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.
Pauli BU, Rossi Straub R.A trabecular adenoma of the pars intermedia of the hypophysis was seen in a 13-year-old half-bred mare that presented symptoms corresponding to Cushing's disease of man. The spindle-shaped tumor cells were for the most part ‘light’, seldom ‘dark’. Both of them were characterized by well-developed rough endoplasmic reticulum, small Golgi apparatus, and typical secretory granules with a diameter of about 200 μm. The pituitary tumor and the symptoms were accompanied by increased plasma adenocorticotrophic hormone (ACTH) and by bilateral hyperplasia of the adrenal cortex. The tumor cells ...
McGuire TC, Poppie MJ, Banks KL.Thirty sick Arabian foals and 78 clinically normal Arabian foals were examined for combined (B- and T-lymphocyte) immunodeficiency. Diagnosis was based on lymphocyte counts and serum immunoglobulin (Ig) content or microscopic examination of lymphoid organs. Ten of the 30 sick foals and 2 of the 78 clinically normal foals had combined immunodeficiency. The 2 affected foals in the group of 78 subsequently developed fatal pneumonia.
Lymphocyte counts were made from 9 of the 12 immunodeficient foals; the range was 0 to 936/cmm., whereas the normal mean was 4,119/cmm., with a standard deviation ...
Beech J, Aguirre G, Gross S.Nuclear cataracts were found in 2 groups of related Morgan horses. The cataracts were finely reticulated central spherical translucencies that sometimes extended to the region of the posterior "Y" suture. The cataracts were not associated with other ocular defects and did not impair vision. In 1 group of 8 horses, 5 were affected; in the other group, 6 of 8 were affected. Although a pattern of inheritance could not be determined, the familial distribution of the cataracts supported the conclusion that the defect was a heritable disorder.
Nasir L, Reid SW.An evolutionary conserved 1.3 kb fragment corresponding to the horse p53 tumour suppressor gene was PCR amplified, cloned and the nucleotide sequence determined. The p53 fragment encoded exons 5 to 9 and the intervening introns. The nucleotide sequence and the predicted aminoacid sequence showed a high level of homology with human and donkey p53 sequences.
Schmid DO, Ek N, Braend M.A silent allele in the transferrin locus (Tf) was observed in a Thoroughbred mare and in five of her offspring from three different matings. Evidence for the silent allele was obtained by quantitative immunodiffusion studies.
Iqbal J, Purewal AS, Edington N.The aim of this study was to investigate the role of immediate early gene (gene63) in the pathogenesis of equine herpesvirus 1 (EHV-1) acute and latent infections in equine and murine models. EHV-1 gene63 mutant virus (g63mut) along with EHV-1 (Ab4) was used for intracerebral and intranasal infection of 3 and 17-day-old mice. Both viruses were recovered at the same frequency from tissues after infection. Two Welsh ponies were infected via the intranasal route with each of the viruses. Acute infection was monitored by virus isolation from nasal swabs and peripheral blood leukocytes. Six weeks p...
Kitchen H, Bunn HF.Studies were made of the O2 affinities of fetal and maternal haemoglobins in the horse, and correlations were found with erythrocytic levels of 2,3-diphosphoglycerate.
Bowling AT, Dileanis S.The C3 polymorphism of equine serum or plasma revealed by agarose gel electrophoresis can be diagnosed with protein stain following acid protein fixation. In addition to the three alleles previously described (C31, C32, C33), a fourth allele (C34) was found. Population data for 25 domestic breeds and Equus przewalskii are presented.
Sátková-Jakabová D, Trandzík J, Hudecová-Kvasnáková L, Hegedüsová-Zetochová E, Bugarský A, Buleca J, Zöldág L, Jakab F, Fl'ak P.Genetic variation at six microsatellite loci was analysed for five Thoroughbred subpopulations to determine the magnitude of genetic differentiation and the genetic relationships among the subpopulations. Significant deviations from Hardy-Weinberg equilibrium were shown for a number of locus-population combinations, with all subpopulations. The genetic diversities and relationships of five Thoroughbred subpopulations were evaluated using six microsatellites recommended by the International Society of Animal Genetics (ISAG). The allele frequencies, the effective numbers of alleles, and the obse...
Costa MF, Davies HM, Anderson GA, Slocombe RF.Studies in man have shown a correlation between Angiotensin I-converting enzyme (ACE) genetic polymorphisms, ACE activity in the blood and superior athletic performance in sports requiring endurance. It has been hypothesised that the same correlation occurs in horses. There is no information in the literature concerning the effects of training on ACE activity in equine plasma. Objective: Exercise training influences the activity of circulating ACE and the response observed is dependent on the exercise protocol. Methods: Thirteen horses of mixed breeds were randomly allocated 2 different traini...
Blendinger C, Müller G, Bostedt H.The lethal white foal syndrome (congenital intestinal aganglionosis) was diagnosed by history, clinical signs and pathological findings in a female foal, born in March 1992, that was an offspring of two overo-spotted paint horses. The syndrome is a congenital innervation defect of the gastrointestinal tract. A literature review of this condition, relatively unknown in Germany, is given.
