Omneity® Pellets
All-In-One Vitamin & Mineral Pellet
Topic:Genetics
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.
Genome-wide association mapping and examination of possible maternal effect for the pace trait of horses. Previously, a single nucleotide polymorphism (SNP) related to gait type was identified at position 22 999 655 of chromosome 23 in the coding region of DMRT3 (DMRT3:Ser301Ter) by showing that a cytosine (C) to adenine (A) mutation of this SNP induced pace in the Icelandic horse. We investigated the effect of DMRT3:Ser301Ter on the gait of Hokkaido Native Horses, a Japanese native breed, and examined genetic factors other than DMRT3 by exploring genome-wide SNPs related to gait determination. All animals exhibiting pace were AA for DMRT3:Ser301Ter, confirming the association of DMRT3:Ser301Ter...
Evaluation of the genetic diversity and population structure of Gasterophilus pecorum in Xinjiang Province, China, using fluorescent microsatellites (SSR) markers. The genetic diversity of Gasterophilus pecorum populations consisting of 192 individuals sampled from Przewalski's horses (Equus ferus przewalskii) in Xinjiang Province, China, was evaluated using 12 microsatellite loci. The genetic variability within populations and genetic differentiation among populations were estimated. A total of 163 alleles were detected and the average value of observed number of alleles at each locus ranged from 7 to 19 (average 13.5625). The expected heterozygosity (He) varied from 0.5933 (GP361) to 0.9208 (GP253) and averaged 0.8426. The effective number of alleles (...
Determination of the activity and relative abundance of mRNA for antioxidant enzymes in stallion testicular and epididymal tissues: A comparison between two breeding seasons. The key prerequisite for successful insemination is sperm characterized to have positive values for morphological and biological variables which are determined by, among others, effective antioxidant protection during the lifespan of sperm cells. This study evaluated the activity and relative abundance of mRNA for antioxidant enzymes in stallion testicular and epididymal tissues during breeding (n = 5) and non-breeding (n = 5) seasons. The activity of superoxide dismutase (SOD) was greater (P < 0.05) during the breeding season, in particular in the testes and the caput epididymis, ...
Genome-wide analyses of the Jeju, Thoroughbred, and Jeju crossbred horse populations using the high density SNP array. The Jeju horse is an indigenous Korean horse breed that is currently registered with the Food and Agriculture Organization of the United Nations. However, there is severe lack of genomic studies on Jeju horse. This study was conducted to investigate genetic characteristics of horses including Jeju horse, Thoroughbred and Jeju crossbred (Jeju × Thoroughbred) populations. We compared the genomes of three horse populations using the Equine SNP70 Beadchip array. Short-range Linkage disequilibrium was the highest in Thoroughbred, whereas r values were lowest in Jeju horse. Expected heterozygos...
Advanced mare age impairs the ability of in vitro-matured oocytes to correctly align chromosomes on the metaphase plate. Advanced mare age is associated with declining fertility and an increased risk of early pregnancy loss. Compromised oocyte quality is probably the primary reason for reduced fertility, but the defects predisposing to embryonic death are unknown. In women, advanced age predisposes to chromosome segregation errors during meiosis, which lead to embryonic aneuploidy and a heightened risk of miscarriage. Objective: To evaluate the effect of advanced mare age on chromosome alignment and meiotic spindle morphology in in vitro-matured (IVM) oocytes. Methods: Morphometric and morphological analysis. M...
Validation of high-resolution melting analysis as a diagnostic tool for endothelin receptor B mutation in American Paint horses and allele frequency estimation. Overo lethal white foal syndrome (OLWFS) is a genetic disorder caused by a dinucleotide mutation in the endothelin receptor type B (EDNRB) gene leading to the death of affected foals shortly after birth. The use of rapid and reliable genetic testing is imperative for the early diagnosis of the mutation avoiding, therefore, either additional suffering or the production of affected animals. In the present study, we developed and validated a high-resolution melting (HRM) genotyping assay to detect the OLWFS causative mutation, and we also determined the frequency of heterozygotes among American P...
Anthelmintic drugs used in equine species. Internal parasites of horses comprise an intractable problem conferring disease, production and performance losses. Parasitism can rarely be controlled in grazing horses by management alone and anthelmintic drugs have formed the basis of therapy and prophylaxis for the last sixty years. The pharmacology of the anthelmintic drugs available dictate their spectrum of activity and degree of efficacy, their optimal routes of administration and characteristics which prevent some routes of administration, their safety tolerance and potential toxicities and as a consequence of their persistence in the...
