Evolutionary biology and horses focus on the study of the evolutionary processes that have shaped the development, adaptation, and diversification of the Equus genus. This field examines the genetic, morphological, and ecological changes that have occurred over millions of years, leading to the modern horse. Researchers explore the transition from small, multi-toed ancestors to the large, single-toed horses of today, analyzing fossil records, genetic data, and environmental factors that influenced these changes. This page compiles peer-reviewed research studies and scholarly articles that investigate the evolutionary history, genetic adaptations, and ecological interactions of horses, providing insights into their development and survival strategies throughout history.
Mialhe PJ.In order to verify possible preferential prey selection by Desmodus rotundus feeding on domestic herbivores in the Municipality of São Pedro (São Paulo, Brazil), vampire bat attacks were surveyed at rural properties where domestic herbivores were being raised and attack frequencies of D. rotundus on the total herd and on different species were calculated. The analysis found that the most frequently attacked herbivores were cattle and horses. The chi-square test (χ2), with a significance level of 5% corroborated the comparative analysis of attack frequency in properties that had these two sp...
Landolt GA.For decades the horse has been viewed as an isolated or "dead-end" host for influenza A viruses, with equine influenza virus being considered as relatively stable genetically. Although equine influenza viruses are genetically more stable than those of human lineage, they are by no means in evolutionary stasis. Moreover, recent transmission of equine-lineage influenza viruses to dogs also challenges the horse's status as a dead-end host. This article reviews recent developments in the epidemiology and evolution of equine influenza virus. In addition, the clinical presentation of equine influenz...
Prado JL, Alberdi MT.The contemporary South American mammalian communities were determined by the emergence of the Isthmus of Panama and by the profound climatic oscillations during the Pleistocene. Horses and gomphotheres were 2 very conspicuous groups of immigrant mammals from North America that arrived in South America during the Pleistocene. The present study compiles updated data on the phylogeny, systematics and ecology of both groups in South America. The horses in South America are represented by 2 genera, Hippidion and Equus, as are the gomphotheres, represented by Cuvieronius and Stegomastodon. Both gene...
Rivals F, Julien MA, Kuitems M, Van Kolfschoten T, Serangeli J, Drucker DG, Bocherens H, Conard NJ.The paleodietary traits of the equid population from Schöningen 13 II-4 were investigated through tooth mesowear and microwear analyses, as well as stable isotopic analyses. The mesowear pattern observed on the upper teeth indicates a low abrasion diet with a significant amount of browse in the diet of the horses. The tooth microwear analysis and the isotopic data confirm that the horses from Schöningen 13 II-4 were mixed feeders, like many populations from other Pleistocene localities in Northern and Eastern Europe. Microwear also provides information on seasonal changes in the diet of the ...
Trewby H, Ayele G, Borzacchiello G, Brandt S, Campo MS, Del Fava C, Marais J, Leonardi L, Vanselow B, Biek R, Nasir L.Papillomaviruses are a family of slowly evolving DNA viruses and their evolution is commonly linked to that of their host species. However, whilst bovine papillomavirus-1 (BPV-1) primarily causes warts in its natural host, the cow, it can also cause locally aggressive and invasive skin tumours in equids, known as sarcoids, and thus provides a rare contemporary example of cross-species transmission of a papillomavirus. Here, we describe the first phylogenetic analysis of BPV-1 in equine sarcoids to our knowledge, allowing us to explore the evolutionary history of BPV-1 and investigate its cross...
Rash A, Woodward A, Bryant N, McCauley J, Elton D.H3N8 equine influenza virus (EIV) has caused disease outbreaks in horses across the world since its first isolation in 1963. However, unlike human, swine and avian influenza, there is relatively little sequence data available for this virus. The majority of published sequences are for the segment encoding haemagglutinin (HA), one of the two surface glycoproteins, making it difficult to study the evolution of the other gene segments and determine the level of reassortment occurring between sub-lineages. Methods: To facilitate the generation of full genome sequences for EIV, we developed a simpl...
Dong J, Cook FR, Haga T, Horii Y, Norimine J, Misawa N, Goto Y, Zhu W.Although equine infectious anemia virus (EIAV) poses a major threat to the equine industry worldwide, the molecular epidemiology of this virus is poorly understood. Recently, an EIAV strain (EIAVMiyazaki2011-A) representing a new monophyletic group was discovered in feral horses in southern Japan. In the present study, the EIAVMiyazaki2011-A proviral genome is compared with evolutionarily divergent EIAV isolates to investigate conservation of functional elements or motifs within the long terminal repeats (LTRs) and structural genes. This analysis represents a significant step forward in increa...
