Phenotype in horses refers to the observable physical and behavioral traits of an individual horse, which result from the interaction of its genetic makeup and environmental influences. These traits include characteristics such as coat color, height, conformation, and temperament. Phenotypic expression is a focal point in equine breeding and management, as it influences performance, health, and suitability for specific disciplines. Research in this area examines the genetic basis of phenotypic traits, the impact of environmental factors, and the interaction between genetics and environment. This page aggregates peer-reviewed research studies and scholarly articles that explore the genetic determinants, environmental effects, and practical implications of phenotypic traits in horses.
Cook D, Brooks S, Bellone R, Bailey E.Champagne coat color in horses is controlled by a single, autosomal-dominant gene (CH). The phenotype produced by this gene is valued by many horse breeders, but can be difficult to distinguish from the effect produced by the Cream coat color dilution gene (CR). Three sires and their families segregating for CH were tested by genome scanning with microsatellite markers. The CH gene was mapped within a 6 cM region on horse chromosome 14 (LOD = 11.74 for theta = 0.00). Four candidate genes were identified within the region, namely SPARC [Secreted protein, acidic, cysteine-rich (osteonectin)], SL...
Gerber V, Swinburne JE, Blott SC, Nussbaumer P, Ramseyer A, Klukowska-Rötzler J, Dolf G, Marti E, Burger D, Leeb T.Recurrent airway obstruction (RAO) is a multifactorial and polygenic disease. Affected horses are typically 7 years of age or older and show exercise intolerance, increased breathing effort, coughing, airway neutrophilia, mucus accumulation and hyperreactivity as well as cholinergic bronchospasm. The environmental factors responsible are predominantly allergens and irritants in haydust, but the immunological mechanisms underlying RAO are still unclear. Several studies have demonstrated a familiar predisposition for RAO and it is now proven that the disease has a genetic basis. In offspring, th...
Rosengren Pielberg G, Golovko A, Sundström E, Curik I, Lennartsson J, Seltenhammer MH, Druml T, Binns M, Fitzsimmons C, Lindgren G, Sandberg K....In horses, graying with age is an autosomal dominant trait associated with a high incidence of melanoma and vitiligo-like depigmentation. Here we show that the Gray phenotype is caused by a 4.6-kb duplication in intron 6 of STX17 (syntaxin-17) that constitutes a cis-acting regulatory mutation. Both STX17 and the neighboring NR4A3 gene are overexpressed in melanomas from Gray horses. Gray horses carrying a loss-of-function mutation in ASIP (agouti signaling protein) had a higher incidence of melanoma, implying that increased melanocortin-1 receptor signaling promotes melanoma development in Gra...
Haase B, Jude R, Brooks SA, Leeb T.The tobiano white-spotting pattern is one of several known depigmentation phenotypes in horses and is desired by many horse breeders and owners. The tobiano spotting phenotype is inherited as an autosomal dominant trait. Horses that are heterozygous or homozygous for the tobiano allele (To) are phenotypically indistinguishable. A SNP associated with To had previously been identified in intron 13 of the equine KIT gene and was used for an indirect gene test. The test was useful in several horse breeds. However, genotyping this sequence variant in the Lewitzer horse breed revealed that 14% of ho...
Sparks WO, Dorman KS, Liu S, Carpenter S.Equine infectious anemia virus (EIAV) exhibits a high rate of genetic variation in vivo, and results in a clinically variable disease in infected horses. In vivo populations of EIAV have been characterized by the presence of distinct, genetic subpopulations of Rev that differ in phenotype and fluctuate in dominance in a manner coincident with each clinical stage of disease. This study examined the specific mutations that arose in vivo and altered the phenotype. The Rev protein was found to be highly conserved, and only 10 aa mutations were observed at a frequency greater than 10 % in the sampl...
Garvican ER, Vaughan-Thomas A, Redmond C, Clegg PD.Our objective was to characterize the variation in gene expression for key genes associated with chondrogenic phenotype of osteochondrosis (OC)-affected and normal chondrocytes, and to identify whether OC chondrocytes can redifferentiate and regain a phenotype similar to normal chondrocytes if appropriate chondrogenic signals are given. Equine articular cartilage removed at surgery to treat clinically significant OC lesions was collected (n = 10), and the gene expression evaluated and compared to aged-matched normal samples (n = 10). Cartilage was harvested from normal (n = 4) and OC (n = 3) j...
