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.
Science (New York, N.Y.)March 1, 2012
Volume 335, Issue 6071 959-962 doi: 10.1126/science.1213859
Secord R, Bloch JI, Chester SG, Boyer DM, Wood AR, Wing SL, Kraus MJ, McInerney FA, Krigbaum J.Body size plays a critical role in mammalian ecology and physiology. Previous research has shown that many mammals became smaller during the Paleocene-Eocene Thermal Maximum (PETM), but the timing and magnitude of that change relative to climate change have been unclear. A high-resolution record of continental climate and equid body size change shows a directional size decrease of ~30% over the first ~130,000 years of the PETM, followed by a ~76% increase in the recovery phase of the PETM. These size changes are negatively correlated with temperature inferred from oxygen isotopes in mammal tee...
Bogaert L, Willemsen A, Vanderstraeten E, Bracho MA, De Baere C, Bravo IG, Martens A.Squamous cell carcinoma (SCC) represents the most common genital malignant tumor in horses. Similar to humans, papillomaviruses (PVs) have been proposed as etiological agents and recently Equine papillomavirus type 2 (EcPV2) has been identified in a subset of genital SCCs. The goals of this study were (1) to determine the prevalence of EcPV2 DNA in tissue samples from equine genital SCCs, penile intraepithelial neoplasia (PIN) and penile papillomas, using EcPV2-specific PCR, (2) to examine the prevalence of latent EcPV2 infection in healthy genital mucosa and (3) to determine genetic variabili...
Achilli A, Olivieri A, Soares P, Lancioni H, Hooshiar Kashani B, Perego UA, Nergadze SG, Carossa V, Santagostino M, Capomaccio S, Felicetti M....Archaeological and genetic evidence concerning the time and mode of wild horse (Equus ferus) domestication is still debated. High levels of genetic diversity in horse mtDNA have been detected when analyzing the control region; recurrent mutations, however, tend to blur the structure of the phylogenetic tree. Here, we brought the horse mtDNA phylogeny to the highest level of molecular resolution by analyzing 83 mitochondrial genomes from modern horses across Asia, Europe, the Middle East, and the Americas. Our data reveal 18 major haplogroups (A-R) with radiation times that are mostly confined ...
Bower MA, McGivney BA, Campana MG, Gu J, Andersson LS, Barrett E, Davis CR, Mikko S, Stock F, Voronkova V, Bradley DG, Fahey AG, Lindgren G....Selective breeding for speed in the racehorse has resulted in an unusually high frequency of the C-variant (g.66493737C/T) at the myostatin gene (MSTN) in cohorts of the Thoroughbred horse population that are best suited to sprint racing. Here we show using a combination of molecular- and pedigree-based approaches in 593 horses from 22 Eurasian and North-American horse populations, museum specimens from 12 historically important Thoroughbred stallions (b.1764-1930), 330 elite-performing modern Thoroughbreds and 42 samples from three other equid species that the T-allele was ancestral and there...
Nam GH, Ahn K, Bae JH, Cho BW, Park KD, Lee HK, Yang YM, Kim TH, Seong HH, Han K, Kim HS.In the mitochondrial matrix, the OXCT1 gene catalyzes the reversible transfer of coenzyme A from succinyl-CoA to acetoacetate in a reaction related to energy production from ketone bodies. Here, horse OXCT1 gene containing coenzyme A transferase domain was identified in the transcriptome analysis of cDNAs derived from skeletal muscles. Horse OXCT1 gene consisted of 1761 [corrected] nucleotide sequences with an open reading frame of 1560 nucleotides encoding a protein of 520 putative amino acid residues.The number of non-synonymous substitutions was lower than the number of synonymous substitut...
McCue ME, Bannasch DL, Petersen JL, Gurr J, Bailey E, Binns MM, Distl O, Guérin G, Hasegawa T, Hill EW, Leeb T, Lindgren G, Penedo MC, Røed KH....An equine SNP genotyping array was developed and evaluated on a panel of samples representing 14 domestic horse breeds and 18 evolutionarily related species. More than 54,000 polymorphic SNPs provided an average inter-SNP spacing of ∼43 kb. The mean minor allele frequency across domestic horse breeds was 0.23, and the number of polymorphic SNPs within breeds ranged from 43,287 to 52,085. Genome-wide linkage disequilibrium (LD) in most breeds declined rapidly over the first 50-100 kb and reached background levels within 1-2 Mb. The extent of LD and the level of inbreeding were highest in the ...
