Genomics in horses involves the study and analysis of the horse genome to understand genetic variations and their implications for equine health, performance, and breeding. This field encompasses the identification and mapping of genes associated with specific traits, diseases, and conditions in horses. Techniques such as whole-genome sequencing and genome-wide association studies (GWAS) are employed to explore genetic diversity and inheritance patterns among different horse breeds. Genomics provides insights into hereditary disorders, informs selective breeding practices, and aids in the development of personalized veterinary care. This page compiles peer-reviewed research studies and scholarly articles that explore the applications, methodologies, and findings of genomic research in equine science.
Slota E, Wnuk M, Bugno M, Pienkowska-Schelling A, Schelling C, Bratus A, Kotylak Z.Cytogenetic investigations of the nucleolar-organizing regions (NORs) show that there is variation in the transcriptional activity of rDNA in many organisms. As a consequence, genetic polymorphism of these regions has been detected. The aim of the present study was to evaluate the hypothetic genetic mechanisms determining the NORs polymorphism of the domestic horse chromosomes. Molecular cytogenetic analyses were carried out on Hucul horses and the following techniques were used: fluorescence in situ hybridization (FISH), telomere primed in situ synthesis (PRINS), in situ nick-translation with...
Ghanem YM, Ibrahim el-SM, Yamada S, Matsumura T, Osterrieder N, Yamaguchi T, Fukushi H.The pathogenicities of RacL11 and Kentucky D strains of equine herpesvirus 1 in the hamster infection model are different from those of Ab4p and the Japanese isolates. Virus genome restriction fragment length polymorphism analysis and sequence comparison of an intergenic region, glycoproteins and tegument genes showed higher conservation but with some strain-specific differences. These results indicate that point nucleotide differences in RacL11 and Kentucky D might be responsible for their pathogenicity in rodent models.
Diesterbeck US, Hertsch B, Distl O.The aim of this study was to identify quantitative trait loci (QTLs) for pathologic changes in the navicular bone in Hanoverian warmblood horses. Seventeen paternal half-sib groups comprising 192 individuals were analyzed in a whole-genome scan. These families included 144 progeny and grandchildren, which were randomly chosen from the Hanoverian warmblood. Three different traits were considered: deformed canales sesamoidales and radiographic changes in the contour and in the structure of the navicular bone. The genome scan included in total 214 highly polymorphic microsatellite markers. The pu...
Piuko K, Bravo IG, Müller M.In the present study we describe the isolation and characterization of putative equine granzyme B for which we propose the designation 'eqGrzmB'. Sequence analysis revealed characteristic features of a GrzmB protease such as the presence of a signal (leader-) peptide and an activation di-peptide. The isolated eqGrzmB is functionally active when expressed in human or in insect cells. Furthermore, exchange of any of three putative active site amino acids, which are highly conserved along granzyme B enzymes, led to a complete loss of enzymatic activity in the newly identified eqGrzmB. Phylogeneti...
Coleman SJ, Gong G, Gaile DP, Chowdhary BP, Bailey E, Liu L, MacLeod JN.Loci for 9322 equine expressed sequence tags (ESTs) were predicted using the Comparative Mapping by Annotation and Sequence Similarity (Compass) strategy in order to evaluate the programme's ability to make accurate locus predictions in species with comparative gene maps. Using human genome sequence information from Build 35 (May 2004) and published marker information from the radiation hybrid (RH) maps for equine chromosomes (ECA) 17 and X, 162 ESTs were predicted to locations on ECA17 and 328 ESTs to locations on ECAX by selection of the 'top blast hit'. The locations of 30 ESTs were assesse...
Morozova-Roche LA.Calcium-binding equine lysozyme (EL) combines the structural and folding properties of c-type lysozymes and alpha-lactalbumins, connecting these two most studied subfamilies. The structural insight into its native and partially folded states is particularly illuminating in revealing the general principles of protein folding, amyloid formation and its inhibition. Among lysozymes EL forms one of the most stable molten globules and shows the most uncooperative refolding kinetics. Its partially-folded states serve as precursors for calcium-dependent self-assembly into ring-shaped and linear amyloi...
Zhou H, Liu C, Wang W.This study was conducted to reconstruct heterogeneous embryos using equine skin fibroblast cells as donor karyoplasts and the bovine oocytes as recipient cytoplast for investigating the reprogramming of equine somatic cell nuclear in bovine oocyte cytoplasm and the developmental potential of the reconstructed embryos. Adult horse skin fibroblast cells serum-starved were used as donor somatic cells. Bovine oocytes matured in vitro were employed as recipient cytoplasts. The fusion of fibroblast cells into recipient cytoplasm was induced by electofusion. The fused eggs were activated by inomycin ...
