Laboratory of Marine Biology Protein Engineering, Marine Science and Technical College, Zhejiang Ocean University, Zhoushan City, Zhejiang, China.
Italian Institute for Environmental Protection and Research (ISPRA), Rome, Italy.
PLoS One. 2023 Oct 27;18(10):e0293565. doi: 10.1371/journal.pone.0293565. eCollection 2023.
Mytilus coruscus is an economically important marine bivalve mollusk found in the Yangtze River estuary, which experiences dramatic pH fluctuations due to seasonal freshwater input and suffer from shell fracture or injury in the natural environment. In this study, we used intact-shell and damaged-shell M. coruscus and performed metabolomic analysis, free amino acids analysis, calcium-positive staining, and intracellular calcium level tests in the mantle to investigate whether the mantle-specific metabolites can be induced by acute sea-water acidification and understand how the mantle responds to acute acidification during the shell repair process. We observed that both shell damage and acute acidification induced alterations in phospholipids, amino acids, nucleotides, organic acids, benzenoids, and their analogs and derivatives. Glycylproline, spicamycin, and 2-aminoheptanoic acid (2-AHA) are explicitly induced by shell damage. Betaine, aspartate, and oxidized glutathione are specifically induced by acute acidification. Our results show different metabolic patterns in the mussel mantle in response to different stressors, which can help elucidate the shell repair process under ocean acidification. furthermore, metabolic processes related to energy supply, cell function, signal transduction, and amino acid synthesis are disturbed by shell damage and/or acute acidification, indicating that both shell damage and acute acidification increased energy consumption, and disturb phospholipid synthesis, osmotic regulation, and redox balance. Free amino acid analysis and enzymatic activity assays partially confirmed our findings, highlighting the adaptation of M. coruscus to dramatic pH fluctuations in the Yangtze River estuary.
厚壳贻贝是一种经济上重要的海洋双壳贝类，分布于长江口，由于季节性淡水输入，其栖息环境的 pH 值会发生剧烈波动，并在自然环境中遭受贝壳断裂或损伤。在这项研究中，我们使用完整贝壳和受损贝壳的厚壳贻贝进行代谢组学分析、游离氨基酸分析、钙正染和外套膜细胞内钙离子水平测试，以研究贝壳特异性代谢物是否可以被急性海水酸化诱导，并了解外套膜在贝壳修复过程中如何应对急性酸化。我们观察到贝壳损伤和急性酸化均诱导了磷脂、氨基酸、核苷酸、有机酸、苯丙素及其类似物和衍生物的改变。甘氨酰脯氨酸、螺旋霉素和 2-氨基庚酸（2-AHA）是由贝壳损伤特异性诱导的。甜菜碱、天冬氨酸和氧化型谷胱甘肽是由急性酸化特异性诱导的。我们的结果表明，贻贝外套膜对不同胁迫因子有不同的代谢模式，这有助于阐明海洋酸化下的贝壳修复过程。此外，与能量供应、细胞功能、信号转导和氨基酸合成相关的代谢过程受到贝壳损伤和/或急性酸化的干扰，表明贝壳损伤和急性酸化均增加了能量消耗，并干扰了磷脂合成、渗透调节和氧化还原平衡。游离氨基酸分析和酶活性测定部分验证了我们的发现，突出了厚壳贻贝对长江口剧烈 pH 值波动的适应能力。
