Genes in horses are segments of DNA that encode the biological instructions necessary for the development, functioning, and reproduction of equine species. These genetic sequences influence a wide range of traits, including coat color, speed, endurance, and susceptibility to diseases. Genetic research in horses focuses on identifying specific genes and genetic markers associated with these traits, as well as understanding the inheritance patterns and genetic diversity within and between horse breeds. Studies in equine genetics contribute to breeding programs, disease prevention strategies, and the overall understanding of horse biology. This page compiles peer-reviewed research studies and scholarly articles that explore the identification, function, and implications of genes in equine health and performance.
Sun Y, MacLean AR, Aitken JD, Brown SM.Equine herpesvirus type 1 (EHV-1) gene 71 encodes a heavily O-glycosylated 192 kDa protein with no identified herpesvirus homologue. Isolation of a deletion mutant in gene 71 (ED71) demonstrated that its protein product is not essential in vitro. To investigate the role of the gene 71 protein in the virus life cycle, ED71 has been characterized in vitro in terms of cellular adsorption, penetration, egress and transmission compared to wild-type and revertant virus. ED71 virions adsorbed to cells less efficiently than wild-type and revertant virus with a consequential effect on virus penetration...
Matsumura T, O'Callaghan DJ, Kondo T, Kamada M.The virulence of the cell culture adapted KyA strain of equine herpesvirus type 1 (EHV-1), which lacks at least six genes by deletions in its genome, was assessed by intranasal inoculation of six young horses that were serologically negative for EHV-1. No horses showed clinical signs, and a neutralizing antibody response against EHV-1 was detected in two horses which had antibodies against EHV-4 prior to the inoculation. A challenge experiment using a highly virulent strain of EHV-1 conducted 4 weeks later against 4 of the 6 horses inoculated intranasally with the KyA strain and 2 control hors...
Chopineau M, Stewart F.Reverse transcription-PCR was used to clone the coding region of the donkey (Equus asinus) glycoprotein hormone alpha-subunit transcript from pituitary gland RNA. The donkey alpha-subunit sequence demonstrated considerable identity with the horse (97% at the nucleotide level), confirming the very close evolutionary linkage between these two species. The predicted amino acid sequence revealed that the donkey alpha-subunit has the same unusual C-terminus as the horse alpha-subunit, when compared with all other mammalian alpha-subunits, including a Tyr-His transposition between positions 87 and 9...
Miserez R, Frey J, Krawinkler M, Nicolet J.A polymerase chain reaction (PCR) for identification of Taylorella equigenitalis was developed. The oligonucleotide primers are based on the DNA sequence of the rrs gene of T. equigenitalis, encoding for the 16S ribosomal RNA. Analysis of 21 strains of T. equigenitalis from England, USA and Switzerland showed an amplification product of 410 bp with identical Sau3A restriction profile. The sensitivity of the PCR-Assay was estimated to detect 50 to 500 bacteria of T. equigenitalis in a mixture with frequently found contaminants. Further analysis of culture from 60 genital swabs, taken in the cou...
Browning GF, Begg AP.Variant types of VP4 and VP7 gene segments of faecal rotaviruses from diarrhoeic foals were identified by restriction endonuclease digestion of reverse transcription/polymerase chain reaction (RT/PCR) products. The variants observed were correlated with serotypes by determination of the sequence of representative RT/PCR products (entire coding sequence for VP7 and the VP8 region of VP4) and comparison to published sequences of equine G and P serotype genes. Both G and P serotypes could be predicted for 95/116 (82%) strains, P serotype only for a further 8 (7%) strains and G serotype only for 1...
Kojima K, Taniguchi K, Kobayashi N.We have sequenced gene 5 encoding NSP1 for three human, two porcine, two bovine, one feline, and five equine rotavirus strains, and compared the nucleotide and deduced amino acid sequences with the published sequences for other various strains. Subgroup I human strains L26, 69M, and DS-1 were found to have a similar NSP1 sequence despite their different G serotypes, VP4 genotypes, and RNA patterns. The NSP1 sequence of the human strain K8 showed a high degree of homology to those of porcine strains OSU and YM. A high degree of homology was found among three equine strains (H2, FI-14, and FI23)...