The Journal of heredityFebruary 21, 2008
Volume 99, Issue 2 130-136 doi: 10.1093/jhered/esm115
Rieder S, Hagger C, Obexer-Ruff G, Leeb T, Poncet PA.White markings and spotting patterns in animal species are thought to be a result of the domestication process. They often serve for the identification of individuals but sometimes are accompanied by complex pathological syndromes. In the Swiss Franches-Montagnes horse population, white markings increased vastly in size and occurrence during the past 30 years, although the breeding goal demands a horse with as little depigmented areas as possible. In order to improve selection and avoid more excessive depigmentation on the population level, we estimated population parameters and breeding value...
Back W, van der Lugt JJ, Nikkels PG, van den Belt AJ, van der Kolk JH, Stout TA.An extreme form of abnormal development, dwarfism, is common in man and some animals, but has not been officially reported in horses. Within the Friesian horse breed, congenital dwarfism has been recognised for many years, but no detailed report exists on its phenotype. The most salient feature of the dwarf syndrome is the physeal growth retardation in both limbs and ribs. Affected animals have approximately 25% shorter fore- and hindlimbs and approximately 50% reduced bodyweight. Postnatal growth is still possible in these animals, albeit at a slower rate: the head and back grow faster than t...
Stock KF, Distl O, Hoeschele I.Simulated data were used to determine the properties of multivariate prediction of breeding values for categorical and continuous traits using phenotypic, molecular genetic and pedigree information by mixed linear-threshold animal models via Gibbs sampling. Simulation parameters were chosen such that the data resembled situations encountered in Warmblood horse populations. Genetic evaluation was performed in the context of the radiographic findings in the equine limbs. The simulated pedigree comprised seven generations and 40 000 animals per generation. The simulated data included additive gen...
Negri S, Fila C, Farinato S, Bellomi A, Pagliaro PP.The scope of our study is to evaluate the possibility of cultivating and expanding human chondrocytes and seeding them on pure equine type I collagen support. Our results show that human articular cartilaginous cells can multiply and grow on type I collagen substrate with production of extracellular matrix. This type of chondrocyte culture on a support can be used for repairing cartilaginous lesions since they show a correct morphology (evaluated by cytological and histological methods) and a suitable differentiation and phenotype as shown by Alcian PAS staining to indicate the presence of muc...
Haase B, Brooks SA, Schlumbaum A, Azor PJ, Bailey E, Alaeddine F, Mevissen M, Burger D, Poncet PA, Rieder S, Leeb T.White coat color has been a highly valued trait in horses for at least 2,000 years. Dominant white (W) is one of several known depigmentation phenotypes in horses. It shows considerable phenotypic variation, ranging from approximately 50% depigmented areas up to a completely white coat. In the horse, the four depigmentation phenotypes roan, sabino, tobiano, and dominant white were independently mapped to a chromosomal region on ECA 3 harboring the KIT gene. KIT plays an important role in melanoblast survival during embryonic development. We determined the sequence and genomic organization of t...
Vidal MA, Kilroy GE, Lopez MJ, Johnson JR, Moore RM, Gimble JM.To characterize equine adipose tissue-derived stromal cell (ASC) frequency and growth characteristics and assess of their adipogenic and osteogenic differentiation potential. Methods: In vitro experimental study. Methods: Horses (n=5; aged, 9 months to 5 years). Methods: Cell doubling characteristics of ASCs harvested from supragluteal subcutaneous adipose tissue were evaluated over 10 passages. Primary, second (P2), and fourth (P4) passage ASCs were induced under appropriate conditions to undergo adipogenesis and osteogenesis. Limit dilution assays were performed on each passage to determine ...
Ewart SL, Robinson NE.This review highlights the critical importance of phenotype definition in the understanding of the pathogenesis of respiratory disease in horses. The general approach to genetic studies is discussed and comparative studies of recurrent airway obstruction (RAO) conditions, such as asthma, described in the context of learning more about equivalent equine conditions. The availability of methods to study genetic tests have previously relied on DNA sequence knowledge from man, laboratory and domesticated animals, but recent data from the horse genome sequence are now available. This should facilita...