Miszczak F, Legrand L, Balasuriya UB, Ferry-Abitbol B, Zhang J, Hans A, Fortier G, Pronost S, Vabret A.During the summer of 2007, an outbreak of equine viral arteritis (EVA) occurred in Normandy (France). After investigation, a link was suggested between an EAV carrier stallion (A) and the index premise of the outbreak. The full-length nucleotide sequence analysis of a study reference strain (F27) isolated from the lung of a foal revealed a 12,710 nucleotides EAV genome with unique molecular hallmarks in the 5'UTR leader sequence and the ORF1a sequence encoding the non-structural protein 2. The evolution of the viral population in the persistently infected Stallion A was then studied by cloning...
Kaczensky P, Ganbataar O, Altansukh N, Enkhsaikhan N, Stauffer C, Walzer C.Large mammals re-introduced into harsh and unpredictable environments are vulnerable to stochastic effects, particularly in times of global climate change. The Mongolian Gobi is home to several rare large ungulates such as re-introduced Przewalski's horses (Equus ferus przewalskii) and Asiatic wild asses (Equus hemionus), but also to a millennium-old semi-nomadic livestock herding culture.The Gobi is prone to large inter-annual environmental fluctuations, but the winter 2009/2010 was particularly severe. Millions of livestock died and the Przewalski's horse population in the Gobi crashed. We u...
Yue XP, Qin F, Campana MG, Liu DH, Mao CC, Wang XB, Lan XY, Chen H, Lei CZ.Previous mitochondrial DNA (mtDNA) D-loop and microsatellite studies have shown that Chinese horses have multiple maternal origins and high genetic diversity. To better characterize maternal genetic origins and diversity of Chinese domestic horses, we conducted a comprehensive analysis of 407 complete 1140 bp sequences of the horse mitochondrially encoded cytochrome b (CYTB) gene, including 323 horses from 13 Chinese indigenous breeds and 84 reference sequences from GenBank. A total of 114 haplotypes were identified, of which 73 appeared among the 13 Chinese horse breeds. The high mitochondria...
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...
Svensson EM, Telldahl Y, Sjöling E, Sundkvist A, Hulth H, Sjøvold T, Götherström A.Domestication of animals and plants marked a turning point in human prehistory. To date archaeology, archaeozoology and genetics have shed light on when and where all of our major livestock species were domesticated. Phenotypic changes associated with domestication have occurred in all farm animals. Coat colour is one of the traits that have been subjected to the strongest human selection throughout history. Here we use genotyping of coat colour SNPs in horses to investigate whether there were any regional differences or preferences for specific colours associated with specific cultural tradit...
Lippold S, Matzke NJ, Reissmann M, Hofreiter M.DNA target enrichment by micro-array capture combined with high throughput sequencing technologies provides the possibility to obtain large amounts of sequence data (e.g. whole mitochondrial DNA genomes) from multiple individuals at relatively low costs. Previously, whole mitochondrial genome data for domestic horses (Equus caballus) were limited to only a few specimens and only short parts of the mtDNA genome (especially the hypervariable region) were investigated for larger sample sets. Results: In this study we investigated whole mitochondrial genomes of 59 domestic horses from 44 breeds an...
Pruvost M, Bellone R, Benecke N, Sandoval-Castellanos E, Cieslak M, Kuznetsova T, Morales-Muñiz A, O'Connor T, Reissmann M, Hofreiter M, Ludwig A.Archaeologists often argue whether Paleolithic works of art, cave paintings in particular, constitute reflections of the natural environment of humans at the time. They also debate the extent to which these paintings actually contain creative artistic expression, reflect the phenotypic variation of the surrounding environment, or focus on rare phenotypes. The famous paintings "The Dappled Horses of Pech-Merle," depicting spotted horses on the walls of a cave in Pech-Merle, France, date back ~25,000 y, but the coat pattern portrayed in these paintings is remarkably similar to a pattern known as...
