Slow decrease in temperature produces readthrough transcripts in mammalian hibernation.

Area of Science:

• Molecular Biology
• Physiology
• Biochemistry

Background:

• Cellular stresses can disrupt mRNA processing, leading to readthrough transcripts (RTTs).
• Small mammals entering deep torpor (DT) experience cellular stresses due to extreme physiological changes.
• The specific triggers for RTT production during torpor remain largely unknown.

Purpose of the Study:

• To investigate the conditions inducing RTTs in Syrian hamsters during deep torpor.
• To identify the specific cellular stresses responsible for RTT formation in hibernating animals.

Main Methods:

• Analysis of RTTs in Syrian hamster liver tissues under deep torpor and summer conditions.
• In vitro experiments using primary hamster hepatocytes exposed to varying temperature changes and hypoxia.

Main Results:

• RTTs were detected from diverse gene loci in hamsters under deep torpor.
• A slow decline in temperature, mimicking torpor entrance, induced RTTs in isolated hepatocytes.
• Rapid cold treatment, hypoxia, or prolonged cold (4°C) did not significantly increase RTT production.

Conclusions:

• Deep torpor-specific RTTs are primarily induced by the gradual decrease in body temperature during the torpor entrance phase.
• The findings elucidate a novel mechanism linking temperature regulation during hibernation to mRNA processing anomalies.