Housing Mice in Thermoneutrality Causes Tissue-specific Changes in Number, Identity, and Phase of Circadian-expressed mRNA Transcripts.

May 18, 2026bioRxiv : the preprint server for biology

Keeping Mice at Comfortable Temperatures Changes Daily Gene Activity in Different Tissues

AI simplified

Circadian Biology on OpenScience ↗PubMed ↗DOI ↗

Abstract

Mice housed at room temperature (25°C) show a 4-fold increase in cardiac transcripts with 24-hour rhythms compared to those in thermoneutrality (30°C).

Cold stress may suppress circadian transcript expression in peripheral tissues.
RNA sequencing identified mRNA transcripts with approximately 24-hour rhythms in hearts, livers, and diaphragms.
Ambient temperature influenced the number, identity, and phase of rhythmically expressed transcripts without affecting core circadian clock levels.
Diaphragm transcripts increased by 1.5-fold, while substantial shifts occurred in hepatic transcript identity.
GO analysis indicated a coordinated reorganization of rhythmic metabolic programs in the heart and liver.

AI simplified

Mice housed at room temperature (RT, 25°C) experience chronic mild cold stress compared with those housed at thermoneutrality (TN, 30°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.