Georgescu SE, Manea MA, Dudu A, Costache M.The existence of the Hucul horse on Romanian territory has been documented from the very distant past; today Hucul is a unique breed that is part of the FAO Program for the Preservation of Animal Genetic Resources. We compared Hucul with several primitive European and Asiatic breeds in order to elucidate the origin of these horses. We analyzed a 683-bp mitochondrial DNA (mtDNA) D-loop fragment in a population of Hucul horses and compared the polymorphic sites with sequences from other primitive breeds, including Exmoor, Icelandic Pony, Sorraia, Przewalski Horse, Mongolian Wild Horse, Konik, an...
Campana MG, Stock F, Barrett E, Benecke N, Barker GW, Seetah K, Bower MA.Despite the Icelandic horse enjoying great popularity worldwide, the breed's gene pool is small. This is because of a millennium of isolation on Iceland, population crashes caused by natural disasters and selective breeding. Populations with small effective population sizes are considered to be more at risk of selection pressures such as disease and environmental change. By analysing historic and modern mitochondrial DNA sequences and nuclear coat colour genes, we examined real-time population dynamics in the Icelandic horse over the last 150 years. Despite the small gene pool of this breed, w...
Cothran EG, Canelon JL, Luis C, Conant E, Juras R.Various horse populations in the Americas have an origin in Spain; they are remnants of the first livestock introduced to the continent early in the colonial period (16th and 17th centuries). We evaluated genetic variability within the Venezuelan Criollo horse and its relationship with other horse breeds. We observed high levels of genetic diversity within the Criollo breed. Significant population differentiation was observed between all South American breeds. The Venezuelan Criollo horse showed high levels of genetic diversity, and from a conservation standpoint, there is no immediate danger ...
Lewis NS, Daly JM, Russell CA, Horton DL, Skepner E, Bryant NA, Burke DF, Rash AS, Wood JL, Chambers TM, Fouchier RA, Mumford JA, Elton DM, Smith DJ.Equine influenza virus is a major respiratory pathogen in horses, and outbreaks of disease often lead to substantial disruption to and economic losses for equestrian industries. The hemagglutinin (HA) protein is of key importance in the control of equine influenza because HA is the primary target of the protective immune response and the main component of currently licensed influenza vaccines. However, the influenza virus HA protein changes over time, a process called antigenic drift, and vaccine strains must be updated to remain effective. Antigenic drift is assessed primarily by the hemagglu...
Rendo F, Iriondo M, Manzano C, Estonba A.Here, we present the results of a genetic analysis of 463 Pottoka ponies corresponding to four generations, using 17 microsatellite markers. Ten years after the beginning of the Pottoka conservation programme, the values for the genetic diversity of the breed are still high and stable, indicating the success of the programme. We found null alleles in Pottoka for the ASB23, HMS3 and HTG10 microsatellites. Together with information obtained from other pony breeds from the Iberian Peninsula, this finding indicates that these microsatellites should not be used for phylogenetic analyses or parentag...
Lippold S, Knapp M, Kuznetsova T, Leonard JA, Benecke N, Ludwig A, Rasmussen M, Cooper A, Weinstock J, Willerslev E, Shapiro B, Hofreiter M.Modern domestic horses display abundant genetic diversity within female-inherited mitochondrial DNA, but practically no sequence diversity on the male-inherited Y chromosome. Several hypotheses have been proposed to explain this discrepancy, but can only be tested through knowledge of the diversity in both the ancestral (pre-domestication) maternal and paternal lineages. As wild horses are practically extinct, ancient DNA studies offer the only means to assess this ancestral diversity. Here we show considerable ancestral diversity in ancient male horses by sequencing 4 kb of Y chromosomal DNA ...
Simmons DR, Letcher PM, Powell MJ, Longcore JE.The order Lobulomycetales contains chytrids from soil, freshwater and marine habitats; environmental DNA sampling has indicated that representatives of this order might be found in deep ocean localities. We describe Alogomyces tanneri as the first lobulomycetalean chytrid isolated from horse manure; A. tanneri is also the first species in the order to possess a rumposome in its zoospore. This species widens the range of habitats, ultrastructural variation and thallus morphology for Lobulomycetales.
Orlando L, Ginolhac A, Raghavan M, Vilstrup J, Rasmussen M, Magnussen K, Steinmann KE, Kapranov P, Thompson JF, Zazula G, Froese D, Moltke I....Second-generation sequencing platforms have revolutionized the field of ancient DNA, opening access to complete genomes of past individuals and extinct species. However, these platforms are dependent on library construction and amplification steps that may result in sequences that do not reflect the original DNA template composition. This is particularly true for ancient DNA, where templates have undergone extensive damage post-mortem. Here, we report the results of the first "true single molecule sequencing" of ancient DNA. We generated 115.9 Mb and 76.9 Mb of DNA sequences from a permafrost-...
