College of Fisheries, Guangdong Ocean University, Zhanjiang 524025, China.
College of Fisheries, Guangdong Ocean University, Zhanjiang 524025, China; Guangdong Provincial Key Laboratory of Aquatic Animal Disease Control and Healthy Culture, 524088, China.
Chemosphere. 2024 Apr;354:141646. doi: 10.1016/j.chemosphere.2024.141646. Epub 2024 Mar 5.
Zinc (Zn) is an essential trace element for the normal physiological function of aquatic organisms, but it could become toxic to organisms when the concentration increased in water. As the first line of defense, the shrimp intestines are the most susceptible organ to environmental stress. In this study, the chronic toxicity of 0 (control, IC), 0.01(IL), 0.1(IM) and 1 mg/L (IH) Zn in intestines of Litopenaeus vannamei was investigated from the perspectives of biochemical, histological and transcriptional changes after exposure for 30 days. The results showed that the intestinal tissue basement membrane is swollen in the IM and IH groups and detached in the IH group. The total antioxidant capacities (T-AOC) were reduced while the content of malondialdehyde (MDA) were increased significantly in IM and IH groups. The production of reactive oxygen species (ROS) was increased significantly in IH group. Many differentially expressed genes (DEGs) were identified in IL, IM and IH groups, respectively. GO and KEGG enrichment analyses were conducted on the DEGs to obtain the underlying biological processes and pathways. The gene modules related to the sample were identified by weighted gene co-expression network analysis (WGCNA), and genes in modules highly corelated with IH group were mainly enriched in immune related pathways. Nine DEGs were selected for validation by quantitative real time PCR (qRT-PCR) and the expression profiles of these DEGs kept a well consistent with the high-throughput data, which confirmed reliability of transcriptome results. Additionally, 10 DEGs were screened to detect the changes of expression level in different groups. All these results indicated that Zn exposure could damage the intestinal barrier, provoke oxidative stress, reduce the immune function, increase the susceptibility to bacterial infections of L. vannamei and cause inflammation, ultimately result in cell apoptosis. Our study provides more perspective on the stress response of crustacean under Zn exposure.
锌（Zn）是水生生物正常生理功能所必需的痕量元素，但当水中浓度增加时，它可能对生物体有毒。作为第一道防线，虾的肠道是最容易受到环境压力影响的器官。在这项研究中，从生化、组织学和转录变化的角度，研究了 0（对照，IC）、0.01（IL）、0.1（IM）和 1mg/L（IH）锌在凡纳滨对虾肠道中的慢性毒性，暴露 30 天后。结果表明，在 IM 和 IH 组中，肠组织基底膜肿胀，在 IH 组中分离。IM 和 IH 组的总抗氧化能力（T-AOC）降低，丙二醛（MDA）含量显著增加。IH 组活性氧（ROS）的产生显著增加。在 IL、IM 和 IH 组中分别鉴定出许多差异表达基因（DEGs）。对 DEGs 进行 GO 和 KEGG 富集分析，以获得潜在的生物学过程和途径。通过加权基因共表达网络分析（WGCNA）鉴定与样品相关的基因模块，与 IH 组高度相关的基因模块主要富集在免疫相关途径中。选择 9 个 DEGs 通过定量实时 PCR（qRT-PCR）进行验证，这些 DEGs 的表达谱与高通量数据保持很好的一致性，证实了转录组结果的可靠性。此外，筛选了 10 个 DEGs 来检测不同组之间表达水平的变化。所有这些结果表明，锌暴露会破坏肠道屏障，引发氧化应激，降低免疫功能，增加凡纳滨对虾对细菌感染的易感性，并导致炎症，最终导致细胞凋亡。我们的研究为甲壳动物在锌暴露下的应激反应提供了更多的视角。