Vashisht K, Rock RW, Summers BA.A 5-year-old National Show horse mare presented with a soft mass on the left dorsolateral aspect of the tongue. Over the next 2 years, the mare developed numerous, similar, coalescing masses that extended along the left dorsolateral aspect to the tip of the tongue. Microscopically, the bases for these masses were slender, fusiform, mesenchymal cells that formed compact whorls around myelinated and unmyelinated nerves. These cells were labeled by antibodies directed against vimentin but not by S-100. Ultrastructurally, multiple, concentrically arranged, long, slender cell processes, with discon...
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...
Reissmann M, Bierwolf J, Brockmann GA.In horses, a pigment dilution acting only on black eumelanin is the so-called silver coat colour, which is characterized by a chocolate-to-reddish body with a white mane and tail. Using information from other species, we focused our study on SILV as a possible candidate gene for the equine silver phenotype. A 1559-bp genomic fragment was sequenced in 24 horses, and five SNPs were detected. Two of the five SNPs (DQ665301:g.697A>T and DQ665301:g.1457C>T) were genotyped in 112 horses representing eight colour phenotypes. Both mutations were completely associated with the silver phenotype: all eum...
Santschi EM, Leibsle SR, Morehead JP, Prichard MA, Clayton MK, Keuler NS.There is little information available about conformational changes in the forelimbs of growing foals. Objective: To describe the conformation of the carpus and fetlock of Thoroughbred foals from birth to yearling sale age. Methods: Subjective assessments of the fetlock and carpal conformation of 119 Thoroughbred foals were made within the first month of life and then at 30 day intervals until at least age 120 days. At least 70 subjects were examined further at 60 day intervals until September of their second year. Conformation grades are reported for 5 age groups: first 7 days and at a mean of...
Górecka A, Słoniewski K, Golonka M, Jaworski Z, Jezierski T.There are studies on the relationship between the position and shape of hair whorls on bovine forehead and phenotypic traits. According to anecdotal beliefs by horse users and handlers, temperamental traits may be related to the position of hair whorls in horses. No previous research on the mechanisms of inheritance of hair whorls has been performed, so the aim of the present study was to determine the heritability of the position of the hair whorl on the forehead of Konik horses. The horses (n = 362) were classified into five groups based on the whorl position on forehead with respect to the ...
Brunberg E, Andersson L, Cothran G, Sandberg K, Mikko S, Lindgren G.The Silver coat color, also called Silver dapple, in the horse is characterized by dilution of the black pigment in the hair. This phenotype shows an autosomal dominant inheritance. The effect of the mutation is most visible in the long hairs of the mane and tail, which are diluted to a mixture of white and gray hairs. Herein we describe the identification of the responsible gene and a missense mutation associated with the Silver phenotype. Results: Segregation data on the Silver locus (Z) were obtained within one half-sib family that consisted of a heterozygous Silver colored stallion with 34...
Li X, Zhou SG, Imreh MP, Ahrlund-Richter L, Allen WR.Inner cell mass (ICM) cells were isolated immunosurgically from day 7-8 horse blastocysts and, after proliferation in vitro for 15-28 passages, three lines of cells were confirmed to be embryonic stem (ES) cells by their continued expression of alkaline phosphatase activity and their ability to bind antisera specific for the recognized stem cell markers, SSEA-1, TRA-1-60, TRA-1-81, and the key embryonic gene Oct-4. When maintained under feeder cell-free conditions in vitro, the three lines of cells differentiated into cells of ectodermal, endodermal, and mesodermal lineages. However, they did ...
Toth Z, Kaps M, Sölkner J, Bodo I, Curik I.The aim of this study was to estimate genetic parameters for coat color in horses. Besides defining coat color classes (gray, chestnut, bay, and black), the phenotypes were also measured quantitatively according to standardized international procedures (Commission Internationale de l'Eclairage L*, a*, b*), where L* describes lightness, a* describes color saturation from red to green, and b* describes color saturation from yellow to blue. The total color saturation was derived from a* and b* and referred to as Chroma. A total of 294 horses from the breeds Lipizzan, Nonius, Arabian Pure Bred, Sh...