Goto H, Ryder OA, Fisher AR, Schultz B, Kosakovsky Pond SL, Nekrutenko A, Makova KD.The endangered Przewalski's horse is the closest relative of the domestic horse and is the only true wild horse species surviving today. The question of whether Przewalski's horse is the direct progenitor of domestic horse has been hotly debated. Studies of DNA diversity within Przewalski's horses have been sparse but are urgently needed to ensure their successful reintroduction to the wild. In an attempt to resolve the controversy surrounding the phylogenetic position and genetic diversity of Przewalski's horses, we used massively parallel sequencing technology to decipher the complete mitoch...
Paria N, Raudsepp T, Pearks Wilkerson AJ, O'Brien PC, Ferguson-Smith MA, Love CC, Arnold C, Rakestraw P, Murphy WJ, Chowdhary BP.Studies of the Y chromosome in primates, rodents and carnivores provide compelling evidence that the male specific region of Y (MSY) contains functional genes, many of which have specialized roles in spermatogenesis and male-fertility. Little similarity, however, has been found between the gene content and sequence of MSY in different species. This hinders the discovery of species-specific male fertility genes and limits our understanding about MSY evolution in mammals. Here, a detailed MSY gene catalogue was developed for the horse--an odd-toed ungulate. Using direct cDNA selection from horse...
Waller AS, Paillot R, Timoney JF.Strangles caused by the host adapted Lancefield group C Streptococcus equi subspecies equi (S. equi) is a frequently diagnosed infectious disease of horses worldwide. Critical to the global success of S. equi is its ability to establish persistent infections within the guttural pouches of recovered apparently healthy horses that can result in transmission to in-contact animals. Recent research has identified key events in the S. equi genome, which occurred during its evolution from an ancestral strain of S. equi subspecies zooepidemicus, that may enhance its ability to evade host innate immune...
Bountouri M, Fragkiadaki E, Ntafis V, Kanellos T, Xylouri E.For first time in Greece equine influenza virus infection was confirmed, by isolation and molecular analysis, as the cause of clinical respiratory disease among unvaccinated horses during 2003 and 2007 outbreaks. Methods: Equine influenza virus (EIV) H3N8 was isolated in MDCK cells from 30 nasal swabs from horses with acute respiratory disease, which were tested positive by Directigen Flu A. Isolation was confirmed by haemagglutination assay and RT-PCR assay of the M, HA and NA gene. Results: HA sequences of the Greek isolates appeared to be more closely related to viruses isolated in early 19...
Geigl EM, Grange T.The Equidae have a long evolutionary history that has interested palaeontologists for a long time. Their morphology-based taxonomy, however, is a matter of controversy. Since most equid species are now extinct, the phylogenetic tree based on genetic data can be established only imperfectly via deduction of present day genomes and little is known about the past genetic diversity of these species. Recent studies of ancient DNA preserved in fossil bones have led to a simplification of the phylogenetic tree and the classification system. The situation is still particularly unclear for the wild ass...
Hampson BA, de Laat MA, Mills PC, Pollitt CC.To investigate the density of the primary epidermal lamellae (PEL) around the solar circumference of the forefeet of near-term fetal feral and nonferal (ie, domesticated) horses. Methods: Left forefeet from near-term Australian feral (n = 14) and domesticated (4) horse fetuses. Methods: Near-term feral horse fetuses were obtained from culled mares within 10 minutes of death; fetuses that had died in utero 2 weeks prior to anticipated birth date and were delivered from live Thoroughbred mares were also obtained. Following disarticulation at the carpus, the left forefoot of each fetus was frozen...
Seyfarth RM, Cheney DL.Convergent evidence from many species reveals the evolutionary origins of human friendship. In horses, elephants, hyenas, dolphins, monkeys, and chimpanzees, some individuals form friendships that last for years. Bonds occur among females, among males, or between males and females. Genetic relatedness affects friendships. In species where males disperse, friendships are more likely among females. If females disperse, friendships are more likely among males. Not all friendships, however, depend on kinship; many are formed between unrelated individuals. Friendships often involve cooperative inte...
