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.
Serov OL, Zakijan SM, Kulichkov VA.Erythrocyte glucose-6-phosphate dehydrogenase (G6PD) was examined by 13% starch gel electrophoresis in 74 mules (42 females and 32 males), 35 donkeys, and ten horses. The quantitative expression of the parental alleles at the Gpd locus varies greatly in female mules from the hemizygous expression of the maternal allele to that of the paternal. The data obtained indicate that the X chromosomes are randomly inactivated in females mules. No selective advantage of a cell population with a maternally (or paternally) derived X active was found in female mule erythrocytes. It is suggested that the ph...
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...
Davies ME.A detailed study was made of 194 equine strains of E. coli, involving biochemical and serological characters. In these, the equine strains closely resembled E. coli from other sources, and shared antigenic characters with strains isolated from different animal species.
Mayhew IG, Watson AG, Heissan JA.From a clinical, radiological and morphological study of 9 horses with congenital malformations of the occiput, atlas and axis, and from a study of 2 reported cases, 3 diseases were defined: A. Familial occipitalisation of the atlas with atlantalisation of the axis in Arabian horses (7 cases in this report and the case reported by Leipold, et al., 1974). These horses had congenital atlantooccipital fusion, hypoplasia of the atlas and dens, malformation of the axis and modification of the atlantoaxial joint. B. Congenital asymmetrical occipitoatlantoaxial malformation (2 cases in this report). ...
Hardy JL, Apperson G, Asman SM, Reeves WC.After prolonged selection, two hybrid strains of Culex tarsalis were evolved that were highly resistant to infection following ingestion of western equine encephalomyelitis virus. These strains were greater than 25,000-fold more resistant than the most susceptible parental strain when fed on viremic chicks. Resistance was associated with a mesenteronal barrier since both refractory and parental strains were equally susceptible to infection by intrathoracic inoculation. Susceptibility was dominant, possibly incompletely dominant, over resistance. Inheritance was probably polyfactorial but this ...
McClure JJ, Muscoplat CC, Johnson DW, Senogles DR.A miniaturized method for the mixed lymphocyte culture test in the horse is described. The test is performed in either round- or flat-bottom microtitration tissue culture plates. Concentrations of responsing and stimulating cells are varied, depening on the experiment. Significant discrimination between isogeneic and allogenic mixtures is possible after 120 hours' culture when cells are labeled ([3H]thymidine) for the last 16 to 18 hours of the test.
Joppich-Kuhn R, Luisi PL.The interaction between horse liver alcohol dehydrogenase and the oxidized and reduced forms of the 3-thionicotinamide--adenine dinucleotide coenzyme analogues (sNAD and sNADH) has been investigated by ultraviolet absorption, fluorescence and circular dichroism. The fluorescence of sNADH is enhanced when bound to the enzyme, and the protein fluorescence is quenched by both sNADH (60--65%) and sNAD (65%). The possible origin of the larger quenching produced by sNAD with respect to that of NAD is discussed. Coenzyme dissociation constants have been determined by monitoring the quenching of the p...
Buening GM, Perryman LE, McGuire TC.Nasal washings and tears were collected from seven Arabian foals with combined immunodeficiency and nine normal foals. The major immunoglobulin in the external secretions of normal foals over 2 months of age was secretory immunoglobulin A, whereas foals with combined immunodeficiency lacked this immunoglobulin. The external secretions of both normal and immunodeficient foals contained free secretory component at birth.
Perryman LE, McGuire TC.Combined immunodeficiency in horses is a genetic disorder in which there is a defect in the production of committed B and T lymphocytes. In this study, peripheral blood mononuclear leukocytes from foals with combined immunodeficiency were examined for their capacity to stimulate and respond in one-way mixed lymphocyte cultures. Irradiated cells from combined immunodeficient foals were uniformly capable of stimulating cells from unrelated horses. However, none were able to respond to allogeneic stimulation. Examination of cells from known carrier horses revealed no difference in capacity to sti...
