Topic:Biotechnology
Biotechnology in horses encompasses the application of biological techniques and tools to enhance equine health, performance, and reproduction. This field includes genetic engineering, cloning, and the development of vaccines and therapeutics tailored to equine physiology. Techniques such as gene editing and stem cell therapy are explored for their potential to address genetic disorders, improve tissue regeneration, and enhance disease resistance in horses. Additionally, advancements in reproductive biotechnology, such as artificial insemination and embryo transfer, contribute to genetic diversity and breeding efficiency. This page compiles peer-reviewed research studies and scholarly articles that investigate the applications, methodologies, and implications of biotechnology in equine science.
[Preservation of genetic variation in domestic animals using biotechnical methods]. The conservation of endangered breeds as live animals is at present the main national strategy of the government and breeding organizations to maintain genetic diversity. Fourty-three breeds and some old strains of cattle, pig, sheep, goat and horses are currently involved. Cryopreservation and banks for sperm, embryos or DNA are another type of genetic material which could subsequently be used for breeding and production in agriculture. Present semen banks involve 9 endangered cattle breeds and also a small amount of deep-frozen sperm of some endangered sheep and horse breeds. Only 2 embryo b...
Gene transfer by adenovirus in smooth muscle cells. 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 (...
Surface plasmon resonance studies of complex formation between cytochrome c and bovine cytochrome c oxidase incorporated into a supported planar lipid bilayer. II. Binding of cytochrome c to oxidase-containing cardiolipin/phosphatidylcholine membranes. Complex formation between horse heart cytochrome c (cyt c) and bovine cytochrome c oxidase (cco) incorporated into a supported planar egg phosphatidylcholine membrane containing varying amounts of cardiolipin (CL) (0-20 mol%) has been studied under low (10 mM) and medium (160 mM) ionic strength conditions by surface plasmon resonance (SPR) spectroscopy. Both specific and nonspecific modes of cyt c binding are observed. The dissociation constant of the specific interaction between cyt c and cco increases from approximately 6.5 microM at low ionic strength to 18 microM at medium ionic strength, ...
Comparison of media and sera used for in vitro culture of equine superficial digital flexor tendon explants. To compare the effects of different commercial nutrient media and sera on protein synthesis and maintenance of cellular density in cultures of the equine superficial digital flexor tendon (SDFT). Methods: 8 healthy 2- to 4-year-old horses. Methods: First Dulbecco's modified Eagle's medium, Ham's F12 nutrient mixture, RPMI 1640 medium, minimum essential medium with Earle's salts, minimum essential medium with Hanks' salts, and a Dulbecco's modified Eagle's medium/Ham's F12 nutrient mixture with 10% fetal bovine serum (FBS) were compared. Then FBS, fetal equine serum, and donor horse serum, each...
Equine rhinovirus serotypes 1 and 2: relationship to each other and to aphthoviruses and cardioviruses. Equine rhinoviruses (ERVs) are picornaviruses which cause a mild respiratory infection in horses. The illness resembles the common cold brought about by rhinoviruses in humans; however, the presence of a viraemia during ERV-1 infection, the occurrence of persistent infections and the physical properties are all more reminiscent of foot-and-mouth disease virus (FMDV). cDNA cloning and sequencing of the genomes of ERV-1 and ERV-2 between the poly(C) and poly(A) tracts showed that the serotypes are heterogeneous. Nevertheless, the genomic architecture of both serotypes is most similar to that of ...
Heterologous antisera and antivenins are essential biologicals: perspectives on a worldwide crisis. Active immunization against infectious disease is important. However, much of our world faces poverty, social injustice, and warfare, all of which cause universal immunization to remain a distant dream. Agents that provide passive immunity thus remain essential biologicals. The most important of these are human or equine antisera against rabies, tetanus, diphtheria, and snake antivenins. Homologous products are either unavailable or unaffordable in places where they are needed the most. Less expensive heterologous (equine) antisera can be purified and are safe to use, but these antisera are al...
Comparison and simulation of different levels of erythrocyte aggregation with pig, horse, sheep, calf, and normal human blood. Erythrocyte aggregation levels in pig, horse, sheep, and calf blood samples were investigated and compared to that of normal human blood. The aggregation kinetics and adhesive forces between red cells, and an index of structure of the aggregates were determined with an erythroaggregameter (Regulest, France) at constant hematocrit (0.40 l/l) and temperature (37 degrees C). The adhesive forces and the index of structure in pig blood were close to those of normal human blood. The results for horse blood showed a very high level of aggregation kinetics and adhesive forces between red cells. For sh...
