三种海洋贻贝类铜积累的种间差异：对生物监测的启示。

Inter-species difference of copper accumulation in three species of marine mussels: Implication for biomonitoring.

机构信息

Shenzhen Key Laboratory of Edible and Medicinal Bioresources, HKUST Shenzhen Research Institute, Shenzhen 518057, China; Department of Ocean Science, Hong Kong University of Science and Technology, Clearwater Bay, Kowloon, Hong Kong, China.

出版信息

Sci Total Environ. 2019 Nov 20;692:1029-1036. doi: 10.1016/j.scitotenv.2019.07.298. Epub 2019 Jul 20.

DOI:10.1016/j.scitotenv.2019.07.298

PMID:31539935

Abstract

Marine mussels have been used widely as biomonitors of coastal contamination in many countries. Due to the restrain of their geographical distributions, it is often necessary to employ more than one species of mussels within a large-scale biomonitoring program. In the present study, we compared the differences of copper (Cu) bioaccumulation in three species of marine mussels (green mussel Perna viridis, blue mussel Mytilus edulis, and hard-shelled mussel Mytilus coruscus) widely distributing along the Chinese coastal waters, under identical Cu exposure conditions. Over the 21-days exposure to dissolved Cu, the green mussels and blue mussels exhibited comparable newly accumulated Cu concentrations, possibly due to their comparable Cu uptake rate constant k (blue mussel, 0.573 L g d; green mussel, 0.530 L g d) and efflux rate constant k (blue mussel, 0.053 d; green mussel, 0.065 d). In contrast, there was no net Cu accumulation in the hard-shell mussels, which may be accounted by the lower k (0.394 L g d) but higher k (0.081 d) than the other two mussel species. Further subcellular distribution analyses showed that the cellular debris and metallothionein-like protein (MTLP) fraction were the key binding sites for Cu, and the MTLP fraction may act as a main contributor in Cu regulation and elimination in the blue mussels and hard-shell mussels. There was no strong evidence that the subcellular partitioning and dynamics of Cu in the mussels were responsible for the difference underlying the Cu accumulation in the three species of mussels. Our comparative study thereby suggested that it may be feasible to directly compare the Cu bioavailability in the green mussels and blue mussels based on their Cu biomonitoring data. Cu biomonitoring data from the hard-shell mussels may underestimate the actual Cu bioavailability of the sampling area given its much stronger regulation of Cu bioaccumulation as compared to the other two mussel species.

摘要

贻贝被广泛用作许多国家沿海污染的生物监测物。由于地理分布的限制，在大规模的生物监测计划中，通常需要使用一种以上的贻贝类。在本研究中，我们比较了三种广泛分布在中国沿海水域的海洋贻贝（青口贻贝 Perna viridis、贻贝 Mytilus edulis 和厚壳贻贝 Mytilus coruscus）在相同的铜暴露条件下，铜（Cu）生物积累的差异。在 21 天的溶解态 Cu 暴露期间，绿贻贝和蓝贻贝表现出可比的新积累 Cu 浓度，这可能是由于它们可比的 Cu 吸收速率常数 k（蓝贻贝，0.573 L g d；绿贻贝，0.530 L g d）和外排速率常数 k（蓝贻贝，0.053 d；绿贻贝，0.065 d）。相比之下，厚壳贻贝没有净 Cu 积累，这可能是由于其 k（0.394 L g d）较低，但 k（0.081 d）高于其他两种贻贝类。进一步的亚细胞分布分析表明，细胞碎片和金属硫蛋白样蛋白（MTLP）是 Cu 的关键结合位点，MTLP 可能是蓝贻贝和厚壳贻贝中 Cu 调节和消除的主要贡献者。没有强有力的证据表明贻贝中 Cu 的亚细胞分配和动力学是导致三种贻贝 Cu 积累差异的原因。因此，我们的比较研究表明，基于绿贻贝和蓝贻贝的 Cu 生物监测数据，直接比较 Cu 生物可利用性可能是可行的。与其他两种贻贝相比，厚壳贻贝对 Cu 生物积累的调节作用更强，因此其 Cu 生物监测数据可能会低估采样区域的实际 Cu 生物可用性。