAV strains. Epitope 18a variation occurred in all three wild-type EIAV strains, while epitope 28b-1 varied in one strain. Further, 12% amino acid changes occurred in the Gag proteins of a recently isolated wild-type strain, documenting a much greater Gag protein variation than previously reported. Evaluation of epitope 18a among two...
Loubière L, Tiraby M, Cazaux C, Brisson E, Grisoni M, Zhao-Emonet J, Tiraby G, Klatzmann D.The herpes simplex virus type 1 thymidine kinase suicide gene (HSV1tk) together with ganciclovir (GCV) have been successfully used for in vivo treatment of various experimental tumors, and many clinical trials using this system have been launched. With the aim to improve this therapeutic system, we compared the potential efficacy of different herpes virus derived thymidine kinases (HSV1, varicella-zoster virus, equine herpes virus type-4 and Epstein-Barr virus) as suicide genes in association with the nucleoside analogs acyclovir, ganciclovir and bromovinyldeoxyur- idine. Using various murine ...
Klei TR, Chapman MR.Defining the characteristics of immunity and immune responses to equine cyathostome infections is clearly important to advancing our understanding of the development of these nematodes within the host, the clinical conditions attributed to them, and in developing more rational and novel strategies for their control. Nonetheless, little is currently known on this topic. Current data based on field observations, worm burdens and fecal egg counts suggest that horses acquire a resistance to cyathostome infection with age. This response is slow to develop and incomplete in that most horses regardle...
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...
Balasuriya UBR, Hedges JF, Nadler SA, McCollum WH, Timoney PJ, MacLachlan NJ.An imported carrier stallion (A) from Europe was implicated in causing an extensive outbreak of equine viral arteritis (EVA) on a Warmblood breeding farm in Pennsylvania, USA. Strains of equine arteritis virus (EAV) present in the semen of two carrier stallions (A and G) on the farm were compared to those in tissues of foals born during the outbreak, as well as viruses present in the semen of two other stallions that became persistently infected carriers of EAV following infection during the outbreak. The 2822 bp segment encompassing ORFs 2-7 (nt 9807-12628; which encode the G(S), GP3, GP4, G(...
Weaver SC, Pfeffer M, Marriott K, Kang W, Kinney RM.Epizootics of Venezuelan equine encephalitis (VEE) involving subtype IAB viruses occurred sporadically in South, Central and North America from 1938 to 1973. Incompletely inactivated vaccines have long been suspected as a source of the later epizootics. We tested this hypothesis by sequencing the PE2 glycoprotein precursor (1,677 nucleotides) or 26S/nonstructural protein 4 (nsP4) genome regions (4,490 nucleotides) for isolates representing most major outbreaks. Two distinct IAB genotypes were identified: 1) 1940s Peruvian strains and 2) 1938-1973 isolates from South, Central, and North America...
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...
Lentz LR, Valberg SJ, Balog EM, Mickelson JR, Gallant EM.To determine whether abnormal regulation of muscle contraction similar to that associated with malignant hyperthermia (MH) was evident in intact external intercostal muscle cells from Thoroughbreds with recurrent exertional rhabdomyolysis (RER). Methods: 5 adult Thoroughbred horses with RER and 7 clinically normal adult Thoroughbred or mixed-breed horses. Methods: Twitch time course variables and contracture responses to various concentrations of potassium, caffeine, and halothane were measured in small bundles of intact external intercostal muscle cells from clinically normal horses and horse...
Brown KA, Boerboom D, Bouchard N, Doré M, Lussier JG, Sirois J.17Beta-hydroxysteroid dehydrogenase type 4 (17betaHSD4) has a unique multidomain structure, with one domain involved in 17beta-estradiol inactivation. The objective of the study was to investigate the regulation of 17betaHSD4 during human chorionic gonadotropin (hCG)-induced ovulation/luteinization. The equine 17betaHSD4 cDNA was cloned and was shown to encode a 735-amino acid protein that is highly conserved (81-87% identity) compared with other mammalian orthologs. RT-PCR/Southern blot analyses were performed to study the regulation of 17betaHSD4 transcripts in equine preovulatory follicles ...
McBride SD, Roberts K, Hemmings AJ, Ninomiya S, Parker MO.Stress and genotype elicit changes in impulse control in a range of species that are attributable to adaptations in both the central and peripheral nervous system. We examined aspects of this mechanism in the horse by assessing the effect of a dopamine receptor genotype (DRD4) and central dopaminergic tone (measured via spontaneous blink rate [SBR] and behavioral initiation rate [BIR]), on measures of impulsivity, compulsivity (3-choice serial reaction time task) and sympathetic/ parasympathetic system balance (heart rate variability [HRV]). Genotype did not have a significant effect on any of...