Novel roles for scleraxis in regulating adult tenocyte function. Tendinopathies are common and difficult to resolve due to the formation of scar tissue that reduces the mechanical integrity of the tissue, leading to frequent reinjury. Tenocytes respond to both excessive loading and unloading by producing pro-inflammatory mediators, suggesting that these cells are actively involved in the development of tendon degeneration. The transcription factor scleraxis (Scx) is required for the development of force-transmitting tendon during development and for mechanically stimulated tenogenesis of stem cells, but its function in adult tenocytes is less well-defined. ...
Exploratory factor analysis of signalment and conformational measurements in Thoroughbred horses with and without recurrent laryngeal neuropathy. Conflicting results have been reported for risk factors for recurrent laryngeal neuropathy (RLN) based on resting endoscopic evaluation and comparison of single conformation traits, with many traits correlated to one another. Objective: To simplify identification of signalment and conformation traits (i.e. variables) associated with RLN cases and controls diagnosed with exercising overground endoscopy (OGE) using exploratory factor analysis (EFA). Methods: Prospective cohort. Methods: Pearson's rank correlation was used to establish significance and association between variables collected from...
An E321G MYH1 mutation is strongly associated with nonexertional rhabdomyolysis in Quarter Horses. An E321G mutation in MYH1 was recently identified in Quarter Horses (QH) with immune-mediated myositis (IMM) defined by a phenotype of gross muscle atrophy and myofiber lymphocytic infiltrates. Objective: We hypothesized that the MYH1 mutation also was associated with a phenotype of nonexertional rhabdomyolysis. The objective of this study was to determine the prevalence of the MYH1 mutation in QH with exertional (ER) and nonexertional (nonER) rhabdomyolysis. Methods: Quarter Horses: 72 healthy controls, 85 ER-no atrophy, 56 ER-atrophy, 167 nonER horses selected regardless of muscle atrophy. M...
Equine MX2 is a restriction factor of equine infectious anemia virus (EIAV). Human myxovirus resistance protein B (hMXB) is a restriction factor of HIV-1 that also inhibits a variety of retroviruses. However, hMXB is not antiviral against equine infectious anemia virus (EIAV). We show here that equine MX2 (eMX2) potently restricts EIAV in vitro. Additionally, eMX2 inhibits HIV-1 and other lentiviruses, including murine leukemia virus. Previously, it was reported that hMXB repression is reduced in hMXB Δ1-25, but not in GTP-binding mutant K131A and GTP-hydrolysis mutant T151A. In contrast to this phenomenon, our study indicates that eMX2 restriction is not diminished i...
eQTL discovery and their association with severe equine asthma in European Warmblood horses. Severe equine asthma, also known as recurrent airway obstruction (RAO), is a debilitating, performance limiting, obstructive respiratory condition in horses that is phenotypically similar to human asthma. Past genome wide association studies (GWAS) have not discovered coding variants associated with RAO, leading to the hypothesis that causative variant(s) underlying the signals are likely non-coding, regulatory variant(s). Regions of the genome containing variants that influence the number of expressed RNA molecules are expression quantitative trait loci (eQTLs). Variation associated with RAO ...
Characterization of the fecal microbiota of healthy horses. OBJECTIVE To characterize the fecal microbiota of horses and to investigate alterations in that microbiota on the basis of sample collection site (rectum vs stall floor), sample location within the fecal ball (center vs surface), and duration of environmental exposure (collection time). ANIMALS 6 healthy adult mixed-breed mares. PROCEDURES From each horse, feces were collected from the rectum and placed on a straw-bedded stall floor. A fecal ball was selected for analysis immediately after removal from the rectum and at 0 (immediately), 2, 6, 12, and 24 hours after placement on the stall floor...
Copy number variations in Friesian horses and genetic risk factors for insect bite hypersensitivity. Many common and relevant diseases affecting equine welfare have yet to be tested regarding structural variants such as copy number variations (CNVs). CNVs make up a substantial proportion of total genetic variability in populations of many species, resulting in more sequence differences between individuals than SNPs. Associations between CNVs and disease phenotypes have been established in several species, but equine CNV studies have been limited. Aim of this study was to identify CNVs and to perform a genome-wide association (GWA) study in Friesian horses to identify genomic loci associated w...
Multiple alleles of ACAN associated with chondrodysplastic dwarfism in Miniature horses. Chondrodysplastic dwarfism in Miniature horses appeared to be a recessive genetic trait based on the occurrence of affected offspring by normal parents. Dwarf phenotypes vary and range from abnormal abortuses to viable offspring with evidence of skeletal dysplasia. A genome-wide association study implicated a region of ECA1 with dwarfism in Miniature horses. Aggrecan (ACAN) was a candidate gene in that region, and exons were sequenced to compare DNA sequences for dwarf and non-dwarf horses. Sequencing led to the discovery of variants in exons 2, 6, 7 and 15 associated with dwarfism. The four v...
