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.
Moon S, Lee JW, Shin D, Shin KY, Kim J, Choi IY, Kim J, Kim H.Using next-generation sequencing, we conducted a genome-wide scan of selective sweeps associated with selection toward genetic improvement in Thoroughbreds. We investigated potential phenotypic consequence of putative candidate loci by candidate gene association mapping for the finishing time in 240 Thoroughbred horses. We found a significant association with the trait for Ral GApase alpha 2 (RALGAP2) that regulates a variety of cellular processes of signal trafficking. Neighboring genes around RALGAP2 included insulinoma-associated 1 (INSM1), pallid (PLDN), and Ras and Rab interactor 2 (RIN2)...
Gardner AK, Kelly CS, van Eps AW, Burns TA, Watts MR, Belknap JK.In sepsis models, mitogen-activated protein kinases (MAPKs) are reported to incite inflammatory injury to tissues and are purported to be a therapeutic target. Objective: To assess MAPK signalling in lamellae in sepsis-related laminitis (SRL) at different time points after induction of laminitis via carbohydrate overload, and to determine the effect of regional deep hypothermia (RDH) on MAPK signalling. Methods: In vitro study using archived tissue samples. Methods: Lamellar concentrations of MAPKs were assessed in archived lamellar samples from 2 studies: 1) the starch gruel model of SRL with...
Lange-Consiglio A, Accogli G, Cremonesi F, Desantis S.Amniotic epithelial cells (AECs) spontaneously transform into amniotic mesenchymal cells (AMCs) in vitro during cell culture. Glycocalyx was analyzed to identify the glycan pattern in AECs, AMCs and epithelial-mesenchymal transdifferentiated cells (EMTCs). Pure cell cultures were derived using cloned AEC and AMC cell lines obtained by the dilution technique from amniotic membranes. Mesenchymal cells generated by differentiation of clonal epithelial cells were considered transdifferentiated. Immunocytoscreen, in vitro multipotent differentiation and molecular characterization of EMTCs were perf...
Whitfield-Cargile CM, Cohen ND, Suchodolski J, Chaffin MK, McQueen CM, Arnold CE, Dowd SE, Blodgett GP.In equids, susceptibility to disease caused by Rhodococcus equi occurs almost exclusively in foals. This distribution might be attributable to the age-dependent maturation of immunity following birth undergone by mammalian neonates that renders them especially susceptible to infectious diseases. Expansion and diversification of the neonatal microbiome contribute to development of immunity in the gut. Moreover, diminished diversity of the gastrointestinal microbiome has been associated with risk of infections and immune dysregulation. We thus hypothesized that varying composition or reduced div...
Pacholewska A, Jagannathan V, Drögemüller M, Klukowska-Rötzler J, Lanz S, Hamza E, Dermitzakis ET, Marti E, Leeb T, Gerber V.Recurrent airway obstruction (RAO) is a common and potentially debilitating lower airway disease in horses, which shares many similarities with human asthma. In susceptible horses RAO exacerbation is caused by environmental allergens and irritants present in hay dust. The objective of this study was the identification of genes and pathways involved in the pathology of RAO by global transcriptome analyses in stimulated peripheral blood mononuclear cells (PBMCs). We performed RNA-seq on PBMCs derived from 40 RAO affected and 45 control horses belonging to three cohorts of Warmblood horses: two h...
Vincze B, Gáspárdy A, Kulcsár M, Baska F, Bálint Á, Hegedűs GT, Szenci O.Alpha-fetoprotein has proved to be a good indicator of fetal well-being in human medicine for decades. Although this molecule is present in most of the mammalian species including horses, reference values in healthy and high-risk pregnant mares have not yet been published. The aim of the present study was to determine whether equine alpha-fetoprotein (eqAFP) is a good indicator of complicated pregnancies in Lipizzaner mares. A total of 111 serum samples from 30 mares have been analyzed for eqAFP levels throughout gestation (Days 60-325). After the pregnancy was confirmed, 23 mares had normal p...
