Prabhat, A.; Naidu, S.; Stumpf, I. G.; Clemons, E.; Nwadialo, S. O.; Rozmus, E.; Wen, Y.; Esser, K. A.; Schroder, E. A.; Delisle, B.

Mice housed at room temperature (RT, 25 {degrees}C) experience chronic mild cold stress compared with those housed at thermoneutrality (TN, 30 {degrees}C). We hypothesized that cold stress suppresses circadian transcript expression in peripheral tissues. RNA-seq of hearts, livers, and diaphragms collected every 4 hours over 48 hours in constant darkness identified mRNA transcripts exhibiting ~24-hour rhythms (REGs). TN produced tissue-specific changes in REG number, identity, and phase without altering core circadian clock transcript levels. Cardiac REGs increased 4-fold, diaphragm REGs 1.5-fold, and hepatic REG identity shifted substantially. GO analysis revealed coordinated reorganization of rhythmic metabolic programs in the heart and liver. These data demonstrate that ambient housing temperature has tissue-specific effects on the number, identity, and temporal organization of rhythmically expressed transcripts in the heart, liver, and diaphragm.