Département de sciences biologiques and Centre de recherches en sciences neurologiques, Université de Montréal, Case postale 6128, Succursale Centre-Ville, Montréal, Québec, Canada H3C 3J7.
Comp Biochem Physiol Part D Genomics Proteomics. 2009 Dec;4(4):268-289. doi: 10.1016/j.cbd.2009.07.001. Epub 2009 Jul 16.
The sequencing of the starlet sea anemone (Nematostella vectensis) genome provides opportunities to investigate the function and evolution of genes associated with chemical neurotransmission and hormonal signaling. This is of particular interest because sea anemones are anthozoans, the phylogenetically basal cnidarians least changed from the common ancestors of cnidarians and bilaterian animals, and because cnidarians are considered the most basal metazoans possessing a nervous system. This analysis of the genome has yielded 20 orthologues of enzymes and nicotinic receptors associated with cholinergic function, an even larger number of genes encoding enzymes, receptors and transporters for glutamatergic (28) and GABAergic (34) transmission, and two orthologues of purinergic receptors. Numerous genes encoding enzymes (14), receptors (60) and transporters (5) for aminergic transmission were identified, along with four adenosine-like receptors and one nitric oxide synthase. Diverse neuropeptide and hormone families are also represented, mostly with genes encoding prepropeptides and receptors related to varying closeness to RFamide (17) and tachykinin (14), but also galanin (8), gonadotropin-releasing hormones and vasopressin/oxytocin (5), melanocortins (11), insulin-like peptides (5), glycoprotein hormones (7), and uniquely cnidarian peptide families (44). Surprisingly, no muscarinic acetylcholine receptors were identified and a large number of melatonin-related, but not serotonin, orthologues were found. Phylogenetic tree construction and inspection of multiple sequence alignments reveal how evolutionarily and functionally distant chemical transmitter-related proteins are from those of higher metazoans.
球星海葵（Nematostella vectensis）基因组测序为研究与化学神经传递和激素信号相关的基因功能和进化提供了机会。这一点特别有趣，因为海葵是刺胞动物门，是从刺胞动物和两侧对称动物的共同祖先分化程度最小的刺胞动物门，并且刺胞动物被认为是最原始的具有神经系统的后生动物。对该基因组的分析产生了 20 个与胆碱能功能相关的酶和烟碱受体的同源物，还有更多编码参与谷氨酸能（28 个）和 GABA 能（34 个）传递的酶、受体和转运体的基因，以及两个嘌呤能受体的同源物。鉴定出了许多编码酶（14 个）、受体（60 个）和转运体（5 个）的基因，用于胺能传递，以及 4 个腺苷样受体和 1 个一氧化氮合酶。还代表了多种神经肽和激素家族，大多数与 RFamide（17 个）和促甲状腺素释放激素（14 个）相关的前肽和受体基因有关，但也与甘丙肽（8 个）、促性腺激素释放激素和加压素/催产素（5 个）、黑素细胞刺激素（11 个）、胰岛素样肽（5 个）、糖蛋白激素（7 个）以及独特的刺胞动物肽家族（44 个）有关。令人惊讶的是，没有鉴定出毒蕈碱乙酰胆碱受体，而是发现了大量与褪黑素相关的但与 5-羟色胺无关的同源物。系统发育树构建和多序列比对检查揭示了化学递质相关蛋白与高等后生动物的蛋白在进化和功能上的差异。