Tryon RC, White SD, Bannasch DL.Hereditary equine regional dermal asthenia (HERDA), a degenerative skin disease that affects the Quarter Horse breed, was localized to ECA1 by homozygosity mapping. Comparative genomics allowed the development of equine gene-specific markers which were used with a set of affected horses to detect a homozygous, identical-by-descent block spanning approximately 2.5 Mb, suggesting a recent origin for the HERDA mutation. We report a mutation in cyclophilin B (PPIB) as a novel, causal candidate gene for HERDA. A c.115G>A missense mutation in PPIB alters a glycine residue that has been conserved acr...
Kniazev SP, Nikitin SV.Two polymorphic blood group systems (E and M) of the pig Sus scrofa L. and one blood group system (D) of the horse Equus caballus L. have been studied. On the basis of phenogroup analysis, models describing the formation of the complex allele spectra of these systems and reflecting the contributions of mutations and recombinations have been constructed. The complementary relationships between the antigens determined by the variants of supergenes within the systems, as ell as the probable number and relative positions of the subloci encoding individual groups of antigens in them, have been dete...
Stock KF, Distl O, Hoeschele I.Requirements for successful implementation of multivariate animal threshold models including phenotypic and genotypic information are not known yet. Here simulated horse data were used to investigate the properties of multivariate estimators of genetic parameters for categorical, continuous and molecular genetic data in the context of important radiological health traits using mixed linear-threshold animal models via Gibbs sampling. The simulated pedigree comprised 7 generations and 40000 animals per generation. Additive genetic values, residuals and fixed effects for one continuous trait and ...
Sá e Silva M, da Costa MM, de Avila Botton S, Barretta C, Groff AC, de Vargas AC.Strangles is an acute and contagious disease characterized by inflammation of the upper respiratory tract of horses. The etiological agent of strangles is the bacteria S. equi subsp. equi, which belongs to the Lancefield group C. Opportunistic agents from the same group are frequently isolated from horses with strangles and may induce mistaken diagnoses. Among the subspecies of S. equi, the phenotypic features are almost undistinguishable; however, the pathogenic potential is widely differentiated. The aim of this study was to characterize S. equi isolates obtained from clinical samples of str...
Benachour N, Sipahutar H, Moslemi S, Gasnier C, Travert C, Séralini GE.Roundup is the major herbicide used worldwide, in particular on genetically modified plants that have been designed to tolerate it. We have tested the toxicity and endocrine disruption potential of Roundup (Bioforce on human embryonic 293 and placental-derived JEG3 cells, but also on normal human placenta and equine testis. The cell lines have proven to be suitable to estimate hormonal activity and toxicity of pollutants. The median lethal dose (LD(50)) of Roundup with embryonic cells is 0.3% within 1 h in serum-free medium, and it decreases to reach 0.06% (containing among other compounds 1.2...
Behl R, Behl J, Gupta N, Gupta SC.The genetic relationships of five Indian horse breeds, namely Marwari, Spiti, Bhutia, Manipuri and Zanskari were studied using microsatellite markers. The DNA samples of 189 horses of these breeds were amplified by polymerase chain reaction using 25 microsatellite loci. The total number of alleles varied from five to 10 with a mean heterozygosity of 0.58 ± 0.05. Spiti and Zansakari were the most closely related breeds, whereas, Marwari and Manipuri were most distant apart with Nei's DA genetic distance of 0.071 and 0.186, respectively. In a Nei's DA genetic distances based neighbour joining...
Sato T, Itou T, Sato G, Kobayashi Y, Endo H, Sakai T.In order to investigate the utilization of glucose in equine skeletal muscle, we determined the coding and proximal promoter sequences of the hexokinase type II (HKII) gene in thoroughbred horse, Grevy's zebra and Hartmann's mountain zebra. The deduced amino acid sequence of thoroughbred horse HKII showed 100, 100, 94.4, 92.7 and 92.6% identities with Grevy's zebra, Hartmann's mountain zebra, human, mouse and rat HKIIs, respectively. In equine HKIIs, specific amino acid substitutions, Ile 159 and Arg 610, were found in the potential binding site for glucose. In addition, the nucleotide sequenc...
