Mitochondria are organelles found in the cells of horses that are responsible for producing energy through the process of oxidative phosphorylation. They play a role in various cellular functions, including energy metabolism, regulation of the cell cycle, and apoptosis. Mitochondria contain their own DNA, which is maternally inherited and can provide insights into genetic lineage and population studies in equines. Research on equine mitochondria encompasses topics such as mitochondrial function, genetic variation, and their implications for health and performance. This page compiles peer-reviewed research studies and scholarly articles that explore the structure, function, and genetic aspects of mitochondria in horses.
Kusliy MA, Druzhkova AS, Popova KO, Vorobieva NV, Makunin AI, Yurlova AA, Tishkin AA, Minyaev SS, Trifonov , Graphodatsky AS, Dymova MA, Filipenko ML.From genetic point of view, differences between ancient and modern horses can be reconstructed by using the phylogeographic analysis of mitochondrial genomes and by studying phenotypically important nuclear loci. The variety of modern horse coat colors resulted from artificial selection indicates a high degree of domestication. We have conducted the phylogenetic analysis of mitochondrial DNA extracted from bone samples of six ancient horses from Tsaramburial in the Republic of Buryatia, and established that they belong to a haplogroup E by Achilli’s classification. This haplogroup is found a...
Guo X, Pei J, Chu M, Wu X, Bao P, Ding X, Liang C, Yan P.The complete mitochondrial genome of Hequ horse was determined in this study. The mitogenome is 16 656 bp in length and contains 13 protein-coding genes, 22 transfer RNA genes, 2 ribosomal RNA genes, and a D-loop region. The overall base composition of the H-strand is 32.20% for A, 28.55% for C, 13.38% for G and 25.86% for T. Tree constructed using MEGA 6 with Maximum-likelihood (ML) methods demonstrated that Hequ horse was clustered in subfamily Equidae.
Rivero JL, Hill EW.Skeletal muscles in horses are characterised by specific adaptations, which are the result of the natural evolution of the horse as a grazing animal, centuries of selective breeding and the adaptability of this tissue in response to training. These adaptations include an increased muscle mass relative to body weight, a great locomotor efficiency based upon an admirable muscle-tendon architectural design and an adaptable fibre-type composition with intrinsic shortening velocities greater than would be predicted from an animal of comparable body size. Furthermore, equine skeletal muscles have a ...
Sessions-Bresnahan DR, Schauer KL, Heuberger AL, Carnevale EM.Obesity is associated with disrupted reproductive cycles in mares, but the impact of obesity on follicles and oocytes has received minimal attention. We investigated the impact of obesity on 1) expression of selected genes in follicle cells for carbohydrate metabolism, inflammatory cytokines, lipid homeostasis, endoplasmic reticulum stress, and mitochondrial function; 2) follicular fluid content of metabolic hormones and metabolites; and 3) lipid fingerprint of oocytes. Mares (9-13 yr) were classified as control (n = 8, normal weight, body condition score [BCS] 5.1, 10.4% body fat) or obese (n...
Marycz K, Kornicka K, Basinska K, Czyrek A.Currently, equine metabolic syndrome (EMS), an endocrine disease linked to insulin resistance, affects an increasing number of horses. However, little is known about the effect of EMS on mesenchymal stem cells that reside in adipose tissue (ASC). Thus it is crucial to evaluate the viability and growth kinetics of these cells, particularly in terms of their application in regenerative medicine. In this study, we investigated the proliferative capacity, morphological features, and accumulation of oxidative stress factors in mesenchymal stem cells isolated from healthy animals (ASCN) and horses s...
Balao da Silva CM, Ortega-Ferrusola C, Morrell JM, Rodriguez Martínez H, Peña FJ.To date, the only repeatable method to select spermatozoa for chromosomal sex is the Beltsville sorting technology using flow cytometry. Improvement of this technology in the equine species requires increasing awareness of the modifications that the sorting procedure induces on sperm intactness. Oxidative stress is regarded as the major damaging phenomenon, and increasing evidence regards handling of spermatozoa - including sex sorting - as basic ground for oxidative damage. The aim of this study was to disclose whether the flow cytometric sorting procedure increases the production of reactive...
Santos FC, Corcini CD, Costa VG, Gheller SM, Nogueira CE, da Rosa Curcio B, Varel AS.Solid storage medium prevents cellular sedimentation, reduces metabolic demand via limiting movement, and avoids the modification of an extender composition in the sedimentary microenvironment. It has been proven to prolong spermatozoa viability in mammalians. Objective: This experiment aims to evaluate the effect of cool storage in solid phase extender on stallion sperms. Methods: Semen was collected from 10 Crioulo stallions (n=30) and submitted to treatments: control group (semen extender) and groups with gelatin addition in different concentrations (semen extender + 1%, 2% and 3%). Seminal...
