Rats lacking Ucp1 present a novel translational tool for the investigation of thermogenic adaptation during cold challenge.

Aim: Valuable studies have tested the role of UCP1 on body temperature maintenance in mice, and we sought to knockout Ucp1 in rats (Ucp1 ) to provide insight into thermogenic mechanisms in larger mammals.

Methods: We used CRISPR/Cas9 technology to create Ucp1 rats. Body weight and adiposity were measured, and rats were subjected to indirect calorimetry.