Christensen H, Hommez J, Olsen JE, Bisgaard M.To investigate if taxon 42 of Bisgaard isolated from pigs represents genuine [Pasteurella] caballi, which was previously only isolated from horses. Results: A total of 15 field isolates from horses and pigs from five different countries representing three continents were subjected to extended phenotypical characterization. Although minor differences were observed between taxon 42 and [P.] caballi, these differences did not allow phenotypic separation. Ribotyping based on HindIII digestion showed five profiles based on nine band positions. One [P.] caballi strain and two taxon 42 strains shared...
Anderson MA, Whitlock JE, Harwood VJ.Escherichia coli is the most completely characterized prokaryotic model organism and one of the dominant indicator organisms for food and water quality testing, yet comparatively little is known about the structure of E. coli populations in their various hosts. The diversities of E. coli populations isolated from the feces of three host species (human, cow, and horse) were compared by two subtyping methods: ribotyping (using HindIII) and antibiotic resistance analysis (ARA). The sampling effort required to obtain a representative sample differed by host species, as E. coli diversity was consis...
Dranchak PK, Valberg SJ, Onan GW, Gallant EM, Binns MM, Swinburne JE, Mickelson JR.To determine whether there was genetic linkage between the recurrent exertional rhabdomyolysis (RER) trait in Thoroughbred horse pedigrees and DNA markers in genes (the sarcoplasmic reticulum calcium release channel [RYR1] gene, the sarcoplasmic reticulum calcium ATPase [ATP2A1] gene, and the transverse tubule dihydropyridine receptor-voltage sensor [CACNA1S] gene) that are important in myoplasmic calcium regulation. Methods: 34 horses in the University of Minnesota RER resource herd and 62 Thoroughbreds from 3 families of Thoroughbreds outside of the university in which RER-affected status wa...
Young AE, Bower LP, Affolter VK, De Cock HE, Ferraro GL, Bannasch DL.Chronic progressive lymphedema (CPL) is a debilitating condition identified in Clydesdales, Shires and Belgian draft horses and results in progressive swelling of the lower legs associated with the development of thick skin folds, ulcerations, fibrosis and marked hyperkeratosis. The result is severe discomfort and recurrent secondary infection, often requiring euthanasia. Due to the delayed onset, many horses are bred prior to diagnosis. CPL has only been documented in three related draft horse breeds, suggesting a genetic cause. Determining the molecular basis would enable owners to test hors...
Wolc A, Bresińska A, Szwaczkowski T.Twinning is a serious problem in Thoroughbred horses, as most of the multiple pregnancies are miscarried and live foals present lower performance values. The aim of this study was to estimate the heritability and repeatability of twinning in Thoroughbred horses. A total of 12648 pregnancies of 2033 Thoroughbred mares born between 1929 and 1994 in 11 studs were included. The analysis was performed by the use of AI-REML algorithm under three threshold animal models. The first model included effects of stud, mare's birth period and interaction between them as fixed. The second model included the ...
Bannasch D, Rinaldo C, Millon L, Latson K, Spangler T, Hubberty S, Galuppo L, Lowenstine L.A female American saddlebred horse was presented for surgical correction of a possible pseudohermaphrodite condition. The horse had abnormal external genitalia and exhibited stallion-like behaviour. No evidence of uterine or ovarian tissue was identified on laparoscopic examination, but hypoplastic testicular-like tissue was removed, although this was found to contain no spermatogonia upon histopathological examination. A karyotype was performed and showed the normal chromosomal complement for a female horse (64,XX). Polymerase chain reaction to detect the SRY gene was negative in peripheral b...
Brooks SA, Bailey E.Sabino (SB) is a white spotting pattern in the horse characterized by white patches on the face, lower legs, or belly, and interspersed white hairs on the midsection. Based on comparable phenotypes in humans and pigs, the KIT gene was investigated as the origin of the Sabino phenotype. In this article we report the genetic basis of one type of Sabino spotting pattern in horses that we call Sabino 1, with the alleles represented by the symbols SB1 and sb1. Transcripts of KIT were characterized by reverse transcriptase polymerase chain reaction (RT-PCR) and sequencing cDNA from horses with the g...
