Evolution of a bitter taste receptor gene cluster in a New World sparrow.
Evolution of a bitter taste receptor gene cluster in a New World sparrow.
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DOI：
10.1093/gbe/evq027
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发表时间：
2010-07-12
影响因子：
3.3
通讯作者：
Thomas JW
中科院分区：
文献类型：
--
作者：
Davis JK;Lowman JJ;Thomas PJ;ten Hallers BF;Koriabine M;Huynh LY;Maney DL;de Jong PJ;Martin CL;NISC Comparative Sequencing Program;Thomas JW
苦味感知可能是作为一种防止摄入食物中有害化合物的保护机制而进化的。因此，2 型味觉受体 (TAS2R) 基因家族的进化引起了人们的极大兴趣，该基因家族编码直接负责检测苦味化合物的化学感受器。尽管已经对许多物种的 TAS2R 库进行了表征，但迄今为止，仅从一只鸟（即具有少量 TAS2R 的鸡）中建立了 TAS2R 的补充。在这里，我们使用白喉麻雀（Zonotrichia albicollis）的靶向作图和基因组测序以及其他密切相关的鸟类的样本测序来重建与进化染色体重排的断点物理相关的 TAS2R 基因簇的历史。在白喉麻雀中，这个 TAS2R 簇编码多达 18 个功能性苦味受体，并且可能在 Emberizinae 亚科辐射到新世界之前和/或同时经历了大规模扩展。除了该簇内基因诞生和死亡进化的特征之外，鸣禽 TAS2R 的 Ka/Ks 估计值与之前在包括人类在内的哺乳动物中观察到的结果相似。最后，对白喉麻雀两个常见单倍型簇的完整基因组序列进行比较，揭示了该物种内的许多非同义变异和功能基因内容的差异。这些结果表明鸟类 TAS2R 中确实存在种间和种内遗传变异，并且这些差异可能导致鸟类苦味感知的变化。
Bitter taste perception likely evolved as a protective mechanism against the ingestion of harmful compounds in food. The evolution of the taste receptor type 2 (TAS2R) gene family, which encodes the chemoreceptors that are directly responsible for the detection of bitter compounds, has therefore been of considerable interest. Though TAS2R repertoires have been characterized for a number of species, to date the complement of TAS2Rs from just one bird, the chicken, which had a notably small number of TAS2Rs, has been established. Here, we used targeted mapping and genomic sequencing in the white-throated sparrow (Zonotrichia albicollis) and sample sequencing in other closely related birds to reconstruct the history of a TAS2R gene cluster physically linked to the break points of an evolutionary chromosomal rearrangement. In the white-throated sparrow, this TAS2R cluster encodes up to 18 functional bitter taste receptors and likely underwent a large expansion that predates and/or coincides with the radiation of the Emberizinae subfamily into the New World. In addition to signatures of gene birth-and-death evolution within this cluster, estimates of Ka/Ks for the songbird TAS2Rs were similar to those previously observed in mammals, including humans. Finally, comparison of the complete genomic sequence of the cluster from two common haplotypes in the white-throated sparrow revealed a number of nonsynonymous variants and differences in functional gene content within this species. These results suggest that interspecies and intraspecies genetic variability does exist in avian TAS2Rs and that these differences could contribute to variation in bitter taste perception in birds.
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影响因子：
30.8
作者：
Bufe, B;Hofmann, T;Meyerhof, W
通讯作者：
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作者：
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