Martin Muñoz P, Ortega Ferrusola C, Vizuete G, Plaza Dávila M, Rodriguez Martinez H, Peña FJ.Oxidative stress has been linked to sperm death and the accelerated senescence of cryopreserved spermatozoa. However, the molecular mechanisms behind this phenomenon remain poorly understood. Reactive oxygen species (ROS) are considered relevant signaling molecules for sperm function, only becoming detrimental when ROS homeostasis is lost. We hereby hypothesize that a major component of the alteration of ROS homeostasis in cryopreserved spermatozoa is the exhaustion of intrinsic antioxidant defense mechanisms. To test this hypothesis, semen from seven stallions was frozen using a standard tech...
Plaza Dávila M, Bucci D, Galeati G, Peña FJ, Mari G, Giaretta E, Tamanini C, Spinaci M.Stallion spermatozoa are highly dependent on oxidative phosphorylation for ATP production to achieve normal sperm function and to fuel the motility. The aim of this study was to evaluate the response of equine sperm under capacitating conditions to the inhibition of mitochondrial complex I by rotenone and to test whether epigallocatechin-3-gallate (EGCG), a natural polyphenol component of green tea, could counteract this effect. After 2-h incubation of stallion spermatozoa in modified Tyrode's medium, rotenone (100 nm, 500 nm and 5 μm) and EGCG (10, 20 and 60 μm), alone or in combination, di...
Zhang Y, Xu WW, Guo DH, Liu ZX, Duan H, Su X, Fu X, Yue DM, Gao Y, Wang CR.The equine pinworm Oxyuris equi (Nematoda: Oxyuridomorpha) is the most common horse nematode, has a worldwide distribution, and causes major economic losses. In the present study, the complete O. equi mitochondrial (mt) genome was sequenced, and the mt genome structure and organization were compared with those of other closely related pinworm species, Enterobius vermicularis and Wellcomia siamensis. The O. equi mt genome is a 13,641-bp circular DNA molecule that encodes 36 genes (12 protein-coding genes, 22 tRNAs, and two rRNAs) and one non-coding region, which is slightly shorter than that ...
Wu Z, Zheng X, Luo Y, Huo F, Dong H, Zhang G, Yu W, Tian F, He L, Chen J.The present study investigates the effects of five cryoprotectants (CPAs) and cryoprotectant combinations on the post-thaw total motility, progressive motility, viability, mitochondrial membrane potential and acrosome integrity in stallion spermatozoa. In Experiment 1, the objective was to compare the impact of different concentrations (2.5%, 3.5% and 5%) of a single CPA, including glycerol (Gly), ethylene glycol (EG), dimethyl sulphoxide (DMSO), methyl formamide (MF), and dimethylformamide (DMF) for stallion spermatozoa cryopreservation. In Experiment 2, two or more CPAs were used to assess w...
Banse HE, Frank N, Kwong GP, McFarlane D.In horses, hyperinsulinemia and insulin resistance (insulin dysregulation) are associated with the development of laminitis. Although obesity is associated with insulin dysregulation, the mechanism of obesity-associated insulin dysregulation remains to be established. We hypothesized that oxidative stress in skeletal muscle is associated with obesity-associated hyperinsulinemia in horses. Thirty-five light breed horses with body condition scores (BCS) of 3/9 to 9/9 were studied, including 7 obese, normoinsulinemic (BCS ≥ 7, resting serum insulin < 30 μIU/mL) and 6 obese, hyperinsulinemic...
Plaza Davila M, Martin Muñoz P, Tapia JA, Ortega Ferrusola C, Balao da Silva C C, Peña FJ.Mitochondria have been proposed as the major source of reactive oxygen species in somatic cells and human spermatozoa. However, no data regarding the role of mitochondrial ROS production in stallion spermatozoa are available. To shed light on the role of the mitochondrial electron transport chain in the origin of oxidative stress in stallion spermatozoa, specific inhibitors of complex I (rotenone) and III (antimycin-A) were used. Ejaculates from seven Andalusian stallions were collected and incubated in BWW media at 37 °C in the presence of rotenone, antimycin-A or control vehicle. Incubation...
Gibb Z, Lambourne SR, Quadrelli J, Smith ND, Aitken RJ.The spermatozoa of many stallions do not tolerate being cooled, restricting the commercial viability of these animals and necessitating the development of a chemically defined room temperature (RT) storage medium. This study examined the impact of two major modulators of oxidative phosphorylation, pyruvate (Pyr) and L-carnitine (L-C), on the storage of stallion spermatozoa at RT. Optimal concentrations of Pyr (10 mM) and L-C (50 mM) were first identified and these concentrations were then used to investigate the effects of these compounds on sperm functionality and oxidative stress at RT. Mito...
