Investigation of a Non-Invasive Method of Assessing the Equine Circadian Clock Using Hair Follicle Cells

The study by Watts et al. demonstrated that RNA extracted from equine hair follicle cells could effectively identify 24-hour oscillations of specific clock genes, providing a non-invasive method for evaluating the equine peripheral circadian clock. Using five mares, hair follicles were collected every 4 hours over a 24-hour period, revealing significant variations in the expression of clock genes PER1, PER2, and DBP. Cosinor analysis confirmed 24-hour rhythmicity for PER1, DBP, and NR1D2. This method, requiring as few as 10 hairs and performable by untrained individuals, offered a valuable tool for future studies on equine circadian rhythms and their environmental responses, potentially aiding in the management of equine health and performance, especially for international competitions.