In vivo antral follicle wall biopsy: a new research technique to study ovarian function at the cellular and molecular levels. In vivo studies involving molecular markers of the follicle wall associated with follicular fluid (FF) milieu are crucial for a better understanding of follicle dynamics. The inability to obtain in vivo samples of antral follicle wall (granulosa and theca cells) without jeopardizing ovarian function has restricted advancement in knowledge of folliculogenesis in several species. The purpose of this study in mares was to develop and validate a novel, minimally invasive in vivo technique for simultaneous collection of follicle wall biopsy (FWB) and FF samples, and repeated collection from the sam...
Horse Y chromosome assembly displays unique evolutionary features and putative stallion fertility genes. Dynamic evolutionary processes and complex structure make the Y chromosome among the most diverse and least understood regions in mammalian genomes. Here, we present an annotated assembly of the male specific region of the horse Y chromosome (eMSY), representing the first comprehensive Y assembly in odd-toed ungulates. The eMSY comprises single-copy, equine specific multi-copy, PAR transposed, and novel ampliconic sequence classes. The eMSY gene density approaches that of autosomes with the highest number of retained X-Y gametologs recorded in eutherians, in addition to novel Y-born and transp...
Haplotype diversity in mitochondrial DNA reveals the multiple origins of Tibetan horse. The Tibetan horse is a species endemic to the Tibetan plateau, with considerable economic value in the region. However, we currently have little genetic evidence to verify whether the breed originated in Tibet or if it entered the area via an ancient migratory route. In the present study, we analyzed the hypervariable segment I sequences of mitochondrial DNA (mtDNA) in 2,050 horses, including 290 individuals from five Tibetan populations and 1,760 from other areas across Asia. Network analysis revealed multiple maternal lineages in the Tibetan horse. Component analysis of sub-lineage F3 indica...
Leukocyte telomere length in the Thoroughbred racehorse. Thoroughbred racehorses possess superior cardiorespiratory fitness levels and are at the pinnacle of athletic performance compared to other breeds of horses. Although equine athletes have undergone years of artificial selection for racing performance, musculoskeletal injuries and illnesses are common and concerns relating to animal welfare have been proposed. Leukocyte telomere length is indicative of biological age, and accelerated telomere shortening occurs with excess physical and psychological stress. This study was designed to explore the association between leukocyte telomere length, bio...
Early colonisation and temporal dynamics of the gut microbial ecosystem in Standardbred foals. Even if horses strictly depend on the gut microbiota for energy homeostasis, only a few molecular studies have focused on its characterisation and none on the perinatal gut microbial colonisation process. Objective: To explore the perinatal colonisation process of the foal gut microbial ecosystem and the temporal dynamics of the ecosystem assembly during the first days of life. Methods: Longitudinal study. Methods: Thirteen Standardbred mare-foal pairs were included in the study. For each pair, at delivery we collected the mare amniotic fluid, faeces and colostrum, and the foal meconium. Milk ...
TGF-β1 upregulates the expression of hyaluronan synthase 2 and hyaluronan synthesis in culture models of equine articular chondrocytes. We investigated the effect of transforming growth factor beta 1 (TGF-β1) on equine hyaluronan synthase 2 () gene expression and hyaluronan (HA) synthesis in culture models of articular chondrocytes. Equine chondrocytes were treated with TGF-β1 at different concentrations and times in monolayer cultures. In three-dimensional cultures, chondrocyte-seeded gelatin scaffolds were cultured in chondrogenic media containing 10 ng/mL of TGF-β1. The amounts of HA in conditioned media and in scaffolds were determined by enzyme-linked immunosorbent assays. mRNA expression was analyzed by semi-quantita...
Genetic structure and connectivity analysis in a large domestic livestock meta-population: The case of the Pura Raza Español horses. The Pura Raza Español (PRE) is an autochthonous Spanish horse population distributed in 65 countries and managed by a single association. Since 1960s, breeding animals have been steadily exported to other countries to establish local subpopulations. We analysed the genetic structure of a PRE horse meta-population (MP) of 215,500 animals from countries with at least 80 active animals (27 countries comprising 77% of the total animals in the complete pedigree). Genotypes from active animals (59% of the total animals in the complete pedigree) were also studied. Genetic analysis of the MP was perf...