Méténier L, Kaminski M.Immunochemical and enzymatic analyses of horse serum carboxylesterase were carried out with respect to the existence of a silent gene. Sera with positive phenotypic expression of esterase, both heterozygotes and presumed homozygotes, were compared with:--sera with positive phenotypic expression but genotypically +/O;--sera with a negative phenotypic expression, i. e. genotypically O/O;--sera of natural +/O "hemi-zygotes": mules (donkey lacking the esterase);--positive sera heated at 60 degrees C;--positive sera after specific inhibition of enzymatic activity. Titration by immunocompetition has...
Ugorski M, Mikulska J, Skibiński G, Wieczorek Z, Lisowski J.Properties of horse natural anti-PSM antibodies are described. The antibodies were of IgG class. Electrostatic forces were mainly involved in reaction of PSM with horse antibodies. The reaction was inhibited by low molecular compounds resembling structural unit of PSM. Studies of difference spectra and ORD and CD spectra showed no major conformational changes in horse antibodies after reaction with PSM.
Trommershausen-Smith A, Suzuki Y.A family study of an index case in the Arabian breed of horses demonstrated the presence of a new allele in the prealbumin (Pr) system of electrophoretically determined markers in horse serum which, when homozygous, results in the absence of any recognizable zones in the Pr region. The symbol PrO is proposed for this allele which has an estimated frequency in Arabian horses of 0.09.
Vollmerhaus B, Knospe C, Roos H.Phylogenetic research on the teeth of equidae beginning with dagger Hyracotherium ('Eohippus') will be summarized, subdivided into its components, analysed in a new way and finally interpreted according to several theories of evolution. In this context, specific cells (ameloblasts, odontoblasts, cementoblasts) are discussed and valued according to Preuss (1987) as active carriers of the evolution of teeth.
Wood AL, Spradbrow PB.Fetal equine fibroblasts exposed to bovine papillomavirus became transformed by the criteria of morphological alterations and the acquisition of an increased life span, although they failed to grow in soft agar. Papillomavirus genome persisted in the transformed fibroblasts and was apparently not integrated with the cellular genome. These findings support the notion that bovine papillomaviruses are involved in the production of equine sarcoids.
Salazar I, Rodriguez JI, Cifuentes JM.In accordance with macroscopic and microscopic features of the tarsal joint degeneration in the greyhound dog, the possibility of establishing a direct relation between this process and spavin or bone spavin is proposed. To date this has been considered limited to equine and occasionally bovine stock. This investigation has been carried out on three different levels: macroscopic, radiological and histological and has been completed with the corresponding graphic documentation.
Dusek J, Munk Z.The study was based on the documentation of the Napajedla Stud Farm of the English Thoroughbred horse for 1888-1972. Evaluating the effect of the age of stallions on their fertility (leaving aside the variability of the age of their mothers), such an effect was found to be significant only in four out of the 26 studs evaluated. In 65% of the selected stallions, the correlation coefficients were found to be negative, but without statistical significance. However, the objective of the study was to evaluate stallions and mares parallelly as to their age variability and fertility. The relationship...
Moore JN, Mcilwraith CW.Two cases of osteochondrosis are presented. Lesions involving the lateral trochlear ridge of the femur are demonstrated on conventional radiographs and double-contrast arthrograms. A radiographic suggestion of osteochondrosis lesions in the patella is noted. Post mortem examination of one case confirmed the presence of partially free cartilaginous flaps. Reference is made to familial tendency to osteochondrosis in man, dog, pig and horse. The significance of rapid growth rate in the pathogenesis of the condition is also discussed.
Hawkins KL.Bilateral salpingitis, hydrosalpinx and oophoritis were diagnosed in a mare with concurrent lymphosarcoma. Salpingitis, hydrosalpinx and oophoritis are rare in the mare (1,2,3,5,8,9,11-13). Bilateral salpingitis is an important cause of infertility in all species and is most often due to ascending infection (3-5,10,11). The source of salpingitis in this mare probably was ascending infection from the uterus after parturition. The apparent infertility of the mare was attributed to debilitation from the lymphosarcoma and multiplicity of genital pathoses.
McCue PM, Bisiau C, Divine C, May E.Congential amastia, a medical condition in which mammary tissue fails to develop, was detected in a 3-year-old Quarter Horse mare. The dam of the mare was also afflicted with amastia, suggesting that the condition was due to an inherited genetic mutation as noted in other species. In addition, on presentation the mare had a purulent vaginal discharge secondary to a pyometra.