Mömke S, Distl O.The mammalian ATP2A2 gene encodes a P-type cation pump located in the sarcoplasmic or endoplasmic reticula of muscle cells. We isolated one bacterial artificial chromosome (BAC) clone containing the equine ATP2A2 gene and determined the complete coding sequence of this gene. Cloning and characterization of the equine ATP2A2 gene revealed that the equine ATP2A2 gene consists of 20 exons. In total, 32 horses out of 16 breeds were analyzed for single nucleotide polymorphisms (SNPs). A mutation scan for SNPs included ten exons and their flanking introns. We detected in total 17 SNPs, 14 of which w...
Mucher E, Jayr L, Rossignol F, Amiot F, Gidrol X, Barrey E.Progress could be achieved by using microarrays to understand metabolic adaptations and disorders in equine muscle in response to exercise. Objective: To test the feasibility of using mouse cDNA microarrays to analyse gene expression profile in normal equine muscles. Methods: Muscular biopsies of dorsal gluteus medius and longissimus lumborum were done in 4 healthy Standardbreds. Total RNA was extracted from the muscle samples. The concentration and quality of RNA were measured before and after amplification. Gene expression profiles were measured using mouse cDNA microarrays including 15,264 ...
Barrey E, Mucher E, Robert C, Amiot F, Gidrol X.Genomics using cDNA microarrays could provide useful information about physiological adaptations and metabolic disorders in endurance horses. Objective: In order to show that genes are modulated in leucocytes in relationship with performance and clinical status of the horses, gene expression in leucocytes, haematological and biochemical parameters were compared between successful and disqualified endurance horses. Methods: Blood samples were collected at rest (TO) and just after a 140-160 km endurance race (T1) in 2 groups of horses: 10 continuing successful (S) and 10 disqualified horses stop...
Miclo L, Girardet JM, Egito AS, Mollé D, Martin P, Gaillard JL.Highly phosphorylated casein with a low molecular mass was isolated from Haflinger mare's milk by RP-HPLC. It accounts for 4.0% of the casein content. Its mass was determined by LC-ESI-MS before and after treatment by alkaline phosphatase. The molecular mass found for the apo-form (10,591 +/- 2 Da) is in agreement with its primary structure, which was established by ESI-MS/MS from tryptic peptides. It appeared that this short protein (94 amino acid residues) is an internally truncated form of the full-length equine beta-casein (226 residues). This low-Mr variant of equine beta-casein displays ...
Tiyawisutsri R, Holden MT, Tumapa S, Rengpipat S, Clarke SR, Foster SJ, Nierman WC, Day NP, Peacock SJ.The bacterial biothreat agents Burkholderia mallei and Burkholderia pseudomallei are the cause of glanders and melioidosis, respectively. Genomic and epidemiological studies have shown that B. mallei is a recently emerged, host restricted clone of B. pseudomallei. Results: Using bacteriophage-mediated immunoscreening we identified genes expressed in vivo during experimental equine glanders infection. A family of immunodominant antigens were identified that share protein domain architectures with hemagglutinins and invasins. These have been designated Burkholderia Hep_Hag autotransporter (BuHA)...
Groot MT, Merkx M, Koper MT.The redox properties of horse and yeast cytochrome c electrostatically immobilized on carboxylic acid-terminated self-assembled monolayers (SAMs) have been determined over a broad pH range (pH 3.5-8) in the absence and presence of nitric oxide. Below pH 6, both proteins exhibit comparable midpoint potentials, coverages, and electron-transfer rate constants, which suggests that they are adsorbed on the SAM in a similar fashion. Above pH 6, a sharp decrease in electron-transfer rate constants is observed for immobilized yeast cytochrome c, which is indicative of a change in the electron tunnelin...
Tozaki T, Hirota K, Hasegawa T, Ishida N, Tobe T.The identification of candidate genes for significant traits is crucial. In this study, we developed and tested effective and systematic methods based on linkage disequilibrium (LD) for the identification of candidate regions for genes with Mendelian inheritance and those associated with complex traits. Our approach entailed the combination of primary screening using pooled DNA samples based on DeltaTAC, secondary screening using an individual typing method and tertiary screening using a permutation test based on the differences in the haplotype frequency between two neighbouring microsatellit...
Green RD, Qureshi MA, Long JA, Burfening PJ, Hamernik DL.Agricultural animal research has been immensely successful over the past century in developing technology and methodologies that have dramatically enhanced production efficiency of the beef, dairy, swine, poultry, sheep, and aquaculture industries. In the past two decades, molecular biology has changed the face of agricultural animal research, primarily in the arena of genomics and the relatively new offshoot areas of functional genomics, proteomics, transcriptomics, metabolomics and metagenomics. Publication of genetic and physical genome maps in the past 15 years has given rise to the possib...