Experimental model for the study by chemiluminescence of the activation of isolated equine leucocytes. The activation of human polymorphonuclear leucocytes (the respiratory burst) can be studied by measuring their chemiluminescent response. This technique was adapted to equine leucocytes to investigate the effects of cell number, activator concentration, enhancers of chemiluminescence, pH, temperature and inhibitors. Leucocytes were isolated from citrated blood from healthy horses and chemiluminescence was measured with a Bio-Orbit luminometer sensitive to 900 nm light. The optimal cell density for the maximal chemiluminescent response ranged from 10(6) to 10(7) leucocytes 600 microliters-1. Ch...
Influence of glycerol on the structure and stability of ferric horse heart myoglobin: a SAXS and circular dichroism study. The influence of glycerol on the structural properties of Fe(III)-horse heart myoglobin has been investigated by absorbance, CD and SR-SAXS spectroscopy. The results obtained indicate that both the tertiary and the secondary (alpha-helix) conformations of the protein are influenced by glycerol; in particular, an increase of approx. 8% in helical content was observed. Further, analysis of both the acid- and guanidine-induced denaturation transitions points to a glycerol-induced decreased stability of the tertiary structure; conversely, the alpha-helix conformation is found to be stabilized by t...
Looking for residues involved in the muscle acylphosphatase catalytic mechanism and structural stabilization: role of Asn41, Thr42, and Thr46. Asn41, Thr42, and Thr46 are invariant residues in both muscle and erythrocyte acylphosphatases isolated so far. Horse muscle acylphosphatase solution structure suggests their close spatial relationship to Arg23, the main substrate binding site. The catalytic and structural role of such residues, as well as their influence on muscle acylphosphatase stability, was investigated by preparing several gene mutants (Thr42Ala, Thr46Ala, Asn41Ala, Asn41Ser, and Asn41Gln) by oligonucleotide-directed mutagenesis. The mutated genes were cloned and expressed in Escherichia coli, and the mutant enzymes were...
Detection of quinine and its metabolites in horse urine by gas chromatography-mass spectrometry. After oral administration of quinine sulfate to a thoroughbred mare, seven urine samples were obtained over a 45.5 h period. Using gas chromatography -electron impact ionization and positive-ion chemical ionization mass spectrometry, quinine and five putative metabolites were detected and tentatively identified in enzyme-hydrolysed post-administration urine; all metabolites involved some form of oxidation. The parent drug could be detected for about 16 h and some phase I biotransformation products for up to 40 h post-administration.
Characterization of bone mineral crystals in horse radius by small-angle X-ray scattering. The size and the orientation of the bone salt (mineral) crystals in the cranial and caudal zones in the transverse midshaft section of the equine radius were investigated by small-angle X-ray scattering (SAXS). The results are interpreted as indicating that the crystals had an elongated shape with an average thickness of T = 3.17 +/- 0. 15 nm in the caudal region and T = 3.79 +/- 0.20 nm in the cranial region. Their orientation was predominantly in the longitudinal direction of the bone. There was no preferential orientation within the transverse plane. The distribution of tilt angles with res...
Cryopreservation of equine embryos. Principles and procedures for cryopreservation of equine embryos are described. Embryos less than 250 microM in diameter can be cryopreserved successfully if glycerol is used as the cryoprotectant. Cooling is takes place in such a way that most of the water leaves the cells before intracellular ice forms, and glycerol is removed after thawing without undue osmotic swelling of cells. Vitrification procedures also show promise for small embryos. Satisfactory procedures for cryopreserving embryos of more than 250 microM in diameter are not yet available.
Methods for induction of capacitation and the acrosome reaction of stallion spermatozoa. Methodologies to capacitate bovine spermatozoa, induce the acrosome reaction, and fertilize bovine oocytes in vitro have been established. The capability to do the same with stallion spermatozoa, however, is not available. Several different methods have been used to capacitate stallion spermatozoa with variable results. More basic research needs to be done to establish in vitro conditions necessary to capacitate and induce an acrosome reaction in stallion spermatozoa. Although much progress can be expected in this area, it is unlikely that the general practitioner will use these technologies i...
Superovulation. Development of a superovulation technique that is successful, safe, and commercially available would revolutionize the equine breeding industry. However, the reality is that ovulation rates for mares following existing superovulatory treatment are much lower than for cattle. This dichotomy has been attributed to the relatively limited area available in the ovulation fossa for ovulation to occur, combined with the large size of the equine preovulatory follicle. In addition, the number of ovulations in the mare may be limited physiologically by the size of the follicular cohort that may be rescu...
Early embryonic development and evaluation of equine embryo viability. Tremendous progress has been made in the development of assisted reproductive techniques that may enhance the reproductive efficiency of the horse. However, techniques that involve the manipulation of oocytes and/or embryos may themselves be detrimental to embryo viability and subsequent development. Therefore, an objective method of assessing viability of embryos before and/or after oocyte/embryo manipulation is desirable. At this time, morphologic evaluation is the most widely used method of determining the viability of equine embryos. Although morphologic assessment of embryo quality will n...
