Genetic background and phenotypic features of the endangered Miyako horse.
Abstract: The Miyako horse is one of the eight Japanese native horse breeds and is scarce in terms of population size. Japanese native horses are believed to be descended from Mongolian horses and represent a precious lineage that has preserved its traits for over a thousand years in Japan. Genetic analysis of the endangered Miyako horse is useful for preserving its original phenotypic traits. This study analysed the genetic variation in trait-related genes for coat colour (), body composition (), gait (), and temperament () in 46 extant Miyako horses. In addition, because numerous Miyako horses have vertical stripes on their backs, we analysed the genes associated with the dorsal stripe (), a characteristic of primitive horses. Until now, Miyako horses were believed to comprise only bays and chestnuts, but genetic analysis revealed that two individuals were black. No mutations were detected in g.66619237delinsSINE, , or , whereas polymorphisms were observed in g.66608679T>C and . Furthermore, analysis suggested that the patterns observed on the backs of Miyako horses could be genetically classified as dorsal stripes. Using the information on trait-related genes obtained in this study as a foundation for breeding plans is expected to contribute significantly to the production of individuals that maintain the phenotype traditionally preserved in Miyako horses. Furthermore, genetic confirmation of the Miyako horse dorsal stripe pattern could provide significant clues regarding similar markings in other Japanese native horses.
©2026 The Japanese Society of Equine Science.
Publication Date: 2026-03-14 PubMed ID: 41859759PubMed Central: PMC12995546DOI: 10.1294/jes.37.27Google Scholar: Lookup The Equine Research Bank provides access to a large database of publicly available scientific literature. Inclusion in the Research Bank does not imply endorsement of study methods or findings by Mad Barn.
- Journal Article
Summary
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The study investigates the genetic makeup and physical traits of the endangered Miyako horse, aiming to support conservation efforts by understanding the genetic basis of their unique characteristics, including coat color and distinctive dorsal stripes.
Background and Importance of the Study
- The Miyako horse is one of eight native Japanese horse breeds with a very small population, making it endangered.
- These native horses are believed to have descended from Mongolian horses, preserving a lineage over 1000 years old.
- Understanding the genetics of Miyako horses is important for preserving their original physical traits, which are valuable both biologically and culturally.
Research Objectives
- To analyze genetic variation in genes linked to important physical traits of Miyako horses.
- Traits examined include coat color, body composition, gait, and temperament — all relevant to the breed’s phenotype.
- To specifically study the genetic basis of the dorsal stripe, a vertical stripe on the horses’ backs characteristic of primitive horses, commonly seen in Miyako horses.
Methods and Subjects
- The study was conducted on 46 living Miyako horses, representing the extant population.
- Genetic analysis focused on particular known genes associated with:
- Coat color, including variations like bay, chestnut, and black.
- Body composition traits.
- Gait and movement patterns.
- Temperament-related genetic markers.
- Dorsal stripe, specifically genes linked to this primitive marking.
Key Genetic Findings
- Contrary to previous beliefs that Miyako horses are only bays and chestnuts, two individuals were genetically identified as black.
- Certain genes previously linked to coat color (such as g.66619237delinsSINE and others) showed no mutation in these horses, indicating genetic uniformity in those regions.
- Polymorphisms (genetic variations) were found in some genes like g.66608679T>C, suggesting subtle genetic diversity related to traits.
- Genetic analysis confirmed the dorsal stripe pattern seen on the horses’ backs is a genetically defined trait, aligning with characteristics of primitive horses.
Implications for Conservation and Breeding
- The detailed genetic information on coat color, gait, temperament, and dorsal stripes can serve as a foundational reference for future breeding programs.
- Breeding strategies informed by this genetic data can help maintain the phenotypic characteristics traditionally found in the Miyako horse, preventing loss of genetic identity.
- Knowledge about the dorsal stripe gene could have broader use, providing insights into similar markings in other Japanese native horse breeds.
- Overall, this genetic characterization supports efforts to conserve the endangered Miyako horse while preserving its unique physical and genetic heritage.
Cite This Article
APA
Masuda M, Tozaki T, Kawate K, Furukawa R, Kikuchi M, Ishige T, Kakoi H.
(2026).
Genetic background and phenotypic features of the endangered Miyako horse.
J Equine Sci, 37(1), 27-34.
https://doi.org/10.1294/jes.37.27 Publication
Researcher Affiliations
- Nikadori Ranch, Okinawa 906-0013, Japan.
- Genetic Analysis Department, Laboratory of Racing Chemistry, Tochigi 320-0851, Japan.
- Genetic Analysis Department, Laboratory of Racing Chemistry, Tochigi 320-0851, Japan.
- Genetic Analysis Department, Laboratory of Racing Chemistry, Tochigi 320-0851, Japan.
- Genetic Analysis Department, Laboratory of Racing Chemistry, Tochigi 320-0851, Japan.
- Genetic Analysis Department, Laboratory of Racing Chemistry, Tochigi 320-0851, Japan.
- Genetic Analysis Department, Laboratory of Racing Chemistry, Tochigi 320-0851, Japan.
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