Hauser Frank, Cazzamali Giuseppe, Williamson Michael, Blenau Wolfgang, Grimmelikhuijzen Cornelis J P
Center for Functional and Comparative Insect Genomics, Department of Cell Biology and Comparative Zoology, Institute of Biology, University of Copenhagen, Universitetsparken 15, DK-2100 Copenhagen, Denmark.
Prog Neurobiol. 2006 Sep;80(1):1-19. doi: 10.1016/j.pneurobio.2006.07.005.
G protein-coupled receptor (GPCR) genes are large gene families in every animal, sometimes making up to 1-2% of the animal's genome. Of all insect GPCRs, the neurohormone (neuropeptide, protein hormone, biogenic amine) GPCRs are especially important, because they, together with their ligands, occupy a high hierarchic position in the physiology of insects and steer crucial processes such as development, reproduction, and behavior. In this paper, we give a review of our current knowledge on Drosophila melanogaster GPCRs and use this information to annotate the neurohormone GPCR genes present in the recently sequenced genome from the honey bee Apis mellifera. We found 35 neuropeptide receptor genes in the honey bee (44 in Drosophila) and two genes, coding for leucine-rich repeats-containing protein hormone GPCRs (4 in Drosophila). In addition, the honey bee has 19 biogenic amine receptor genes (21 in Drosophila). The larger numbers of neurohormone receptors in Drosophila are probably due to gene duplications that occurred during recent evolution of the fly. Our analyses also yielded the likely ligands for 40 of the 56 honey bee neurohormone GPCRs identified in this study. In addition, we made some interesting observations on neurohormone GPCR evolution and the evolution and co-evolution of their ligands. For neuropeptide and protein hormone GPCRs, there appears to be a general co-evolution between receptors and their ligands. This is in contrast to biogenic amine GPCRs, where evolutionarily unrelated GPCRs often bind to the same biogenic amine, suggesting frequent ligand exchanges ("ligand hops") during GPCR evolution.
G蛋白偶联受体（GPCR）基因是每种动物中的大型基因家族，有时占动物基因组的1-2%。在所有昆虫GPCR中，神经激素（神经肽、蛋白质激素、生物胺）GPCR尤为重要，因为它们与其配体一起，在昆虫生理学中占据很高的层级位置，并掌控着诸如发育、繁殖和行为等关键过程。在本文中，我们综述了目前关于黑腹果蝇GPCR的知识，并利用这些信息注释了最近测序的蜜蜂基因组中存在的神经激素GPCR基因。我们在蜜蜂中发现了35个神经肽受体基因（果蝇中有44个）以及两个编码富含亮氨酸重复序列的蛋白质激素GPCR的基因（果蝇中有4个）。此外，蜜蜂有19个生物胺受体基因（果蝇中有21个）。果蝇中神经激素受体数量较多可能是由于果蝇近期进化过程中发生的基因复制。我们的分析还得出了本研究中鉴定的56个蜜蜂神经激素GPCR中40个的可能配体。此外，我们对神经激素GPCR的进化及其配体的进化和共同进化进行了一些有趣的观察。对于神经肽和蛋白质激素GPCR，受体与其配体之间似乎存在普遍的共同进化。这与生物胺GPCR形成对比，在生物胺GPCR中，进化上不相关的GPCR常常结合相同的生物胺，这表明在GPCR进化过程中频繁发生配体交换（“配体跳跃”）。
