Data from: Enhanced stability and polyadenylation of select mRNAs support rapid thermogenesis in the brown fat of a hibernator

During hibernation, animals cycle between torpor and arousal. These cycles involve dramatic but poorly understood mechanisms of dynamic physiological regulation at the level of gene expression. Each cycle, Brown Adipose Tissue (BAT) drives periodic arousal from torpor by generating essential heat. We applied digital transcriptome analysis to precisely timed samples to identify molecular pathways that underlie the intense activity cycles of hibernator BAT. A cohort of transcripts increased during torpor, paradoxical because transcription effectively ceases at these low temperatures. We show that this increase occurs not by elevated transcription but rather by enhanced stabilization associated with maintenance and/or extension of long poly(A) tails. Mathematical modeling further supports a temperature-sensitive mechanism to protect a subset of transcripts from ongoing bulk degradation instead of increased transcription. This subset was enriched in a C-rich motif and genes required for BAT activation, suggesting a model and mechanism to prioritize translation of key proteins for thermogenesis.

在动物冬眠期间，机体在蛰伏（torpor）与觉醒状态之间循环往复。此类循环涉及剧烈却尚未被充分阐明的动态生理调控机制，其调控层级可延伸至基因表达层面。每一轮循环中，棕色脂肪组织（Brown Adipose Tissue, BAT）通过产生必需热量，驱动动物从蛰伏状态周期性觉醒。我们对精准计时的样本实施数字化转录组分析，旨在解析冬眠动物棕色脂肪组织的剧烈活性循环背后的分子通路。有一类转录本在蛰伏期出现表达量上调，这一现象看似矛盾：因为在这类低温条件下，转录过程实际上已基本停止。我们的研究证实，此类表达上调并非由转录水平升高所致，而是源于与长poly(A)尾（poly(A) tails）的维持和/或延长相关的稳定性增强。数学建模进一步佐证了这一结论：存在一种温度敏感的机制，可保护部分转录本免于持续的整体降解，而非通过提升转录水平实现调控。该部分转录本富含C碱基基序，且涉及棕色脂肪组织激活所需的基因，这提示了一种可优先翻译产热相关关键蛋白的模型与调控机制。