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.
DAVIES J, DEMPSEY EW, WISLOCKI GB.A fetal horse ovary at the 6th month of gestation and a fetal ovary and testis at the 9th month have been studied histochemically with special reference to the cytoplasmic lipids of the interstitial cells. At least two lipid fractions appeared to be present, one which was soluble in acetone and was mainly responsible for the positive "plasmal" reaction, and another, insoluble in acetone, which was responsible for the sudanophilic, Ashbel-Seligman and periodic acid-Schiff positive material remaining after acetone extraction. The interstitial cell lipids in the older ovary and testis were also a...
KIVALO E, TALANTI S.A good deal of hypothetical evidence has been presented for the view that the antidiuretic and oxytocic hormones are not produced in the posterior lobe of the hypophysis. These hormones appear to originate from a neurosecretory process in the neurosecretory nerve cells of the supraoptic and paraventricular nuclei in the hypothalamus and to migrate within the nerve fibers of the supraoptico-hypophysial tract and into the neurohypophysis (Hild, 1951, 1954 a, b and Hild & Zetler, 1951, 1952, 1953 a, b). Here they are stored and if necessary released. Neurosecretory neurons are described in many s...
Gürelli G, Canbulat S, Aldayarov N.Species composition and distribution of intestinal ciliates were investigated in the feces from 15 domestic horses living in Bishkek, Kyrgyzstan. Twenty-three species belonging to 14 genera were identified. This is the first study on intestinal ciliates in domestic horses living in Kyrgyzstan. The mean number of ciliates was 14.1 ± 6.8 x10(4) cells ml(-1) of feces and the mean number of ciliate species per host was 6.0 ± 3.2. No endemic or new species were detected. Blepharocorys was the major genus as these ciliates were detected in high proportions. In contrast Holophryoides, Allantosoma w...
The Journal of heredityAugust 4, 2021
Volume 112, Issue 5 443-446 doi: 10.1093/jhered/esab037
Hammons V, Ribeiro L, Munyard K, Sadeghi R, Miller D, Antczak D, Brooks SA.Chestnut coat color in horses is determined by a missense mutation within the MC1R gene. However, the intensity of the chestnut color can vary widely within individuals possessing this genotype. Here, we investigated this variation using standardized photographs of 96 horses. Each horse was ranked lightest to darkest within the cohort for phenotype by 3 blinded observers. A genome-wide association study utilizing the relative shade ranking as the phenotype and using 268 487 single-nucleotide polymorphisms (SNPs) genotyped using the Affymetrix Equine 670k array identified a single significantly...
Thompson NE, Bergdoll MS, Pattee PA.The factor in normal sera primarily responsible for the enhancement of transfection (and transformation) of Staphylococcus aureus was identified as fibronectin. Serum samples which were depleted of fibronectin by affinity chromatography showed a marked decrease in enhancing activity. Fibronectin isolated from sera of several animal species demonstrated enhancing activity.
Raeside JI, Christie HL, Betteridge KJ.Steroid production and metabolism by early conceptuses are very important for the establishment and maintenance of pregnancy in horses. Our earlier work suggested the possible formation of 5alpha-reduced steroids in equine conceptuses. We have now demonstrated the formation of 5alpha-reduced metabolites of androstenedione, testosterone, and progesterone by the embryo and its membranes. A total of 44 conceptuses were collected from 26 mares between 20 and 31 days of pregnancy. Tissues from the embryo proper and from the separated components of the conceptus (bilaminar and trilaminar trophoblast...
Kettler MK, Weil MR, Mascotti K, Perryman LE.A group of diseases termed combined immunodeficiency (CID) results in a severe form of immunodeficiency. While CID in humans has two genetics bases, in Arabian it is inherited in an autosomal recessive manner. Kettler et al. (1989) determined that uric acid was significantly (p 0.05) between carrier and non-carrier horse's serum levels of hypoxanthine or xanthine. These data, combined with our previous ones suggest that an enzymatic lesion in the purine salvage pathway may occur at the urate oxidase step. ZUSAMMENFASSUNG: Serum-Hypoxanthin- und -Xanthin-Spiegel in Pferden mit Heterozygotie fÃ...
Kirisawa R, Hashimoto N, Tazaki M, Yamanaka H, Ishii R, Hagiwara K, Iwai H.cDNA generated from lipopolysaccharide-stimulated equine peripheral blood mononuclear cells was used to amplify and clone type I and type II equine interleukin-1 receptors (IL-1RI and IL-1RII) using primers derived from semi-conserved regions between human and mouse IL-1RI and IL-1RII sequences, respectively. 5' and 3' terminal sequences of equine IL-1RI and IL-1RII were amplified by 5' and 3' rapid amplification of cDNA ends. The deduced amino acid sequence of equine IL-1RI demonstrated 77, 64 and 63% similarity with human, mouse and rat sequences, respectively. The predicted amino acid seque...
