Key Laboratory of Animal Models and Human Disease Mechanisms of Chinese Academy of Sciences/Key Laboratory of bioactive peptides of Yunnan Province, Kunming Institute of Zoology, Kunming, Yunnan, China.
University of Chinese Academy of Sciences, Beijing, China.
PLoS Biol. 2018 Jul 12;16(7):e2004921. doi: 10.1371/journal.pbio.2004921. eCollection 2018 Jul.
Spicy foods elicit a pungent or hot and painful sensation that repels almost all mammals. Here, we observe that the tree shrew (Tupaia belangeri chinensis), which possesses a close relationship with primates and can directly and actively consume spicy plants. Our genomic and functional analyses reveal that a single point mutation in the tree shrew's transient receptor potential vanilloid type-1 (TRPV1) ion channel (tsV1) lowers its sensitivity to capsaicinoids, which enables the unique feeding behavior of tree shrews with regards to pungent plants. We show that strong selection for this residue in tsV1 might be driven by Piper boehmeriaefolium, a spicy plant that geographically overlaps with the tree shrew and produces Cap2, a capsaicin analog, in abundance. We propose that the mutation in tsV1 is a part of evolutionary adaptation that enables the tree shrew to tolerate pungency, thus widening the range of its diet for better survival.
辛辣食物会引发一种刺鼻或热辣疼痛的感觉，几乎能驱赶所有的哺乳动物。在这里，我们观察到树鼩（Tupaia belangeri chinensis），它与灵长类动物关系密切，可以直接积极地食用辛辣植物。我们的基因组和功能分析表明，树鼩瞬时受体电位香草酸型 1（TRPV1）离子通道（tsV1）中的一个单点突变降低了其对辣椒素的敏感性，使树鼩具有独特的辛辣植物摄食行为。我们表明，tsV1 中该残基的强烈选择可能是由地理上与树鼩重叠并大量产生辣椒素类似物 Cap2 的辣蓼（Piper boehmeriaefolium）驱动的。我们提出，tsV1 中的突变是进化适应的一部分，使树鼩能够耐受辛辣，从而扩大其饮食范围，以更好地生存。
