• Animal Bioscience
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• v.37 no.4
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• pp.600-608
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• 2024

Objective: In this study, we aimed to evaluate the usability single nucleotide polymorphisms (SNPs) for parentage testing of horse breeds in Korea. Methods: The genotypes of 93 horse samples (38 Thoroughbred horses, 17 Jeju horses, 20 Quarter horses, and 18 American miniature horses) were determined using 15 microsatellite (Ms) markers (AHT4, AHT5, ASB2, ASB17, ASB23, CA425, HMS1, HMS2, HMS3, HMS6, HMS7, HTG4, HTG10, LEX3, and VHL20) and 101 SNP markers. Results: Paternity tests were performed using 15 Ms markers and 101 SNP markers in Thoroughbred horses and Quarter horses. AHT5, ASB2, ASB17, ASB23, CA425, HMS7, HTG10, and LEX3 did not follow Mendelian inheritance in Thoroughbred horses, whereas in Quarter horses, only AHT4, ASB2, and HMS2 showed Mendelian inheritance, consequently, paternity was not established. Meanwhile, 31 markers, including MNEc_2_2_2_98568918_BIEC2_502451, in Thoroughbred horses, and 30 markers, including MNEc_2_30_7430735_BIEC2_816793, in Quarter horses did not conform with Mendelian inheritance and therefore, could not be used for establishing parentage. Conclusion: The possibility of replacing Ms markers with SNP markers for paternity testing in horses was confirmed. However, further research using more samples is necessary.

• Journal of Veterinary Clinics
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• v.26 no.3
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• pp.220-225
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• 2009

The present study demonstrates a new approach that enables effective horse parentage testing using 22 ISAG microsatellite markers involving 6 heads of Thoroughbred horse(TB) and non-TB. In the comparison allele distribution between these horses, the alleles found in the TB were numerously detected in the non-TB. As results, we confirmed that these ISAG microsatellite markers might apply the pedigree registration of Korean native horse(Jeju horse).

• Journal of Practical Agriculture & Fisheries Research
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• v.25 no.4
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• pp.39-43
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• 2024

Little research has been done on investigating the specific characteristics of Jeju Ponies (Korean native horse) and Jeju Pony crossbreds. The authors performed evaluation of skin thickness of the skin of these breeds (n=205) at Jeju Race Park as a way of find of hippological difference. Results of this study showed that the Jeju Pony's skin were thicker than the Jeju Pony crossbred. The male's skin were thicker than the female's skin in two breeds respectively. Especially, in the Jeju Pony show significant differences (P < 0.05). In Jeju Pony crossbreds, as the skin thickness were thinner with age increase. 2-year-old group's skin significantly thinner than 3 and over 4-year-old groups. However, the Jeju Pony's skin were not significantly different by age. In conclusion, the authors thought that causes of the difference of the breeds were origin and genetic differences among the horse and the pony. Furthermore, the modified umbilical herniorrhaphy with rubber rings must be used cautiously in the Jeju Pony. It should be taken into account the animals' skin thickness when the leather goods created by using their skin.

• Animal Bioscience
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• v.35 no.12
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• pp.1827-1838
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• 2022

Objective: The semen quality of stallions including sperm motility is an important target of selection as it has a high level of individual variability. However, effects of the molecular architecture of the genome on the mechanisms of sperm formation and their preservation after thawing have been poorly investigated. Here, we conducted a genome-wide association study (GWAS) for the sperm motility of cryopreserved semen in stallions of various breeds. Methods: Semen samples were collected from the stallions of 23 horse breeds. The following semen characteristics were examined: progressive motility (PM), progressive motility after freezing (FPM), and the difference between PM and FPM. The respective DNA samples from these stallions were genotyped using Axiom Equine Genotyping Array. Results: We performed a GWAS search for single nucleotide polymorphism (SNP) markers and potential genes related to motility properties of frozen-thawed semen in the stallions of various breeds. As a result of the GWAS analysis, two SNP markers, rs1141327473 and rs1149048772, were identified that were associated with preservation of the frozen-thawed stallion sperm motility, the relevant putative candidate genes being NME/NM23 family member 8 (NME8), olfactory receptor family 2 subfamily AP member 1 (OR2AP1), and olfactory receptor family 6 subfamily C member 4 (OR6C4). Potential implications of effects of these genes on sperm motility are herein discussed. Conclusion: The GWAS results enabled us to localize novel SNPs and candidate genes for sperm motility in stallions. Implications of the study for horse breeding and genetics are a better understanding of genomic regions and candidate genes underlying stallion sperm quality, and improvement in horse reproduction and breeding techniques. The identified markers and genes for sperm cryotolerance and the respective genomic regions are promising candidates for further studying the biological processes in the formation and function of the stallion reproductive system.