Pelkola K, Heinikainen S, Pohjanvirta T.In Finland, Taylorella equigenitalis, the causative agent of contagious equine metritis (CEM), was first detected in 1992. The aim of this study was to genotype Finnish T. equigenitalis isolates to investigate the epidemiology of the infection in the Finnish horse population. A total of 34Â T. equigenitalis isolates from 24 horses obtained during 1992-2021 were subjected to whole genome sequencing (WGS) and subsequent local ad hoc core genome multi-locus sequence typing (cgMLST) targeting 1259 loci. Classical MLST profiles were extracted from the whole-genome sequence data. Three novel MLST ty...
Metenier L, Grosclaude J, Meriaux JC.The chief application of blood typing in domestic animals is in the verification of parentage. However, the acquisition of good standardized reagents in sufficient quantity remains an obstacle for the development of this work. The production of monoclonal antibodies directed against blood group determinants offers an attractive means of improving both the quality and quantity of serological reagents, and could facilitate the definition of new specificities. Fusions between a mouse myeloma line and splenocytes from mice immunized with horse red cells have resulted in four hybridomas producing a...
Theodorakis JL, Armes LG, Margoliash E.beta-Thiopropionyl derivatives of horse cytochrome c singly modified at each of 18 different lysine epsilon-amino groups have been prepared using sulfosuccinimidyl-2-(biotinamido)ethyl-1,3-dithiopropionate and purified to homogeneity by high-pressure liquid chromatography. These derivatives were characterized by determination of: (i) the location of the modification; (ii) reduction potentials; (iii) visible and NMR spectra: and by (iv) measurement of electron transfer activity with cytochrome-c oxidase. No significant changes in structure were indicated, except for the ferric forms of the deri...
Zielińska-Dawidziak M, Błaszak R, Piasecka-Kwiatkowska D.The presented experiments show the model of expectation of equine spleen ferritin extraction in a new aqueous two-phase system which was formed by mixing polyethylene glycol (PEG) and hydroxyethyl starch (HES). The tendency of the protein to migrate in the analyzed systems was dependent on the concentrations of HES and PEG as well as PEG molecular weight. The highest concentration of ferritin in the top phase (rich in PEG) was recorded in the system composed of 6% PEG 3000 and 3% HES. The obtained concentration was 0.88 mg mL(-1). The lowest concentration was 0.42 mg mL(-1) in the system compo...
Ledermann W.With the apparition of the crazy cows disease at the end of twentieth century, great was the temptation for denominate "crazy horses disease" an ancient enzootic encephalo-myelitis, known from the 17th century and now named "Borna disease" in 1970, because severe outbreaks affecting horses in this city of Germany since 1885. But the sickness was not a prion disease but a viral one, causing also encephalopathy in several other animal species. After seventy years of investigation, the finding of the virus in human patients with psychiatric pathology in the eighties gave an incentive to work hard...
Le Goff D, Hannan J, Maboundou JC, Ayrault-Jarrier M.Equine plasma lipoproteins were fractionated into VLDL, LDL-1, LDL-2 and HDL by density gradient ultracentrifugation. From each lipoprotein fraction, five apo C like peptides of approx. M(r) 1400, 10000, 9500, 9000 and 8000 were detected by SDS-polyacrylamide gel electrophoresis. After partial purification by Sephadex G-75, one fraction, showing a strong activation of lipoprotein lipase, was further purified by Mono Q anion exchange column. Two of the apo C like peptides (M(r) 10000 and 8000) activated the bovine milk lipoprotein lipase in vitro; only one (M(r) 9500) inhibited the lipolytic ac...
Word TA, Larsen RW.Treatment of horse heart Cytochrome-c (Cc) with N-chloro-4-toluosulfonamide (Chloramine-t, CT) results in the oxidation of methionine (Met) residues to the corresponding sulfoxide including the distal heme ligand, Met80. The resulting Fe-sulfoxide coordination is sufficiently labile in the ferrous form to be displaced by gaseous ligands, including CO. Photolysis of the CO-CT-Cc complex provides an opportunity to examine ligand binding dynamics that are associated with a relatively rigid distal heme pocket. In this work, photoacoustic calorimetry (PAC) was utilized to obtain the kinetics as wel...