Takasu M, Ishihara N, Tozaki T, Kakoi H, Maeda M, Mukoyama H.To determine genetic characteristics of the maternal lineage of the Kiso horse based on polymorphisms of the mitochondrial DNA D-loop region, we collected blood samples from 136 Kiso horses, 91% of the entire population, and sequenced 411 bp from 15,437 to 15,847 in the region. First of all, we estimated the demographic history; by searching homology between the obtained and known sequences using Basic Local Alignment Search Tool, by mismatch analysis to evaluate the mutation processes using Arlequin, and by building a phylogenetic tree showing the relationship of the mtDNA haplotypes for 24 h...
Collins PJ, Vachieri SG, Haire LF, Ogrodowicz RW, Martin SR, Walker PA, Xiong X, Gamblin SJ, Skehel JJ.In 2004 an hemagglutinin 3 neuraminidase 8 (H3N8) equine influenza virus was transmitted from horses to dogs in Florida and subsequently spread throughout the United States and to Europe. To understand the molecular basis of changes in the antigenicity of H3 hemagglutinins (HAs) that have occurred during virus evolution in horses, and to investigate the role of HA in the equine to canine cross-species transfer, we used X-ray crystallography to determine the structures of the HAs from two antigenically distinct equine viruses and from a canine virus. Structurally all three are very similar with...
Metzger J, Tonda R, Beltran S, Agueda L, Gut M, Distl O.Domestication has shaped the horse and lead to a group of many different types. Some have been under strong human selection while others developed in close relationship with nature. The aim of our study was to perform next generation sequencing of breed and non-breed horses to provide an insight into genetic influences on selective forces. Results: Whole genome sequencing of five horses of four different populations revealed 10,193,421 single nucleotide polymorphisms (SNPs) and 1,361,948 insertion/deletion polymorphisms (indels). In comparison to horse variant databases and previous reports, w...
Cooper KL, Sears KE, Uygur A, Maier J, Baczkowski KS, Brosnahan M, Antczak D, Skidmore JA, Tabin CJ.A reduction in the number of digits has evolved many times in tetrapods, particularly in cursorial mammals that travel over deserts and plains, yet the underlying developmental mechanisms have remained elusive. Here we show that digit loss can occur both during early limb patterning and at later post-patterning stages of chondrogenesis. In the 'odd-toed' jerboa (Dipus sagitta) and horse and the 'even-toed' camel, extensive cell death sculpts the tissue around the remaining toes. In contrast, digit loss in the pig is orchestrated by earlier limb patterning mechanisms including downregulation of...
Gonzalez G, Marshall JF, Morrell J, Robb D, McCauley JW, Perez DR, Parrish CR, Murcia PR.Influenza A viruses (IAVs) can jump species barriers and occasionally cause epidemics, epizootics, pandemics, and panzootics. Characterizing the infection dynamics at the target tissues of natural hosts is central to understanding the mechanisms that control host range, tropism, and virulence. Canine influenza virus (CIV; H3N8) originated after the transfer of an equine influenza virus (EIV) into dogs. Thus, comparing CIV and EIV isolates provides an opportunity to study the determinants of influenza virus emergence. Here we characterize the replication of canine, equine, and human IAVs in the...
Dolejska M, Villa L, Minoia M, Guardabassi L, Carattoli A.To determine the structure of two multidrug-resistant IncHI1 plasmids carrying blaCTX-M-1 in Escherichia coli isolates disseminated in an equine clinic in the Czech Republic. Methods: A complete nucleotide sequencing of 239 kb IncHI1 (pEQ1) and 287 kb IncHI1/X1 (pEQ2) plasmids was performed using the 454-Genome Sequencer FLX system. The sequences were compared using bioinformatic tools with other sequenced IncHI1 plasmids. Results: A comparative analysis of pEQ1 and pEQ2 identified high nucleotide identity with the IncHI1 type 2 plasmids. A novel 24 kb module containing an operon involved in ...
Na W, Hong M, Yeom M, Kim S, Kim JK, Song D.We analyzed the complete genome sequence containing the 3' and 5' noncoding regions (NCRs) of the Korean H3N8 equine influenza virus (EIV), which will provide a better understanding of the pathogenesis, transmission, and evolution of EIV.
