| 摘要: |
| 以厚壳贻贝(Mytilus coruscus)为研究对象，开展不同暴露浓度(4、20和100 µg/L)菲(phenanthrene, PHE)的富集(10 d)和释放(5 d)实验，分别利用高效液相色谱法和荧光定量qPCR法分析了厚壳贻贝内脏团、外套膜、闭壳肌对PHE的富集和释放实验及HSP70 mRNA表达量的变化。结果显示，在10 d的富集阶段，厚壳贻贝3个组织对PHE的富集能力大小表现为内脏团>外套膜>闭壳肌；3个组织对PHE的富集含量随时间的增加而增加，同时，也随暴露浓度的增加而增加；在释放实验阶段，厚壳贻贝3个组织中PHE含量在释放前期迅速下降，但在15 d时，3个组织中PHE残留量仍均高于对照组；PHE对厚壳贻贝体内HSP70 mRNA诱导表达具有组织特异性，其中外套膜中HSP70 mRNA表达量最高。研究结果可为PHE在贝类体内的富集动力学及致毒机制研究提供参考依据。 |
| 关键词: 菲 厚壳贻贝 生物富集 HSP70 |
| DOI：10.19663/j.issn2095-9869.20200811002 |
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| 基金项目: |
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| Enrichment and release of phenanthrene in mussels (Mytilus coruscus) and its effect on HSP70 mRNA expression |
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ZENG Mengni1,2, LI Lei2, MA Liyan2, WANG Cuihua2, ZHANG Xuan2, HUANG Dongmei2, JIANG Mei2
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1.School of Marine Ecology and Environment, Shanghai Ocean University, Shanghai 201306, China;2.East China Sea Fisheries Research Institute, Shanghai 200090, China
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| Abstract: |
| Phenanthrene (PHE) is one of the most abundant polycyclic aromatic hydrocarbons (PAHs) in aquatic ecosystems. It has strong hydrophobicity and is often adsorbed on sediment and suspended particles in water, which has potential toxicity to aquatic organisms. Mussels (Mytilus coruscus) are widely distributed in the ocean and live in a fixed environment. They are filter feeders and have a strong accumulation of organic pollutants in water. They are often used as indicator organisms in monitoring marine environmental pollution. In this study, enrichment (10 d) and release (5 d) tests of PHE with different exposure concentrations were carried out. Three groups of PHE (4 μg/L, 20 μg/L, and 100 μg/L) and artificial seawater group (control group: 0.01% acetone) were set up. Three parallel experimental replicates were set up in each group, and 16 mussels were placed in each group. Two mussels were randomly selected on the 1st, 3rd, 6th, 10th, 12th, and 15th day. Their visceral mass, outer membrane, and closed shell muscle tissue were separated and stored at –80℃ for identification and analysis. Enrichment and release of PHE and the change in HSP70 gene expression in visceral mass, outer membrane, and closed shell muscle tissue were analyzed using HPLC and qPCR, respectively. Results showed that the concentration of PHE in the three tissues of mussels was in this order: visceral mass > outer membrane > closed shell muscle at the same time and concentration. The enrichment content of PHE in the three tissues increased with an increase in time and concentration, owing to the higher n-octanol/water partition coefficient and fat solubility of PHE, filter feeding life of mussels, and the fact that tissues with high fat content are more likely to enrich PHE. For the release test, the PHE content in the three tissues of mussels decreased rapidly in the early stage of release; however, on the 15th day, the residual amount of PHE in the three tissues was still higher than that in the control group. This is because the release of PHE in different tissues was mainly controlled by diffusion driven by thermodynamics, metabolic activity regulated by enzyme system, and excretion when mussels were in the state of water release. In addition, PHE content in mussel tissues began to decrease rapidly in the early stage of release and gradually decreased with the extension of release time. Furthermore, HSP70 was induced to enhance the anti-stimulation and survival ability of the organism under PHE stress; the expression of HSP70 mRNA in mussels was tissue-specific, and the expression level of HSP70 in the outer membrane was the highest. These results provide a reference for the study of enrichment kinetics and toxic mechanisms of PHE in shellfish. |
| Key words: Phenanthrene Mytilus coruscus Bioconcentration HSP70 |