Carraro U, Kern H, Gava P, Hofer C, Loefler S, Gargiulo P, Mosole S, Zampieri S, Gobbo V, Ravara B, Piccione F, Marcante A, Baba A, Schils S, Pond A....There is something in our genome that dictates life expectancy and there is nothing that can be done to avoid this; indeed, there is not yet any record of a person who has cheated death. Our physical prowess can vacillate substantially in our lifetime according to our activity levels and nutritional status and we may fight aging, but we will inevitably lose. We have presented strong evidence that the atrophy which accompanies aging is to some extent caused by loss of innervation. We compared muscle biopsies of sedentary seniors to those of life long active seniors, and show that these groups i...
Winton CL, Plante Y, Hind P, McMahon R, Hegarty MJ, McEwan NR, Davies-Morel MC, Morgan CM, Powell W, Nash DM.Most species exist as subdivided ex situ daughter population(s) derived from a single original group of individuals. Such subdivision occurs for many reasons both natural and manmade. Traditional British and Irish pony breeds were introduced to North America (U.S.A. and Canada) within the last 150 years, and subsequently equivalent breed societies were established. We have analyzed selected U.K. and North American equivalent pony populations as a case study for understanding the relationship between putative source and derived subpopulations. Diversity was measured using mitochondrial DNA and ...
Houben R, Leleu C, Fraipont A, Serteyn D, Votion DM.This prospective cohort study evaluated the potential of high-resolution respirometry applied to permeabilized muscle fibers for fitness evaluation in French Standardbred racehorses. Fitness evaluation by means of respirometric parameters did not correlate with racing performance registered over the following racing season. However, altered mitochondrial energy metabolism was associated with higher risk of developing exertional rhabdomyolysis, a common cause of exercise intolerance in racehorses. These data represent a first step towards establishing reference values for muscle OXPHOS capacity...
Criscione A, Moltisanti V, Chies L, Marletta D, Bordonaro S.Salernitano (SAL) is an ancient Italian horse breed developed over the course of the ages together with Napoletano and, during the 20th century, by crossing with Thoroughbred horse lines. Excellent in hurdle jumping, this breed is currently facing a concrete risk of extinction due to the lack of appropriate management strategies. This research is the first SAL genetic characterization that aims to set up the basic knowledge for a conservation plan. A representative sample of 61 SALs was analyzed by means of a set of 16 microsatellites markers (short tandem repeats (STRs)). The sequence of hype...
Duan H, Gao JF, Hou MR, Zhang Y, Liu ZX, Gao DZ, Guo DH, Yue DM, Su X, Fu X, Wang CR.The complete mitochondrial (mt) genome sequence of Triodontophorus brevicauda, an intestinal equine nematode parasite was determined for the first time. The circular T. brevicauda mt genome is 14,305 bp in length and contains 36 genes, of which 12 code for protein, 22 for transfer RNA, and two for ribosomal RNA, and lacks atp8 mtDNA gene. Phylogenetic analysis based on the concatenated amino acid sequence of the 12 protein-coding genes was performed using three different tree-building methods. The Strongyloidea cluster divides into two large branches, and each nematode family included in our s...
Peña FJ, Plaza Davila M, Ball BA, Squires EL, Martin Muñoz P, Ortega Ferrusola C, Balao da Silva C.The traditional assessment of stallion sperm comprises evaluation of sperm motility and membrane integrity and identification of abnormal morphology of the spermatozoa. More recently, the progressive introduction of flow cytometry is increasing the number of tests available. However, compared with other sperm structures and functions, the evaluation of mitochondria has received less attention in stallion andrology. Recent research indicates that sperm mitochondria are key structures in sperm function suffering major changes during biotechnological procedures such as cryopreservation. In this p...
Collins JA, Moots RJ, Clegg PD, Milner PI.Mature articular cartilage is an avascular tissue characterized by a low oxygen environment. In joint disease, acidosis and further reductions in oxygen levels occur, compromising cartilage integrity.This study investigated how acidosis and very low oxygen levels affect components of the cellular redox system in equine articular chondrocytesand whether the antioxidants resveratrol and N-acetylcysteine could modulate this system. We used articular chondrocytes isolated from nondiseased equine joints and cultured them in a 3-D alginate bead system for 48h in <1, 2, 5, and 21% O2 at pH 7.2 or ...
Hendriks WK, Colleoni S, Galli C, Paris DB, Colenbrander B, Roelen BA, Stout TA.Advanced maternal age and in vitro embryo production (IVP) predispose to pregnancy loss in horses. We investigated whether mare age and IVP were associated with alterations in mitochondrial (mt) DNA copy number or function that could compromise oocyte and embryo development. Effects of mare age (<12 vs ≥12 years) on mtDNA copy number, ATP content and expression of genes involved in mitochondrial replication (mitochondrial transcription factor (TFAM), mtDNA polymerase γ subunit B (mtPOLB) and mitochondrial single-stranded DNA-binding protein (SSB)), energy production (ATP synthase-couplin...