Lyskova P, Hubka V, Petricakova A, Dobias R, Cmokova A, Kolarik M.Trichophyton bullosum is a zoophilic dermatophyte from the Arthroderma benhamiae complex with a poorly known distribution. In this study, we report a case of dermatophytosis caused by T. bullosum in a 6-year-old male horse who had a skin lesion located in a saddle area. The infection spread rapidly to the upper chest and to both sides of the trunk. The dermatophyte was isolated in culture and identified by sequence analysis of the internal transcribed spacer regions (ITS rDNA). To date, this is the first verified case of animal infection due to T. bullosum in Europe following the 2012 report o...
Norris JW, Pombo M, Shirley E, Blevins G, Tablin F.Two congenital bleeding diatheses have been identified in Thoroughbred horses: Glanzmann thrombasthenia (GT) and a second, novel diathesis associated with abnormal platelet function in response to collagen and thrombin stimulation. Objective: Platelet dysfunction in horses with this second thrombasthenia results from a secretory defect. Methods: Two affected and 6 clinically normal horses. Methods: Ex vivo study. Washed platelets were examined for (1) expression of the αIIb-β3 integrin; (2) fibrinogen binding capacity in response to ADP and thrombin; (3) secretion of dense and α-granules; (...
Dierks C, Sieme H, Piechotta M, Lehner S, Merkt JC, Uphaus H, Klug E, Distl O.A female thoroughbred successful in horse racing was positively tested for high testosterone values. This horse neither showed stallion-like-behaviour nor signs of ambiguous external genitalia. The karyotype of this horse was 2n = 64,XY and the sex-determining region of Y (SRY) PCR was positive. Hair samples tested for naturally testosterone revealed values normal for stallions, and tests for eight synthetic testosterone esters remained negative. The phenotype, ultrasonographic examination, hormone status, cytogenetic evaluation and molecular diagnostics lead to the diagnosis of an XY testicul...
The Journal of heredityAugust 18, 2015
Volume 106, Issue 6 734-740 doi: 10.1093/jhered/esv062
Jäderkvist Fegraeus K, Johansson L, Mäenpää M, Mykkänen A, Andersson LS, Velie BD, Andersson L, Árnason T, Lindgren G.Previous studies showed a positive effect of the DMRT3 "gait keeper" mutation on harness racing performance in Standardbreds, French-, and Nordic trotters. The mutation has also been shown to influence riding traits in multiple breeds. This study investigated the effect of the DMRT3 mutation on harness racing performance and riding traits in Finnhorses. Finnhorses used for harness racing (n = 180) and for riding (n = 59) were genotyped for the DMRT3 mutation. For the trotters the genotypes were evaluated for association with racing performance (number of starts, victories, placings, earnings, ...
Schoster A, Mosing M, Jalali M, Staempfli HR, Weese JS.The intestinal microbiota is important for health and disease. Factors that disturb the equine intestinal microbiota need further investigation. Objective: To determine the effects of transport, fasting and anaesthesia on the faecal microbiota of healthy adult horses using next-generation sequencing. Methods: Experimental trial. Methods: Faecal samples were taken from 8 horses at baseline, after transport, 12 h of fasting and 24, 48 and 72 h after a 6 h anaesthesia. Next generation sequencing of the V4 region of the 16S rRNA gene was used to assess the microbial composition of faeces. Alpha...
Ressel L, Ward S, Kipar A.Equine cutaneous mast cell tumours (CMCTs) are generally considered to be benign skin lesions, although recurrent and multicentric tumours have been described. For canine CMCTs, grading and prognostic approaches are well established and aberrant KIT expression as well as high proliferation indices are associated with poor outcome. However, in the case of equine CMCTs, morphological features, proliferative activity and KIT expression pattern have not been assessed or related to biological behaviour, and there is discussion as to whether CMCTs are true neoplastic processes. The present study des...
Nemoto M, Oue Y, Murakami S, Kanno T, Bannai H, Tsujimura K, Yamanaka T, Kondo T.Equine coronavirus has been responsible for several outbreaks of disease in the United States and Japan. Only one complete genome sequence (NC99 isolated in the US) had been reported for this pathogenic RNA virus. Here, we report the complete genome sequences of three equine coronaviruses isolated in 2009 and 2012 in Japan. The genome sequences of Tokachi09, Obihiro12-1 and Obihiro12-2 were 30,782, 30,916 and 30,916 nucleotides in length, respectively, excluding the 3'-poly (A) tails. All three isolates were genetically similar to NC99 (98.2-98.7%), but deletions and insertions were observed i...
