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.
The goal of this work was the development of suitable (real-time) RT-PCR techniques for fast and sensitive diagnosis of EAV and for molecular-epidemiological characterisation of viral strains, as an alternative to virus isolation. To this purpose two conventional RT-PCR methods and one real-time RT-PCR were adapted to detect the broadest possible spectrum of viral strains. Several dilutions with Bucyrus strain showed a 100-fold higher sensitivity of real-time RT-PCR and heminested RT-PCR compared to simple RT-PCR. Making use of 11 cell culture supernatants of different EAV isolates and 7 semen...
Feral horses in Theodore Roosevelt National Park (TRNP) represent an iconic era of the North Dakota Badlands. Their uncertain history raises management questions regarding origins, genetic diversity, and long-term genetic viability. Hair samples with follicles were collected from 196 horses in the Park and used to sequence the control region of mitochondrial DNA (mtDNA) and to profile 12 autosomal short tandem repeat (STR) markers. Three mtDNA haplotypes found in the TRNP horses belonged to haplogroups L and B. The control region variation was low with haplotype diversity of 0.5271, nucleotide...
The results of integrated human and veterinary surveillance for West Nile virus (WNV) infections in Austria during the transmission seasons 2015 and 2016 are shown. Altogether WNV nucleic acid was detected in 21 humans, horses, wild birds and mosquito pools. In detail: in four human clinical cases [two cases of West Nile fever (WNF) and two cases of West Nile neuroinvasive disease (WNND)]; eight blood donors [among 145,541 tested donations], of which three remained asymptomatic and five subsequently developed mild WNF; two horses with WNND, of which one recovered and one had to be euthanized; ...
Osteochondrosis (OC) develops in growing horses due to disturbed differentiation and maturation of cartilage, particularly at the predilection sites of the fetlock, hock and stifle joints. Horses with osteochondrotic lesions are at a high risk of developing orthopaedic problems later in life. This article briefly reviews the published heritability estimates for OC and offers perspectives for selection in the horse industry. Heritabilities for OC in Warmblood and Standardbred horses have been estimated at 0.1-0.4 in animal threshold models. Whole genome scans using microsatellites have identifi...
Equine arteritis virus (EAV) is the causative agent of equine viral arteritis (EVA), a respiratory and reproductive disease of equids. There has been significant recent progress in understanding the molecular biology of EAV and the pathogenesis of its infection in horses. In particular, the use of contemporary genomic techniques, along with the development and reverse genetic manipulation of infectious cDNA clones of several strains of EAV, has generated significant novel information regarding the basic molecular biology of the virus. Therefore, the objective of this review is to summarize cur...
Exertional rhabdomyolysis (ER) and its familial basis in Warmblood horses is incompletely understood. Objective: To describe the case details, clinical signs and management of ER-affected Warmblood horses from a family with a high prevalence of ER, to determine if histopathological signs of polysaccharide storage myopathy (PSSM) and the glycogen synthase (GYS1) mutation are associated with ER in this family, and to investigate potential risk factors for development of ER. Methods: A family consisting of a sire with ER and 71 of his descendants was investigated. History of episodes of ER, husba...
Serum anti-Müllerian hormone (AMH), a marker of equine cryptorchidism, is detectable in intact and cryptorchid stallions but not in geldings because it is secreted from Sertoli cells. A 4-year-old uncastrated Thoroughbred racehorse had no visible testes; therefore, the horse was considered a bilateral cryptorchidism. However, the serum AMH was undetectable (<0.08 ng/ml). Human chorionic gonadotrophin (hCG) stimulating test result indicated that the horse was a gelding. The results of sex chromosomal analysis and sequence analysis of SRY gene suggested that the horse was a genetically-intac...
A breed known for its versatility, the American Quarter Horse (QH), is increasingly bred for performance in specific disciplines. The impact of selective breeding on the diversity and structure of the QH breed was evaluated using pedigree analysis and genome-wide SNP data from horses representing 6 performance groups (halter, western pleasure, reining, working cow, cutting, and racing). Genotype data (36 037 single nucleotide polymorphisms [SNPs]) from 36 Thoroughbreds were also evaluated with those from the 132 performing QHs to evaluate the Thoroughbred's influence on QH diversity. Results s...
Unlike in Warmblood horses, aortic rupture is quite common in Friesian horses, in which a hereditary trait is suspected. The aortic connective tissue in affected Friesians shows histological changes such as medial necrosis, elastic fibre fragmentation, mucoid material accumulation and fibrosis with aberrant collagen morphology. However, ultrastructural examination of the collagen fibres of the mid-thoracic aorta has been inconclusive in further elucidating the pathogenesis of the disease. Objective: To assess several extracellular matrix (ECM) components biochemically in order to explore a pos...
Rouby S, Ewies S.Bovine papillomatosis is an infectious viral disease of cattle characterized by development of benign cutaneous warts. The present study describes bovine papillomavirus infection in cattle on clinco-pathological and molecular bases and compares the identified strains with the previously characterized papillomavirus isolates in Egypt either of bovine or equine origin. Out of sixty examined cattle, skin lesions were collected from eleven clinically diseased cattle exhibiting typical papillomatosis clinical signs and subjected to histopathological and molecular identification. Histological sectio...
Murphy S.Cancer is disease of the genome. The Hallmarks of cancer are a way of thinking of cancer to help rationalize what occurs in this disease process. A solid tumor is a complex of normal and neoplastic cells, arising through an evolutionary process to survive and grow. By understanding how normal cellular mechanisms are subverted to promote cancer we can refine our approach to improve outcomes. It gives us opportunities to prevent some cancers and allowing earlier diagnosis. We can refine conventional diagnostic tools and give more accurate prognoses. It offers novel targets to improve treatment o...
