TAS2R20 variants confer dietary adaptation to high-quercitrin bamboo leaves in Qinling giant pandas

Sensitivity to bitter tastes provides animals with an important means of interacting with their environment and thus, influences their dietary preferences. Genetic variants encoding functionally distinct receptor types contribute to variation in bitter taste sensitivity. Our previous study showed that two nonsynonymous sites, A52V and Q296H, in the TAS2R20 gene are directionally selected in giant pandas from the Qinling Mountains, which are speculated to be the causative base-pair changes of Qinling pandas for the higher preference for bamboo leaves in comparison with other pandas. Here, we used functional expression in engineered cells to identify agonists of pTAS2R20 (i.e. giant panda’s TAS2R20) and interrogated the differences in perception in the in vitro responses of pTAS2R20 variants to the agonists. Our results show that pTAS2R20 is specifically activated by quercitrin and that pTAS2R20 variants exhibit differences in the sensitivity of their response to the agonist. Compared to ...

苦味味觉感知敏感性是动物与环境交互的重要途径，进而影响其饮食偏好。编码功能差异化受体类型的遗传变异，可导致苦味感知敏感性的个体差异。我们既往研究发现，秦岭大熊猫TAS2R20基因存在两个非同义突变位点A52V与Q296H，该位点受到定向选择；据此推测，此类致因性碱基突变，或是秦岭大熊猫相较于其他大熊猫对竹叶偏好性更强的分子基础。本研究通过在工程化细胞中开展功能表达实验，鉴定出大熊猫TAS2R20（pTAS2R20）的激动剂，并体外探究了不同pTAS2R20变体对该激动剂的应答感知差异。研究结果显示，pTAS2R20可被槲皮苷特异性激活，且不同pTAS2R20变体对该激动剂的应答敏感性存在差异。相较于……