Peeters LM, Janssens S, Brebels M, Buys N.Genetic factors involved in susceptibility to insect bite hypersensitivity (IBH) in Belgian Warmblood horses (BWP) were investigated. Data relating to 3409 horses were collected using a questionnaire, administered to owners during sport competitions, BWP breeding days, breeder visits and after phone calls. Horses were classified as IBH-affected or unaffected, based on two 'disease classifiers': a lifetime record, based on owner information (life_status) and another based on whether or not the horse was showing clinical signs at the time of questioning (clin_status). IBH prevalence was 10% base...
Takasuga A.A recent progress on stature genetics has revealed simple genetic architecture in livestock animals in contrast to that in humans. PLAG1 and/or NCAPG-LCORL, both of which are known as a locus for adult human height, have been detected for association with body weight/height in cattle and horses, and for selective sweep in dogs and pigs. The findings indicate a significant impact of these loci on mammalian growth or body size and usefulness of the natural variants for selective breeding. However, association with an unfavorable trait, such as late puberty or risk for a neuropathic disease, was ...
Rapacz-Leonard A, Kankofer M, Leonard M, Wawrzykowski J, Dąbrowska M, Raś A, Paździor-Czapula K, Janowski T.In mammals, placenta separation at term may involve degradation of the extracellular matrix by matrix metalloproteinases (MMPs). The activity of MMPs is modulated by TIMPs. We hypothesized that the placentas of mares that deliver fetal membranes physiologically and those that retain fetal membranes (FMR) differ in terms of histology; mRNA expression of MMP-2 and MMP-9; protein expression of MMP-2, MMP-9, and TIMP-2; and the potential activity of both MMPs. Methods: Placenta biopsies were taken from mares (n = 9; 4 FMR, 5 controls) immediately after foal expulsion. Retention was defined as fail...
Finno CJ, Valberg SJ, Shivers J, D'Almeida E, Armién AG.Equine degenerative myeloencephalopathy (EDM) is characterized by a symmetric general proprioceptive ataxia in young horses, and is likely underdiagnosed for 2 reasons: first, clinical signs overlap those of cervical vertebral compressive myelopathy; second, histologic lesions--including axonal spheroids in specific tracts of the somatosensory and motor systems--may be subtle. The purpose of this study was (1) to utilize immunohistochemical (IHC) markers to trace axons in the spinocuneocerebellar, dorsal column-medial lemniscal, and dorsospinocerebellar tracts in healthy horses and (2) to dete...
Sarkar S, Balasuriya UB, Horohov DW, Chambers TM.Equine herpesvirus-1 (EHV-1) is one of the most common and important respiratory viral pathogens of horses. EHV-1 in horses replicates initially in the respiratory epithelium and then spreads systematically to endothelial cells lining the small blood vessels in the uterus and spinal cord, and highly pathogenic virus strains can produce aborted fetuses or myeloencephalopathy. Like other herpes viruses, EHV-1 employs a variety of mechanisms for immune evasion. Some herpes viruses down-regulate the type-I interferon (IFN) response to infection, but such activity has not been described for EHV-1. ...
Schroeder DI, Jayashankar K, Douglas KC, Thirkill TL, York D, Dickinson PJ, Williams LE, Samollow PB, Ross PJ, Bannasch DL, Douglas GC, LaSalle JM.Over the last 20-80 million years the mammalian placenta has taken on a variety of morphologies through both divergent and convergent evolution. Recently we have shown that the human placenta genome has a unique epigenetic pattern of large partially methylated domains (PMDs) and highly methylated domains (HMDs) with gene body DNA methylation positively correlating with level of gene expression. In order to determine the evolutionary conservation of DNA methylation patterns and transcriptional regulatory programs in the placenta, we performed a genome-wide methylome (MethylC-seq) analysis of hu...