Ravara B, Gobbo V, Carraro U, Gelbmann L, Pribyl J, Schils S.Functional Electrical Stimulation (FES) has been used extensively over several decades to reverse muscle atrophy during rehabilitation for spinal cord injury patients. The benefits of the technology are being expanded into other areas, and FES has been recently utilized for injury rehabilitation and performance enhancement in horses. Six retired horses (age from 10 to 17 yrs) that had been previously used mainly for dressage riding were selected for this study. Clinical evaluation found epaxial muscle spasms in all horses with minimal to no pelvic extension when manually palpated. FES treatmen...
Swegen A, Curry BJ, Gibb Z, Lambourne SR, Smith ND, Aitken RJ.Stallion spermatozoa continue to present scientific and clinical challenges with regard to the biological mechanisms responsible for their survival and function. In particular, deeper understanding of sperm energy metabolism, defence against oxidative damage and cell-cell interactions should improve fertility assessment and the application of advanced reproductive technologies in the equine species. In this study, we used highly sensitive LC-MS/MS technology and sequence database analysis to identify and characterise the proteome of Percoll-isolated ejaculated equine spermatozoa, with the aim ...
Ning T, Li J, Lin K, Xiao H, Wylie S, Hua S, Li H, Zhang YP.The domestic horse is the most widely used and important stock and recreational animal, valued for its strength and endurance. The energy required by the domestic horse is mainly supplied by mitochondria via oxidative phosphorylation. Thus, selection may have played an essential role in the evolution of the horse mitochondria. Besides, demographic events also affect the DNA polymorphic pattern on mitochondria. To understand the evolutionary patterns of the mitochondria of the domestic horse, we used a deep sequencing approach to obtain the complete sequences of 15 mitochondrial genomes, and fo...
Van Driessche K, Ducatelle R, Chiers K, Van Coster R, van der Kolk JH.Very few mitochondrial myopathies have been described in horses. Objective: To examine the ultrastructure of muscle mitochondria in equine cases of myopathy of unknown origin. Methods: Biopsies of vastus lateralis of the Musculus quadriceps femoris were taken predominantly immediately post mortem and processed for transmission electron microscopy. As a result, electron micrographs of 90 horses in total were available for analysis comprising 4 control horses, 16 horses suffering from myopathy and 70 otherwise diseased horses. Results: Following a thorough clinical and laboratory work-up, four o...
Han L, Zhu S, Ning C, Cai D, Wang K, Chen Q, Hu S, Yang J, Shao J, Zhu H, Zhou H.The donkey (Equus asinus) is an important domestic animal that provides a reliable source of protein and method of transportation for many human populations. However, the process of domestication and the dispersal routes of the Chinese donkey are still unclear, as donkey remains are sparse in the archaeological record and often confused with horse remains. To explore the maternal origins and dispersal route of Chinese donkeys, both mitochondrial DNA D-loop and cytochrome b gene fragments of 21 suspected donkey remains from four archaeological sites in China were amplified and sequenced. Result...
Giara and Sarcidano are 2 of the 15 extant native Italian horse breeds with limited dispersal capability that originated from a larger number of individuals. The 2 breeds live in two distinct isolated locations on the island of Sardinia. To determine the genetic structure and evolutionary history of these 2 Sardinian breeds, the first hypervariable segment of the mitochondrial DNA (mtDNA) was sequenced and analyzed in 40 Giara and Sarcidano horses and compared with publicly available mtDNA data from 43 Old World breeds. Four different analyses, including genetic distance, analysis of molecular...
Hendriks WK, Roelen BA, Colenbrander B, Stout TA.Equine embryos are cryopreserved by slow-freezing or vitrification. While small embryos (<300 μm) survive cryopreservation reasonably well, larger embryos do not. It is not clear if slow-freezing or vitrification is less damaging to horse embryos. Objective: To compare the type and extent of cellular damage suffered by small and large embryos during cryopreservation by slow-freezing vs. vitrification. Methods: Sixty-three Day 6.5-7 embryos were subdivided by size and assigned to one of 5 treatments: control, exposure to slow-freezing or vitrification cryoprotectants (CPs), and cryopreser...
Balao da Silva CM, Ortega Ferrusola C, Gallardo Bolaños JM, Plaza Dávila M, Martín-Muñoz P, Morrell JM, Rodriguez Martínez H, Peña FJ.Flow cytometry is considered the only reliable method for the separation of X and Y chromosome bearing spermatozoa in equines. The MoFlo SX DP sorter is highly efficient, allowing the production of foals of the desired sex. However, to achieve acceptable pregnancy rates the currently used protocol requires working with fresh semen obtained close to, or at, the sorting facility. An alternative protocol was tested during two consecutive breeding seasons. Fresh stallion semen was cooled for 20 h, during which staining with Hoechst 33342 took place. On the following day, this sample was flow sort...