Balasuriya UB, Timoney PJ, McCollum WH, MacLachlan NJ.The variation and phylogenetic relationship of open reading frame 5 (ORF5) of 3 different laboratory strains of the original prototype Bucyrus strain of equine arteritis virus (EAV), the modified live virus vaccine (ARVAC, Fort Dodge Laboratories), and 18 field isolates of EAV from North America and Europe were determined by comparison of their gene sequences. The viruses differed from the published sequence by between 3 (99.6% homology) and 94 (87.8%) nucleotides and by between 3 (98.8%) and 24 (90.6%) amino acids. The field isolates differed from each other by between 2 (99.7%) and 110 (85.7...
Bell K, Arthur H, Breen M.Eleven apparent mutations of the equine plasma transferrin and esterase gene (10 in TF and one in ES) were found in an analysis of approximately 240,000 thoroughbred horses. Eight of the transferrin mutations produced variants not previously recognized in horses. In the two remaining transferrin mutations and the esterase mutation, reduced plasma concentrations of the proteins were demonstrated by immunological techniques and together with the family data indicated the existence of 'null' alleles.
Baxi MK, Efstathiou S, Lawrence G, Whalley JM, Slater JD, Field HJ.Neural tissues from specific pathogen-free ponies that had been experimentally infected with equine herpesvirus 1 (EHV-1) were analysed by in situ hybridization. Digoxigenin-labelled EHV-1 BamHI fragments spanning almost the entire EHV-1 genome were hybridized to RNA in tissue sections from latently infected trigeminal ganglia. The BamHI E fragment detected EHV-1 RNA antisense to gene 63 (HSV-1 homologue ICP0) in a small number of neurons. Sixteen other BamHI fragments gave negative results in 20 sections tested with each fragment. Latency associated transcripts (LATs) were localized to the ne...
Hinshelwood MM, Liu Z, Conley AJ, Simpson ER.Conversion of androgens to estrogens is catalyzed by aromatase P450 (P450arom; the product of the CYP19 gene). Regulation of tissue-specific expression of P450arom in humans is due, in part, to alternative transcriptional start sites that arise as a consequence of the use of granulosa cells and placental tissue from cows, horses, and pigs (ungulates) in order to determine whether these species, like the human, utilize tissue-specific promoters to drive P450arom expression. The majority of transcripts in the placenta have 5'-termini that differ from those in the ovary upstream of a common site ...
Lennard SN, Stewart F, Allen WR.In situ hybridization, Northern blotting, and immunohistochemical techniques were used to study the expression of transforming growth factor beta 1 (TGF beta 1) in the endometrium of the mare during the first 150 days of pregnancy (term = 330-340 days). In situ hybridization using an oligonucleotide (45mer) probe, based on a homologous region within all known mammalian TGF beta 1 DNA sequences, demonstrated TGF beta 1 mRNA accumulation in the glandular and lumenal epithelial cells of the endometrium from day 33 onwards which corresponds to the time of implantation (day 33-45). Expression in th...
Kato H, Ohashi T, Nakamura N, Nishimura Y, Watari T, Goitsuka R, Tsujimoto H, Hasegawa A.Equine interleukin-1 alpha (IL-1 alpha) and IL-1 beta were molecularly cloned to establish a basis for research on inflammatory and immune responses in the horse. Equine peripheral blood mononuclear cells (PBMC) were stimulated with lipopolysaccharide (LPS), and cDNA clones of equine IL-1 alpha and IL-1 beta covering the whole coding sequences were isolated from them. These equine IL-1 alpha and IL-1 beta clones contained open reading frames encoding 271 and 269 amino acids, respectively. The deduced amino acid sequence of equine IL-1 alpha showed 71.6% and 60.2% similarity with that of human ...
Yamanouchi K, Yoshida S, Hasegawa T, Ikeda A, Chang KT, Matsuyama S, Nishihara M, Miyazawa K, Takahashi M.cDNA encoding equine inhibin alpha-subunit precursor protein was isolated from an equine ovarian cDNA library. For screening, the DNA probe was amplified by the RT-PCR using primers designed based on the rat inhibin alpha-subunit cDNA sequence. Out of 1.2 x 10(5) plaques screened, 19 positive clones were isolated, and one of these clones (Eq-alpha-11) contained a complete open reading frame encoding 367 amino acids. The similarity of the deduced amino acid sequences of both equine inhibin alpha-subunit precursor protein and the mature protein were greater than 80% to those of other six mammali...