Winton CL, Plante Y, Hind P, McMahon R, Hegarty MJ, McEwan NR, Davies-Morel MC, Morgan CM, Powell W, Nash DM.Most species exist as subdivided ex situ daughter population(s) derived from a single original group of individuals. Such subdivision occurs for many reasons both natural and manmade. Traditional British and Irish pony breeds were introduced to North America (U.S.A. and Canada) within the last 150 years, and subsequently equivalent breed societies were established. We have analyzed selected U.K. and North American equivalent pony populations as a case study for understanding the relationship between putative source and derived subpopulations. Diversity was measured using mitochondrial DNA and ...
Savini F, Gallina L, Prosperi A, Battilani M, Bettini G, Scagliarini A.BPV-1 is known as the main causative agent of equine sarcoid, but the virus has also been detected in skin and blood of healthy horses. Previous reports demonstrated the presence of E5 variants in sarcoids of donkeys and horses; we investigated whether this genetic variability might be also found in BPV-1, PBMC associated, of sub-clinically infected horses. With this aim, we analyzed the E5 gene of 21 BPV-1 strains from diseased and sub-clinically infected horses. Our analyses lead us to demonstrate that multiple sequence variants can be present in the blood of sub-clinically infected horses, ...
Weiss N, Mardo E, Avidan G.A major question in the domain of face perception is whether faces comprise a distinct visual category that is processed by specialized mechanisms, or whether face processing merely represents an extreme case of visual expertise. Here, we examined O.H, a 22 years old woman with congenital prosopagnosia (CP), who despite her severe deficits in face processing, acquired superior recognition skills for horses. To compare the nature of face and horse processing, we utilised the inversion manipulation, known to disproportionally affect faces compared to other objects, with both faces and horses. O....
Doud MB, Ashenberg O, Bloom JD.Evolution drives changes in a protein's sequence over time. The extent to which these changes in sequence lead to shifts in the underlying preference for each amino acid at each site is an important question with implications for comparative sequence-analysis methods, such as molecular phylogenetics. To quantify the extent that site-specific amino acid preferences shift during evolution, we performed deep mutational scanning on two homologs of human influenza nucleoprotein with 94% amino acid identity. We found that only a modest fraction of sites exhibited shifts in amino acid preferences tha...
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...
Gaynor AM, Zhu KW, Dela Cruz FN, Affolter VK, Pesavento PA.Bovine papillomaviruses (BPV1/BPV2) have long been associated with equine sarcoids; deciphering their contribution has been difficult due to their ubiquitous presence on skin and in the environment, as well as the lack of decent techniques to interrogate their role in pathogenesis. We have developed and characterized an in situ hybridization (ISH) assay that uses a pool of probes complementary to portions of the E5, E6, and E7 genes. This assay is highly sensitive for direct visualization of viral transcript and nucleic acid in routinely processed histopathologic samples. We demonstrate here t...
Walther S, Rusitzka TV, Diesterbeck US, Czerny CP.Our understanding of how equine immunoglobulin genes are organized has increased significantly in recent years. For equine heavy chains, 52 IGHV, 40 IGHD, 8 IGHJ and 11 IGHC are present. Seven of these IGHCs are gamma chain genes. Sequence diversity is increasing between fetal, neonatal, foal and adult age. The kappa light chain contains 60 IGKV, 5 IGKJ and 1 IGKC, whereas there are 144 IGLV, 7 IGLJ, and 7 IGLC for the lambda light chain, which is expressed predominantly in horses. Significant transcriptional differences for IGLV and IGLC are identified in different breeds. Allotypic and allel...
Xie FY, Feng YL, Wang HH, Ma YF, Yang Y, Wang YC, Shen W, Pan QJ, Yin S, Sun YJ, Ma JY.Prior to the mechanization of agriculture and labor-intensive tasks, humans used donkeys (Equus africanus asinus) for farm work and packing. However, as mechanization increased, donkeys have been increasingly raised for meat, milk, and fur in China. To maintain the development of the donkey industry, breeding programs should focus on traits related to these new uses. Compared to conventional marker-assisted breeding plans, genome- and transcriptome-based selection methods are more efficient and effective. To analyze the coding genes of the donkey genome, we assembled the transcriptome of donke...