The Journal of heredityOctober 26, 2005
Volume 96, Issue 6 663-669 doi: 10.1093/jhered/esi116
Royo LJ, Alvarez I, Beja-Pereira A, Molina A, Fernández I, Jordana J, Gómez E, Gutiérrez JP, Goyache F.Despite a number of recent studies that have focused on the origin of domestic horses, genetic relationships between major geographical clusters still remain poorly understood. In this study we analyzed a 296 bp mtDNA fragment from the HVI region of 171 horses representing 11 native Iberian, Barb, and Exmoor breeds to assess the maternal phylogeography of Iberian horses. The mtDNA haplogroup with a CCG motif (nucleotide position 15,494 to 15,496) was the most frequent in Iberian and Barb breeds (0.42 and 0.57, respectively), regardless of geographic location or group of breeds. This finding su...
Meiseberg LK, Delarocque J, de Buhr N, Ohnesorge B.Equine asthma is a common, non-infectious, chronic lung disease that affects up to 80% of the horse population. Strict phenotyping and identification of subclinically asthmatic horses can be challenging. The aim of this study was to describe equine asthma phenotypes (mild, moderate, and severe asthma) defined by BALF cytology and occurrence of clinical signs in a population of privately owned horses and to identify the variables and examination steps with best discriminative potential. The standardised examination protocol included clinical examinations, blood work, airway endoscopy with bronc...
Murakami M, Shimonishi Y, Hobo S, Niwa H, Ito H.We describe here the first isolation of Actinobacillus genomospecies 2 in Japan. The isolate was found in a septicemic foal and characterized by phenotypic and genetic analyses, with the latter consisting of 16S rDNA nucleotide sequence analysis plus multilocus sequence analysis using three housekeeping genes, recN, rpoA and thdF, that have been proposed for use as a genomic tool in place of DNA-DNA hybridization.
Rodgerson DH, Belknap JK, Fontaine GL, Kroll DL.To develop methods to isolate, culture, and characterize smooth muscle cells (SMC) from equine palmar digital arteries. Methods: Segments of the medial or lateral palmar digital arteries from the forelimbs of 6 horses. Methods: To obtain smooth muscle explants, arterial segments were incised longitudinally. The tunica intima was gently scraped from the underlying tunica media, and explants were obtained from the tunica media. Approximately 18 to 24 explants were obtained from each palmar digital arterial segment. A substrate-attached technique was used to initiate primary culture of SMCCulture...
Lindsay-McGee V, Massey C, Li YT, Clark EL, Psifidi A, Piercy RJ.Equine exercise-associated myopathies are prevalent, clinically heterogeneous, generally idiopathic disorders characterised by episodes of myofibre damage that occur in association with exercise. Episodes are intermittent and vary within and between affected horses and across breeds. The aetiopathogenesis is often unclear; there might be multiple causes. Poor phenotypic characterisation hinders genetic and other disease analyses. Objective: The aim of this study was to characterise phenotypic patterns across exercise-associated myopathies in horses. Methods: Historical cross-sectional study, w...
Weitkamp LR.Polymorphism of equine Gc protein was demonstrated by immunofixation electrophoresis with a goat anti-human Gc antibody. Three different phenotypes, F, FS and S, were found. Family data supported the genetic theory of two autosomal codominant alleles, GcF and GcS. Both alleles occurred in Standardbred, Thoroughbred and Arabian horses and in Shetland ponies. A frequency of 0.23 for GcS in the American Standardbred horse indicates the system should be useful for problems of identification and parentage.
Villagomez DAF, Welsford EG, King WA, Revay T.In the domestic horse; failure of normal masculinization and virilization due to deficiency of androgenic action leads to a specific disorder of sexual development known as equine androgen insensitivity syndrome (AIS). Affected individuals appear to demonstrate an incoherency between their genetic sex and sexual phenotype; i.e., XY-sex chromosome constitution and female phenotypic appearance. AIS is well documented in humans. Here we report the finding of two novel genetic variants for the AR-gene identified in a Tennessee Walking Horse and a Thoroughbred horse mare; each in individual clinica...
Bowling AT, Wictum E.A fourth allele at the horse erythrocyte phosphohexose isomerase (Phi) locus was proposed to account for phenotypes observed after starch gel electrophoresis and enzymatic staining of red cell lysates from American Saddlebred and Tennessee Walking Horse breeds. The gene was rare, having an estimated frequency of 0.009 in 949 Saddlebreds tested.