Nemoto K, Osawa R, Hirota K, Ono T, Miyake Y.Gram-negative tannin-protein complex degrading bacteria (T-PCDB) were first isolated from animals except for the koala. The occurrence of T-PCDB in feces of 15 species of mammals with different feeding habits was investigated. T-PCDB occurred in 7 of 54 horses but they could not be isolated from other mammals tested. These T-PCDB comprised less than 0.1% of the facultative anaerobic microflora in horse feces and it was much less than that previously reported in koala feces ( > 60%). A total of 7 T-PCDB fecal isolates showed a range of phenotypic diversities. They were all Gram-negative rods...
Clément F, Barrey E.The heart rate fluctuations at rest were studied in order to explore the emotionality of the horses by isolating the influence of the autonomic control. This paper presents a method of spectral analysis which was used to analyse the heart rate variability in the frequency domain. The heartbeat intervals were recorded during 1 h and a series of 1,024 heartbeats was extracted to compute a power spectrum of density. This was obtained by calculating the Fourier transform of the autocorrelation function of the series. This spectral analysis was applied to heart rate recordings in order to illustrat...
Ishida N, Oyunsuren T, Mashima S, Mukoyama H, Saitou N.The noncoding region between tRNAPro and the large conserved sequence block is the most variable region in the mammalian mitochondrial DNA D-loop region. This variable region (ca. 270 bp) of four species of Equus, including Mongolian and Japanese native domestic horses as well as Przewalskii's (or Mongolian) wild horse, were sequenced. These data were compared with our recently published Thoroughbred horse mitochondrial DNA sequences. The evolutionary rate of this region among the four species of Equus was estimated to be 2-4 x 10(-8) per site per year. Phylogenetic trees of Equus species demo...
Ochoa M, Bárcena J, de la Luna S, Melero JA, Douglas AR, Nieto A, Ortín J, Skehel JJ, Portela A.Characterization of the epitopes recognized by 21 monoclonal antibodies (MAbs) specific for the influenza A virus PA (13 MAbs) and PB2 (8 MAbs) polypeptides (Bárcena et al. (1994) J. Virol. 68, 6900-6909) raised against denatured polypeptides produced in E. coli is described. MAbs were characterized by: (1) competitive binding ELISAs; (2) mapping of the protein regions that specify their binding sites; and (3) analyses of their ability to recognize the corresponding viral protein in a number of viral isolates. Five and three non-overlapping antigenic areas were defined by the anti-PA and anti...
Chopineau M, Stewart F, Allen WR.The coding regions of the horse (Equus caballus) and donkey (E. asinus) luteinizing hormone (LH) beta-subunit transcripts were cloned from pituitary gland RNA, in order to investigate their relationships to the corresponding equine chorionic gonadotropin (CG) beta-subunits and to further understand the unusual receptor-binding properties of equine LH and CG. The horse and donkey LH beta-subunit sequences were very similar (97% identity at the nucleotide (nt) level; 93% at the amino acid (aa) level), confirming their very close evolutionary linkage and also indicating that the C-terminal extens...
Dudhia J, Platt D.Investigation of the structure of the equine articular cartilage link protein (LP) from individuals ranging in age from 1 to 15 years identified 3 distinct isoforms having molecular weights of 46,000, 43,000 and 41,000. The relative amounts of each of the 3 isoforms altered with age. The largest form did not change with age; however, amounts of the Mr 43,000 and 41,000 forms increased with increasing age. The results suggested that an accumulation, in the extracellular matrix of cartilage, of these 2 smaller products may have arisen from proteolytic cleavage. The complete amino acid sequence o...
Ellis SA, Martin AJ, Holmes EC, Morrison WI.Nineteen horse MHC class I specificities have been serologically identified previously at a single locus (ELA-A), and two other specificities appear to be coded at other loci. Biochemical studies indicate that there are at least two expressed loci. In order to establish the number of transcribed horse MHC class I genes, we made a cDNA library from a heterozygous animal (ELA-A3/A7), and screened for positive clones using a bovine class I probe. More than 200 class I clones were isolated in this way, and so far seven unique full length sequences have been identified. All of the sequences are pre...