May-Davis S, Hunter R, White R.In this study, we examined the ventral process of C6 in extinct and extant (sister taxa to only) with the purpose of describing normal morphology and identifying anomalous variations relevant to recent studies describing a congenital malformation in . Overall, 83 specimens from 9 museums and 3 research/educational facilities were examined, totalling 71 extinct specimens from 12 species and 12 extant specimens from 5 species. The lateral view revealed that a large convexity exists in the ventral process between the cranial ventral tubercle (CrVT) and the caudal ventral tubercle (CVT) in the e...
Xu LX, Yang SL, Lin RY, Yang HB, Li AP, Wan QS.China is one of the principal origins of ponies in the world. We made a comprehensive analysis of genetic diversity and population structure of Chinese ponies based on 174 animals of five indigenous Chinese pony breeds from five provinces using 13 microsatellite markers. One hundred and forty-four alleles were detected; the mean number of effective alleles among the pony breeds ranged from 5.38 (Guizhou) to 6.78 (Sichuan); the expected heterozygosity ranged from 0.82 (Guizhou) to 0.85 (Debao, Sichuan). Although abundant genetic variation was found, the genetic differentiation was low between t...
Self Davies ZT, Spence AJ, Wilson AM.Horse locomotion is remarkably economical. Here, we measure external mechanical work of the galloping horse and relate it to published measurements of metabolic cost. Seven Thoroughbred horses were galloped (ridden) over force plates, under a racing surface. Twenty-six full strides of force data were recorded and used to calculate the external mechanical work of galloping. The mean sum of decrements of mechanical energy was -876 J (±280 J) per stride and increments were 2163 J (±538 J) per stride as horses were accelerating. Combination with published values for internal work and metabolic c...
Frontiers in geneticsOctober 5, 2022
Volume 13 944933 doi: 10.3389/fgene.2022.944933
Xu B, Yang G, Jiao B, Zhu H. The domestication of horses has played critical roles in human civilizations. The excavation of ancient horse DNA provides crucial data for studying horse domestication. Studies of horse domestication can shed light on the general mechanisms of animal domestication. We wish to explore the gene transcription regulation by long noncoding RNAs (lncRNAs) that influence horse domestication. First, we assembled the ancient DNA sequences of multiple horses at different times and the genomes of horses, donkeys, and Przewalski horses. Second, we extracted sequences of lncRNA genes shared in ancient ...
Kavanagh KD, Bailey CS, Sears KE.Previous work comparing the developmental mechanisms involved in digit reduction in horses with other mammals reported that horses have only a 'single digit', with two flanking metapodials identified as remnants of digit II and IV. Here we show that early embryos go through a stage with five digit condensations, and that the flanking splint metapodials result from fusions of the two anterior digits I and II and the two posterior digits IV and V, in a striking parallel between ontogeny and phylogeny. Given that even this most extreme case of digit reduction exhibits primary pentadactyly, we re...
Bayerova Z, Janova E, Matiasovic J, Orlando L, Horin P.Immunity-related genes are a suitable model for studying effects of selection at the genomic level. Some of them are highly conserved due to functional constraints and purifying selection, while others are variable and change quickly to cope with the variation of pathogens. The SLC11A1 gene encodes a transporter protein mediating antimicrobial activity of macrophages. Little is known about the patterns of selection shaping this gene during evolution. Although it is a typical evolutionarily conserved gene, functionally important polymorphisms associated with various diseases were identified in ...
Delsol N, Stucky BJ, Oswald JA, Reitz EJ, Emery KF, Guralnick R.Unlike other European domesticates introduced in the Americas after the European invasion, equids (Equidae) were previously in the Western Hemisphere but were extinct by the late Holocene era. The return of equids to the Americas through the introduction of the domestic horse (Equus caballus) is documented in the historical literature but is not explored fully either archaeologically or genetically. Historical documents suggest that the first domestic horses were brought from the Iberian Peninsula to the Caribbean in the late 15th century CE, but archaeological remains of these early introduct...
