Liu Zhaoqun, Wang Lingling, Yan Yunchen, Zheng Yan, Ge Wenjing, Li Meijia, Wang Weilin, Song Xiaorui, Song Linsheng
Liaoning Key Laboratory of Marine Animal Immunology, Dalian Ocean University, Dalian, 116023, China; Functional Laboratory of Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266235, China.
Liaoning Key Laboratory of Marine Animal Immunology, Dalian Ocean University, Dalian, 116023, China; Functional Laboratory of Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266235, China; Liaoning Key Laboratory of Marine Animal Immunology and Disease Control, Dalian Ocean University, Dalian, 116023, China.
Dev Comp Immunol. 2018 Jul;84:337-342. doi: 10.1016/j.dci.2018.03.009. Epub 2018 Mar 14.
Dopamine (DA), a significant member of catecholamines, is reported to induce biomineralization of calcium carbonate vaterite microspheres via dopamine receptor (DR) in bivalves, implying the modulation of dopaminergic system on shell formation during larval development. In this research, a homologue of D1 type DR (CgD1DR-1) was identified from oyster Crassostrea gigas, whose full length cDNA was 1197 bp. It was widely expressed in various tissues of C. gigas, with the significantly higher levels in hepatopancreas, mantle, muscle and gill. During developmental stages, the mRNA transcripts of CgD1DR-1 in D-shape larvae were obviously higher (p < 0.05) than those in trochophore and umbo larvae, and CO exposure could inhibit the synthesis of DA and mRNA expression of CgD1DR-1. After cell transfection and DA treatment, intracellular cAMP in cells with the expression of CgD1DR-1 increased significantly (p < 0.05). Furthermore, the incubation with SCH 23390 for the blockage of CgD1DR-1 significantly restrained the expressions of six shell formation-related genes including CgTyrosinase-1, CgTyrosinase-3, CgChitinaseLP, CgAMC, CgBMP and CgBMPR in trochophore and D-shape larvae. These results jointly suggested that DA together with its receptor CgD1DR-1 might be involved in shell formation during oyster larval development from trochophore to D-shape larvae, and CO-induced ocean acidification (OA) might influence marine bivalves by inhibiting the DA-D1DR pathway to prohibit their shell formation.
多巴胺（DA）是儿茶酚胺的重要成员，据报道它可通过双壳贝类中的多巴胺受体（DR）诱导球霰石型碳酸钙微球的生物矿化，这意味着多巴胺能系统在幼虫发育过程中对贝壳形成具有调节作用。在本研究中，从太平洋牡蛎中鉴定出一种D1型DR的同源物（CgD1DR-1），其全长cDNA为1197 bp。它在太平洋牡蛎的各种组织中广泛表达，在肝胰腺、外套膜、肌肉和鳃中的表达水平显著更高。在发育阶段，D形幼虫中CgD1DR-1的mRNA转录本明显高于担轮幼虫和壳顶幼虫（p<0.05），并且一氧化碳暴露可抑制多巴胺的合成和CgD1DR-1的mRNA表达。细胞转染和多巴胺处理后，表达CgD1DR-1的细胞内cAMP显著增加（p<0.05）。此外，用SCH 23390阻断CgD1DR-1后，显著抑制了担轮幼虫和D形幼虫中六个与贝壳形成相关基因的表达，包括Cg酪氨酸酶-1、Cg酪氨酸酶-3、Cg几丁质酶LP、CgAMC、CgBMP和CgBMPR。这些结果共同表明，多巴胺及其受体CgD1DR-1可能参与了牡蛎幼虫从担轮幼虫到D形幼虫发育过程中的贝壳形成，并且一氧化碳诱导的海洋酸化可能通过抑制多巴胺-D1DR途径来影响海洋双壳贝类，从而阻止它们的贝壳形成。
