Silver effects on silkworm, <i>Bombyx mori</i>

Abstract

Silver nanoparticles (Ag-NPs) are known as a noble metal, and owing to their exclusive properties, their use is widespread in consumer products and they are mostly incorporated into food packaging and food contact products. The aim of this work was to evaluate the effects of direct ingestion of Ag-NPs through food to assess their toxicity effects on the growth and development of silkworms at different concentrations (1 mg•L-1 to 100 mg•L-1), in addition to the examination of the distribution of Ag-NPs in the silkworm body and midgut histopathological analysis. RNA sequencing was performed to investigate the transcriptomic responses to Ag-NPs exposure. Our results show that the highest Ag-NPs' concentrations induced a significant increase in the silkworm body weight with histopathological changes in the midgut compared to the control group. The gene ontology (GO) and pathway enrichment analysis for differentially expressed genes showed that Ag-NPs altered the gene expressions and that they were significantly involved in carbohydrate metabolism, digestive system, and energy metabolism. These findings indicate that the Ag-NPs may induce harmful effects on the primary target organs (alimentary system) with energy deregulation and nutrition digestion and absorption imbalance. This study is an important step in understanding the molecular mechanisms of Ag-NPs' toxicity in vivo.

Effect of acute exposure of Hg on physiological parameters and transcriptome expression in silkworms (Bombyx mori)

“…Consistent with previous research, a decrease in average insect weight emerged as a common response to heavy metal treatment, attributed to elevated protein, glycogen, and lipid consumption ( 52 ), or a reduction in the anti-damage and self-repair mechanisms ( 21 , 22 , 53 ). In this study, the basal metabolic processes, including “amino sugar and nucleotide sugar metabolism,” “biosynthesis of amino acids,” “glycine, serine and threonine metabolism,” “pentose and glucuronate interconversions,” “ascorbate and aldarate metabolism,” and “retinol metabolism” were significantly affected both in the midgut and fat body.…”

“…The Chinese Oak silkworm ( Antheraea pernyi ) among the best-known species of wild silkworms has been used as a well-known wild silk moth in sericultural and medicine industry for hundreds of years. Notably, they have seen increased utilization in studies involving heavy metals, with research focusing on the potential toxicity effects of cadmium ( 21 ), silver ( 22 ), uranium ( 23 ), and lead ( 24 ) in vivo . However, there remains a paucity of research specifically addressing Hg exposure processes, which could be pivotal in elucidating the underlying mechanisms of Hg toxicity and tracking out the vital targets for Hg tolerance.…”

Toward Spinning Greener Advanced Silk Fibers by Feeding Silkworms with Nanomaterials

“…Some et al reported that Ag NPs at concentrations of 10 mg/L fed to silkworms presented no toxic effect, promoting silkworm survival and increasing larvae and cocoon weight while negative effects were observed at the 100 mg/L concentration. Nouara et al fed silkworms with Ag NPs at 1, 10, 25, 50, and 100 mg/L, and no significant toxicity was observed at all concentrations although the highest concentrations promoted histopathological changes in the midgut, altered gene expressions, and interfered in several metabolic pathways. It was also found that the incorporation of Ag NPs on silkworm diet at concentrations less than 400 mg/L can improve larvae growth and cocoon weight, although Ag NPs at a higher concentration (>800 mg/L) can cause larvae death, affecting their protein and metabolic metabolism and reducing resistance to oxidative stress, leading to cell apoptosis and necrosis. , …”

Advances in Editing Silkworms (Bombyx mori) Genome by Using the CRISPR-Cas System

“…B. mori is one of the most important domesticated insects due to its great potential as a biotechnological platform to produce recombinant proteins, but also because of its great success as an experimental model organism [92,110]. Due to its extraordinary prospects, a wide range of studies have been performed that accelerated fundamental research and beyond in silkworms.…”