Non-Synonymous Substitutions in Cadherin 13, Solute Carrier Family 6 Member 4, and Monoamine Oxidase A Genes Are Associated with Personality Traits in Thoroughbred Horses

Overview

Journal Behav Genet

Date 2024 Jun 10

PMID 38856811

Authors

Tamu Yokomori

Teruaki Tozaki

Aoi Ohnuma

Mutsuki Ishimaru

Fumio Sato

Yusuke Hori

Takao Segawa

Takuya Itou

Affiliations

Soon will be listed here.

Abstract

Retraining retired racehorses for various purposes can help correct behavioral issues. However, ensuring efficiency and preventing accidents present global challenges. Based on the hypothesis that a simple personality assessment could help address these challenges, the present study aimed to identify genetic markers associated with personality. Eight genes were selected from 18 personality-related candidate genes that are orthologs of human personality genes, and their association with personality was verified based on actual behavior. A total of 169 Thoroughbred horses were assessed for their tractability (questionnaire concerning tractability in 14 types of situations and 3 types of impressions) during the training process. Personality factors were extracted from the data using principal component analysis and analyzed for their association with single nucleotide variants as non-synonymous substitutions in the target genes. Three genes, CDH13, SLC6A4, and MAOA, demonstrated significant associations based on simple linear regression, marking the identification of these genes for the first time as contributors to temperament in Thoroughbred horses. All these genes, as well as the previously identified HTR1A, are involved in the serotonin neurotransmitter system, suggesting that the tractability of horses may be correlated with their social personality. Assessing the genotypes of these genes before retraining is expected to prevent problems in the development of a racehorse's second career and shorten the training period through individual customization of training methods, thereby improving racehorse welfare.

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References

Akimova E, Lanzenberger R, Kasper S . The serotonin-1A receptor in anxiety disorders. Biol Psychiatry. 2009; 66(7):627-35. DOI: 10.1016/j.biopsych.2009.03.012. View

Andresen T, Lunden D, Drewes A, Arendt-Nielsen L . Pain sensitivity and experimentally induced sensitisation in red haired females. Scand J Pain. 2018; 2(1):3-6. DOI: 10.1016/j.sjpain.2010.08.005. View

Canli T, Zhao Z, Desmond J, Kang E, Gross J, Gabrieli J . An fMRI study of personality influences on brain reactivity to emotional stimuli. Behav Neurosci. 2001; 115(1):33-42. DOI: 10.1037/0735-7044.115.1.33. View

Carroll J, Boyce-Rustay J, Millstein R, Yang R, Wiedholz L, Murphy D . Effects of mild early life stress on abnormal emotion-related behaviors in 5-HTT knockout mice. Behav Genet. 2006; 37(1):214-22. DOI: 10.1007/s10519-006-9129-9. View

Farries G, McGettigan P, Gough K, McGivney B, MacHugh D, Katz L . Genetic contributions to precocity traits in racing Thoroughbreds. Anim Genet. 2017; 49(3):193-204. DOI: 10.1111/age.12622. View

Forero A, Rivero O, Waldchen S, Ku H, Kiser D, Gartner Y . Cadherin-13 Deficiency Increases Dorsal Raphe 5-HT Neuron Density and Prefrontal Cortex Innervation in the Mouse Brain. Front Cell Neurosci. 2017; 11:307. PMC: 5623013. DOI: 10.3389/fncel.2017.00307. View

Giakoumaki S, Roussos P, Tsapakis E, Koiliari E, Pasparakis E, Zouraraki C . Cognitive and personality analysis of startle reactivity in a large cohort of healthy males. Biol Psychol. 2013; 94(3):582-91. DOI: 10.1016/j.biopsycho.2013.09.005. View

Gottschalk M, Domschke K . Novel developments in genetic and epigenetic mechanisms of anxiety. Curr Opin Psychiatry. 2015; 29(1):32-8. DOI: 10.1097/YCO.0000000000000219. View

Guo A, Hirai R, Ohashi A, Chiba Y, Tsunomori Y, Higashinaka R . Personality prediction from task-oriented and open-domain human-machine dialogues. Sci Rep. 2024; 14(1):3868. PMC: 10873327. DOI: 10.1038/s41598-024-53989-y. View

10.

Hausberger M, Bruderer C, Le Scolan N, Pierre J . Interplay between environmental and genetic factors in temperament/personality traits in horses (Equus caballus). J Comp Psychol. 2004; 118(4):434-46. DOI: 10.1037/0735-7036.118.4.434. View

11.

Hoffmann M, Bernstorff M, Kreitz N, Roetman B, Schildhauer T, Wenning K . Horse-related injury patterns: a single center report. J Orthop Surg Res. 2023; 18(1):83. PMC: 9893574. DOI: 10.1186/s13018-023-03549-3. View

12.

Holcomb K, Stull C, Kass P . Unwanted horses: The role of nonprofit equine rescue and sanctuary organizations. J Anim Sci. 2010; 88(12):4142-50. DOI: 10.2527/jas.2010-3250. View

13.

Holcomb K, Stull C, Kass P . Characteristics of relinquishing and adoptive owners of horses associated with U.S. nonprofit equine rescue organizations. J Appl Anim Welf Sci. 2012; 15(1):21-31. DOI: 10.1080/10888705.2012.624049. View

14.

Holtby A, McGivney B, Browne J, Katz L, Murphy K, Hill E . Variation in salivary cortisol responses in yearling Thoroughbred racehorses during their first year of training. PLoS One. 2023; 18(4):e0284102. PMC: 10079128. DOI: 10.1371/journal.pone.0284102. View

15.

Hori Y, Tozaki T, Nambo Y, Sato F, Ishimaru M, Inoue-Murayama M . Evidence for the effect of serotonin receptor 1A gene (HTR1A) polymorphism on tractability in Thoroughbred horses. Anim Genet. 2016; 47(1):62-7. DOI: 10.1111/age.12384. View

16.

Jacobs L, Staiger E, Albright J, Brooks S . The MC1R and ASIP Coat Color Loci May Impact Behavior in the Horse. J Hered. 2016; 107(3):214-9. PMC: 4885240. DOI: 10.1093/jhered/esw007. View

17.

Joos E, Vansteenwegen D, Hermans D . Worry as a predictor of fear acquisition in a nonclinical sample. Behav Modif. 2012; 36(5):723-50. DOI: 10.1177/0145445512446477. View

18.

Kalbfleisch T, Rice E, DePriest Jr M, Walenz B, Hestand M, Vermeesch J . Improved reference genome for the domestic horse increases assembly contiguity and composition. Commun Biol. 2018; 1:197. PMC: 6240028. DOI: 10.1038/s42003-018-0199-z. View

19.

Kanen J, Arntz F, Yellowlees R, Cardinal R, Price A, Christmas D . Serotonin depletion amplifies distinct human social emotions as a function of individual differences in personality. Transl Psychiatry. 2021; 11(1):81. PMC: 7847998. DOI: 10.1038/s41398-020-00880-9. View

20.

Kim J, Park Y, Kim E, Jung H, Yoon M . Relationship between oxytocin and serotonin and the fearfulness, dominance, and trainability of horses. J Anim Sci Technol. 2021; 63(2):453-460. PMC: 8071747. DOI: 10.5187/jast.2021.e29. View