College of Life Sciences, Tianjin Key Laboratory of Conservation and Utilization of Animal Diversity, Tianjin Normal University, Tianjin, China.
College of Life Sciences, Tianjin Key Laboratory of Conservation and Utilization of Animal Diversity, Tianjin Normal University, Tianjin, China.
Ecotoxicol Environ Saf. 2022 Oct 1;244:114027. doi: 10.1016/j.ecoenv.2022.114027. Epub 2022 Aug 29.
Chironomids are characterized by their ubiquitous distribution, global diversity and tolerant ability to deal with environmental stressors. To our knowledge, this is the first study presenting the gut microbial structure of chironomid larvae and examining the microbial alteration induced by invading chlorpyrifos and copper with different dosages. Lethal bioassay displayed a significantly decreased percentage survival of Propsilocerus akamusi larvae exposed to 800 mg/L copper and 50 μg/L chlorpyrifos at 96 h. Larvae with deficient gut microbiota exhibited a depressed level of glutathione S-transferase activity after stressful exposure. The high-throughput 16S rRNA gene sequencing was adopted to investigate the community structure and it turned out that both copper and chlorpyrifos were able to generate distinguished variations of gut microbiota in the stressor-specific and concentration-dependent manner. Of note, the relative abundance of Comamonas, Stenotrophomonas, and Yersinia remarkably elevated in the presence of copper while chlorpyrifos exposure upregulated the prevalence of certain genera (e.g. Serratia). Flavobacterium was greatly attenuated in chlorpyrifos group with lethal dosage exhibiting more severe impacts. The predicted gene functions of the gut commensals differed between normal samples and those subjected to distinct toxins. Besides, more positive associations and limited modularity of microbial interactions were observed in stressor-challenged larvae, presenting a network with impaired complexity and stability. The appearance of either copper or chlorpyrifos exhibited strong positive correlations with genera belonging to Proteobacteria and Firmicutes. Collectively, this investigation introduces a general outline of gut microbiota obtained from chironomid individuals with latent adaptive tactics to nocuous factors (heavy metal and pesticide), which could build a fundamental basis for us to further explore the protective roles of chironomid gut bacterial colonizers in defending against aquatic contaminants.
摇蚊的特点是分布广泛、全球多样性高，并且具有耐受环境胁迫的能力。据我们所知，这是首次研究报道摇蚊幼虫的肠道微生物结构，并检查了不同剂量的氯菊酯和铜入侵引起的微生物变化。致死生物测定显示，暴露于 800mg/L 铜和 50μg/L 氯菊酯 96 小时后，Prospilus akamusi 幼虫的存活率显著降低。缺乏肠道微生物群的幼虫在应激暴露后表现出谷胱甘肽 S-转移酶活性降低。采用高通量 16S rRNA 基因测序来研究群落结构，结果表明铜和氯菊酯都能够以应激特异性和浓度依赖性的方式产生肠道微生物群的显著变化。值得注意的是，在铜存在的情况下，Comamonas、 Stenotrophomonas 和 Yersinia 的相对丰度显著升高，而氯菊酯暴露则增加了某些属（如 Serratia）的流行率。在氯菊酯致死剂量组中，Flavobacterium 显著减少，表现出更严重的影响。正常样本和暴露于不同毒素的样本之间，肠道共生菌的预测基因功能存在差异。此外，在受到胁迫的幼虫中，微生物相互作用的正关联更多，模块性有限，呈现出一个复杂性和稳定性受损的网络。铜或氯菊酯的出现与属于 Proteobacteria 和 Firmicutes 的属呈强烈正相关。总之，这项研究从具有潜在适应策略的摇蚊个体中获得了肠道微生物群的总体概况，这些策略可以为我们进一步探索摇蚊肠道细菌定植体在抵御水生污染物方面的保护作用奠定基础。