Hernández-Vidal G, Jeffcott LB, Davies ME.A polyclonal antiserum raised in sheep against human cathepsin B was tested for specificity and cross-reactivity with the horse homologue by SDS-PAGE and Western blotting, prior to being used for immunolocalization of the enzyme in equine articular cartilage. In Western blots, the antiserum recognized the 30 kDa single chain and 25 kDa heavy chain of the mature enzyme in purified bovine cathepsin B, and corresponding bands at 32 and 27 kDa in equine chondrocyte and fibroblast lysates. This antiserum was then used to compare the expression and distribution of cathepsin B in normal and dyschondr...
Fontes KFLP, Silva-Júnior LC, Nascimento SA, Chaves DP, Pinheiro-Júnior JW, Freitas AC, Castro RS, Jesus ALS.A codon-optimized equine infectious anemia virus p26 gene was fused to a maltose-binding protein (MBP) and expressed in Escherichia coli for use as an antigen in agar gel immunodiffusion (AGID) and enzyme-linked immunosorbent assay (ELISA) for diagnosis of equine infectious anemia. An analysis of analytical sensitivity and specificity showed that the antigen MBP-p26rec reacted positively with a reference World Organization for Animal Health serum and demonstrated no cross-reaction against sera from vaccinated animals in either test. The diagnostic characteristics were evaluated and presented e...
Farrar RG, Klei TR.Strongylus edentatus was successfully cultured in vitro to the fourth larval stage (L4). Some growth continued for periods of 40-50 days at which time reductions in viability were observed in some of the culture systems tested. Various combinations of media, sera, buffers and organ explant cultures were tested. All cultures were incubated at 37 C in an atmosphere of 95% air and 5% CO2. Larvae underwent growth and differentiation to the L4 in all medium-serum combinations with and without organ explant cultures. Development and growth did occur but viability was reduced to insignificant levels ...
Schaller J, Rickli EE.The N-terminal amino acid sequence of equine, ovine, canine, goat and rabbit plasminogen were determined and compared with those already known of the human, bovine, porcine and feline molecule. Furthermore, the kringle 4 domains of equine, ovine, canine and goat plasminogen, prepared by limited cleavage with elastase, were sequenced and compared with the known species of human, bovine, porcine and chicken plasminogen. Homology with the human kringle 4 ranges between 73% (chicken) and 90% (bovine). Comparison of sequences, fragmentation patterns with elastase and adsorption on lysine-Bio-Gel su...
Bousfield GR, Liu WK, Ward DN.LH hybrids were prepared by combining eLH alpha and eLH beta with the corresponding subunits of oLH, pLH and hCG. Recombinants were isolated by gel filtration and assessed by SDS-polyacrylamide gel electrophoresis under both dissociating and non-dissociating conditions. All combinations of subunits produced hybrid LH molecules. Hybrids prepared by combining eLH beta with oLH alpha, pLH alpha or hCG alpha were very inactive in rat radioligand and Leydig cell in vitro bioassays. Hybrids prepared with eLH alpha were very active in both assays. The greatest potentiating activity was observed when ...
Jolly RD, Dalefield RR.The lipopigments are a heterogenous group of pigments whose pathogenesis and terminology is confused. Whereas there is epidemiological and observational evidence that ceroid is derived from degeneration and peroxidation of unsaturated lipid, the assumption that all so-called lipopigments are similarly formed, is questioned. In particular, recent studies have distanced the pathogenesis of the pigment found in the ceroid-lipofuscinoses from that perceived for ceroid. The importance of protein rather than lipid in the pathogenesis of the pigment of ceroid-lipofuscinosis and of age pigment from th...
Richard F, Martinat N, Remy JJ, Salesse R, Combarnous Y.Among all mammalian FSH receptors (FSH-R; including donkey (dk) FSH-R), only horse (hs) FSH-R does not bind hsLH/chorionic gonadotrophin (CG). In order to delineate the structural origin of hsFSH-R specificity precisely, we have cloned dkFSH-R cDNA from donkey testis mRNA by RT-PCR. Transiently expressed dkFSH-R endowed COS-7 cells with both hsLH/CG- and FSH-binding activity, as well as FSH-induced cAMP production. The deduced dkFSH-R amino acid sequence shares 96% identity with the hsFSH-R: notably, in the hormone-binding domain, the specificity of hsFSH-R may be ascribed to only four diverge...