Huang J, Zhao Y, Shiraigol W, Li B, Bai D, Ye W, Daidiikhuu D, Yang L, Jin B, Zhao Q, Gao Y, Wu J, Bao W, Li A, Zhang Y, Han H, Bai H, Bao Y, Zhao L....Karyotypic diversification is more prominent in Equus species than in other mammals. Here, using next generation sequencing technology, we generated and de novo assembled quality genomes sequences for a male wild horse (Przewalski's horse) and a male domestic horse (Mongolian horse), with about 93-fold and 91-fold coverage, respectively. Portion of Y chromosome from wild horse assemblies (3 M bp) and Mongolian horse (2 M bp) were also sequenced and de novo assembled. We confirmed a Robertsonian translocation event through the wild horse's chromosomes 23 and 24, which contained sequences th...
Karamendin K, Kydyrmanov A, Kasymbekov Y, Khan E, Daulbayeva K, Asanova S, Zhumatov K, Seidalina A, Sayatov M, Fereidouni SR.Equine influenza (EI) continues to be an important respiratory pathogen of horses worldwide. Since 2007 several outbreaks of EI have occurred in Central Asian countries, including Kazakhstan, western Mongolia, India and western China. Phylogenetic analysis showed that two H3N8 equine influenza virus (EIV) isolates from Kazakhstan, A/equine/Almaty/26/2007 and A/equine/South Kazakhstan/236/12, were related to Florida sublineage 2, with high similarity to EIVs circulating in the same period in neighbouring countries. New outbreaks of EI during 2011 and 2012 in Kazakhstan and other Central Asian c...
Birn-Jeffery AV, Higham TE.Animals must continually respond dynamically as they move through complex environments, and slopes are a common terrain on which legged animals must move. Despite this, non-level locomotion remains poorly understood. In this study, we first review the literature on locomotor mechanics, metabolic cost, and kinematic strategies on slopes. Using existing literature we then performed scaling analyses of kinematic variables, including speed, duty factor, and stride-length across a range of body sizes from ants to horses. The studies that examined locomotion on inclines vastly outnumbered those focu...
Bigi D, Perrotta G, Zambonelli P.To understand the origin and genetic diversity of Italian horses, mitochondrial DNA D-loop sequences were generated for 163 horses from seven breeds. Sequence analysis of a 480-bp segment revealed a total of 84 haplotypes with 57 polymorphic sites, indicating multiple maternal origins and high genetic diversity. Comparison of the haplotypes with the equine mtDNA haplotype/haplogroup nomenclature showed a haplogroup distribution in the Italian breeds more similar to that found in the Middle East breeds than in the European breeds, probably due to the economic and cultural relationship with the ...
Song SD, Barker SC, Shao R.The genus Haematopinus contains 21 species of blood-sucking lice, parasitizing both even-toed ungulates (pigs, cattle, buffalo, antelopes, camels and deer) and odd-toed ungulates (horses, donkeys and zebras). The mitochondrial genomes of the domestic pig louse, Haematopinus suis, and the wild pig louse, Haematopinus apri, have been sequenced recently; both lice have fragmented mitochondrial genomes with 37 genes on nine minichromosomes. To understand whether the composition of mitochondrial minichromosomes and the gene content and gene arrangement of each minichromosome are stable within the g...
Park W, Kim J, Kim HJ, Choi J, Park JW, Cho HW, Kim BW, Park MH, Shin TS, Cho SK, Park JK, Kim H, Hwang JY, Lee CK, Lee HK, Cho S, Cho BW.Previous studies of horse RNA-seq were performed by mapping sequence reads to the reference genome during transcriptome analysis. However in this study, we focused on two main ideas. First, differentially expressed genes (DEGs) were identified by de novo-based analysis (DBA) in RNA-seq data from six Thoroughbreds before and after exercise, here-after referred to as "de novo unique differentially expressed genes" (DUDEG). Second, by integrating both conventional DEGs and genes identified as being selected for during domestication of Thoroughbred and Jeju pony from whole genome re-sequencing (WG...