Vo AT, van Duijkeren E, Fluit AC, Gaastra W.To investigate the genotypic resistance of integron-carrying Salmonella Typhimurium isolates from horses and their genetic relationship. Methods: Sixty-one Salmonella isolates were screened for the presence of class 1 integrons by PCR. The gene cassettes of integron-positive isolates were detected by PCR, restriction fragment length polymorphism typing, and sequencing. The potential for the transfer of resistance determinants was investigated by conjugation experiments. The presence of Salmonella genomic island 1 (SGI1) or its variants was studied by PCR and nucleotide sequencing. PFGE was use...
Brown KA, Sayasith K, Bouchard N, Lussier JG, Sirois J.The type 1 form of 17beta-hydroxysteroid dehydrogenase (17betaHSD1) was the first isoform to be identified and is capable of converting estrone to 17beta-estradiol. This study was aimed at characterizing the molecular structure of the equine 17betaHSD1 gene and cDNA, as well as its molecular regulation during human chorionic gonadotropin (hCG)-induced follicular luteinization/ovulation in vivo. The equine 17betaHSD1 gene was cloned from an equine genomic library and shown to have a conserved genomic structure composed of six exons. Its cDNA sequence was also identified and coded for a 308 amin...
Johannessen MK, Skretting G, Ytrehus B, Røed KH.Endochondral bone formation is an important process in development and growth of the skeleton; still many of the mechanisms of growth cartilage remain unknown. The aim of this study was to identify genes specifically expressed in growth cartilage by constructing a subtraction cDNA library of the articular-epiphyseal cartilage complex from neonatal foal. Two hundred and eighty-four differently expressed clones, representing five novel and 37 known genes, were detected by subtraction hybridization. The tissue specificity of these genes was verified by reverse Northern analysis, and tissue distri...
Tozaki T, Swinburne J, Hirota K, Hasegawa T, Ishida N, Tobe T.Genetic maps are extremely important tools for tracing the genes that govern economically significant traits, and microsatellites are a significant component of these. In this study, we isolated 2346 novel horse microsatellites as resources for the construction of high-density horse genetic maps. Of these 2346 markers, 339 (14.5%) horse sequences showed sequence homology to DNA sequences in the human genome, demonstrating that microsatellites as type II markers are valuable resources for developing linkage maps and that they have a potential equal to that of type I markers for developing compa...
Luís C, Bastos-Silveira C, Costa-Ferreira J, Cothran EG, Oom MM.A common female founder individual of the Portuguese horse breeds Sorraia and Lusitano was found while conducting research on the variation of the Lusitano mitochondrial DNA lineages in relation to studbook information. We obtained 416-bp control region sequences from 16 descendents of a female Sorraia founder (Pomba) still represented in the living population of the Lusitano, according to the most recent edition of this breed's studbook. The same haplotype was found for all analysed samples and belongs to the haplogroup described by several authors as having predominantly Iberian, South Ameri...
Mömke S, Distl O.The mammalian ATP2A2 gene encodes a P-type cation pump located in the sarcoplasmic or endoplasmic reticula of muscle cells. We isolated one bacterial artificial chromosome (BAC) clone containing the equine ATP2A2 gene and determined the complete coding sequence of this gene. Cloning and characterization of the equine ATP2A2 gene revealed that the equine ATP2A2 gene consists of 20 exons. In total, 32 horses out of 16 breeds were analyzed for single nucleotide polymorphisms (SNPs). A mutation scan for SNPs included ten exons and their flanking introns. We detected in total 17 SNPs, 14 of which w...
Mentoor JL, Lubisi AB, Gerdes T, Human S, Williams JH, Venter M.We report here the complete genome sequence of a lineage 2 West Nile virus (WNV) strain that resulted in fatal neurological disease in a horse in South Africa. Several recent reports exist of neurological disease associated with lineage 2 WNV in humans and horses in South Africa and Europe; however, there are a lack of sequencing data from recent fatal cases in Southern Africa, where these strains likely originate. A better understanding of the genetic composition of highly neuroinvasive lineage 2 strains may facilitate the identification of putative genetic factors associated with increased v...