Saint-Dizier M, Foulon-Gauze F, Lecompte F, Combarnous Y, Chopineau M.Pituitary equine luteinizing hormone (eLH) and fetal chorionic gonadotrophin (eCG) have identical polypeptidic chains, but different linked carbohydrates. In equine tissues, eCG and eLH bind only to the LH/CG receptor (eLH/CG-R) and have no FSH activity. However, radio-receptor assays on equine luteal or testicular tissues have shown that eCG binds to the eLH/CG-R with only 2-4% of the binding activity of eLH. In order to study the structure-function relationship of eLH and eCG in a homologous system, we undertook the cloning and functional expression of the eLH/CG-R. Based on sequence homolog...
Taira T, Fujinaga T, Tamura K, Izumi M, Itoh H, Tsunoda N, Yamashita K, Okumura M, Mizuno S.Equine alpha 1-acid glycoprotein (alpha 1AG) was isolated from equine serum by successive ammonium precipitation, anion- and cation-exchange chromatographies, and gel filtration. Purified equine alpha 1AG had a molecular weight of 46,000 +/- 1,000, and contained 31.4% carbohydrate. Gel isoelectric focusing revealed an isoelectric point range of 2.8 to 3.7. With immunoelectrophoresis, it was found that alpha 1AG migrated to the alpha 1-globulin region. Single radial immunodiffusion was used for quantitative measurement of alpha 1AG in equine serum. In clinically normal foals, serum alpha 1AG wa...
Archambault D, Laganière G, Carman S, St-Laurent G.The genetic variation in equine arteritis virus (EAV) protein-encoding open reading frames (ORFs) 3 and 4 genes was investigated. Nucleic and deduced amino acid sequences from seven different EAV isolates (one European, one American and five Canadian isolates) and the Arvac vaccine strain were compared with those of Bucyrus reference strain. ORF 3 nucleotide and amino acid sequence identities between these isolates (including the Arvac vaccine strain) and the Bucyrus reference strain ranged from 85.6 to 98.8%, and 85.3 to 98.2%, respectively, whereas ORF 4 nucleotide and amino acid sequence id...
Gerber V.Genetic factors influence the development of guttural pouch tympany, recurrent laryngeal neuropathy, severe equine asthma, exercise-induced pulmonary hemorrhage, and possibly also some malformations and infectious diseases of the respiratory tract. The current data suggest that most of these diseases are complex, resulting from the interaction between several genes and environmental factors. To date, no specific genes or causative mutations have been identified that would allow the development of practical genetic tests. In the future, genetic profiling panels, based on multiple genetic marker...
Ishiyama T, Shinagawa M, Sato G, Fujinaga K, Padmanabhan R.Equine adenovirus (EAd) DNA prepared from infected bovine kidney (MDBK) cells contained additional sequences of about 100 to 700 bp at the left-hand end of the genome. These aberrant viral genomes were produced even after the first passage of the wild type EAd in MDBK cells and their relative amounts did not change significantly during serial passage. The left terminal fragments of two defective viral DNAs were cloned into the plasmid vector pBR322 and the nucleotide sequences of their terminal regions were analyzed. The data indicate that one viral DNA contained a duplication of the inverted ...
Chapus C, Desnuelle P, Foglizzo E.Pig and horse colipases have been purified by a common procedure using trypsin and carboxypeptidase inhibitors as stabilizers. Two forms of pig colipase were identified: a predominant A1 form with about 103-105 residues, and a minor slightly degraded A2 form in which the last two C-terminal residues, Asp and Ser, were lacking. This type of degradation is considerably slowed down by carboxypeptidase inhibitors. A total of four forms of the horse cofactor were characterized: two (A1 and B1) were probably isocolipases which differed by only a few substitutions. Both contained the same number of r...
O'Donovan LH, McMonagle EL, Taylor S, Argyle DJ, Nicolson L.Interleukin 18 (IL-18) is a cytokine capable of induction of IFNgamma, granulocyte monocyte-colony stimulating factor (GM-CSF), TNFalpha and IL-1 in immunocompetent cells. Equine and feline plasmid vectors expressing pro-IL-18, mature IL-18 and IL-18 fused to a synthetic signal sequence from human IL-1beta receptor antagonist protein (ILRAP), ILRAP-IL-18, have been generated. In vitro protein expression of these constructs was compared by Western blot analysis. These data demonstrated that ILRAP-IL-18 protein was secreted readily from transfected chinese hamster ovary (CHO) cells. A simple bio...
