Decreased genetic diversity in Kiso horses revealed through annual microsatellite genotyping.
Abstract: The Kiso horse is native to Japan and is on the verge of extinction. Here, we used microsatellites to characterize changes in their genetic diversity over time. We divided a population of Kiso horses that genotyped during 2007-2017 into three groups based on birth year: Group 1, 1980-1998 (70 horses); Group 2, 1999-2007 (61 horses); and Group 3, 2008-2017 (42 horses). We genotyped 31 microsatellites to calculate average number of alleles, observed heterozygosity, and expected heterozygosity. All indicators decreased across age groups. The results indicate that Kiso horses have been experiencing a drop in genetic diversity, and the population is expected to experience further decline unless appropriate measures are implemented.
Publication Date: 2020-03-09 PubMed ID: 32147602PubMed Central: PMC7192717DOI: 10.1292/jvms.19-0535Google Scholar: Lookup
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- Journal Article
Summary
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This research aims to evaluate the changes in the genetic diversity of Kiso horses, a breed native to Japan that is nearing extinction. It was found that the breed is experiencing a reduction in genetic diversity, which could worsen without intervention.
Research Context
- The Kiso horse, a breed native to Japan, is nearing extinction. This concern triggered the research to examine their genetic diversity and assess any changes occurring over the years.
- Understanding genetic diversity is crucial as it guides the direction for conservation efforts. Lower genetic diversity can lead to inbreeding depression and decreased survival rates.
Methodology
- The researchers conducted a genotyping process, examining the genetic variations within the Kiso horse population between 2007 to 2017. They utilized microsatellites, a type of genetic marker, to achieve this.
- They divided the population into three groups based on birth years. Group 1 consisted of 70 horses born between 1980-1998, Group 2 included 61 horses born from 1999-2007, and Group 3 consisted of 42 horses born in the period 2008-2017.
- Once the groups were defined, the researchers used 31 microsatellites to calculate three key variables related to genetic diversity: the average number of alleles, observed heterozygosity, and expected heterozygosity.
Findings
- All measures of genetic diversity, i.e., average number of alleles, observed heterozygosity, and expected heterozygosity, were found to decrease over time across the three groups.
- These results suggest a decline in the genetic diversity of Kiso horses, an alarming state considering the breed’s near-extinct status.
Implications
- The decrease in genetic diversity indicates that the Kiso horse population is likely to experience further decline, posing a threat to the breed’s survival.
- Unless conservation measures, such as controlled mating to promote genetic variation, are taken, it is expected that the Kiso horse population will continue to dwindle.
- This study provides valuable insight that can help in the planning and implementation of conservation efforts, especially in terms of managing the genetic diversity of the Kiso breed.
Cite This Article
APA
Nakamura M, Tozaki T, Kakoi H, Nakamura K, Rajabi-Toustani R, Ohba Y, Matsubara T, Takasu M.
(2020).
Decreased genetic diversity in Kiso horses revealed through annual microsatellite genotyping.
J Vet Med Sci, 82(4), 503-540.
https://doi.org/10.1292/jvms.19-0535 Publication
Researcher Affiliations
- Department of Veterinary Medicine, Faculty of Applied Biological Sciences, Gifu University, 1-1 Yanagido, Gifu 501-1193, Japan.
- Department of Veterinary Medicine, Faculty of Applied Biological Sciences, Gifu University, 1-1 Yanagido, Gifu 501-1193, Japan.
- Laboratory of Racing Chemistry, 1731-2 Tsurutamachi, Utsunomiya, Tochigi 320-0851, Japan.
- Laboratory of Racing Chemistry, 1731-2 Tsurutamachi, Utsunomiya, Tochigi 320-0851, Japan.
- Department of Veterinary Medicine, Faculty of Applied Biological Sciences, Gifu University, 1-1 Yanagido, Gifu 501-1193, Japan.
- Department of Veterinary Medicine, Faculty of Applied Biological Sciences, Gifu University, 1-1 Yanagido, Gifu 501-1193, Japan.
- Department of Veterinary Medicine, Faculty of Applied Biological Sciences, Gifu University, 1-1 Yanagido, Gifu 501-1193, Japan.
- Education and Research Center for Food Animal Health (GeFAH), Gifu University, 1-1 Yanagido, Gifu 501-1193, Japan.
- Department of Veterinary Medicine, Faculty of Applied Biological Sciences, Gifu University, 1-1 Yanagido, Gifu 501-1193, Japan.
- Department of Veterinary Medicine, Faculty of Applied Biological Sciences, Gifu University, 1-1 Yanagido, Gifu 501-1193, Japan.
- Education and Research Center for Food Animal Health (GeFAH), Gifu University, 1-1 Yanagido, Gifu 501-1193, Japan.
MeSH Terms
- Animals
- Conservation of Natural Resources
- Endangered Species
- Female
- Genetic Variation
- Genotype
- Horses / genetics
- Japan
- Male
- Microsatellite Repeats
References
This article includes 15 references
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