Diurnal oscillations in murine brown adipose tissue analyzed by ChIP-seq

Brown adipose tissue (BAT) burns fatty acids to produce heat, and shows diurnal oscillation with peak activity in glucose and triglyceride-derived fatty acid uptake at wakening. To gain further insight in the diurnal regulation of metabolic BAT activity, we performed chromatin immunoprecipitation sequencing (ChIP-seq) on pooled interscapular (i)BAT samples collected from chow-fed male C57BL/6J mice (10 weeks old) exposed to mild cold (22°C) at 3-hour intervals throughout a 24-hour period (n=8 mice per time point). All mice were entrained to a 12h:12h light:dark cycle, and therefore time is denoted as Zeitgeber Time (ZT) in which ZT0 indicates the onset of the light (active) phase. We applied ChIP-seq on murine iBAT obtained at 3 hour-intervals throughout a 24-hour period (8 time points in total; 1 replicate per time point).

棕色脂肪组织（Brown Adipose Tissue，BAT）可通过氧化脂肪酸产热，并呈现昼夜节律振荡，其摄取葡萄糖及甘油三酯衍生脂肪酸的活性在觉醒时刻达到峰值。为深入解析棕色脂肪组织代谢活性的昼夜调控机制，我们对24小时周期内每3小时采集一次的混合肩胛间棕色脂肪组织（interscapular BAT，iBAT）样本开展了染色质免疫共沉淀测序（chromatin immunoprecipitation sequencing，ChIP-seq）。该样本取自普通饲料喂养的10周龄雄性C57BL/6J小鼠，每一时间点采集8只小鼠的样本，所有小鼠均处于温和低温（22℃）环境中。所有小鼠均经12小时光照:12小时黑暗的光暗周期完成节律同步化，因此实验时间以授时因子时间（Zeitgeber Time，ZT）标注，其中ZT0代表光照（活跃）阶段的起始时刻。我们对24小时周期内每3小时采集的小鼠肩胛间棕色脂肪组织样本进行了ChIP-seq实验，共计8个时间点，每个时间点设置1次重复。