Gim JA, Kim HS.Endogenous retroviruses (ERVs) have been integrated into vertebrate genomes and have momentously affected host organisms. Horses () have been domesticated and selected for elite racing ability over centuries. ERVs played an important role in the evolutionary diversification of the horse genome. In the present study, we identified six equine ERV families (EqERVs-E1, I1, M2, P1, S1, and Y4), their full-length viral open reading frames (ORFs), and elucidated their phylogenetic relationships. The divergence time of EqERV families assuming an evolutionary rate of 0.2%/Myr indicated that EqERV-S3 (7...
Raudsepp T, Chowdhary BP.Whole chromosome paints for human (HSA) chromosomes 9, 12, 15 and 20 and arm-specific paints for HSA16p, 19p and 19q were applied on donkey metaphase spreads. All probes, except HSA19p, gave distinct hybridization signals on donkey chromosomes/chromosomal segments. The results show direct segmental homology between human and donkey genomes, and enable refinement of correspondence between donkey and horse karyotypes. Of specific interest is the identification of hitherto unknown correspondence between four equine acrocentric chromosomes (ECA22, 23, 25 and 28) and the donkey chromosomes. Overall...
Gaudaire D, Lazić S, Lupulović D, Petrovic T, Lazić G, Berthet N, Hans A.Here, we report the first whole-genome sequence of an equine arteritis virus (EAV) strain, RS1, isolated from the semen of a Lipizzaner stallion held in the Vojvodina region of Serbia.
May CE, Schulman ML, Howell PG, Lourens CW, Gouws J, Joone C, Monyai MS, le Grange M, Bezuidt OK, Harper CK, Guthrie AJ.Taylorella equigenitalis is the causative agent of contagious equine metritis (CEM), a sexually transmitted infection of horses. We report here the genome sequence of T. equigenitalis strain ERC_G2224, isolated in 2015 from a semen sample collected in 1996 from a Lipizzaner stallion in South Africa.
Pierrot M, Astier JP, Astier M, Charles M, Drenth J.A detailed study of the crystallization of hog and horse colipases has been undertaken. Several crystallographic varieties have been obtained and a 0.3-nm resolution structure determination is actually in progress. The sequence of the A form of horse colipase (one methionine) is given. From spectrophotometric experiments and sequence comparisons, the involvement of the aromatic residue in position 52 in the micelle binding site has been demonstrated.
Solberg OD, Jackson KA, Millon LV, Stott JL, Vandenplas ML, Moore JN, Watson JL.Three overlapping fragments of the equine interleukin-4 receptor alpha chain gene (IL4R) were cloned and sequenced. The resulting 3553 bp cDNA sequence exhibited homology to human, murine and bovine IL4R. The equine IL4R exhibits many conserved features when compared to other species, including intron-exon boundary positions and amino acid sequence motifs characteristic of type I cytokine receptors. The IL4R gene was localized to horse chromosome ECA13 by synteny mapping on a somatic cell hybrid panel. Evidence for an alternative splice variant of IL4R was found in the genomic sequence and sub...
Li JK, Moloney BK, Shupe JL, Gardner EJ, Leone NC, Elsner Y.Genomic DNA polymorphisms obtained by restriction fragment-length polymorphism from healthy horses and horses with hereditary multiple exostoses were analyzed. These DNA were digested by 12 restriction enzymes and were hybridized against 6 isotopically labeled oncogene probes. Hybridization was not detected with the viral oncogene, v-ras, which indicated this oncogene was absent in the equine genome. Oncogenes (c-raf-1, c-fes, c-myb, c-myc, and c-sis) were present and had similar hybridization patterns and signal intensities in DNA from healthy horses and horses with hereditary multiple exosto...
Cothran EG, van Dyk E.Genetic variability at 7 blood-group and 10 biochemical genetic loci was examined in 3 South African horse breeds, the Nooitgedacht, Boerperd and Basuto Pony. Observed heterozygosity for these breeds was intermediate for domestic horses, with the highest heterozygosity in the Boerperd and the lowest in the Basuto Pony. The 3 breeds show greater genetic similarity to each other than to other domestic horse breeds. Compared to other breeds, the South African breeds show greater genetic similarity to breeds such as the Thoroughbred, Holstein, Trakehner and Hanovarian and also to North American br...
Na W, Hong M, Yeom M, Kim S, Kim JK, Song D.We analyzed the complete genome sequence containing the 3' and 5' noncoding regions (NCRs) of the Korean H3N8 equine influenza virus (EIV), which will provide a better understanding of the pathogenesis, transmission, and evolution of EIV.