Famoso NA, Davis EB.Four groups of equids, "Anchitheriinae," Merychippine-grade Equinae, Hipparionini, and Equini, coexisted in the middle Miocene, but only the Equini remains after 16 Myr of evolution and extinction. Each group is distinct in its occlusal enamel pattern. These patterns have been compared qualitatively but rarely quantitatively. The processes influencing the evolution of these occlusal patterns have not been thoroughly investigated with respect to phylogeny, tooth position, and climate through geologic time. We investigated Occlusal Enamel Index, a quantitative method for the analysis of the comp...
Promerová M, Andersson LS, Juras R, Penedo MC, Reissmann M, Tozaki T, Bellone R, Dunner S, Hořín P, Imsland F, Imsland P, Mikko S, Modrý D....For centuries, domestic horses have represented an important means of transport and served as working and companion animals. Although their role in transportation is less important today, many horse breeds are still subject to intense selection based on their pattern of locomotion. A striking example of such a selected trait is the ability of a horse to perform additional gaits other than the common walk, trot and gallop. Those could be four-beat ambling gaits, which are particularly smooth and comfortable for the rider, or pace, used mainly in racing. Gaited horse breeds occur around the glob...
Millard JT, Chuang E, Lucas JS, Nagy EE, Davis GT.A simple and robust biochemistry laboratory experiment is described that uses restriction fragment length polymorphism (RFLP) of polymerase chain reaction (PCR) products to verify the identity of a potentially valuable horse. During the first laboratory period, students purify DNA from equine samples and amplify two loci of mitochondrial DNA. During the second laboratory period, students digest PCR products with restriction enzymes and analyze the fragment sizes through agarose gel electrophoresis. An optional step of validating DNA extracts through realtime PCR can expand the experiment to th...
Yin X, Lin Y, Cai W, Wei P, Wang X.Equine infectious anemia virus (EIAV) is an important animal model for understanding the relationship between viral persistence and the host immune response during lentiviral infections. Comparison and analysis of the codon usage model between EIAV and its hosts is important for the comprehension of viral evolution. In our study, the codon usage pattern of EIAV was analyzed from the available 29 full-length EIAV genomes through multivariate statistical methods. Results: Effective number of codons (ENC) suggests that the codon usage among EIAV strains is slightly biased. The ENC-plot analysis d...
Hendrickson SL.Life at high altitude results in physiological and metabolic challenges that put strong evolutionary pressure on performance due to oxidative stress, UV radiation and other factors dependent on the natural history of the species. To look for genes involved in altitude adaptation in a large herbivore, this study explored genome differentiation between a feral population of Andean horses introduced by the Spanish in the 1500s to the high Andes and their Iberian breed relatives. Results: Using allelic genetic models and Fst analyses of ~50 K single nucleotide polymorphisms (SNPs) across the horse...
Shoemaker L, Clauset A.Horses (family Equidae) are a classic example of adaptive radiation, exhibiting a nearly 60-fold increase in maximum body mass and a peak taxonomic diversity of nearly 100 species across four continents. Such patterns are commonly attributed to niche competition, in which increased taxonomic diversity drives increased size disparity. However, neutral processes, such as macroevolutionary 'diffusion', can produce similar increases in disparity without increased diversity. Using a comprehensive database of Equidae species size estimates and a common mathematical framework, we measure the contribu...
How MJ, Zanker JM.The functional significance of the zebra coat stripe pattern is one of the oldest questions in evolutionary biology, having troubled scientists ever since Charles Darwin and Alfred Russel Wallace first disagreed on the subject. While different theories have been put forward to address this question, the idea that the stripes act to confuse or 'dazzle' observers remains one of the most plausible. However, the specific mechanisms by which this may operate have not been investigated in detail. In this paper, we investigate how motion of the zebra's high contrast stripes creates visual effects tha...
Cozzi B, Povinelli M, Ballarin C, Granato A.The horse is a common domestic animal whose anatomy has been studied since the XVI century. However, a modern neuroanatomy of this species does not exist and most of the data utilized in textbooks and reviews derive from single specimens or relatively old literature. Here, we report information on the brain of Equus caballus obtained by sampling 131 horses, including brain weight (as a whole and subdivided into its constituents), encephalization quotient (EQ), and cerebellar quotient (CQ), and comparisons with what is known about other relevant species. The mean weight of the fresh brains in o...
