Zhang Yan, Shikina Shinya, Ho Yu-Ying, Chiu Yi-Ling, I-Chen Yao Jack, Zatylny-Gaudin Céline, Dufour Sylvie, Chang Ching-Fong
Center of Excellence for the Oceans, National Taiwan Ocean University, Keelung, Taiwan; Zhejiang Marine Fisheries Research Institute, Zhejiang, China; Marine and Fishery Research Institute, Zhejiang Ocean University, Zhejiang, China.
Center of Excellence for the Oceans, National Taiwan Ocean University, Keelung, Taiwan; Institute of Marine Environment and Ecology, National Taiwan Ocean University, Keelung, Taiwan.
Gen Comp Endocrinol. 2021 Dec 1;314:113905. doi: 10.1016/j.ygcen.2021.113905. Epub 2021 Sep 15.
The distribution and functions of neurons in scleractinian corals remain largely unknown. This study focused on the Arg-Phe amide family of neuropeptides (RFamides), which have been shown to be involved in a variety of biological processes in animals, and performed molecular identification and characterization in the adult scleractinian coral Euphyllia ancora. The deduced amino acid sequence of the identified RFamide preprohormone was predicted to contain 20 potential neuropeptides, including 1 Pro-Gly-Arg-Phe (PGRF) amide and 15 Gln-Gly-Arg-Phe (QGRF) amide peptides. Tissue distribution analysis showed that the level of transcripts in the tentacles was significantly higher than that in other polyp tissues. Immunohistochemical analysis with the FMRFamide antibody showed that RFamide neurons were mainly distributed in the epidermis of the tentacles and mouth with pharynx. Treatment of E. ancora polyps with synthetic QGRFamide peptides induced polyp contraction. The induction of polyp contraction by QGRFamide peptide treatment was also observed in another scleractinian coral, Stylophora pistillata. These results strongly suggested that RFamides play a role in the regulation of polyp contraction in adult scleractinians.
石珊瑚中神经元的分布和功能在很大程度上仍然未知。本研究聚焦于神经肽的精氨酸 - 苯丙氨酸酰胺家族（RFamides），该家族已被证明参与动物的多种生物学过程，并在成年石珊瑚锚纹真叶珊瑚（Euphyllia ancora）中进行了分子鉴定和特征分析。所鉴定的RFamide前体激素的推导氨基酸序列预计包含20种潜在的神经肽，包括1种脯氨酸 - 甘氨酸 - 精氨酸 - 苯丙氨酸（PGRF）酰胺和15种谷氨酰胺 - 甘氨酸 - 精氨酸 - 苯丙氨酸（QGRF）酰胺肽。组织分布分析表明，触手中转录本水平显著高于其他水螅体组织。用FMRFamide抗体进行的免疫组织化学分析表明，RFamide神经元主要分布在触手和带有咽的口的表皮中。用合成的QGRFamide肽处理锚纹真叶珊瑚水螅体可诱导水螅体收缩。在另一种石珊瑚——尖枝石芝珊瑚（Stylophora pistillata）中也观察到QGRFamide肽处理诱导水螅体收缩。这些结果有力地表明，RFamides在成年石珊瑚水螅体收缩的调节中发挥作用。