Genomic sequencing and characterization of Theiler’s disease-associated virus identified in commercial equine sera in China. Theiler's disease-associated virus (TDAV) could be the aetiological agent of Theiler's disease. Horses experimentally inoculated with equine plasma containing TDAV develop acute and chronic infections with viraemia. Since its first identification in 2013, TDAV has not been detected in equines in the epidemiological studies that have been conducted. Until now, only one genome sequence of TDAV (HorseA1_serum) had been obtained. In this study, we sequenced the genome of four TDAV strains (A/China, F/China, H/USA and I/USA) in commercial equine sera used for cell culture propagation in China using...
D159 and S167 are protective residues in the prion protein from dog and horse, two prion-resistant animals. Prion diseases are fatal neurodegenerative diseases caused by misfolding of the prion protein (PrP). These conditions affect humans and animals, including endemic forms in sheep and deer. Bovine, rodents, and many zoo mammals also developed prion diseases during the "mad-cow" epidemic in the 1980's. Interestingly, rabbits, horses, and dogs show unusual resistance to prion diseases, suggesting that specific sequence changes in the corresponding endogenous PrP prevents the accumulation of pathogenic conformations. In vitro misfolding assays and structural studies have identified S174, S167, and ...
DNA methylation patterns of the S100A14, POU2F3 and SFN genes in equine sarcoid tissues. Genetic and epigenetic alterations in the equine sarcoid, a locally invasive skin tumour of equids, are still poorly characterized. Numerous studies have provided reliable evidence for the relationship between the development of cancer and the loss of function of a number of tumour suppressor genes. In the present study, we assessed methylation levels in the promoter region of SFN, S100A14 and POU2F3 genes in sarcoid samples to clarify whether DNA methylation may be associated with previously identified changes in the expression level of these genes during the course of tumour progression. Usi...
ACTN3 gene variants as potential phenotype and performance biomarkers in Brazilian sport horses training for eventing in a tropical climate. The aim of this study was to look for mutations in the equine gene and to identify sequence variants that might be associated with the phenotype and performance of Brazilian sport horses training for events in a tropical climate. Among 17 such horses direct DNA sequencing and mutation analysis of the exon 15 and the intron-exon boundaries of revealed 2 new sequence variants in the intron 14-15, designated c.1681-86G > A and c.1681-129delA. Wild-type/deletion heterozygotes (A/del) had a lower mean subcutaneous fat layer in the region of the gluteus medius, as measured by ultrasonography, tha...
Genome-Wide Signatures of Selection Reveal Genes Associated With Performance in American Quarter Horse Subpopulations. Selective breeding for athletic performance in various disciplines has resulted in population stratification within the American Quarter Horse (QH) breed. The goals of this study were to utilize high density genotype data to: (1) identify genomic regions undergoing positive selection within and among QH subpopulations; (2) investigate haplotype structure within each QH subpopulation; and (3) identify candidate genes within genomic regions of interest (ROI), as well as biological pathways, predicted to play a role in elite performance in each group. For that, 65K SNP genotyping data on 143 elit...
Mutational Analysis of the Bovine Hepacivirus Internal Ribosome Entry Site. In recent years, hepatitis C virus (HCV)-related viruses were identified in several species, including dogs, horses, bats, and rodents. In addition, a novel virus of the genus has been discovered in bovine samples and was termed bovine hepacivirus (BovHepV). Prediction of the BovHepV internal ribosome entry site (IRES) structure revealed strong similarities to the HCV IRES structure comprising domains II, IIIabcde, pseudoknot IIIf, and IV with the initiation codon AUG. Unlike HCV, only one microRNA-122 (miR-122) binding site could be identified in the BovHepV 5' nontranslated region. In this ...
Genetic risk for squamous cell carcinoma of the nictitating membrane parallels that of the limbus in Haflinger horses. Squamous cell carcinoma (SCC) is the most common cancer affecting the equine eye, with a higher incidence documented in Haflinger horses. Recently, a missense variant in the gene damage specific DNA binding protein 2 (DDB2, p.Thr338Met) on ECA12 was identified as a risk factor for the development of limbal SCC in Haflinger horses. SCC also occurs on the nictitating membrane; therefore, investigating the role of this missense variant in nictitating membrane SCC is warranted. In this study, a common ancestor was identified among Haflinger horses affected with limbal SCC or with nictitating membr...
Molecular identification of Trichomonas tenax in the oral environment of domesticated animals in Poland – potential effects of host diversity for human health. The protozoan is considered to be a human specific flagellate of the oral cavity, found in humans with poor oral hygiene and advanced periodontal disease. Morphological variability and great similarity between species occurring in humans and animals, complicate the specific identification of trichomonads, using microscopic examination and other standard parasitological techniques. Objective: The aim of the study was to search for and identify in domesticated animals using molecular methods. The obtained data were assessed in terms of potential effects of a spread of the species deriving from...