• Journal of Life Science
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• v.14 no.4
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• pp.696-701
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• 2004

The present study was carried out to investigate the redcell types of horse breeds. A total of 210 horses (73 Korean native horses, 118 crossbreed horses, and 19 Mongolian horses) were tested a redcell types by serological procedure, and their phenotypes and gene frequencies were estimated. The blood groups phenotypes observed with highest frequency were Aa (27.4%, 63.6%, 63.2%), Ca (97.3%, 94.9%, 89.5%), K- (97.3%, 99.2%, 84.2%), Pa (39.7%, 44.9%, 42.1%), and Ua (71.2%, 70.3%, 63.2%) in the Korean native horse, crossbreed horse, and Mongolian horse, respectively. In the D system and Q system, phenotypes observed with highest frequency were Dbcm/dghm (12.3%), Dbcm/cgm (14.4%), Dcgm/dghm (15.8%), and Qc (56.2%), Qabc (36.4%), Qc (31.6%) in the Korean native horse, crossbreed horse, and Mongolian horse, respectively Alleles observed with highest frequency were A- (0.287), Ca(0.827), Ddghm (0.226), K- (0.985), Pa (0.358), Qc (0.494), U-(0.529) in the Korean native horse, Aa (0.529), Ca (0.776), Dbcm (0.306), K- (0.995), P- (0.531), Q- (0.504), U- (0.548) in crossbreed horse, and Aa (0.421), Ca (0.895), Ddghm (0.421), K- (0.842), Pa (0.447), Qc (0.448), Ua (0.632) in Mongolian horse. Dcfgk and D- alleles were not detected in these horses. These results present basic information for estimating the genetic relationships between the Korean native horse, and developing a system for parentage verification and individual identification in these horses.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.12
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• pp.1696-1702
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• 2008

In order to learn the origin of the Chinese Mongolian horse, we analyzed polymorphisms within the mtDNA D-loop variable region in 305 horses of 6 types of 3 different breeds, including one imported breed, one cultivated breed and 4 types of one local breed. We detected 13 different haplotypes, and subsequent sequence analysis showed that all 6 horse types were genetically diverse. By constructing a cladogram of mtDNA D-loop sequences from the 6 horse types along with homologous sequences from several other horse types obtained from GenBank, we showed that Chinese Mongolian horses have a close genetic relationship with other horse types from Mongolia. We also speculate that several Chinese Mongolian horses descended from Przewalskii horse. Additionally, the 13 haplotypes were dispersed throughout the cladogram, suggesting that Chinese Mongolian horses likely originated from multiple female ancestors. A phylogenetic map of the 6 horse types showed that the genetic relationship between the local Wuzhumuqin and Wushen types were the closest. The Xinihe and Baerhu were also closely related to each other, and slightly more distantly related to the cultivated Sanhe breed. All five of the local Chinese horse types had a much more distant relationship with the imported Thoroughbred breed.

• Journal of Life Science
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• v.17 no.10
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• pp.1441-1446
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• 2007

This study was conducted to establish the individual identification system and to estimate the genetic characteristic of Jeju native horse (JNH) using 13 microsatellite markers located on different horse autosomes. The markers were genotyped on 191 animals from five horse breeds including Jeju native horse (JNH). In total, 138 alleles were detected from the genotypes of 13 microsatellite markers. The average heterozygosities ranged from 0.317 to 0.902 and the polymorphic information content (PIC) ranged from 0.498 to 0.799 in JNH. We found that there were significant differences in allele frequencies in JNH when compared with other horse breeds. In ATH4 marker, there were specific allele frequence pattern that some of allele only found in JNH, Mongolian horse (MONG) and Jeju racing horse (JRH). The calculated cumulative power of discrimination (CPD) was 99.9% when nine microsatellite loci were used for analysis in the individual identification system. Also, the matching probability that two unrelated animals would show the same genotypes, was estimated to be $0.60{\times}10^{-10}$. Therefore, in the nine markers used in this study can be used for individual identification in the Jeju native horse population.

