Key Laboratory of South China Sea Fishery Resources Exploitation & Utilization, Ministry of Agriculture and Rural Affairs, Guangdong Provincial Key Laboratory of Fishery Ecology and Environment, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, 510300, PR China.
Key Laboratory of South China Sea Fishery Resources Exploitation & Utilization, Ministry of Agriculture and Rural Affairs, Guangdong Provincial Key Laboratory of Fishery Ecology and Environment, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, 510300, PR China; Shenzhen Base of South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Shenzhen, 518121, PR China.
Environ Pollut. 2020 Oct;265(Pt A):114774. doi: 10.1016/j.envpol.2020.114774. Epub 2020 May 12.
Microcystis aeruginosa (MA) is a primary hazardous cyanobacteria species in aquatic ecosystems that can produce microcystin-LR (MC-LR), which harms aquatic animals. The intestine is an important target tissue for MA and MC-LR. In this study, we investigated the effects of MA and MC-LR exposure on the intestinal microbiota variation and immune responses of Litopenaeus vannamei. Shrimp were experimentally exposed to MA and MC-LR for 72 h. The results showed that both MA and MC-LR exposure caused marked histological variation and apoptosis characteristics and increased oxidative stress in the intestine. Furthermore, the relative expression levels of antimicrobial peptide genes (ALF, Crus, Pen-3) decreased, while those of pro-inflammatory cytokines (MyD88, Rel, TNF-a), a pattern-recognition receptor (TLR4) and a mediator of apoptosis (Casp-3) increased. MA and MC-LR exposure also caused intestinal microbiota variation, including decreasing microbial diversity and disturbing microbial composition. Specifically, the relative abundance of Proteobacteria decreased in the two stress groups; that of Bacteroidetes decreased in the MA group but increased in the MC-LR group, while Tenericutes varied inversely with Bacteroidetes. Our results indicate that MA and MC-LR exposure causes intestinal histopathological and microbiota variations and induces oxidative stress and immune responses in L. vannamei. In conclusion, this study reveals the negative effects of MA and MC-LR on the intestinal health of shrimp, which should be considered in aquaculture.
铜绿微囊藻（MA）是水生生态系统中一种主要的有害蓝藻物种，能够产生微囊藻毒素-LR（MC-LR），对水生动物造成危害。肠道是 MA 和 MC-LR 的重要靶组织。在本研究中，我们研究了 MA 和 MC-LR 暴露对凡纳滨对虾肠道微生物群变化和免疫反应的影响。虾被实验性地暴露于 MA 和 MC-LR 中 72 小时。结果表明，MA 和 MC-LR 暴露均导致肠道组织学变化明显，出现凋亡特征，并增加了氧化应激。此外，抗菌肽基因（ALF、Crus、Pen-3）的相对表达水平降低，而促炎细胞因子（MyD88、Rel、TNF-a）、模式识别受体（TLR4）和凋亡介质（Casp-3）的相对表达水平增加。MA 和 MC-LR 暴露还导致肠道微生物群发生变化，包括降低微生物多样性和扰乱微生物组成。具体来说，两种应激组的变形菌门相对丰度降低；MA 组的拟杆菌门相对丰度降低，但 MC-LR 组的相对丰度增加，而厚壁菌门与拟杆菌门呈相反变化。我们的结果表明，MA 和 MC-LR 暴露导致凡纳滨对虾肠道组织病理学和微生物群发生变化，并诱导其发生氧化应激和免疫反应。总之，本研究揭示了 MA 和 MC-LR 对虾类肠道健康的负面影响，在水产养殖中应予以考虑。
