Breed Differences in Dopamine Receptor D4 Gene (<i>DRD4</i>) in Horses

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Author(s)

    • HORI Yusuke
    • Department of Psychology, Graduate School of Letters, Kyoto University, Japan|Japan Society for the Promotion of Science, Japan
    • FUJITA Kazuo
    • Department of Psychology, Graduate School of Letters, Kyoto University, Japan
    • KIM Heui-Soo
    • Department of Biological Sciences, College of Natural Sciences, Pusan National University, Korea
    • TAKIMOTO Ayaka
    • Department of Psychology, Graduate School of Letters, Kyoto University, Japan|Japan Society for the Promotion of Science, Japan
    • ENDO Maiko
    • Animal Resource Science Center, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Japan
    • MANABE Noboru
    • Animal Resource Science Center, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Japan

Abstract

Genetic polymorphisms in genes related to neurotransmitters or hormones affect personality or behavioral traits in many animal species including humans. In domestic animals, the allele frequency of such genes has been reported to be different among breeds and it may account for breed differences in behavior. In this study, we investigated breed differences in horses in the dopamine receptor D4 gene (<i>DRD4</i>), which has been reported to affect horse personality. We collected samples from seven horse breeds including those native to Japan and Korea, and compared the sequence of the <i>DRD4</i> exon3 region among these breeds. We found that there were two types of polymorphisms (VNTR and SNPs) in the exon3 region, and some of them seemed to be breed-specific. In addition, we found that the allele frequency of G292A, reported to be associated with horse personality, differed greatly between native Japanese horses and Thoroughbred horses. The frequency of the A allele which is associated with low curiosity and high vigilance, was much lower in native Japanese horses (Hokkaido, 0.03; Taishu, 0.08) than in Thoroughbreds (0.62). This difference may account for breed differences in personality or behavioral traits. Further studies of the function of these polymorphisms and their effect on behavior are indicated.

Journal

  • Journal of Equine Science

    Journal of Equine Science 24(3), 31-36, 2013

    Japanese Society of Equine Science

Codes

  • NII Article ID (NAID)
    130004431257
  • Text Lang
    ENG
  • ISSN
    1340-3516
  • Data Source
    J-STAGE 
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