Zhang T, Lu H, Chen C, Jiang H, Wu S.In order to protect the genetic resource of native horse breeds, the genetic diversity of mitochondrial DNA (mtDNA) D-loop of three native horse breeds in western China were investigated. Forty-three 600 bp mtDNA D-loop sequences were analyzed by PCR and sequencing techniques, 33 unique haplotypes with 70 polymorphic sites were detected in these horses, which account for 11.67% of 600 bp sequence analyzed, showing the abundant genetic diversity of the three native horse breeds in western China. The Neighbour-Joining (NJ) phylogenetic tree based on 247 bp of 43 D-loop sequences demonstrated the...
Chikuni K, Muroya S, Nakajima I.Nucleotide sequences which included the full coding region for three types of myosin heavy chain (MyHC) isoforms were determined from equine skeletal muscles. The deduced amino acid sequences were 1937, 1938, and 1935 residues for the MyHC-2a, -2x, and -slow, respectively. No MyHC-2b isoform was amplified from the equine muscle cDNA except for one pseudogene fragment. One nucleotide was inserted in the coding region of the equine pseudogene product, a minute amount of which was expressed in the skeletal muscle. The 596 bp sequence of the equine MyHC pseudogene was categorized into the MyHC-2b ...
Taylor WTT, Bayarsaikhan J, Tuvshinjargal T, Bender S, Tromp M, Clark J, Lowry KB, Houle JL, Staszewski D, Whitworth J, Fitzhugh W, Boivin N.From the American West to the steppes of Eurasia, the domestic horse transformed human societies, providing rapid transport, communication, and military power, and serving as an important subsistence animal. Because of the importance of oral equipment for horse riding, dentistry is an essential component of modern horse care. In the open grasslands of northeast Asia, horses remain the primary form of transport for many herders. Although free-range grazing on gritty forage mitigates many equine dental issues, contemporary Mongolian horsemen nonetheless practice some forms of dentistry, includin...
Ahrens E, Stranzinger G.Previous research revealed that the karyotypes of Equus przewalskii (2n = 66) and Equus caballus (2n = 64) differ by one pair of metacentric chromosomes, present in ECA but not in EPR, and two pairs of acrocentric chromosomes found only in the EPR karyotype. The formation of a trivalent during meiosis in a male F1 hybrid and the homologies in G-banding patterns suggest that ECA 5 corresponds to two acrocentric EPR chromosomes resulting from a Robertsonian fusion or fission event. Chromosomal investigations of a female interspecies F1 hybrid including banded karyograms and fluorescence in situ ...
McLoughlin PD, Lysak K, Debeffe L, Perry T, Hobson KA.Sea-to-land nutrient transfers can connect marine food webs to those on land, creating a dependence on marine webs by opportunistic species. We show how nitrogen, imported by gray seals, Halichoerus grypus, and traced through stable isotope (δ N) measurements in marram grass, Ammophila breviligulata, significantly alters foraging behavior of a free-roaming megaherbivore (feral horses, Equus ferus caballus) on Sable Island, Canada. Values of δ N correlated with protein content of marram and strongly related to pupping-seal densities, and positively influenced selective foraging by horses. The...
Dam Van P, Desmecht D, Garigliany MM, Bui Tran Anh D, Van Laere AS.Type I/III interferons provide powerful and universal innate intracellular defense mechanisms against viruses. Among the antiviral effectors induced, Mx proteins of some species appear as key components of defense against influenza A viruses. It is expected that such an antiviral protein must display a platform dedicated to the recognition of said viruses. In an attempt to identify such platform in human MxA, an evolution-guided approach capitalizing on the antagonistic arms race between MxA and its viral targets and the genomic signature it left on primate genomes revealed that the surface-ex...
The Journal of heredityNovember 8, 2013
Volume 105, Issue 2 163-172 doi: 10.1093/jhered/est075
McCoy AM, Schaefer R, Petersen JL, Morrell PL, Slamka MA, Mickelson JR, Valberg SJ, McCue ME.A dominantly inherited gain-of-function mutation in the glycogen synthase (GYS1) gene, resulting in excess skeletal muscle glycogen, has been identified in more than 30 horse breeds. This mutation is associated with the disease Equine Polysaccharide Storage Myopathy Type 1, yet persists at high frequency in some breeds. Under historical conditions of daily work and limited feed, excess muscle glycogen may have been advantageous, driving the increase in frequency of this allele. Fine-scale DNA sequencing in 80 horses and genotype assays in 279 horses revealed a paucity of haplotypes carrying th...