The Journal of heredityMay 1, 1989
Volume 80, Issue 3 173-178 doi: 10.1093/oxfordjournals.jhered.a110831
Woolf CM.The hypothesis was tested that white facial markings in the Arabian horse show multifactorial inheritance. The hypothesis assumes that (1) alleles at different loci acting in a cumulative manner influence the variation in white facial markings, (2) the amount of whiteness is correlated with the number of genes, and (3) interacting nongenetic factors influence the variation. The study was based on computerized data obtained from the Arabian Horse Registry of America, Inc. The facial region was divided into five areas, and each horse was given a score according to the number of areas with a whit...
The Journal of heredityJuly 1, 1978
Volume 69, Issue 4 214-216 doi: 10.1093/oxfordjournals.jhered.a108933
Trommershausen-Smith A.Genetic segregation patterns among blood type markers and various phenotypically observed traits were studied in a small herd of ponies. The herd consisted of 10 mares without white spotting and a single stallion with the dominant pattern of tobiano spotting. Comparison of segregation patterns at loci for which the stallion was heterozygous showed tight linkage for the Alb-B and tobiano markers. In 17 cases in which the Alb contribution of the sire could be determined, all 10 foals that inherited AlbB from him were tobiano spotted, and all 7 non-spotted foals inherited his AlbA. The use of the...
Nakamura K, Tozaki T, Kakoi H, Owada S, Takasu M.Kiso horse is a breed of Japanese native horses. In this study, to clarify coat color gene variation in Kiso horses, we used SNaPshot™ genotyping to evaluate variation in MC1R, ASIP, and MATP genes at the Extension (E), Agouti (A), and Cream dilution (C) loci. The coat color of 149 horses was documented. The coat color of 140, 3, and 6 horses was bay, chestnut, and buckskin, respectively. Furthermore, the frequency of alleles E, e, A, a, C, and Cr was 0.80, 0.20, 0.86, 0.14, 0.98, and 0.02, respectively. Current status of coat color genes in Kiso horses was clarified, and this information wi...
Suontama M, van der Werf JH, Juga J, Ojala M.Heritability and repeatability and genetic and phenotypic correlations were estimated for trotting race records with linear and generalized linear models using 510,519 records on 17,792 Finnhorses and 513,161 records on 25,536 Standardbred trotters. Heritability and repeatability were estimated for single racing time and earnings traits with linear models, and logarithmic scale was used for racing time and fourth-root scale for earnings to correct for nonnormality. Generalized linear models with a gamma distribution were applied for single racing time and with a multinomial distribution for si...
Roy MM, Norton EM, Rendahl AK, Schultz NE, McFarlane D, Geor RJ, Mickelson JR, McCue ME.An 11G nucleotide repeat in the 3' UTR of FAM174A was recently postulated as a risk allele with a dominant mode of inheritance for equine metabolic syndrome (EMS) and laminitis status in Arabian horses. The objective of this project was to evaluate this hypothesis in a large and diverse across-breed population. A total of 301 ponies, 292 Morgans, 64 Arabians, 49 Tennessee Walking Horses and 59 Quarter Horses were genotyped for six observed G repeat alleles in the FAM174A 3' UTR. Phenotype data included laminitis status, baseline insulin, glucose, non-esterified fatty acids, triglycerides, adip...
Zerbe H, Engelke F, Klug E, Schoon HA, Leibold W.An endometritis model was used to investigate the influence of degenerative endometrial changes (endometrosis) on functional parameters of uterine neutrophils in the horse. Six hours after intrauterine application of recombinant human interleukin-8 (rhIL-8), the uteri of 15 mares were flushed with phosphate-buffered saline. Quantitative and qualitative flow cytometric assays were then made to determine the absolute numbers, viability, phenotype, generation of reactive oxygen species (ROS), and phagocytic activity of immigrated polymorphonuclear neutrophilic granulocytes (PMN). Recombinant hIL-...
The Journal of heredityMay 1, 1978
Volume 69, Issue 3 146-148 doi: 10.1093/oxfordjournals.jhered.a108913
Adalsteinsson S.The coat colors of 161 progeny from matings between 10 yellow dun and 6 blue dun stallions and mares of 8 different colors are described. The results confirm the previous hypothesis that a dominant dilution gene, D, converts bay to yellow dun with dark mane and tail, chestnut to yellow dun and dun mane and tail, and black to blue dun (mouse, grullo). The palomino gene, c cr, on the other hand, is hypostatic to black and blue dun. In heterozygous form, c cr converts bay to buckskin, and chestnut and sorrel to palomino, and results in blue-eyed white when homozygous. No particular effect of D is...