Open life sciencesSeptember 26, 2022
Volume 17, Issue 1 1269-1281 doi: 10.1515/biol-2022-0487
Pan J, Purev C, Zhao H, Zhang Z, Wang F, Wendoule N, Qi G, Liu Y, Zhou H.The Mongolian horses have excellent endurance and stress resistance to adapt to the cold and harsh plateau conditions. Intraspecific genetic diversity is mainly embodied in various genetic advantages of different branches of the Mongolian horse. Since people pay progressive attention to the athletic performance of horse, we expect to guide the exercise-oriented breeding of horses through genomics research. We obtained the clean data of 630,535,376,400 bp through the entire genome second-generation sequencing for the whole blood of four Abaga horses and ten Wushen horses. Based on the data an...
Vega-Pla JL, Calderón J, Rodríguez-Gallardo PP, Martinez AM, Rico C.In the 1980s, a conservation programme involving a feral horse population, the Retuertas horses from the Guadalquivir marshes, was started in the Doñana National Park. The analysis of an extensive genetic survey of this population, which now numbers 100 animals, and 10 additional European and North African breeds using DNA polymorphisms from 22 microsatellites is presented. Highly significant fixation indexes were obtained for all pairwise comparisons between the Retuertas population and other breeds. A population neighbour-joining breed phenogram was built using different distance measures, ...
Harmer CJ.Conjugative plasmids are a major contributor to the global spread of antibiotic resistance determinants, but the tracking of their evolutionary history is often neglected. serovar Typhimurium ( Typhimurium) strain SRC27 was isolated from an equine infection in Australia in 1999. SRC27 was known to carry conjugative HI1 and I1 resistance plasmids. In this study, SRC27 was sequenced to determine the relationship between these HI1 and I1 resistance plasmids it was known to carry and HI1 and I1 resistance plasmids circulating worldwide. The resistance genes in the HI1 plasmid, pSRC27-H, are all l...
Soana S, Gnudi G, Bertoni G.The aim of this work was to study the ontogenetic process in teeth from their early appearance in the ossifying matrix of the mandible and maxilla, in different foetuses of scalar ages. Radiographic examinations of the skull and mandible hemisections were performed and the latero-medial (LM) and dorsoventral (DV) projections for the skull and mandible were analysed. A high-definition film-screen combination was used for this study. The exposure values ranged from 35 kV/6 mAs to 58 kV/10 mAs, according to the size of the skulls and their degree of ossification. The first dental germ observed wa...
Chandra Paul R, Ba Nguyen T, Okuda Y, Nu Anh Le T, Mosese Dau Tabuyaqona J, Konishi Y, Kawamoto Y, Nozawa K, Kunieda T.There are currently eight native horse populations in Japan, namely, Hokkaido, Kiso, Noma, Taishu, Misaki, Tokara, Miyako, and Yonaguni horses. Since locomotion traits, including gaitedness, are important for riding and packing horses, the genetic properties associated with these traits could be informative for understanding the characteristics and history of these horses. In this study, we investigated the distribution of the mutant allele of DMRT3 gene (DMRT3:p.Ser301Ter) associated with ambling gaits in the Japanese native horse. We also examined haplotypes of SNPs in the 83-kb region inclu...
Kang Z, Shi J, Liu T, Zhang Y, Zhang Q, Liu Z, Wang J, Cheng S.The study investigated the origin of the Akhal-Teke horse using genome-wide single-nucleotide polymorphism (SNP) data and mitochondrial hypervariable region 1 (HVR-1) nucleotide sequences. Methods: Genome-wide SNP data from 22 breeds (481 horses) and mitochondrial HVR-1 sequences from 24 breeds (544 sequences) worldwide to examine the origin of the Akhal- Teke horse. The data were analyzed using principal component analysis, linkage disequilibrium analysis, neighbor-joining dendrograms, and ancestry inference to determine the population relationships, ancestral source, genetic structure, and r...
Priskin K, Szabó K, Tömöry G, Bogácsi-Szabó E, Csányi B, Eördögh R, Downes CS, Raskó I.Movements of human populations leave their traces in the genetic makeup of the areas affected; the same applies to the horses that move with their owners This study is concerned with the mitochondrial control region genotypes of 31 archaeological horse remains, excavated from pre-conquest Avar and post-conquest Hungarian burial sites in the Carpathian Basin dating from the sixth to the tenth century. To investigate relationships to other ancient and recent breeds, modern Hucul and Akhal Teke samples were also collected, and mtDNA control region (CR) sequences from 76 breeds representing 921 in...