Yue XP, Qin F, Campana MG, Liu DH, Mao CC, Wang XB, Lan XY, Chen H, Lei CZ.Previous mitochondrial DNA (mtDNA) D-loop and microsatellite studies have shown that Chinese horses have multiple maternal origins and high genetic diversity. To better characterize maternal genetic origins and diversity of Chinese domestic horses, we conducted a comprehensive analysis of 407 complete 1140 bp sequences of the horse mitochondrially encoded cytochrome b (CYTB) gene, including 323 horses from 13 Chinese indigenous breeds and 84 reference sequences from GenBank. A total of 114 haplotypes were identified, of which 73 appeared among the 13 Chinese horse breeds. The high mitochondria...
Kayar SR, Hoppeler H, Armstrong RB, Laughlin MH, Lindstedt SL, Jones JH, Conley KR, Taylor CR.The mean minimal capillary transit time was estimated in muscles of various animals using a combination of physiological and morphometric methods. Radioactive microspheres were injected intravascularly in various animals running on a treadmill at maximum oxygen consumption rate (VO2,max) to label blood flow to individual muscles. The muscles were then removed and preserved by standard methods for electron microscopy. The volume density of mitochondria was measured to assess muscle oxidative capacity. Capillary densities in muscle cross-sections, capillary diameters and tortuosities were incorp...
Ning T, Li J, Lin K, Xiao H, Wylie S, Hua S, Li H, Zhang YP.The domestic horse is the most widely used and important stock and recreational animal, valued for its strength and endurance. The energy required by the domestic horse is mainly supplied by mitochondria via oxidative phosphorylation. Thus, selection may have played an essential role in the evolution of the horse mitochondria. Besides, demographic events also affect the DNA polymorphic pattern on mitochondria. To understand the evolutionary patterns of the mitochondria of the domestic horse, we used a deep sequencing approach to obtain the complete sequences of 15 mitochondrial genomes, and fo...
Choi YH, Ritthaler J, Hinrichs K.Cloned animals possess mitochondria derived from the host ooplast, which typically differ genetically from those of the donor. This is of special concern to horse breeders, as maternal lines are prized and athletic performance is a key factor in genetic value. To evaluate the feasibility of producing mitochondrial-identical cloned foals, we collected oocytes from immature follicles of two mares, BL and SM, maternally related to the donor stallion. In vitro matured, enucleated oocytes were treated with roscovitine-synchronized donor cells and blastocysts were transferred transcervically to reci...
Hristov P, Yordanov G, Ivanova A, Mitkov I, Sirakova D, Mehandzyiski I, Radoslavov G.It is believed that population structure of mountain horse breeds is preserved from any genetic introgression, because of their geographical isolation and specific semi-wild life style of husbandry. Till date there are no molecular data for the Balkan horses. In this study we try to give information about some autochthonous mountain horse breeds from Bulgaria. A total of 121 horses from three different mountain massifs are presented: Stara Planina (the Balkan mountain), the Rhodopes and Rila-Pirin massif were genotyped according to mitochondrial D-loop region. The results showed huge diversity...
Liu G, Xu CQ, Cao Q, Zimmermann W, Songer M, Zhao SS, Li K, Hu DF.Przewalski's horses have been imported from the western zoos to China since 1985. Yet the genetic diversity in China's populations has not been studied, thus lacking of such knowledge inevitably affects this population's management. The aim of this study was to assess genetic diversity in Chinese population of Przewalski's horses via mitochondrial DNA (mtDNA) control region and pedigree analysis. Methods: Two captive and one reintroduced populations were examined based on mitochondrial DNA control region variation via fecal sampling from 2010 to 2012, together with pedigree analysis. Results: ...
Winton CL, Plante Y, Hind P, McMahon R, Hegarty MJ, McEwan NR, Davies-Morel MC, Morgan CM, Powell W, Nash DM.Most species exist as subdivided ex situ daughter population(s) derived from a single original group of individuals. Such subdivision occurs for many reasons both natural and manmade. Traditional British and Irish pony breeds were introduced to North America (U.S.A. and Canada) within the last 150 years, and subsequently equivalent breed societies were established. We have analyzed selected U.K. and North American equivalent pony populations as a case study for understanding the relationship between putative source and derived subpopulations. Diversity was measured using mitochondrial DNA and ...