Giles C, Vanniasinkam T, Barton M, Mahony TJ.Equine adenovirus 2 (EAdV-2) is one of two serotypes of adenoviruses known to infect equines. Initial studies did not associate EAdV-2 infections with any specific clinical syndromes, although more recent evidence suggests that EAdV-2 may be associated with clinical and subclinical gastrointestinal infections of foals and adults respectively. In contrast, Equine adenovirus 1 is well recognised as a pathogen associated with upper respiratory tract infections of horses. In this study the complete genome sequence of EAdV-2 is reported. As expected, genes common to the adenoviruses were identified...
He S, Zhang L, Li W, Liu M.Recently, a SNP (BIEC2-808543) was demonstrated to be associated with equine body size in horses. In this study, we genotyped BIEC2-808543 SNPs in 314 Yili horses in order to evaluate the association between genotype and body composition traits, such as body weight, withers height, chest circumference, and cannon circumference. Results indicate significant associations between polymorphisms of this SNP and body conformation in Yili horse populations. Based on these results, we hypothesize that BIEC2-808543 is strongly related to body conformation of Yili horses and has the potential to be used...
Socha W, Rola J, Żmudziński JF.The genetic stability of ORF1a encoding non-structural proteins nsp1, nsp2, nsp3 and nsp4 of equine arteritis virus (EAV) has been analysed for nearly seven years in a persistently infected stallion of the Malopolska breed. Between November 2004 and June 2011, 11 semen samples were collected. Viral RNA extracted from semen of this carrier stallion was amplified, sequenced and compared with the sequences of the other known strains of EAV. Sequence analysis of ORF1a showed 84 synonymous and 16 non-synonymous mutations. The most variable part of ORF1a was the region encoding nsp2 protein with 13 ...
Giesecke K, Hamann H, Stock KF, Klewitz J, Martinsson G, Distl O, Sieme H.The research of fertility in humans and other mammals has strongly advanced in the recent years. The examination of molecular mechanisms influencing horse fertility is relatively recent. We chose the angiotensin converting enzyme (ACE), the sperm autoantigenic protein 17 (SP17) and the follicle stimulating hormone (FSHB) as candidates for determining stallion fertility and to analyze associations of intragenic single nucleotide polymorphisms (SNPs), flanking microsatellites and candidate-gene linked haplotypes with the pregnancy rate per oestrus (PRO) in 179 Hanoverian stallions. Fertility tra...
Cunha CW, McGuire TC, Kappmeyer LS, Hines SA, Lopez AM, Dellagostin OA, Knowles DP.In this study, the kinetics of specific immunoglobulin G (IgG) isotypes were characterized in Babesia equi (Theileria equi)-infected horses. IgGa and IgGb developed during acute infection, whereas IgG(T) was detected only after resolution of acute parasitemia. The same IgG isotype profile induced during acute infection was obtained by equi merozoite antigen 1/saponin immunization.
Thompson DL, Pickett BW, Squires EL, Amann RP.Factors affecting testicular measurements in situ and the relationships among the measurements and various reproductive characteristics were studied using data from 48 stallions. Mean values during the breeding season are provided for scrotal width, widths and lengths of individual testes, combined weight of testicular parenchyma, daily sperm production and daily sperm output. Testicular measurements were highly repeatable from day to day and for repeated measurements on a given day; technician provided the largest source of variation in the measurements of a given stallion. Age significantly ...
Do KT, Lee JH, Lee HK, Kim J, Park KD.This study was conducted to estimate the effective population size using SNPs data of 240 Jeju horses that had raced at the Jeju racing park. Of the total 61,746 genotyped autosomal SNPs, 17,320 (28.1%) SNPs (missing genotype rate of >10%, minor allele frequency of <0.05 and Hardy-Weinberg equilibrium test P-value of <10(-6)) were excluded after quality control processes. SNPs on the X and Y chromosomes and genotyped individuals with missing genotype rate over 10% were also excluded, and finally, 44,426 (71.9%) SNPs were selected and used for the analysis. The measures of the LD, square of cor...