Adeyefa CA, McCauley JW, Tomori O.The complete amino acid sequences of the hemagglutinin (HA) glycoprotein of three equine-2 influenza viruses from tropical Africa are presented in comparison with that of a well characterized European equine-2 virus (Suffolk/89) and a consensus sequence from the database. The sequences of the tropical African viruses were deduced from the complete nucleotide sequences of their HA genes reported earlier. Mutational changes in the nucleotide sequences resulted in amino acid changes in the HA which led to the introduction of a new asparagine-linked (N-linked) glycosylation site in two viruses. Th...
Bowling AT, Ewalt-Evans R.Family data are presented for a new allele (Aabdg) in the A system of horse erythrocyte alloantigens which includes factors Aa and Ab traditionally thought to be products of allelic genes. Evidence for incorrect assignment of the codominant factor Ae in the presence of Ab and Ac and the absence of Aa is discussed.
Gupta AK, Kaur D, Rattan B, Yadav MP.Three abortigenic Indian isolates of equine herpesvirus-1 (EHV-1) (Tohana, Hisar and Bikaner), along with two exotic abortigenic isolates (AB4 and V592) and another EHV-1 isolate (Jind) obtained from a case of perinatal foal mortality, were studied for variability. For this purpose, PCR and restriction endonuclease (RE) digestion techniques were used simultaneously as a DNA fingerprinting system. Nine different regions of EHV-1 virus were amplified by PCR using primer pairs specific for the regions and the products obtained from these regions were subsequently subjected to various restriction ...
Schuetz AW, Whittingham DG, Legg RF.Granulosa cells at different stages of differentiation were collected from ovarian follicles and oviducts during the periovulatory period, and their nuclear DNA content was monitored by flow cytometry to establish their cell cycle characteristics (G0 + G1, S, G2 + M). The proportion of cells in the three phases of the cell cycle varied in characteristics patterns depending upon the time they were collected, before or following ovulation. Granulosa (cumulus) cells recovered from ovulated oocytes were mitotically inactive as shown by the large proportion of cells with a 2C amount of DNA and the ...
Sahmi F, Nicola E, Price CA.The objective was to establish a cell line-based bioassay for FSH in horse serum for screening samples with high eCG bioactivity. A cell line (HEK293) was transiently cotransfected with an FSH reporter expression plasmid and a cAMP-responsive β-galactosidase reporter plasmid. Cells were bulk frozen, and thawed for assay purposes. This assay was specific for FSH, with no cross-reaction with LH or insulin-like growth factor-1. Standard curves (eCG) and serum samples from pregnant mares passed parallel line bioassay validity tests (linearity and parallelism). Estimates of bioactivity with this b...
Timoney PJ, Dillon PB, Geraghty VP, McArdle JF.Aspects of experimental transmission of the causal bacterium of contagious equine metritis (CEM) to albino Swiss mice were investigated. Whereas infection was established in the majority of female mice, the organism was recovered from only a limited number of male mice after challenge. No clinical evidence of infection was observed in the experimental mice. There was only one instance of presumptive venereal transmission of the CEM bacterium. One third of infected females conceived and had normal litters.
Berndtson WE, Jones LS.Testes were obtained from 47 1-20-year-old stallions during the natural breeding season. Total testicular testosterone and testosterone/g testis increased with age (P less than 0.005), and total testicular testosterone was associated with larger testis size (P less than 0.05). Neither testosterone per gram nor per paired testes were related to total Sertoli cell number (P greater than 0.05), but greater testosterone per paired testes was associated with fewer Sertoli cells per unit of seminiferous tubule length (P less than 0.005) or basement membrane area (P less than 0.02) and with a higher ...
Suminda GGD, Ghosh M, Son YO.For more than a decade, next-generation sequencing (NGS) has been emerging as the mainstay of agrigenomics research. High-throughput technologies have made it feasible to facilitate research at the scale and cost required for using this data in livestock research. Scale frameworks of sequencing for agricultural and livestock improvement, management, and conservation are partly attributable to innovative informatics methodologies and advancements in sequencing practices. Genome-wide sequence-based investigations are often conducted worldwide, and several databases have been created to discover ...
Sugo T, Kato H, Iwanaga S, Fujii S.On incubation of purified horse plasma high-molecular-weight kininogen with purified plasma kallikrein, three new peptides, named fragment 1.2, fragment 1 and fragment 2, were released, in addition to the vasopeptide, bradykinin. Fragment 2 contained an extremely high level of histidine, in which eleven residues out of the total 48 residues were characterized. Thus the result proves the existence of the histidine-rich region in horse high-molecular-weight kininogen, which is similar to the region previously identified in bovine high-molecular-weight kininogen. Moreover, we have identified a ne...