Albrizio M, Lacalandra GM, Micera E, Guaricci AC, Nicassio M, Zarrilli A.Opioid receptors and endogenous opioid peptides act not only in the control of nociceptive pathways, indeed several reports demonstrate the effects of opiates on sperm cell motility and morphology suggesting the importance of these receptors in the modulation of reproduction in mammals. In this study we investigated the expression of delta opioid receptors on equine spermatozoa by western blot/indirect immunofluorescence and its relationship with sperm cell physiology. Methods: We analyzed viability, motility, capacitation, acrosome reaction and mitochondrial activity in the presence of naltri...
Lavoie JP, Thompson D, Hamilton E, Debrue M, David F, Hickey G.It has been suggested that many of the beneficial effects of corticosteroids are mediated through mitogen-activated protein kinase (MAPK) p38 inhibition. Objective: To investigate the efficacy of the MAPK p38 inhibitor compound MRL-EQ1 to either prevent (Phase 1) or treat (Phase 2) recurrent airway obstruction (RAO) in horses. Methods: MRL-EQ1 was administered i.v. at a dosage of 0.75-1.5 mg/kg bwt q. 12 h. In Phase 1, susceptible horses in clinical remission were divided into 2 groups (n = 5/group), based on historical values of respiratory mechanics. All horses were entered in the study in p...
Kornicka K, Al Naem M, Röcken M, Zmiertka M, Marycz K.Osteochondritis dissecans (OCD) in equids, especially in sport horses, has become a growing issue as it contributes to the occurrence of lameness. Thus the aim of this study was to investigate the cytophysiological properties of OCD chondrocytes including expression of chondrogenic genes, apoptosis, mitochondria dynamics and autophagy. Horse chondrocytes were isolated from healthy (HE) and OCD cartilages. Properties of cells were evaluated using multiple assays e.g., polymerase chain reaction (PCR), immunofluorescence, Western blot. OCD chondrocytes were characterized by increased apoptosis an...
Bulkeley E, Santistevan AC, Varner D, Meyers S.Low levels of intracellular reactive oxygen species (ROS) are essential for normal sperm function and are produced by sperm mitochondria as a byproduct of metabolism, but in excess, ROS can cause catastrophic cellular damage and has been correlated with infertility, poor sperm motility and abnormal morphology in humans. Stallion sperm motility is fueled predominantly by oxidative phosphorylation-produced ATP, requiring high basal rates of mitochondrial function. Consequently, whether elevated ROS production by stallion sperm is an indicator of dysfunctional or highly motile cells has been deba...
Wu Z, Zheng X, Luo Y, Huo F, Dong H, Zhang G, Yu W, Tian F, He L, Chen J.The present study investigates the effects of five cryoprotectants (CPAs) and cryoprotectant combinations on the post-thaw total motility, progressive motility, viability, mitochondrial membrane potential and acrosome integrity in stallion spermatozoa. In Experiment 1, the objective was to compare the impact of different concentrations (2.5%, 3.5% and 5%) of a single CPA, including glycerol (Gly), ethylene glycol (EG), dimethyl sulphoxide (DMSO), methyl formamide (MF), and dimethylformamide (DMF) for stallion spermatozoa cryopreservation. In Experiment 2, two or more CPAs were used to assess w...
Khaudov AD, Duduev AS, Kokov ZA, Amshokov KK, Zhekamukhov MK, Zaitsev AM, Reissmann M.Studies of mitochondrial DNA (mtDNA) as well as the non-recombining part of the Y chromosome help to understand the origin and distribution of maternal and paternal lineages. The Kabardian horse from Northern Caucasia which is well-known for strength, stamina and endurance in distance riding has a large gap in its breeding documentation especially in the recent past. A 309 bp fragment of the mitochondrial D-loop (156 Kabardian horses) and six mutations in Y chromosome (49 Kabardian stallions), respectively, were analyzed to get a better insight into breeding history, phylogenetic relationship ...
Campos GA, Garcia VFC, Freitas-Dell'Aqua CP, Segabinazzi LGTM, Maciel LFS, Alvarenga MA, Papa FO, Dell'Aqua JA.This study aimed to assess the effects of sodium caseinate and cholesterol to extenders used for stallion semen cooling. Two ejaculates from 19 stallions were extended to 50 million/mL in four different extenders and cooled-stored for 24 hours at 5°C. The extender 1 (E1) consisted of a commercially available skim milk-based extender. The extender 2 (E2) consisted of E1 basic formula with the milk component being replaced by sodium caseinate (20 g/L). The extender 3 (E3) consisted of E1 basic formula added to cholesterol (1.5 mg/120 million sperm). The extender 4 (E4) consisted of a combinat...
Campana MG, Stock F, Barrett E, Benecke N, Barker GW, Seetah K, Bower MA.Despite the Icelandic horse enjoying great popularity worldwide, the breed's gene pool is small. This is because of a millennium of isolation on Iceland, population crashes caused by natural disasters and selective breeding. Populations with small effective population sizes are considered to be more at risk of selection pressures such as disease and environmental change. By analysing historic and modern mitochondrial DNA sequences and nuclear coat colour genes, we examined real-time population dynamics in the Icelandic horse over the last 150 years. Despite the small gene pool of this breed, w...