Cloning and sequencing of an equine insulin-like growth factor I cDNA and its expression in fetal and adult tissues. A cDNA for equine insulin-like growth factor I (IGF I) has been isolated by reverse transcriptase-polymerase chain reaction and subsequently sequenced. The sequenced fragment contained 465 bp including the coding regions for the signal peptide, the entire mature protein, and 4 amino acids into the E-peptide. Like its human counterpart, the mature equine IGF I peptide contains 70 amino acids and was 100% homologous between horse and man. The 49-amino-acid signal peptide had the threonine in position 26 of the human signal peptide substituted by isoleucine. The nucleotide homology across the ent...
Similarities and differences in supporting and chromaffin cells in the mammalian adrenal medullae: an immunohistochemical study. The adrenal medulla is a typical paraganglion, having the same origin as the sympathetic ganglia, and contains at least two types of parenchymal cells: chromaffin cells and supporting cells. We previously reported that the extent of cellular association of chromaffin cells with supporting cells was remarkably higher in noradrenaline (NA)-than in adrenaline (A)-cell regions in the adrenal medullae of the rat and pig. Methods: Cryostat sections of adrenal medullae of nine mammalian species fixed with Zamboni fluid for 24 h were immunostained by ABC methods using antisera to S-100 protein and PNM...
Role of heme axial ligands in the conformational stability of the native and molten globule states of horse cytochrome c. One unique aspect of cytochrome c folding concerns the involvement of the covalently attached heme group and its axial ligands. To elucidate the role of the ligands in stabilizing the native and molten globule states, we studied the conformational and thermodynamic features of the iron-free derivative of horse cyctochrome c (porphyrin-cytochrome c). At neutral pH, far-UV circular dichroism suggested that porphyrin-cytochrome c has native-like alpha-helices, whereas near-UV CD suggested that the side-chains are flexible. Its stability against heat or denaturants was much less than that of the i...
Effects of holmium: YAG laser energy on cartilage metabolism, healing, and biochemical properties of lesional and perilesional tissue in a weight-bearing model. Comparison of perilesional cartilage, lesional repair tissue, and subchondral bone activity 6 months after application of holmium-yttrium-aluminum-garnet (Ho:YAG) laser energy to chronic (10 week) induced 10-mm full-thickness (FT) circular articular cartilage craters followed by 6 months' intermittent active motion (IAM) in a free exercise environment was investigated. The 2.1-microns wavelength was delivered in hand-controlled near-contact mode by arthroscopic surgery in a saline medium. Bilateral arthroscopy was performed on normal antebrachiocarpal, intercarpal, and metacarpophalangeal join...
Cloning and analysis of the cDNA for the common alpha-subunit of the donkey pituitary glycoprotein hormones. Reverse transcription-PCR was used to clone the coding region of the donkey (Equus asinus) glycoprotein hormone alpha-subunit transcript from pituitary gland RNA. The donkey alpha-subunit sequence demonstrated considerable identity with the horse (97% at the nucleotide level), confirming the very close evolutionary linkage between these two species. The predicted amino acid sequence revealed that the donkey alpha-subunit has the same unusual C-terminus as the horse alpha-subunit, when compared with all other mammalian alpha-subunits, including a Tyr-His transposition between positions 87 and 9...
Nucleotide sequence of exons 5 to 9 of the p53 tumour-suppressor gene of the horse (Equus caballus). An evolutionary conserved 1.3 kb fragment corresponding to the horse p53 tumour suppressor gene was PCR amplified, cloned and the nucleotide sequence determined. The p53 fragment encoded exons 5 to 9 and the intervening introns. The nucleotide sequence and the predicted aminoacid sequence showed a high level of homology with human and donkey p53 sequences.
Neutron anatomy. The familiar extremes of crystalline material are single-crystals and random powders. In between these two extremes are polycrystalline aggregates, not randomly arranged but possessing some preferred orientation and this is the form taken by constructional materials, be they steel girders or the bones of a human or animal skeleton. The details of the preferred orientation determine the ability of the material to withstand stress in any direction. In the case of bone the crucial factor is the orientation of the c-axes of the mineral content-the crystals of the hexagonal hydroxyapatite- and this...
Demonstration of three DRB loci in a domestic horse family. Single-strand conformational polymorphism (SSCP) gel electrophoresis and DNA sequencing were used to characterize the second exon of the horse DRB homologue as well as to identify eight new DRB alleles. The SSCP gels presented a complex pattern, with phenotypes exhibiting between 4 and 13 bands. The DRB SSCP patterns were studied for two families (6 to 13 bands per pattern). For both families, the patterns showed simple Mendelian inheritance. The polymerase chain reaction products from two individuals possessing homozygous major histocompatibility complex (MHC) alleles by descent were cloned a...