Chambers TM, Reedy SE.Equine influenza viruses are cultured in embryonated hen eggs, or in mammalian cells, generally Madin-Darby canine kidney (MDCK) cells, using methods much the same as for other influenza A viruses. Mutations associated with host adaptation occur in both eggs and MDCK cells, but the latter show greater heterogeneity and eggs are the generally preferred host. Both equine-1 H7N7 and equine-2 H3N8 viruses replicate efficiently in 11-day-old eggs, but we find that equine-1 viruses kill the embryos whereas equine-2 viruses do not.
Murase H, Miyazawa M, Harada T, Ozawa M, Sato F, Hada T.The degree of fetal growth restriction has been unclear in equine reproduction. In this study, 2,195 fetuses from 2,137 abortions during 11 seasons were examined to determine the causes of abortion, and fetal size dimensions (crown rump length and body weight) were measured. In total, 900 cases (42.1%) of abortion were identified as caused by viral infection (215, 10.1%), bacterial infection (156, 7.3%), fungal infection (25, 1.2%), circulation failure (406, 19.0%), multiple causes (66, 3.1%), deformity (13, 0.6%), placental abnormality (12, 0.6%), and other causes (7, 0.3%). All viral infecti...
Comparini L, Podestà A, Russo C, Cecchi F."The Club Foot" (or "Mismatched Foot") is an acquired or congenital flexural deformity of the distal interphalangeal joint, caused by a shortening of the musculotendinous unit of the deep digital flexor tendon. The aim of this research was to detect the incidence of the disorder in Arabian Pureblood horses, attempting to understand its causes and to analyze a possible role of inbreeding in its expression. In this breed, in fact, the pathology is widespread because in the environment of origin, the rocky desert, a hard and almost goat's hoof is not disabling so the selection against this disord...
Warmuth V, Manica A, Eriksson A, Barker G, Bower M.Many events in the history of eastern Eurasia, including the process of domestication itself, the initial spread of domestic horses and subsequent movements, are believed to have affected the genetic structure of domestic horse populations in this area. We investigated levels of within- and between-population genetic diversity in 'non-breed horses' (working horses sampled in remote areas) from 17 locations in Asia and parts of Eastern Europe, using 26 autosomal microsatellite loci. Non-breed horses have not been subject to the same intensity of artificial selection and closed breeding as have ...
Lee HG, Choi JY, Park JW, Park TS, Song KD, Shin D, Cho BW.To examine the regulatory effects of exercise on myokine expression in horse skeletal muscle cells, we compared the expression of several myokine genes (interleukin 6 [IL-6], IL-8, chemokine [C-X-C motif] ligand 2 [CXCL2], and chemokine [C-C motif] ligand 4 [CCL4]) after a single bout of exercise in horses. Furthermore, to establish in vitro systems for the validation of exercise effects, we cultured horse skeletal muscle cells and confirmed the expression of these genes after treatment with hydrogen peroxide. Methods: The mRNA expression of IL-6, IL-8, CXCL2, and CCL4 after exercise in skelet...
Steiner CC, Mitelberg A, Tursi R, Ryder OA.Short divergence times and processes such as incomplete lineage sorting and species hybridization are known to hinder the inference of species-level phylogenies due to the lack of sufficient informative genetic variation or the presence of shared but incongruent polymorphism among taxa. Extant equids (horses, zebras, and asses) are an example of a recently evolved group of mammals with an unresolved phylogeny, despite a large number of molecular studies. Previous surveys have proposed trees with rather poorly supported nodes, and the bias caused by genetic introgression or ancestral polymorphi...
Schaefer RJ, McCue ME.High-quality genomic tools have been integral in understanding genomic architecture and function in the modern-day horse. The equine genetics community has a long tradition of pooling resources to develop genomic tools. Since the equine genome was sequenced in 2006, several iterations of high throughput genotyping arrays have been developed and released, enabling rapid and cost-effective genotyping. This review highlights the design considerations of each iteration, focusing on data available during development and outlining considerations in selecting the genetic variants included on each arr...
Stefaniuk M, Ropka-Molik K.RNA sequencing (RNA-seq) by next-generation technology is a powerful tool which creates new possibilities in whole-transcriptome analysis. In recent years, with the use of the RNA-seq method, several studies expanded transcriptional gene profiles to understand interactions between genotype and phenotype, supremely contributing to the field of equine biology. To date, in horses, massive parallel sequencing of cDNA has been successfully used to identify and quantify mRNA levels in several normal tissues, as well as to annotate genes. Moreover, the RNA-seq method has been applied to identify the ...
