Tran Cawa, Hadfield Michael G
Kewalo Marine Laboratory, University of Hawaii at Manoa, 41 Ahui Street, Honolulu, HI 96813, USA.
Biol Bull. 2012 Apr;222(2):128-36. doi: 10.1086/BBLv222n2p128.
Larvae of the scleractinian coral Pocillopora damicornis are induced to settle and metamorphose by the presence of marine bacterial biofilms, and the larvae of Montipora capitata respond to a combination of filamentous and crustose coralline algae. The primary goal of this study was to better understand metamorphosis of cnidarian larvae by determining what types of receptors and signal-transduction pathways are involved during stimulation of metamorphosis of P. damicornis and M. capitata. Evidence from studies on larvae of hydrozoans suggests that G-protein-coupled receptors (GPCRs) are good candidates. Settlement experiments were conducted in which competent larvae were exposed to neuropharmacological agents that affect GPCRs and their associated signal-transduction pathways, AC/cAMP and PI/DAG/PKC. On the basis of the results of these experiments, we conclude that GPCRs and these pathways do not mediate settlement and metamorphosis in either coral species. Two compounds that had an effect on both species, forskolin and phorbol-12-myristate-13-acetate (TPA), may be acting on other cellular processes not related to GPCRs. This study strengthens our understanding of the underlying physiological mechanisms that regulate metamorphosis in coral larvae.
造礁石珊瑚鹿角杯形珊瑚的幼虫会因海洋细菌生物膜的存在而被诱导附着和变态，而头状微孔珊瑚的幼虫则对丝状和壳状珊瑚藻的组合有反应。本研究的主要目标是通过确定在鹿角杯形珊瑚和头状微孔珊瑚变态刺激过程中涉及哪些类型的受体和信号转导途径，来更好地理解刺胞动物幼虫的变态。来自对水螅虫幼虫研究的证据表明，G蛋白偶联受体（GPCRs）是很好的候选者。进行了附着实验，将有能力的幼虫暴露于影响GPCRs及其相关信号转导途径AC/cAMP和PI/DAG/PKC的神经药理学试剂中。基于这些实验结果，我们得出结论，GPCRs和这些途径在这两种珊瑚物种中均不介导附着和变态。两种对两种物种都有影响的化合物，福斯可林和佛波醇-12-肉豆蔻酸酯-13-乙酸酯（TPA），可能作用于与GPCRs无关的其他细胞过程。这项研究加强了我们对调节珊瑚幼虫变态的潜在生理机制的理解。
