Shared and Unique G Alpha Proteins in the Zebrafish Versus Mammalian Senses of Taste and Smell
Shared and Unique G Alpha Proteins in the Zebrafish Versus Mammalian Senses of Taste and Smell
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DOI：
10.1093/chemse/bjq138
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发表时间：
2011-05-01
期刊：
影响因子：
3.5
通讯作者：
Korsching, Sigrun I.
中科院分区：
文献类型：
--
作者：
Oka, Yuichiro;Korsching, Sigrun I.
脊椎动物的化学感觉系统使用G蛋白偶联受体作为传感器。在哺乳动物中，已经确定了几个嗅觉和味觉受体家族以及与它们偶联的特定G α蛋白，例如，味觉蛋白。鱼类的同源受体家族已被确定，但相应的G α基因尚未得到很好的研究。我们对几种低等脊椎动物基因组进行了全面的搜索，以建立这些分类群中的G α蛋白家族，并鉴定可能参与鱼类化学感觉信号转导的基因。我们报告说，在所有被分析的硬骨鱼和两栖动物物种的基因组中都没有gustducin，可能是由于这些谱系中独立的基因丢失。然而，斑马鱼味蕾中表达另外2个G α基因Gi1b和G14a，嗅觉上皮中检测到4个G蛋白Go1、Go2、Gi1b和Golf2。Golf2、Gi1b和G14a在孵化后不久就已经表达，这与幼虫对气味和味觉的生理和行为反应一致。我们的结果显示了与哺乳动物情况的一般相似性，但也有明显的差异，因此对于使用斑马鱼模型系统来研究化学感觉知觉是必不可少的。
Chemosensory systems in vertebrates employ G protein-coupled receptors as sensors. In mammals, several families of olfactory and gustatory receptors as well as specific G alpha proteins coupling to them have been identified, for example, gustducin for taste. Orthologous receptor families have been characterized in fish, but the corresponding G alpha genes have not been well investigated so far. We have performed a comprehensive search of several lower vertebrate genomes to establish the G alpha protein family in these taxa and to identify those genes that may be involved in chemosensory signal transduction in fish. We report that gustducin is absent from the genomes of all teleost and amphibian species analyzed, presumably due to independent gene losses in these lineages. However, 2 other G alpha genes, Gi1b and G14a, are expressed in zebrafish taste buds and 4 G proteins, Go1, Go2, Gi1b, and Golf2, were detected in the olfactory epithelium. Golf2, Gi1b, and G14a are expressed already shortly after hatching, consistent with the physiological and behavioral responses of larvae to odorants and tastants. Our results show general similarity to the mammalian situation but also clear-cut differences and as such are essential for using the zebrafish model system to study chemosensory perception.