Yoshida S, Yamanouchi K, Hasegawa T, Ikeda A, Suzuki M, Chang KT, Matsuyama S, Nishihara M, Takahashi M.cDNAs encoding equine inhibin/activin beta A subunit were isolated from an equine follicle cDNA library and characterized. Using primers based on the rat inhibin/activin beta A subunit cDNA sequence, a RT-PCR was performed to generate the probe for screening. Four positive clones were isolated. Analysis of the nucleotide sequence of these clones revealed that two pairs of identical clones were present, Eq-beta A-1 (0.9 kb) and Eq-beta A-2 (1.5 kb). Eq-beta A-2 clone contained a complete open reading frame encoding 426 amino acids. The deduced amino acid sequence of equine inhibin/activin beta ...
Zhao Y, Holden VR, Smith RH, O'Callaghan DJ.The UL3 protein of equine herpesvirus 1 (EHV-1) KyA strain is a homolog of the ICP27 alpha regulatory protein of herpes simplex virus type 1 (HSV-1) and the ORF 4 protein of varicella-zoster virus. To characterize the regulatory function of the UL3 gene product, a UL3 gene expression vector (pSVUL3) and a vector expressing a truncated version of the UL3 gene (pSVUL3P) were generated. These effector plasmids, in combination with an EHV-1 immediate-early (IE) gene expression vector (pSVIE) and chimeric EHV-1 promoter-chloramphenicol acetyltransferase (CAT) reporter constructs, were used in trans...
Timoney JF, Walker J, Zhou M, Ding J.Streptococcus equi subsp. zooepidemicus, a Lancefield group C streptococcus, is a frequently isolated opportunist pathogen from a variety of animal hosts, including the horse. Previous studies have indicated that equine strains carry antigens with characteristics of the antiphagocytic M proteins on the Lancefield groups A and G streptococci. We have cloned a protective M-like protein gene (SzPW60) of an equine strain of S. equi subsp. zooepidemicus W60 and determined its sequence. This gene encodes a protein with a molecular weight of 40,123 which protects mice against subsp. zooepidemicus but...
Johansson KE, Pettersson B, Uhlén M, Gunnarsson A, Malmqvist M, Olsson E.Seven Swedish isolates of Ehrlichia species from the blood of four dogs and three horses with clinical granulocytic ehrlichiosis, were identified by direct solid phase DNA sequencing of polymerase chain reaction (PCR) products from the 16S rRNA gene. The amplified DNA fragments were produced with primers complementary to the universal regions, U1, U2, U5 and U8 of the 16S rRNA molecule. Identical sequences were obtained from all seven isolates. This nucleotide sequence was similar to the sequences deposited in GenBank for Ehrlichia phagocytophila and E equi. The sequence of the Swedish ehrlich...
Schelp C, Böse R, Micha A, Hentrich B.High-titre equine immune sera were used to screen a lambda gt 11 expression library of Babesia equi cDNA fragments. Two cDNA clones which did not cross-hybridize to each other were studied. Both clones hybridized specifically to DNA from B. equi but not to DNA from B. caballi, B. divergens or B. ovis. Recombinant proteins were expressed as glutathione S-transferase (GST) fusion proteins with apparent molecular weights of 40 kDa and 75 kDa. Polyclonal antibodies directed against the 40 kDa and 75 kDa recombinant proteins detected native antigens of 55 kDa and 50 kDa respectively in crude lysate...
Pailhoux E, Cribiu EP, Parma P, Cotinot C.In this study, cytogenetic analysis of an infertile mare revealed a 64, XY karyotype. The XY sex-reversed animal had a female phenotype with gonadal dysgenesis. Using Southern blot analysis, we tested for the presence of two Y-specific genes SRY and ZFY by using DNA isolated from peripheral blood leukocytes. The results showed that at least the DNA-binding domain of the SRY gene was deleted from the Y chromosome of the XY mare but that the ZFY gene was present on this chromosome.
Nasir L, Reid SW.The evolutionary conserved region of the equine homologue of the p53 gene from the donkey genome was PCR amplified and cloned. The 1380 bp fragment consisted of exons 5 to 9 and the intervening introns. The exonic and intronic DNA sequences showed a variable but high level of homology with previously published human sequences. The aminoacid sequences corresponding to the evolutionary conserved domains II, III, and V were identical to the human regions, whilst domain IV was 96% homologous.
