There may be some truth to the long-held belief that whorls can indicate the temperament of horses, the findings of fresh research in Brazil suggest.
Little is known about the biological events that potentially drive this association, Diogo Felipe Pereira de Assis Lima and his fellow researchers reported in the journal Animals.
The study team, with the Federal University of Bahia and the São Paulo State University Franca Campus, set out to identify the main genomic regions that influence whorl traits in livestock, using horses as a model.
The researchers performed a genome-wide association analysis to identify chromosome regions and candidate genes associated with hair whorl traits.
Data from 342 Quarter Horses genotyped for about 53,000 single nucleotide polymorphisms (SNPs) were used in an association study using a single-step procedure. An SNP is a variation at a single position in a DNA sequence among individuals.
Genomic regions associated with hair whorl traits in horses were successfully identified, they reported. In these regions, many genes related to hair follicle growth were investigated, with evidence indicating they influenced whorl-related traits.
“Curiously, some of these genes also have known neurological and behavioral functions,” the study team reported.
This, they said, is the first indication of genetic–biological support of the association between hair whorls and temperament in animals, providing a plausible explanation for hair whorl position as an indicator of behavior.
The study team comprised Diogo Felipe Pereira de Assis Lima, Valdecy Aparecida Rocha da Cruz, Raphael Bermal Costa and Gregório Miguel Ferreira de Camargo, all with the Federal University of Bahia; and Guilherme Luís Pereira and Rogério Abdallah, with São Paulo State University Franca Campus
Lima, D.F.P.d.A.; da Cruz, V.A.R.; Pereira, G.L.; Curi, R.A.; Costa, R.B.; de Camargo, G.M.F. Genomic Regions Associated with the Position and Number of Hair Whorls in Horses. Animals 2021, 11, 2925. https://doi.org/10.3390/ani11102925