Human existence is basically circadian. Most of us wake in the morning, sleep in the evening, and eat in between. Body temperature, metabolism, and hormone levels all fluctuate throughout the day, and it is increasingly clear that disruption of those cycles can lead to metabolic disease.
This image shows color coding of genes that are activated in the liver (yellow) as waves of activation relative to the time of day. “ZT” stands for ‘Zeitbeger time,’ where ZT0= 7 AM, ZT3=10 AM, ZT6=1 PM, etc
Credit: Bin Fang, PhD, Perelman School of Medicine, University of Pennsylvania
Other Penn authors on the study include Erika Briggs, Sean Armour, Dan Feng, Ankur Roy, Zachary Gerhart-Hines, and Zheng Sun.
The study was funded by the National Institutes of Health (R01 DK45586, F32 DK095526, K99 DK099443, F32 DK095563) and the JPB Foundation.