Feh C, Munkhtuya B.The sexual selection hypothesis explains infanticide by males in many mammals. In our 11-year study, we investigated this hypothesis in a herd of Przewalski's horses where we had witnessed infanticidal attacks. Infanticide was highly conditional and not simply linked to takeovers. Attacks occurred in only five of 39 cases following a takeover, and DNA paternity revealed that, although infanticidal stallions were not the genetic fathers in four cases out of five, stallions present at birth did not significantly attempt to kill unrelated foals. Infanticide did not reduce birth intervals; only in...
Abdel-Moneim AS, Shehab GM, Abu-Elsaad AA.Phylogenetic and evolutionary patterns of the six internal genes of an equine H5N1 influenza A virus isolated in Egypt on 2009 were analyzed using direct sequencing. All of the internal genes of the equine H5N1 strain showed a genetic pattern potentially related to Eurasian lineages. Variable dendrogram topologies revealed an absence of reassortment in the equine strain while confirming its close relatedness to other Egyptian H5N1 strains from human and avian species. The equine strain is characterized by a variety of amino acid substitutions in six internal proteins compared to the available ...
Maury W, Thompson RJ, Jones Q, Bradley S, Denke T, Baccam P, Smazik M, Oaks JL.Equine infectious anemia virus (EIAV) is a lentivirus with in vivo cell tropism primarily for tissue macrophages; however, in vitro the virus can be adapted to fibroblasts and other cell types. Tropism adaptation is associated with both envelope and long terminal repeat (LTR) changes, and findings strongly suggest that these regions of the genome influence cell tropism and virulence. Furthermore, high levels of genetic variation have been well documented in both of these genomic regions. However, specific EIAV nucleotide or amino acid changes that are responsible for cell tropism changes have ...
Liu S, Yang Y, Pan Q, Sun Y, Ma H, Liu Y, Wang M, Zhao C, Wu C.Extremely low nucleotide diversity of modern horse Y-chromosome has been reported, and only poor phylogenetic resolution could be resulted from limited Y-chromosome markers. In this study, three types of horse Y-chromosome markers, including Single-nucleotide polymorphisms (SNPs), copy number variants (CNVs), and allele-specific CNVs, were developed by screening more than 300 male horses from 23 indigenous Chinese horse populations and 4 imported horse breeds. Fourteen segregating sites including a novel SNP in the AMELY gene were found in approximately 53 kb of male-specific Y-chromosome sequ...
Catania KC.In March 1800, Alexander von Humboldt observed the extraordinary spectacle of native fisherman collecting electric eels (Electrophorus electricus) by "fishing with horses" [von Humboldt A (1807) Ann Phys 25:34-43]. The strategy was to herd horses into a pool containing electric eels, provoking the eels to attack by pressing themselves against the horses while discharging. Once the eels were exhausted, they could be safely collected. This legendary tale of South American adventures helped propel Humboldt to fame and has been recounted and illustrated in many publications, but subsequent investi...
Almarzook S, Reissmann M, Brockmann GA.Arabian horse registries classify Arabian horses based on their dam lineages into five main strains. To test the maternal origin of Syrian Arabian horses, 192 horses representing the three major strains Saglawi, Kahlawi, and Hamdani were sequenced for 353 bp of their mitochondrial displacement loop (D-loop) region. Sequencing revealed 28 haplotypes comprising 38 sequence variations. The haplotype diversity values were 0.95, 0.91, and 0.90 in Kahlawi, Hamdani, and Saglawi strains, respectively. The pair-wise population differentiation estimates (Fst) between strains were low, ranging between 0...
Murphy BA, Vick MM, Sessions DR, Cook RF, Fitzgerald BP.The master mammalian pacemaker in the brain controls numerous diverse physiological and behavioral processes throughout the organism. Timing information is continually transmitted from the master clock to peripheral organs to synchronize rhythmic daily oscillations of clock gene transcripts and control local physiology. To investigate the presence of peripheral clocks in the horse, quantitative real-time RT-PCR assays were designed to detect levels of equine clock genes. Expression profiles for Per2, Bmal1 and Cry1 were first determined in a synchronized equine cell line. Subsequently, express...