Hartmann FA, West SE.Phenotypic and molecular techniques, including antimicrobial susceptibility testing, plasmid analysis, and pulsed-field gel electrophoresis (PFGE) were used to characterize 15 isolates of multidrug-resistant (MDR) Salmonella anatum cultured during a 16 mo period from horses and a veterinary clinic environment. The isolates were resistant to multiple antimicrobial agents and could be placed into 4 groups based on their antimicrobial resistance patterns. The isolates contained multiple plasmids ranging in size from 2 to > 100 kb that could be grouped into 3 different plasmid profile patterns;...
The Journal of physiologyDecember 1, 1996
Volume 497 ( Pt 2), Issue Pt 2 349-364 doi: 10.1113/jphysiol.1996.sp021773
Hanna WJ, Tsushima RG, Sah R, McCutcheon LJ, Marban E, Backx PH.1. The Na+ channel mutation associated with equine hyperkalaemic periodic paralysis (HPP) affects a highly conserved phenylalanine residue in an unexplored region of the alpha-subunit. This mutation was introduced into the rat skeletal muscle Na+ channel gene at the corresponding location (i.e. F1412L) for functional expression and characterization in Xenopus oocytes. 2. In comparison with wild-type (WT) channels, equine HPP channels showed clear evidence for disruption of inactivation: increased time-to-peak current, slowed rates of whole-cell current decay, significant increases in sustained...
Tikhonov VN, Cothran EG, Kniazev SP.This study was the first to analyze the polymorphic characteristics of a wide range of biochemical markers in aboriginal Yakut horses. A total of 124 alleles, including 48 alleles of seven blood-group loci and 76 alleles of ten loci for enzymes and other proteins, were studied. For these polymorphic systems, a computer analysis of the genetic distances between 85 horse breeds of different origin from all parts of the world was performed. The low level of hereditary variation in the Yakut horses confirmed that this breed is old and has long been an isolated population. Phylogenetic analysis dem...
Gim JA, Kim HS.MicroRNAs (miRNAs) are single-stranded, small RNAs (21-23 nucleotides) that function in gene silencing and translational inhibition via the RNA interference mechanism. Most miRNAs originate from host genomic regions, such as intergenic regions, introns, exons, and transposable elements (TEs). Here, we focused on the palindromic structure of medium reiteration frequencies (MERs), which are similar to precursor miRNAs. Five MER consensus sequences (MER5A1, MER53, MER81, MER91C, and MER117) were matched with paralogous transcripts predicted to be precursor miRNAs in the horse genome (equCab2) and...
Evans MJ, Marshall AG, Kitson NE, Summers K, Donald RA.The multifactorial control of ACTH is well established. We wished to establish and characterize an in-vitro perifusion system, using equine anterior pituitary cells and physiological concentrations of secretagogues, to investigate factors which affect the dynamics of ACTH secretion. Anterior pituitary tissue was divided for dispersion into cells with collagenase, trypsin or dispase, or by mechanical dispersion. After dispersal followed by 18-h incubation, cells were perifused and the ACTH response to 10-min pulses of arginine vasopressin (AVP; 100 nmol/l), corticotrophin-releasing hormone (CRH...
Archambault D, St-Louis MC, Martin S.The genome of equine arteritis virus (EAV) produces a 3' coterminal-nested set of six subgenomic (sg) viral RNAs during virus replication cycle, and each set possesses a common leader sequence of 206 nucleotides (nt) in length derived from the 5' end of the viral genome. Given the presence of the leader region within both genomic and sg mRNAs, it is likely to contain cis-acting signals that may interact with cellular or viral proteins for RNA synthesis. Gel mobility shift assays indicated that proteins in Vero cell cytoplasmic extracts formed complexes with the positive (+) and negative (-) st...