Schrenzel MD, Ferrick DA.Horse (Equus caballus) T-cell receptor alpha (TCRA), gamma (TCRG), and delta (TCRD) chain genes were isolated from a cDNA library and characterized. Five unique TCRAV families, including four full-length sequences, five distinct TCRAJ genes, and a single TCRAC gene were identified. TCRAV genes had closest homology with human sequences and least similarity to rat genes. Among eight horse TCRG genes, two distinct constant region genes with considerable variation in the connecting region were identified, but no variable or joining genes were present. Southern blot hybridization confirmed the pres...
Marchio SP, El-Sheikh Ali H, Scott MA, Barbosa Fernandes C, Scoggin KE, Troedsson M, Boakari Y.Despite its critical role in protecting the fetus, the amniotic membrane remains poorly understood in the context of disease response. The equine amniotic membrane is an important physical barrier to the amniotic compartment, and there is evidence that it may contribute to surfactant synthesis. Surfactants are essential for normal fetal lung development, and disruptions in its availability may be linked to future neonatal complications. Therefore, understanding the molecular changes that occur in fetal-maternal tissues during placentitis would clarify how this condition leads to abortion, pret...
Frontiers in geneticsAugust 29, 2025
Volume 16 1651628 doi: 10.3389/fgene.2025.1651628
Su Y, Ren W, Ma S, Meng J, Yao X, Zeng Y, Li Z, Li L, Wang R, Wang J.This study employed Yili horses participating in a 5000-meter race as a model to investigate exercise-induced gene expression alterations in peripheral blood using whole transcriptome sequencing. Jugular vein blood samples from the three leading horses were collected pre- and immediately post-race, yielding 2,171 differentially expressed mRNAs (2,080 upregulated, 91 downregulated), 4,375 differentially expressed LncRNAs (4,354 upregulated), and 68 differentially expressed circRNAs (64 upregulated). GO/KEGG analyses demonstrated significant enrichment of differential mRNAs in transmembrane tran...
Wubuli A, Su Y, Yao X, Meng J, Wang J, Zeng Y, Li L, Ren W.The Kazakh horse, a versatile breed, is renowned for stable genetic performance and strong tolerance to coarse feed. Sex is a key factor influencing skeletal muscle development. However, the mechanisms underlying sex-specific regulation of equine muscle growth remain obscure. This study employed transcriptomic analysis to investigate sex-associated molecular differences in skeletal muscle of Kazakh horses. The experimental cohort comprised four three-year-old Kazakh stallions and four three-year-old Kazakh mares. After slaughter, six groups of muscle samples were collected immediately, includi...
Ren W, Zhou J, Zhu J, Zhang J, Zhao X, Yao X.The ovary is among the earliest organs to undergo age-related degeneration, limiting the reproductive potential of elite horses and constraining the growth of the equine industry. Follicular development during estrus is a key determinant of fertility, yet the molecular mechanisms underlying its decline, particularly at the level of specific ovarian cell types, remain poorly understood in equids. Here, we constructed a single-cell transcriptomic atlas to investigate ovarian changes in Kazakh horses. Using single-cell RNA sequencing (scRNA-seq), we profiled 112,861 cells from follicle-containing...
Zhou Y, Yao X, Meng J, Wang J, Zeng Y, Li L, Ren W.The Kazakh horse is a highly valuable indigenous Chinese breed known for its use in both milk and meat production. However, the mechanisms underlying color variation in the abdominal adipose tissue of this breed remain poorly understood. In this study, the sequencing of non-coding RNAs (ncRNAs) was conducted on abdominal adipose tissue of different colors from Kazakh horses, with the aim of investigating the molecular mechanisms responsible for this variation. A total of 205 differentially expressed long non-coding RNAs (DELncRNAs) including , , and ; 52 differentially expressed microRNAs (DEm...
Wójtowicz A, Sadowska A, Piotrowska-Tomala K, Szóstek-Mioduchowska A.The role of AREG in the development of fibrosis in the progression of endometrosis in mare remains unknown. We aimed to determine the effects of AREG on fibroblast functional characteristics as well as the expression of extracellular matrix (ECM)-associated genes in fibroblast derived from non-fibrotic and fibrotic equine endometria. Our findings suggest that the mechanisms associated with ECM remodeling regulated by AREG in non-fibrotic fibroblasts may be dysregulated in the progression of fibrosis in endometrosis.