Ma H, Wu Y, Xiang H, Yang Y, Wang M, Zhao C, Wu C.There are large populations of indigenous horse () in China and some other parts of East Asia. However, their matrilineal genetic diversity and origin remained poorly understood. Using a combination of mitochondrial DNA (mtDNA) and hypervariable region (HVR-1) sequences, we aim to investigate the origin of matrilineal inheritance in these domestic horses. Methods: To investigate patterns of matrilineal inheritance in domestic horses, we conducted a phylogenetic study using 31 mtDNA genomes together with 317 others from the GenBank. In terms of the updated phylogeny, a total of 5,180 horse mit...
McAnulty JF, Stone WC, Darien BJ.The purpose of this study was to examine the effects of ischemia and reperfusion on the biochemical integrity of equine colonic mucosa to assess the relative roles of ischemic- and reperfusion-induced damage. Methods: Two hours of no-flow ischemia experimentally induced by 720 degrees counterclockwise ascending colon volvulus followed by 2 hours reperfusion after derotation. Methods: Ten ponies. Methods: Ascending colon biopsies were obtained every hour for measurement of mucosal adenosine triphosphate (ATP), water, sodium, and potassium content. Additional samples were homogenized for assay o...
Dell AC, Curry MC, Yarnell KM, Starbuck GR, Wilson PB.Genetic diversity and maternal ancestry line relationships amongst a sample of 96 Cleveland Bay horses were investigated using a 479bp length of mitochondrial D-loop sequence. The analysis yielded at total of 11 haplotypes with 27 variable positions, all of which have been described in previous equine mitochondrial DNA d-loop studies. Four main haplotype clusters were present in the Cleveland Bay breed describing 89% of the total sample. This suggests that only four principal maternal ancestry lines exist in the present-day global Cleveland Bay population. Comparison of these sequences with ot...
Martín Muñoz P, Anel-López L, Ortiz-Rodríguez JM, Álvarez M, de Paz P, Balao da Silva C, Rodríguez Martinez H, Gil MC, Anel L, Peña FJ....Oxidative stress is a major factor explaining sperm dysfunction of spermatozoa surviving freezing and thawing and is also considered a major inducer of a special form of apoptosis, visible after thawing, in cryopreserved spermatozoa. To obtain further insights into the link between oxidative stress and the induction of apoptotic changes, stallion spermatozoa were induced to oxidative stress through redox cycling after exposure to 2-methyl-1,4-naphthoquinone (menadione), or hydroxyl radical formation after FeSO exposure. Either exposure induced significant increases (p < 0.05) in two marke...
Mislei B, Bucci D, Malama E, Bollwein H, Mari G.Oxidative stress is regarded as an important cause of sperm damage during cryopreservation. However, seasonal changes in oxidative status in unfrozen and frozen-thawed stallion sperm have not been well established. We tested the hypothesis that sperm ROS concentrations and lipid peroxidation change between breeding and non-breeding seasons and influence quality of unfrozen and frozen-thawed sperm. Eighteen ejaculates from six Warmblood stallions (8-21 y) known to be fertile, were collected in winter and summer and processed for freezing. After 90 min at +4 °C, some straws from each ejacu...
Sabeur K, Ball BA.To identify the generation of the superoxide anion by equine spermatozoa. Methods: Multiple ejaculates collected from 3 Thoroughbred stallions. Methods: Induced superoxide production by reduced nicotinamide adenine dinucleotides (NAD[P]H; ie, reduced nicotinamide adenine dinucleotide [NADH] and reduced nicotinamide adenine dinucleotide phosphate [NADPH]) was measured by use of a nitroblue tetrazolium (NBT) reduction assay on whole spermatozoa and a cytochrome c reduction assay on isolated membrane fractions of spermatozoa. Localization of superoxide generation was determined by use of NBT cyto...
Meyer W, Kacza J, Schnapper A, Verspohl J, Hornickel I, Seeger J.Based on cryo-SEM, standard and high resolution TEM, glycoconjugate histochemistry, and microbiological differentiation, the present study demonstrates the colonisation of the epithelium of the equine oesophagus with microorganisms. As particularly apparent using cryo-SEM to illustrate natural conditions, the present microbiota were clearly dominated by bacteria, forming a one-layer system, as attached to and embedded in concentrated mannose/mannan substances covering the outer stratum corneal cells. Bacterial numbers ranged from 5600 to 7200 per mm(2) in the central part of the oesophagus, th...