Qi T, Wang X.Reverse genetics is one of the most powerful tools in modern virology. Equine arteritis virus (EAV) is the prototype member of the Equartevirus. In this study, a new reverse genetics system for the recovery of equine arteritis virus from a cDNA plasmid, which contains viral cDNA sequence flanked by hammerhead ribozyme (HamRz) and hepatitis delta virus ribozyme (HdvRz) sequences in both terminals of the viral genome, was developed by optimization of the promoter and terminator regions. Cellular RNA polymerase II drove the transcription of the viral genome. The results showed that the rescued vi...
Merkies K, Buhr MM.Spermatozoal function is affected by the ability to regulate intracellular calcium concentrations ([Ca2+]i), and may be influenced by epididymal maturation as well as environmental components. Regulation of [Ca2+]i in ejaculated and epididymal stallion spermatozoa was monitored over time in various media. Spermatozoa from each of 5 pony stallions (3 ejaculate samples and 1 caput and cauda sample) were labeled with the fluorescent calcium indicator probe Indo-1 in a calcium-free modified Tyrode's buffer. Fluorescent emissions were monitored by a dual wavelength spectrofluorometer over 5 h. Calc...
Liberatori J, Morisio Guidetti L, Conti A.By double diffusion in agarose gel, in well defined experimental conditions, cross reactions were observed between porcine beta-lactoglobulins and anti-bovine beta-lactoglobulin antisera. The immunological reactivity between these beta-lactoglobulins from a monogastric and the ruminant anti beta-lactoglobulin antiserum thus implies a certain degree of similarity between the monomeric beta-lactoglobulins examined and the dimeric of the ruminants. With the same antisera it also proved possible to demonstrate the presence of beta-lactoglobulins in the mammary secretions of another monogastric, na...
Bresnahan DR, Lupole RE, Stilz CR, Carnevale EM.Zona pellucida (ZP) proteins are important for fertilization and sperm binding and are closely associated with cumulus cells. Communication between cumulus and oocytes is facilitated by intracellular membrane channels composed of connexins. The extent aging impacts potential differences in fertilization and reductions in fertility is not well understood. This study characterized age-related differences in transcript abundance of ZP proteins and connexins in cells from ovarian follicles. Additionally, differences in sperm binding to oocytes from old and young mares was evaluated. For experiment...
Leite RO, Ferreira JF, Araújo CET, Delfiol DJZ, Takahira RK, Borges AS, Oliveira-Filho JP.Glanzmann's thrombasthenia (GT) is an autosomal recessive inherited disorder characterized by changes in platelet aggregation, leading to hemorrhage and epistaxis. To date, two independent mutations have been described in horses and associated with this disorder, a point mutation (c.122G > C) and a 10-base-pair deletion (g.1456_1466del) in the Integrin subunit alpha2β gene (ITGA2B) of horses of different breeds (Quarter Horse, Thoroughbred, Oldenburg, and Peruvian Paso). ITGA2B codifies the αIIb subunit of the αIIbβ3 integrin, also termed platelet fibrinogen receptor. Horses with GT have b...
Nic An Ultaigh S, Ryan MF.Proteinases released during the in vitro maintenance of asynchronous cultures of the free-living nematode Caenorhabditis elegans were characterized on the basis of subunit composition, fluorogenic substrate specificity, inhibitor sensitivity and pH optima. Cysteine proteinases are present in the excretory-secretory products (ESP) as indicated by the hydrolysis of cathepsin fluorogenic substrates and confirmed by immunoblotting. Serine proteinases were predominant as indicated by substrate gel analysis and inhibitor studies. The presence of metallo-proteinases was also indicated by inhibitor st...
Magnuson NS, Perryman LE.The effect of adenosine on the mitogenic response of peripheral blood lymphocytes (PBL) and on the nucleotide pools of erythrocytes from normal horses, horses heterozygous for the combined immunodeficiency (CID) trait (carriers), and foals with CID was studied. When PBL from normal, carrier, and CID horses were stimulated by phytohemagglutinin (PHA), concanavalin A, or pokeweed mitogen, [3H]thymidine uptake was inhibited by adenosine (0.1 microM) to 1.0 mM) in a dose-dependent manner. Adenosine (100 microM) mediated inhibition of [3H]thymidine uptake was prevented in both normal and carrier ho...