Amat JAR, Patton V, Chauché C, Goldfarb D, Crispell J, Gu Q, Coburn AM, Gonzalez G, Mair D, Tong L, Martinez-Sobrido L, Marshall JF, Marchesi F....The mechanisms and consequences of genome evolution on viral fitness following host shifts are poorly understood. In addition, viral fitness -the ability of an organism to reproduce and survive- is multifactorial and thus difficult to quantify. Influenza A viruses (IAVs) circulate broadly among wild birds and have jumped into and become endemic in multiple mammalian hosts, including humans, pigs, dogs, seals, and horses. H3N8 equine influenza virus (EIV) is an endemic virus of horses that originated in birds and has been circulating uninterruptedly in equine populations since the early 1960s. ...
Bennett EA, Weber J, Bendhafer W, Champlot S, Peters J, Schwartz GM, Grange T, Geigl EM.Before the introduction of domestic horses in Mesopotamia in the late third millennium BCE, contemporary cuneiform tablets and seals document intentional breeding of highly valued equids called kungas for use in diplomacy, ceremony, and warfare. Their precise zoological classification, however, has never been conclusively determined. Morphometric analysis of equids uncovered in rich Early Bronze Age burials at Umm el-Marra, Syria, placed them beyond the ranges reported for other known equid species. We sequenced the genomes of one of these ~4500-year-old equids, together with an ~11,000-year-o...
Debeffe L, Poissant J, McLoughlin PD.Costs associated with reproduction are widely known to play a role in the evolution of reproductive tactics with consequences to population and eco-evolutionary dynamics. Evaluating these costs as they pertain to species in the wild remains an important goal of evolutionary ecology. Individual heterogeneity, including differences in individual quality (i.e., among-individual differences in traits associated with survival and reproduction) or state, and variation in environmental and social conditions can modulate the costs of reproduction; however, few studies have considered effects of these ...
Wijers ER, Zijlstra C, Lenstra JA.The major satellite of the horse genome consists of about 1 million copies of a 221-bp tandem repeat unit. By fluorescence in situ hybridization it has been localized in the centromeres of 58 of the 64 horse chromosomes. The donkey genome contains a similar but not identical satellite. Strikingly, the equine repeat did not hybridize to DNA of the Grevy zebra, despite the divergence of the horse and zebra only 3 to 5 million years ago and the ability of these species to crossbreed. The evolution of satellite DNA in the Equidae is more rapid than that in other mammalian families, which may be ex...
Aberle KS, Hamann H, Drögemüller C, Distl O.We analysed a 610-bp mitochondrial (mt)DNA D-loop fragment in a sample of German draught horse breeds and compared the polymorphic sites with sequences from Arabian, Hanoverian, Exmoor, Icelandic, Sorraia and Przewalski's Horses as well as with Suffolk, Shire and Belgian horses. In a total of 65 horses, 70 polymorphic sites representing 47 haplotypes were observed. The average percentage of polymorphic sites was 11.5% for the mtDNA fragment analysed. In the nine different draught horse breeds including South German, Mecklenburg, Saxon Thuringa coldblood, Rhenisch German, Schleswig Draught Hors...
Devi KM, Ghosh SK.Manipuri pony is the geographically distant breed of horse from the five recognized horse breeds found in the Indian subcontinent. The phylogenetic relationship of Manipuri pony with the other breeds is unknown. The diversity in the mitochondrial (mt) DNA D-loop region is employed as an important tool to understand the origin and genetic diversification of domestic horses and to examine genetic relationships among breeds around the world. This study was carried out to understand the maternal lineages of Manipuri pony using the 247 bp region of the mtDNA D-loop. The dataset comprised of eleven ...
Kusliy MA, Vorobieva NV, Tishkin AA, Makunin AI, Druzhkova AS, Trifonov VA, Iderkhangai TO, Graphodatsky AS.The Mongolian horse is one of the most ancient and relatively unmanaged horse breeds. The population history of the Mongolian horse remains poorly understood due to a lack of information on ancient and modern DNA. Here, we report nearly complete mitochondrial genome data obtained from five ancient Mongolian horse samples of the Khereksur and Deer Stone culture (late 2nd to 1st third of the 1st millennium BC) and one ancient horse specimen from the Xiongnu culture (1st century BC to 1st century AD) using target enrichment and high-throughput sequencing methods. Phylogenetic analysis involving a...