Gamboa S, Rodrigues AS, Henriques L, Batista C, Ramalho-Santos J.A group of stallions with different reproductive indexes were used to study seasonal variations in sperm quality (Equus caballus). Semen samples were collected from late September to July and analyzed according to four seasonal periods: late September-December, January-March, late March-May, and June-July. Parameters monitored included sperm concentration, sperm motility, sperm morphology, sperm viability, acrosomal status, plasma membrane stability, and sperm mitochondrial membrane potential. Overall, seminal parameters monitored are affected mostly by time period, followed by animal and last...
Csizmár N, Mihók S, Jávor A, Kusza S.The Hungarian draft is a horse breed with a recent mixed ancestry created in the 1920s by crossing local mares with draught horses imported from France and Belgium. The interest in its conservation and characterization has increased over the last few years. The aim of this work is to contribute to the characterization of the endangered Hungarian heavy draft horse populations in order to obtain useful information to implement conservation strategies for these genetic stocks. Methods: To genetically characterize the breed and to set up the basis for a conservation program, in the present study a...
Anzai T, Sheoran AS, Kuwamoto Y, Kondo T, Wada R, Inoue T, Timoney JF.Streptococcus equi causes equine strangles. The acute disease has many of the hallmarks of an acute response including high fever, elevated plasma fibrinogen and neutrophilia, affects known to be mediated by proinflammatory cytokines. The objective of this study was to screen-culture supernatants from equine clinical isolates of S. equi and S. zooepidemicus for stimulation of mitogenic responses by horse peripheral blood mononuclear cells. Mitogenicity comparable to that of concanavalin A was detected in culture supernatants of S. equi strains but not in those of S. zooepidemicus. Mitogenicity...
Kayar SR, Hoppeler H, Jones JH, Longworth K, Armstrong RB, Laughlin MH, Lindstedt SL, Bicudo JE, Groebe K, Taylor CR.The mean minimal transit time for blood in muscle capillaries (tc) was estimated in six species, spanning two orders of magnitude in body mass and aerobic capacity: horse, steer, dog, goat, fox and agouti. Arterial (CaO2) and mixed venous (CvO2) blood O2 concentrations, blood hemoglobin concentrations ([Hb]) and oxygen uptake rates were measured while the animals ran on a treadmill at a speed that elicited the maximal oxygen consumption rate (VO2max) from each animal. Blood flow to the muscles (Qm) was assumed to be 85% of cardiac output, which was calculated using the Fick relationship. Total...
Cauchard S, Van Reet N, Büscher P, Goux D, Grötzinger J, Leippe M, Cattoir V, Laugier C, Cauchard J.Trypanozoon parasites infect both humans, causing sleeping sickness, and animals, causing nagana, surra, and dourine. Control of nagana and surra depends to a great extent on chemotherapy. However, drug resistance to several of the front-line drugs is rising. Furthermore, there is no official treatment for dourine. Therefore, there is an urgent need to develop antiparasitic agents with novel modes of action. Host defense peptides have recently gained attention as promising candidates. We have previously reported that one such peptide, the equine antimicrobial peptide eCATH1, is highly active a...
Gastal GD, Alves BG, Alves KA, Souza ME, Vieira AD, Varela AS, Figueiredo JR, Feugang JM, Lucia T, Gastal EL.The method of transportation and the conditions imposed on the ovarian tissue are pivotal aspects for the success of ovarian tissue cryopreservation (OTC). The aim of this study was to evaluate the effect of the size of the ovarian tissue (e.g. whole ovary, biopsy size and transplant size) during different times of storage (0, 6, 12 and 24 h) on the structural integrity of equine ovarian tissue transported at 4°C. Eighteen pairs of ovaries from young mares (<10 years old) were harvested in a slaughterhouse and processed to simulate the fragment sizes (biopsy and transplant size groups) o...
Treulen F, Aguila L, Arias ME, Jofré I, Felmer R.During cryopreservation procedures, the spermatozoa are exposed to physical and chemical stressors that generate an increase in the intracellular concentration of reactive oxygen species (ROS). If ROS concentrations are too great, this can lead to a state of oxidative stress that are detrimental to sperm quality. The aim of this study was to ascertain the profile the ROS production and assess the effects of post-thaw supplementation of a semen extender with different antioxidant compounds on the quality and function variables of frozen-thawed stallion spermatozoa incubated in vitro. Frozen-tha...
The present equine genetic variation mirrors the deep influence of intensive breeding programs during the last 200 years. Here, we provide a comprehensive current state of knowledge on the trends and prospects on the variation in the equine male-specific region of the Y chromosome (MSY), which was assembled for the first time in 2018. In comparison with the other 12 mammalian species, horses are now the most represented, with 56 documented MSY genes. However, in contrast to the high variability in mitochondrial DNA observed in many horse breeds from different geographic areas, modern horse pop...
