哺乳动物的夜间-白天切换的细胞基础
Andrew D Beale1, Matthew J Christmas2, Nina M Rzechorzek1,3
1MRC Laboratory of Molecular Biology, Cambridge, UK.
Science (New York, N.Y.)
|February 26, 2026
概括
恐龙灭绝后,哺乳动物从夜间活动转向白天活动,这是由于细胞机制使它们的生物钟更耐热. 在夜间活动的小鼠中,mTOR通路的抑制促进了白天活动,揭示了时间利基选择的遗传基础.
科学领域:
- 进化生物学 进化生物学
- 时间生物学 时间生物学
- 细胞信号传输 细胞信号传输
背景情况:
- 早期的哺乳动物主要是夜间活动,而恐龙则占据了白天的.
- 纪-古纪灭绝后哺乳动物过渡到白天活动缺乏明确的机制解释.
- 了解时间利基选择的细胞基础对于进化研究至关重要.
研究的目的:
- 为了确定哺乳动物从夜间活动转变为白天活动的细胞内在机制.
- 为了研究热力学特性在细胞钟在这个进化过渡期间的作用.
- 探索参与调节白天与夜间行为的遗传和信号通路.
主要方法:
- 比较基因组学以确定信号通路中的加速进化.
- 对白天和夜间哺乳动物细胞中蛋白质合成,酸化和昼夜时间对温度的敏感性进行分析.
- 在夜间活动的小鼠中,药理上抑制了拉巴胺素 (mTOR) 途径的机械性标.
主要成果:
- 与夜间哺乳动物相比,来自日间哺乳动物的细胞对温度波动的蛋白质合成,酸化和昼夜计时的敏感性降低.
- 对比基因组学揭示了关键信号通路的加速进化,特别是mTOR,增强了细胞时钟的强度.
- 在夜间活动的小鼠中,mTOR的抑制诱导了在细胞,组织和行为层面上向白天活动的转变.
结论:
- 一个保存的,细胞内在的热力学机制,包括耐温度的细胞钟,促进了哺乳动物转向白天活动.
- 像mTOR这样的信号通路的加速进化为适应时提供了遗传和生化基础.
- 细胞信号网络在编码复杂的表型中发挥着关键作用,例如时间利基选择.
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