Rooney MF, Neto NGB, Monaghan MG, Hill EW, Porter RK.Thoroughbred racehorse performance is largely influenced by a major quantitative trait locus at the () gene which determines aptitude for certain race distances due to a promoter region insertion mutation influencing functional phenotypes in skeletal muscle. To develop an system for functional experiments we established three novel equine skeletal muscle cell lines reflecting the variation in phenotype associated with genotype (CC/II, CT/IN and TT/NN for SNP g.66493737C > T/SINE insertion 227 bp polymorphism). Primary equine skeletal muscle myoblasts, isolated from Thoroughbred horse , we...
Ek N.Selected transferrin phenotypes from 14 horses were investigated by antigen-antibody crossed electrophoresis. Horse sera were subjected to starch gel electrophoresis followed by right angle electrophoresis in agarose gels containing rabbit produced anti-horse transferrin. This technique gave an additional zone in the front as compared with 2 transferrin zones seen after ordinary starch gel electrophoresis. Comparisons of transferrin concentrations in horse sera were performed by an immunodiffusion technique. Values were related to a chosen reference serum. A total of 372 horses (210 Norwegian ...
Brooks SA.The sheer diversity of heritable physiological traits, and the ingenuity of genome derived research technologies, extends the study of genetics to impact diverse scientific fields. Equine science is no exception, experiencing a number of genome-enabled discoveries that spur further research in areas like nutrition, reproduction, and exercise physiology. Yet unexpected findings, especially those that over-turn commonly held beliefs in the horse industry, can create challenges in outreach, education and communication with stakeholders. For example, studies of ancient DNA revealed that the oldest...
Klecel W, Drobik-Czwarno W, Martyniuk E.Arabian show horses are well known for their exceptional beauty and elegance. The breed type, body conformation and movement are assessed during horse shows by licensed judges. The 5 judging categories are type, head and neck, body and topline, legs and movement, which are scored on a 20 point scale. It can be hypothesized that the scores in different categories are related to each other, and that the score for the most subjective type category depends on the scores for conformation categories. We analyzed 762 sets of average scores obtained by 583 unique horses at the World Championships. Cor...
Basso RM, Andrade DGA, Alves CEF, Laufer-Amorim R, Borges AS, Oliveira-Filho JP.Dwarfism is a skeletal disorder that causes abnormal growth. In Miniature horses, dwarfism can occur as chondrodysplastic dwarfism, an autosomal recessive disorder associated with five mutations (D1, D2, D3*, D4 and c.6465A > T variant) in the aggrecan (ACAN) gene. The aim of this study was to evaluate the expression of aggrecan (at the gene and protein level) and specific cytokines (IL-1β, IL-6, and TNF-α) in the articular cartilage of Miniature horses with chondrodysplastic dwarfism (D4/c.6465A > T genotype). Metatarsal bone samples from eight dwarf Miniature horses were collected fo...
Larrasa J, Garcia A, Ambrose NC, Alonso JM, Parra A, de Mendoza MH, Salazar J, Rey J, de Mendoza JH.Dermatophilus congolensis is the pathogenic actinomycete that causes dermatophilosis in cattle, lumpy wool in sheep and rain scald in horses. Phenotypic variation between isolates has previously been described, but its genetic basis, extent and importance have not been investigated. Standard DNA extraction methods are not always successful for D. congolensis due to its complex life cycle, one stage of which is encapsulated. Here we describe the development of rapid and reliable DNA extraction and random amplified polymorphic DNA (RAPD) methods that can be used for genotyping D. congolensis fie...
Ghosh S, Kjöllerström J, Metcalfe L, Reed S, Juras R, Raudsepp T.We present cytogenetic and genotyping analysis of a Thoroughbred foal with congenital neurologic disorders and its phenotypically normal dam. We show that the foal has non-mosaic trisomy for chromosome 26 (ECA26) but normal 2n = 64 diploid number because two copies of ECA26 form a metacentric derivative chromosome der(26q;26q). The dam has normal 64,XX karyotype indicating that der(26q;26q) in the foal originates from errors in parental meiosis or post-fertilization events. Genotyping ECA26 microsatellites in the foal and its dam suggests that trisomy ECA26 is likely of maternal origin and tha...