Gable TL, Woods GL.The objective was to test the hypothesis that increasing equine oocyte culture time from 48 to 96 or 144 h increases nucleus maturation of equine oocytes. The hypothesis was not supported because condensed chromatin-stage oocytes decreased (P<0.01) from 33/126 (26.2%) at 48 h or 34/95 (35.8%) at 96 h to 11/117 (9.4%) at 144 h, and polar body-stage oocytes decreased (P<0.01) from 65/126 (51.6%) at 48 h to 25/95 (26.3%) at 96 h and (P<0.01) to 1/117 (0.9%) at 144 h. Negative (non-staining) oocytes increased (P<0.01) from 16/126 (12.7%) at 48 h or 15/95 (15.8%) at 96 h to 39/117 (33.3%) at 144 h....
Parés-Casanova PM, Salamanca-Carreño A, Crosby-Granados RA, Bentez-Molano J.Skull size and shape have been widely used to study domestic animal populations and breeds. Although several techniques have been proposed to quantify cranial form, few attempts have been made to compare the results obtained by different techniques. While linear morphometrics has traditionally been used in breed characterization, recent advances in geometric morphometrics have created new techniques for specifically quantifying shape and size. The objective of this study was to compare two morphometric methods for their ability to describe external morphology. For this purpose, 20 skull specim...
Löfgren M, Ekman S, Svala E, Lindahl A, Ley C, Skiöldebrand E.Formation of synovial joints includes phenotypic changes of the chondrocytes and the organisation of their extracellular matrix is regulated by different factors and signalling pathways. Increased knowledge of the normal processes involved in joint development may be used to identify similar regulatory mechanisms during pathological conditions in the joint. Samples of the distal radius were collected from prenatal and postnatal equine growth plates, zones of Ranvier and articular cartilage with the aim of identifying Notch signalling components and cells with stem cell-like characteristics and...
Pedersen CE, Eddy GA.Polyacrylamide gel electrophoretic examination of viruses selected from the Venezuelan equine encephalomyelitis (VEE) complex revealed distinct strain to strain differences in profiles of the two virion envelope proteins. The core protein was identical in all viruses tested. We detected five electrophoretic patterns into which the virus strains could be classified and these were designated alpha (alpha), beta (beta), gamma (gamma), delta (delta), and episolon (episolon). Isolates representing variant E of subtype I exhibited a profile characterized by only one apparent envelope band. The epizo...
Gérard N, Monget P.The profiles of insulin-like growth factor-binding proteins (IGFBPs) in follicular fluid have been characterized in a number of mammals (rats, pigs, sheep, cattle, humans) and are good indicators of follicular status. We studied the IGFBP profiles of equine serum and ovarian follicular fluid recovered at various stages of the follicular phase. The levels of IGFBPs were related to the morphology and the steroidogenic activity of the follicles. Follicular fluids were recovered by ultrasound-guided follicular aspiration. In the first experiment, the dominant follicles of 10 mares were partly punc...
Vincze B, Varga M, Kutasi O, Zenke P, Szenci O, Baska F, Bartels A, Spisák S, Cseh S, Solymosi N.Equine grass sickness (also known as dysautonomia) is a life-threatening polyneuropathic disease affecting horses with approx. 80% mortality. Since its first description over a century ago, several factors, such as the phenotype, intestinal microbiome, environment, management and climate, have been supposed to be associated with the increased risk of dysautonomia. In this retrospective study, we examined the possible involvement of genetic factors. Medical and pedigree datasets regarding 1,233 horses with 49 affected animals born during a 23-year period were used in the analysis. Among the des...
Harnal VK, Wildt DE, Bird DM, Monfort SL, Ballou JD.Genome resource banks (GRBs) and assisted reproductive techniques are increasingly recognized as useful tools for the management and conservation of biodiversity, including endangered species. Cryotechnology permits long-term storage of valuable genetic material. Although, the actual application to endangered species management requires technical knowledge about sperm freezing and thawing, a systematic understanding of the quantitative impacts of various germ plasm storage and use scenarios is also mandatory. In this study, various GRB strategies were analyzed using the historical data from th...
Anaya G, Fernández ME, Valera M, Molina A, Azcona F, Azor P, Solé M, Moreno-Millán M, Demyda-Peyrás S.Twin foaling is associated with chimaerism in several domestic species and is recognised in horses. In this study, 21,097 purebred Spanish (Pura Raza Español) horse births from the 2015 to 2016 breeding season were investigated for chimaerism. Twin foaled and chimaeric individuals were assessed on the basis of foaling records, short-tandem repeat (STR) parentage test results and a sex-linked STR-based technique. Fourteen twin pregnancies with 23 twin foals born alive were identified (0.066% twin foaling prevalence), including five blood chimaeric cases (21.7%; overall prevalence 0.011%), sugg...