Grignard E, Morin J, Vernet P, Drevet JR.We report here on the cloning of cDNAs coding bovine and equine orthologs of mouse epididymis-restricted and sperm-bound glutathione peroxidase 5 (GPX5), a selenium-independent member of the multigenic GPX family in mammals. The complete sequence of bovine GPX5 as well as a partial sequence of the equine GPX5 were characterized, conceptually translated and aligned with other known mammalian GPX5 proteins. Using Northern blotting assays, we show that the level of expression of GPX5 is high in bovine but low in equine and that in both species the regionalization of GPX5 expression in epididymis ...
Chandley AC, Fletcher J, Rossdale PD, Peace CK, Ricketts SW, McEnery RJ, Thorne JP, Short RV, Allen WR.Chromosomal abnormalities have been detected in seven mares isolated by their poor reproductive performance. All had small or rudimentary gonads and absent or irregular oestrous cycles. Two mares had an XO genotype, one was a 65,XXX female and another a 64,XY sex-reversed female. Two other mares were sex chromosome mosaics of the 63,X/64,XX type. The seventh mare showed a normal female karyotype but a small extra autosomal fragment was found in a few cells.
Hurtgen JP.The breeding soundness evaluation of a stallion is a thorough investigation of a stallion's libido, mating ability, and semen quality. The evaluation should include historical data about the medical aspects of the horse's performance and breeding career, observations and breeding behavior characteristics, collection and evaluation of semen, tests to determine freedom from infectious or contagious disease, and production of foals free of genetic defects. This information should allow the examiner to anticipate the impact of the stallion on the reproductive efficiency of a group of mares. The br...
Ducheyne KD, Rizzo M, Cuervo-Arango J, Claes A, Daels PF, Stout TAE, de Ruijter-Villani M.Invitro embryo production is an increasingly popular means of breeding horses. However, success is limited by a high incidence of early embryo loss. Although there are various possible causes of pregnancy failure, chromosomal abnormalities, including aneuploidy, are important potential contributors. This study evaluated the frequency of micronucleus formation as a proxy for aneuploidy in invitro-produced (IVP) and invivo-derived horse blastocysts. Associations between IVP embryo morphology, frequency of nuclear abnormalities and the likelihood of pregnancy were investigated. IVP blastocysts ex...
Stewart F, Kennedy MW, Suire S.Horses, donkeys, and therefore, probably all equids, secrete a nonglycosylated, progesterone-dependent, 19-kDa protein (P19) into the uterine lumen during early pregnancy, and significant quantities of it are taken up by the developing conceptus. Sequence analysis and structural modelling have identified P19 as a lipocalin with greatest similarity to the murine major urinary protein lipocalins. However, lack of strong identity with any particular group of lipocalins and several unusual structural features, including a unique amino acid triplet within one of the invariant domains and an unusual...
Seo JH, Park KD, Lee HK, Kong HS.Currently about 26,000 horses are breeding in Korea and 57.2% (14,776 horses) of them are breeding in Jeju island. According to the statistics published in 2010, the horses breeding in Jeju island are subdivided into Jeju horse (6.1%), Thoroughbred (18.8%) and Halla horse (75.1%). Halla horses are defined as a crossbreed between Jeju and Thoroughbred horses and are used for horse racing, horse riding and horse meat production. However, little research has been conducted on Halla horses because of the perception of crossbreed and people's weighted interest toward Jeju horses. Methods: Using 17 ...
Wilsher S, Allen WR.An opportunity to monitor equine chorionic gonadotrophin (eCG) production during 61 pregnancies in 25 Thoroughbred mares mated to the same Thoroughbred stallion was utilised in order to further knowledge regarding factors involved in the production of this hormone. Objective: To examine the effects of maternal body condition, exercise and parity on eCG production. Methods: In the first experiment, maiden mares were fed either a moderate (n = 9) or an excessive (n = 10) food intake throughout gestation. In the second experiment, 5 mares were exercised daily during pregnancy and eCG production r...