Arias KD, Cervantes I, Gutiérrez JP.In genetic evaluation of horses, the genetic trend does not correspond into a phenotypic trend when using ranking as a phenotype due to its uniform distribution, and some other effects might be absorbing that trend. From a founder population, a further four discrete generations of 100 individuals were simulated under random mating. Then, ten additional discrete generations were simulated by selecting the best 10% of the animals. Likewise, an underlying variable with heritability 0.1 or 0.2, affected by an event environmental influence, generation and permanent environment, was simulated to est...
Kuiper H, Blum N, Distl O.In a 1.5-year-old Oldenburg horse, a clitoris-like structure instead of a penis was identified in the prepuce. The external genital organs did not show any abnormalities at visual inspection except that exteriorization of the penis was not possible, not even under general anesthesia. The horse's owner observed a continuous dripping of urine and a tendency to mild colics beginning 2 weeks after birth. Testosterone concentration was 0.01 ng/ml and therefore under the threshold for geldings, and the horse did not respond to the application of gonadotropin-releasing hormone (GnRH). The inner genit...
Anzai T, Timoney JE, Kuwamoto Y, Wada R, Oikawa M, Higuchi T.To develop polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis for molecular typing of strains of Streptococcus zooepidemicus and to use the new typing method to analyze a collection of isolates from the respiratory tract of Thoroughbreds. Methods: 10 strains of S zooepidemicus, 65 isolates from the respiratory tract of 9 yearlings following long distance transportation, and 89 isolates from tracheal aspirates of 20 foals with pneumonia. Methods: Phenotypic variations in the SzP protein were detected by western immunoblot analysis. Using PCR-RFLP analysis, ge...
Bastos MS, Solar Diaz IDP, Alves JS, de Oliveira LSM, de Araújo de Oliveira CA, de Godói FN, de Camargo GMF, Costa RB.The measurement of morphometric traits in horses is important for determining breed qualification and is one of the main selection criteria for the species. The development of an index (HPC) that consists of principal components weighted by additive genetic values allows to explore the most relevant relationships using a reduced number of variables that explain the greatest amount of variation in the data. Genome-wide association studies (GWAS) using HPC are a relatively new approach that permits to identify regions related to a set of traits. The aim of this study was to perform GWAS using HP...
Juneja RK, Andersson L, Sandberg K, Gahne B, Adalsteinsson S, Gunnarsson E.Two-dimensional agarose gel (pH 8.6)-horizontal polyacrylamide gel (pH 9.0) electrophoresis of horse serum proteins revealed genetic polymorphism of ceruloplasmin (Cp) and two unidentified serum proteins tentatively designated serum protein 1 (SP1) and serum protein 2 (SP2). Family data were consistent with the hypothesis that the observed Cp and SP1 phenotypes were each controlled by two codominant, autosomal alleles. The three common SP2 phenotypes were shown to be controlled by two codominant, autosomal alleles. Population data and limited family data indicated the occurrence of two additio...
Hendrickson DA, Nixon AJ, Erb HN, Lust G.Equine neonatal chondrocytes were cultured in three-dimensional fibrin matrices under conditions of immediate implantation or implantation following monolayer culture for 6 days, and 3 cell concentrations (1 x 10(5), 1 x 10(6), and 5 x 10(6) chondrocytes/cm3). Equine fibrinogen was collected by cryoprecipitation and polymerized by use of activated bovine thrombin. The fibrin implants were harvested and analyzed histologically and biochemically at 3, 7, and 14 days after the chondrocytes were implanted in fibrin. The differentiation ratio (ratio of rounded, chondrocyte-like cells to stellate, f...
Weitkamp LR, MacCluer JW, Guttormsen SA, King RH.The transmission ratios of alleles at 12 protein marker loci were computed individually for American Standardbred stallions in a genealogy of 5392 phenotyped horses. Over all loci there was significant gene transmission distortion for trotting stallions (p = 0.0019) but not for pacing stallions (p = 0.99). The transmission distortion was due to sire-specific effects (p = 0.0024) and not to increased transmission of one or the other allele of a given heterozygous genotype (p = 0.21). Individual-specific, non-random transmission of homologous chromosomes may provide a mechanism for selection to ...