• Journal of Animal Science and Technology
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• v.65 no.5
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• pp.1094-1104
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• 2023

Aggression in horses may cause serious accidents during riding and non-riding activities. Hence, predicting the temperament of horses is essential for selecting suitable horses and ensuring safety during the activity. In certain animals, such as hamsters, plasma melatonin concentrations have been correlated with aggressive behavior. However, whether this relationship applies to horses remains unclear. To address this research gap, this study aimed to evaluate differences in the plasma melatonin concentrations among horses of different breeds, ages, and sexes and examine the correlation between plasma melatonin concentrations and the temperament of the horses, including docility, affinity, dominance, and trainability. Blood samples from 32 horses were collected from the Horse Industry Complex Center of Jeonju Kijeon College. The docility, affinity, dominance, and trainability of the horses were assessed by three professional trainers who were well-acquainted with the horses. Plasma melatonin concentrations were measured using an enzyme-linked immunosorbent assay. The consequent values were compared between the horses of different breeds, ages, and sexes using a three-way analysis of variance and least significant difference post hoc test. Linear regression analysis was employed to identify the relationship between plasma melatonin concentrations and docility, affinity, dominance, and trainability. The results showed that the plasma melatonin concentrations significantly differed with breeds in Thoroughbred and cold-blooded horses. However, there were no differences in the plasma melatonin concentrations between the horse ages and sexes. Furthermore, plasma melatonin concentrations did not exhibit a significant correlation with the ranking of docility, affinity, dominance, and trainability.

• Genes and Genomics
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• v.40 no.11
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• pp.1249-1258
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• 2018

The Jeju horse is an indigenous Korean horse breed that is currently registered with the Food and Agriculture Organization of the United Nations. However, there is severe lack of genomic studies on Jeju horse. This study was conducted to investigate genetic characteristics of horses including Jeju horse, Thoroughbred and Jeju crossbred (Jeju${\times}$Thoroughbred) populations. We compared the genomes of three horse populations using the Equine SNP70 Beadchip array. Short-range Linkage disequilibrium was the highest in Thoroughbred, whereas $r^2$ values were lowest in Jeju horse. Expected heterozygosity was the highest in Jeju crossbred (0.351), followed by the Thoroughbred (0.337) and Jeju horse (0.311). The level of inbreeding was slightly higher in Thoroughbred (-0.009) than in Jeju crossbred (-0.035) and Jeju horse (-0.038). $F_{ST}$ value was the highest between Jeju horse and Thoroughbred (0.113), whereas Jeju crossbred and Thoroughbred showed the lowest value (0.031). The genetic relationship was further assessed by principal component analysis, suggesting that Jeju crossbred is more genetically similar to Thoroughbred than Jeju horse population. Additionally, we detected potential selection signatures, for example, in loci located on LCORL/NCAPG and PROP1 genes that are known to influence body. Genome-wide analyses of the three horse populations showed that all the breeds had somewhat a low level of inbreeding within each population. In the population structure analysis, we found that Jeju crossbred was genetically closer to Thoroughbred than Jeju horse. Furthermore, we identified several signatures of selection which might be associated with traits of interest. To our current knowledge, this study is the first genomic research, analyzing genetic relationships of Jeju horse, Thoroughbred and Jeju crossbred.

• Journal of Veterinary Clinics
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• v.33 no.6
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• pp.400-401
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• 2016

The object of this study was to evaluate the possibility and incidence of innate pacer in Jeju raceresource. This peculiar gait occurs naturally in some foreign breeds. To author's knowledge, this is the first report of innate pacers on the Korean native horse. In order to determine the incidence of pacer in Jeju Ponies and Jeju Pony crossbreds, gait analysis and pedigree check were performed at the Let's Run Park Jeju (total 547 ponies and pony crossbred racers) in 2013. Results of this study showed that 16 (8.1%) of the 198 examined Jeju Ponies. However, 349 Jeju Pony crossbreds had no innate pacers. Of the 16 Jeju Pony pacers, 11 males (68.8%) and 5 females (31.2%) are included in the present study. In conclusion, only the Jeju Pony was innate pacers like other foreign breeds. The authors suspect that the causes of the difference of the breeds were origin of the pony and genetic differences.