Amjadi MA, Yeganeh HM, Sadeghi M, Abbas Raza SH, Yang J, Najafabadi HA, Batool U, Shoorei H, Abdelnour SA, Ahmed JZ.Native breeds are essential for national stocks and genetic reservoir; therefore, the preservation of indigenous breeds is a key policy priority for countries around the world. Many conservationists would assert that genetic diversity is a prerequisite for adaptive evolution, and preserving genetic diversity will need conservation efforts for the long-term survival of domestic species. This study intended to evaluate the genetic diversity of the Iranian Kurdish horse population based on microsatellite indicators, which can partially prevent it from becoming extinct. Fifty-eight tail hair and b...
Hudson W.Egyptian Arabian horses have been maintained in a state of genetic isolation for over a hundred years. There is only limited genetic proof that the studbook records of female lines of Egyptian Arabian pedigrees are reliable. This study characterized the mitochondrial DNA (mtDNA) signatures of 126 horses representing 14 matrilines in the Egyptian Agricultural Organization (EAO) horse-breeding program. Results: Analysis of the whole D-loop sequence yielded additional information compared to hypervariable region-1 (HVR1) analysis alone, with 42 polymorphic sites representing ten haplotypes compar...
Perrocheau M, Boutreux V, Chadi S, Mata X, Decaunes P, Raudsepp T, Durkin K, Incarnato D, Iannuzzi L, Lear TL, Hirota K, Hasegawa T, Zhu B, de Jong P....A medium-density map of the horse genome (Equus caballus) was constructed using genes evenly distributed over the human genome. Three hundred and twenty-three exonic primer pairs were used to screen the INRA and the CHORI-241 equine BAC libraries by polymerase chain reaction and by filter hybridization respectively. Two hundred and thirty-seven BACs containing equine gene orthologues, confirmed by sequencing, were isolated. The BACs were localized to horse chromosomes by fluorescent in situ hybridization (FISH). Overall, 165 genes were assigned to the equine genomic map by radiation hybrid (RH...
Gu J, Li S, Zhu B, Liang Q, Chen B, Tang X, Chen C, Wu DD, Li Y.Understanding the genetic variations of the horse (Equus caballus) genome will improve breeding conservation and welfare. However, genetic variations in long segments, such as structural variants (SVs), remain understudied. We de novo assembled 10 chromosome-level three-dimensional horse genomes, each representing a distinct breed, and analysed horse SVs using a multi-assembly approach. Our findings suggest that SVs with the accumulation of mammalian-wide interspersed repeats related to long interspersed nuclear elements might be a horse-specific mechanism to modulate genome-wide gene regulato...
Levine MA.Before the development of firearms, the horse was crucial to warfare and, before the invention of the steam engine, it was the fastest and most reliable form of land transport. It is crucial to the life of nomadic pastoralists on the Eurasian steppe and played a major role in the evolution of human society during the Bronze Age and Iron Age. Understanding the human past requires knowledge of the origins and development of horse husbandry. The problem of being able to identify the early stages of horse domestication is one that many researchers have grappled with for the most part unsuccessfull...
Cappellato A, Miletto Petrazzini ME, Bisazza A, Dadda M, Agrillo C.The perception of different size illusions is believed to be determined by size-scaling mechanisms that lead individuals to extrapolate inappropriate 3D information from 2D stimuli. The Muller-Lyer illusion represents one of the most investigated size illusions. Studies on non-human primates showed a human-like perception of this illusory pattern. To date, it is not clear whether non-primate mammals experience a similar illusory effect. Here, we investigated whether horses perceive the Muller-Lyer illusion by using their spontaneous preference for the larger portion of carrot. In control trial...
Weitkamp LR, Allen PZ.Ancient origin of the equine vitamin D binding protein (Gc) polymorphism is suggested by the finding of two alleles, Gc(F) and Gc(S), in each of three equine subgenera, Equus, Asinus and Hippotigris. The equine Gc and albumin loci are closely linked (lod score = 6). Although no recombinants were observed, the data are not inconsistent with a map distance similar to the 2 centimorgans reported for the human albumin/Gc linkage relationship. Gametic association between the Gc(F) and Alb(F) alleles appears probable in the American Standardbred horse, perhaps as a result of population structure. Si...
