PDF(Pubmed)
Abstract：
Mercury (Hg) contamination poses a global threat to the environment, given its elevated ecotoxicity. Herein, we employed the lepidopteran model insect, silkworm (Bombyx mori), to systematically investigate the toxic effects of Hg-stress across its growth and development, histomorphology, antioxidant enzyme activities, and transcriptome responses. High doses of Hg exposure induced evident poisoning symptoms, markedly impeding the growth of silkworm larvae and escalating mortality in a dose-dependent manner. Under Hg exposure, the histomorphology of both the midgut and fat body exhibited impairments. Carboxylesterase (CarE) activity was increased in both midgut and fat body tissues responding to Hg treatment. Conversely, glutathione S-transferase (GST) levels increased in the fat body but decreased in the midgut. The transcriptomic analysis revealed that the response induced by Hg stress involved multiple metabolism processes. Significantly differently expressed genes (DEGs) exhibited strong associations with oxidative phosphorylation, nutrient metabolisms, insect hormone biosynthesis, lysosome, ribosome biogenesis in eukaryotes, and ribosome pathways in the midgut or the fat body. The findings implied that exposure to Hg might induce the oxidative stress response, attempting to compensate for impaired metabolism. Concurrently, disruptions in nutrient metabolism and insect hormone activity might hinder growth and development, leading to immune dysfunction in silkworms. These insights significantly advance our theoretical understanding of the potential mechanisms underlying Hg toxicity in invertebrate organisms.
摘要：
汞（Hg）污染对环境构成全球威胁，鉴于其生态毒性升高。在这里，我们采用了鳞翅目模式昆虫，家蚕,为了系统地研究汞胁迫对其生长发育的毒性作用，组织形态学,抗氧化酶活性，和转录组反应。高剂量汞暴露引起明显的中毒症状，显着阻碍家蚕幼虫的生长，并以剂量依赖的方式增加死亡率。在汞接触下，中肠和脂肪体的组织形态学均表现出损伤。响应Hg处理，中肠和脂肪体组织中的羧酸酯酶（CarE）活性均增加。相反，谷胱甘肽S-转移酶（GST）水平在脂肪体中增加，但在中肠中降低。转录组分析表明，汞胁迫引起的反应涉及多个代谢过程。显著不同表达的基因（DEGs）表现出与氧化磷酸化的强关联，营养素代谢，昆虫激素生物合成，溶酶体,真核生物的核糖体生物发生，中肠或脂肪体内的核糖体通路。研究结果表明，暴露于汞可能会引起氧化应激反应，试图补偿受损的新陈代谢。同时,营养代谢和昆虫激素活性的破坏可能会阻碍生长和发育，导致家蚕免疫功能紊乱.这些见解极大地促进了我们对无脊椎动物生物中汞毒性潜在机制的理论理解。