Chowdhary BP, Harbitz I, Davies W, Gustavsson I.In situ hybridization techniques were used to localize regionally the calcium release channel (CRC) gene on cattle and horse chromosomes, using a porcine CRC cDNA probe. In cattle, the hybridization signal peaked on the 18q23-q26 bands and in horse on the 10pter region. Previous studies have shown that the glucose phosphate isomerase (GPI) gene localizes at the same site in both species, indicating that the two loci are syntenic. As CRC and GPI are syntenic in human, pig and mouse, the present results in cattle and horse represent another example of synteny conservation in the evolution of mam...
Gallagher PC, Lear TL, Coogle LD, Bailey E.BLAST searches of 61 equine microsatellite sequences revealed two related families of retroposons. The first family included seven markers, all of which showed significant homology to the Equine Repetitive Element-1 (ERE-1) Short Interspersed Nucleotide Element (SINE) sequence. Length of homology ranged from 76 to 171 bases with identities to the ERE-1 consensus sequence ranging from 71% to 83%. The second family referred to as Equine Repetitive Element-2 (ERE-2) has a consensus sequence that showed homology to ERE-1 over approximately 60 bases. These 60 bases comprised subunit I. Sequence com...
Jankunis ES, Whishaw IQ.Evidence suggests that behavioural affective reactions to sweet and bitter substances are homologous in humans, nonhuman primates, and rodents. The sweet taste of sucrose elicits facial responses that include rhythmic tongue protrusions whereas the bitter taste of quinine elicits facial responses that include gapes, featuring an opening of the mouth and protrusion of the tongue. The present study using the horse (Equus caballus) was undertaken for three reasons: (1) there is debate about the presence of a sweet receptor gene in the horse, (2) there is a need to expand the examination of facial...
Othman OE, Mahrous KF, Shafey HI.Horses are one of the early domesticated animals in the world that changed societies and civilizations on a continent-wide scale. Due to the rare information about the genetic characterization of different horse populations in Egypt, this study aimed to identify the genetic biodiversity and relationships between four horse populations reared in Egypt. Genomic DNA was extracted and mtDNA region was amplified using polymerase chain reaction (PCR). The alignment of 384-bp amplified fragments showed the presence of 41 polymorphic sites resulting in 29 haplotypes which their sequences were submitte...
Effa K, Rosenbom S, Han J, Dessie T, Beja-Pereira A.Matrilineal genetic diversity and relationship were investigated among eight morphologically identified native Ethiopian horse populations using polymorphisms in 46 mtDNA D-loop sequences (454 base pairs). The horse populations identified were Abyssinian, Bale, Borana, Horro, Kafa, Kundido feral horses, Ogaden and Selale. Mitochondrial DNA D-loop sequences were characterized by 15 variable sites that defined five different haplotypes. All genetic diversity estimates, including Reynolds' linearized genetic distance, genetic differentiation () and nucleotide sequence divergence (), revealed a lo...
Gray ME.Infanticide by adult males occurs in a variety of species. While infanticidal attacks have been documented in several equid species in captivity, it has never been witnessed in free-roaming feral horses. I report an infanticide attempt by a free-living feral stallion on a recently born female foal. The stallion picked up the foal by the shoulders, tossed it around twice and bit in on the neck several times. The dam of the foal charged the stallion and successfully protected her foal from additional attacks. The foal survived the attack and later weaned successfully. The stallion recently took ...
Capomaccio S, Cappelli K, Cook RF, Nardi F, Gifford R, Marenzoni ML, Passamonti F.Equine infectious anaemia virus (EIAV) is classified within the Retroviridae and, like other lentivirus, has the propensity for considerable antigenic variation. An extensive phylogenetic analysis in Bayesian fashion, with significant amounts of new EIAV gag sequence information, revealed a strong geographic compartmentalization clearly related to the phylogeographic history of modern horses, pointing out that New World EIAV strains form a distinct group with a potentially common origin. This evidence suggests that a single founder event may have occurred during the reintroduction of horses to...
Álvarez I, Fernández I, Lorenzo L, Payeras L, Cuervo M, Goyache F.Pedigree information and 179 mtDNA sequences from two endangered Spanish horse breeds, the Asturcón pony (143) and the Mallorquí horse (36), were analysed to asses: (i) the pedigree and molecular maternal genetic diversity of the two breeds; (ii) the concordance between the dam lines recorded in the corresponding studbooks and the mtDNA haplotypes identified; and (iii) to assess the losses of maternal genetic variability occurred from the foundation of the studbooks to present. Up to 50 Asturcón and 18 Mallorquí founder dam lines were identified in the studbooks analysed. Up to 315 Asturc...