Martin G, Tyson GH, Guag J, Strain E, Ceric O.Klebsiella spp. is an important human and animal pathogen, and it is commonly found with resistance to clinically important antimicrobials worldwide. The main goals of this study were to determine the prevalence of antimicrobial resistance genes in our study population and to assess the relatedness between Klebsiella spp. isolated from humans and animals. Isolates were collected in 2019 and 2020 from various animal hosts that presented to veterinary hospitals in the U.S. that participate in the FDA's Center for Veterinary Medicine Veterinary Laboratory Investigation and Response Network's anti...
Tasnim Y, Rahman MK, Awosile B.We aimed to determine the genetic relatedness among β-lactamase-producing Escherichia coli isolated from soil, lake water, and feces of geese, pigs, dogs, cattle, coyotes, wild hogs, and horses at one health interface in West Texas. Results: Previously isolated 56 β-lactamase-producing E. coli isolates from the feces of geese, pigs, horses, coyotes, dogs, cattle, and wild hogs, and soil and lake water from different locations in West Texas were analyzed for genetic relatedness using whole-genome sequencing, core genome multilocus sequence typing, and phylogenetic single-nucleotide polymorphi...
Huang Q, Wen M, Wen L, Li Q, Zeng Y, Wang J, Meng J, Ren W, Yao X.This study aims to elucidate the miRNA regulatory mechanisms during the developmental process of Kazakh horse testes at 1 and 3 years of age. Through miRNA sequencing and bioinformatics analysis of testicular tissues from 1-year-old and 3-year-old horses, a developmentally stage-specific miRNA expression profile was constructed. A total of 1640 miRNAs were identified, among which 437 (380 up-regulated and 57 down-regulated) exhibited significant differential expression between the two age groups, including eca-miR-16, eca-miR-17, eca-miR-103, and eca-miR-199a-5p. Functional enrichment analysis...
Abdulkadir A, Kabir J, Bello M, Olayinka B.Methicillin resistant Staphylococcus aureus (MRSA) represents a worrying example of antimicrobial resistance, and it is essential to acquire new information to monitor the spread and limit it further diffusion. This study aimed to characterise 22 MRSA isolates from horses, dogs, cats, and their human handlers focusing on spa typing. In the analysis of the sequences obtained, the spa type is "unknown" (unidentified) and all the sequences except one had repeats previously not known in all databases potentially indicating new spa-repeats. This could possibly indicate either permanent import of no...
Kovács M, Hegedűs B, Mihók S, Knop R, Szabó C, Posta J.The conservation of genetic diversity in historically structured horse breeds requires fi-ne-scale population genetic evaluation beyond conventional pedigree-based approaches. The present study assessed genetic diversity, population structure, and mare family differentiation in a Lipizzan horse population using 16 ISAG/FAO-recommended microsatellite markers. A total of 172 mares representing 29 mare families were genotyped. All loci were polymorphic, with a mean number of alleles per locus of 6.69 and a mean effective number of alleles of 3.56. The average polymorphism information content (PIC...
Caceres AM, Sperandio LMS, Alvarenga NACA, Borges AS, Oliveira-Filho JP.Bull-catching (vaquejada) accounting for approximately 13% of sport horses in Brazil. Genetic screening has enabled strategies to reduce the spread of inherited disorders, including Hereditary Equine Regional Dermal Asthenia (HERDA), a major skin disease included in the Six Panel required for registration by the Brazilian Quarter Horse Breeders Association. Although the HERDA-associated variant has been extensively studied in other disciplines, it had not been evaluated in Bull-catching Quarter Horses (QH). Objective: The present study aimed to determine the allele frequency of the pathogenic ...
Maharana BR, Ganguly A, Malik R, Kumar A, Khanna S, Kumar B, Potliya S, Singh H, Dash A, Sahu S.Equine piroplasmosis, caused by Theileria equi, has been widely studied globally, but genetic diversity research in India remains limited. Analysis of 306 horse blood samples revealed T. equi infection in 10.78% by microscopy and 21.24% by PCR. Universal primers targeting 18S rRNA of T. equi and Babesia caballi were used, followed by species-specific primers generating 435 bp amplicons. Sequenced PCR-positive samples revealed high homology (99.52-100% in India, 95.89-100% globally), with all Indian isolates classified as genotype A. The EMA-1 gene phylogenetic analysis confirmed the insights f...
Vanderbiest L, Rousseau L, Renaville B, Aleman M, Finno C, Milan A, Vinardell T.Occipitoatlantoaxial malformations (OAAM) are developmental disorders occurring at the occiput, atlas and axis. OAAM type 1 is a familial disorder affecting Arabian horses. Currently, a single genetic mutation in the HOXD3 gene region can be tested to confirm the diagnosis. This case describes a 3-year-old Arabian gelding affected with OAAM. Clinical examination revealed a proximal cervical deformation on the right side and severe stiffness of the neck in the sagittal plane without associated pain. Neurological examination demonstrated a generalized proprioceptive ataxia. Radiographs revealed ...
Ibrahim MA, Noshy MM, Mohamed HRH, Abd El-Gawad MEH.This study combined classical cytogenetics and ISSR molecular markers to characterize genetic diversity in 24 Egyptian Arabian horses. Karyotyping revealed the standard equine chromosome number (2n = 64) with no numerical or structural abnormalities. Chromosome measurements were consistent with ISCN Equine standards: autosomal relative lengths (RL%) followed the expected size hierarchy, biarmed chromosomes displayed metacentric to submetacentric morphology (CI = 37-50%), and recalculated centromeric indices confirmed the presence of measurable p-arms on all acrocentric chromosomes. ISSR an...