Zhang L, Hu M, Chilton NB, Huby-Chilton F, Beveridge I, Gasser RB.The expansion segments or divergent (D) domains in the large subunit (LSU) of the ribosomal DNA have been suggested as genetic markers for taxonomic and/or phylogenetic studies of parasites. In the present study, we assessed the degree of sequence variation in the D3 domain and flanking core regions of the LSU for 21 species of equine strongyles (Strongylida: Strongylidae) and determined which positions in the secondary structure of the LSU were associated with the nucleotide alterations. No intraspecific sequence variation was detected in 17 species, for which multiple individual worms were a...
The commentary by Gallup and Anderson (Anim Cogn https://doi.org/10.1007/s10071-021-01538-9 , 2021) on the original article by Baragli, Scopa, Maglieri, and Palagi (Anim Cogn https://doi.org/10.1007/s10071-021-01502-7 , 2021) raised some concerns about the methodological approach used by the authors to demonstrate Mirror Self-Recognition (MSR) in horses. The commentary does not take into account horse physiology and psychology, leading Gallup and Anderson to inappropriately discredit the findings obtained by Baragli et al. Anim Cogn 2021. In this reply, we underlined the importance of a blinke...
Jung YH, Han SH, Shin T, Oh MY.We determined the nucleotide sequences of the hypervariable D-loop region of mitochondrial DNA (mtDNA) from horse bone (humerus, A.D. 700 to A.D. 800) that was excavated from the Kwakji archaeological site, Jeju, Korea. We compared them with ones from extant horses. We designed three pairs of oligonucleotide primers from the tRNA-Thr and tRNA-Phe gene regions of mtDNA that are highly conserved among many other animal species. We cloned 232, 336, and 644 bp from the horse bone in order to determine the mtDNA D-loop sequence. The sequence was 1,124 bp long; the middle contained 19 tandem repeats...
Han L, Lan T, Lu Y, Zhou M, Li H, Lu H, Wang Q, Li X, Du S, Guan C, Zhang Y, Sahu SK, Qian P, Zhang S, Zhou H, Guo W, Chai H, Wang S, Liu Q, Liu H....The evolution of parasites is often directly affected by the host's environment. Studies on the evolution of the same parasites in different hosts are of great interest and are highly relevant to our understanding of divergence. Methods: Here we performed whole-genome sequencing of Parascaris univalens from different Equus hosts (horses, zebras and donkeys). Phylogenetic and selection analyses were performed to study the divergence and adaptability of P. univalens. Results: At the genetic level, multiple lines of evidence indicate that P. univalens is mainly separated into two clades (horse-de...
Barrón-Ortiz CI, Rodrigues AT, Theodor JM, Kooyman BP, Yang DY, Speller CF.Horses were a dominant component of North American Pleistocene land mammal communities and their remains are well represented in the fossil record. Despite the abundant material available for study, there is still considerable disagreement over the number of species of Equus that inhabited the different regions of the continent and on their taxonomic nomenclature. In this study, we investigated cheek tooth morphology and ancient mtDNA of late Pleistocene Equus specimens from the Western Interior of North America, with the objective of clarifying the species that lived in this region prior to t...
Fenger CK, Granstrom DE, Langemeier JL, Gajadhar A, Cothran G, Tramontin RR, Stamper S, Dubey JP.Sarcocystis neurona is a coccidial parasite that causes a neurologic disease of horses in North and South America. The natural host species are not known and classification is based on ultrastructural analysis. The small subunit ribosomal RNA (SSURNA) gene of S. neurona was amplified using polymerase chain reaction techniques and sequenced by Sanger sequencing reactions. The sequence was compared with partial sequences of S. muris, S. gigantea, S. tenella, S. cruzi, S. arieticanis, S. capracanis, Toxoplasma gondii, Eimeria tenella, and Cryptosporidium parvum. Alignments of available sites for ...
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...
Vorobieva NV, Makunin AI, Druzhkova AS, Kusliy MA, Trifonov VA, Popova KO, Polosmak NV, Molodin VI, Vasiliev SK, Shunkov MV, Graphodatsky AS.A growing number of researchers studying horse domestication come to a conclusion that this process happened in multiple locations and involved multiple wild maternal lines. The most promising approach to address this problem involves mitochondrial haplotype comparison of wild and domestic horses from various locations coupled with studies of possible migration routes of the ancient shepherds. Here, we sequenced complete mitochondrial genomes of six horses from burials of the Ukok plateau (Russia, Altai Mountains) dated from 2.7 to 1.4 thousand years before present and a single late Pleistocen...
