Genomic regions and candidate genes associated with forehead whorl positioning in Thoroughbred horses.

The research article in question discusses a study examining the genetic factors associated with the positioning of the forehead whorl (a hair pattern) in Thoroughbred horses. Sharing anecdotal evidence of a link between the position of this whorl and the horse’s temperament, the researchers identified five candidate genes potentially involved in this process.

Introduction and Background

• The researchers highlight an interest in the relationship between hair characteristics and temperament traits based on previous studies carried out on different animal species. It’s also stated that partial genetic association has been suggested in humans, given that the formation of hair whorls and neurological development happen simultaneously during fetal development.
• In the horse industry, it’s claimed that there is anecdotal evidence suggesting a link between the position of the forehead hair whorl and the animal’s temperament. This is significant as nuances in a horse’s temperament can have a major influence on its training and performance in different spheres of equestrian sport.
• The researchers index their prior study which found the heritability of forehead whorl positioning in thoroughbreds to be h=0.653, establishing that there is a significant genetic influence in thoroughbreds, and forming the basis for this study.

Methods

• This study is designed as a genome-wide association study, a common approach to investigate genetic associations with observable traits, diseases, and conditions.
• A total of 192 Thoroughbred horses were used for the research. This sample size provided the research with a broad basis for the genetic study exploring forehead whorl placement.

Results and Discussion

• The genome-wide association study revealed 11 potential markers located on chromosomes 2, 14, 15, 19, and 26. Even though no significant markers were discovered, these suggestive markers provide certain leads towards understanding genetics behind the hair whorl placement.
• Specifically, five genes, PTTG1, CCNH, RASA1, COX7C, and CLDN1, located in proximity to these markers, were identified as those having functions related to skin cell or hair follicle development and temperament. The study suggests that these genes may play a role in the positioning of the forehead whorl in Thoroughbred horses.
• Despite no decisive results, the finding of these candidate genes is considered significant as they are expected to contribute to further research and understanding regarding the genetic factors influencing the forehead whorl position in horses.
• In addition, this study’s findings can potentially help to interpret the common developmental process of whorls and temperament, providing a scientific basis to substantiate the anecdotal evidences.