An T, Dugarjaviin M, Han H.The Mongolian horse, one of the oldest and most genetically diverse breeds, exhibits a wide variety of coat colors and patterns, including both wild-type and unique features. A notable characteristic of dun Mongolian horses is the presence of Bider markings-symmetrical, black-mottled patterns observed on the shoulder blades. These markings are also seen in Przewalski's horses. The dun coat color, a common wild-type phenotype in domestic horses, is characterized by pigment dilution with distinct dark areas and is regulated by mutations in the gene. This study aimed to investigate the role of ...
Köhne M, Diel E, Packeiser EM, Böttcher D, Tönissen A, Unruh C, Goericke-Pesch S, Ulrich R, Sieme H.In the past, most research in equine reproduction has been performed in vivo but the use of in vitro and ex vivo models has recently increased. This study aimed to evaluate the functional stability of an ex vivo hemoperfused model for equine uteri with molecular characterization of marker genes and their proteins. In addition, the study validated the respective protein expression and the aptness of the software QuPath for identifying and scoring immunohistochemically stained equine endometrium. After collection, uteri (n = 12) were flushed with preservation solution, transported to the labor...
Bubenikova J, Plasil M, Futas J, Stejskalova K, Klumplerova M, Oppelt J, Suchentrunk F, Burger PA, Horin P.The immunogenome is the part of the genome that underlies immune mechanisms and evolves under various selective pressures. Two complex regions of the immunogenome, major histocompatibility complex (MHC) and natural killer cell receptor (NKR) genes, play an important role in the response to selective pressures of pathogens. Their importance is expressed by their genetic polymorphism at the molecular level, and their diversity associated with different types of diseases at the population level. Findings of associations between specific combinations of MHC/NKR haplotypes with different diseases i...
Martineau M, Ambroset C, Lefebvre S, Kokabi É, Léon A, Tardy F.Mycoplasma spp. are wall-less bacteria with small genomes (usually 0.5-1.5 Mb). Many Mycoplasma (M.) species are known to colonize the respiratory tract of both humans and livestock animals, where they act as primary pathogens or opportunists. M. equirhinis was described for the first time in 1975 in horses but has been poorly studied since, despite regular reports of around 14% prevalence in equine respiratory disorders. We recently showed that M. equirhinis is not a primary pathogen but could play a role in co-infections of the respiratory tract. This study was a set up to propose the fir...
Pielok A, Kępska M, Steczkiewicz Z, Grobosz S, Bourebaba L, Marycz K.Medicinal signaling cells (MSC) exhibit distinct molecular signatures and biological abilities, depending on the type of tissue they originate from. Recently, we isolated and described a new population of stem cells residing in the coronary corium, equine hoof progenitor cells (HPCs), which could be a new promising cell pool for the treatment of laminitis. Therefore, this study aimed to compare native populations of HPCs to well-established adipose-derived stem cells (ASCs) in standard culture conditions and in a pro-inflammatory milieu to mimic a laminitis condition. ASCs and HPCs were either...
Johnson MG, Adam E, Watt A, Page AE.Accumulating high-speed exercise has been identified as a significant risk factor for catastrophic injuries in racing Thoroughbreds. Injuries, regardless of severity, are a main cause of withdrawal from the racing industry, raising animal welfare concerns and resulting in significant economic losses. While most of the current literature focuses on injuries incurred during racing rather than training, the present study aims to help fill this gap. As such, peripheral blood was collected weekly, prior to exercise or administration of medication, from eighteen, two-year-old Thoroughbreds throughou...
Dall'Olio S, Davoli R, Costa LN.The research focuses on the analysis of the catechol-O-methyltransferase (COMT) gene in horses. The study was specifically interested in the role this gene might have in behavioral trait variability due […]
Potocki L, Bugno-Poniewierska M, Tischner M, Wnuk M.The development of molecular techniques with fluorochromes has had an invaluable impact on discovering the nature of chromatin structure. Here, we show the application of a locus specific identifier probe (LSI) for precise and selective visualization of the horse IGF2 gene in the metaphase, interphase nuclei and sperm cells. Our study may be helpful for interpretation of results of interphase fluorescence in situ hybridization (I-FISH). We analyze and discuss the variation in the number and localization of FISH signals in somatic and sperm cells of horse.