Resveratrol elongates the lifespan and improves antioxidant activity in the silkworm Bombyx mori / 药物分析学报

A number of research has shown that the plant polyphenol resveratrol,one of the most prominent small molecules,has beneficial protective effects in multiple organisms,including worms,flies,and killifish.To understand the effects of resveratrol on lifespan,we evaluated its effects in the silkworm Bombyx mori.In this study,we found that lifespan was significantly prolonged in both female and male silkworms treated with resveratrol.Silkworm larval weight was significantly increased from day 3 of the 5th larval instar(L5D3) to day 7 of the 5th larval instar (L5D7).However,the weight of the pupa,cocoon,and total cocoon was not significantly different in female silkworms with resveratrol treatment than that in controls.Meanwhile,resveratrol significantly improved the thermotolerance of the silkworms,which enhanced their survival rate.Moreover,antioxidant activity was increased by resveratrol in both female and male silkworms.Furthermore,an antioxidant-related signalling pathway,SIRT7-FoxO-GST,was activated in silkworms with resveratrol treatment.Collectively,these results help us to understand the molecular pathways underlying resveratrol induced pro-longevity effects and indicate that silkworm is a promising animal model for evaluating the effects of lifespan-extending drugs.

Mitochondrial genome nucleotide substitution pattern between domesticated silkmoth, Bombyx mori, and its wild ancestors, Chinese Bombyx mandarina and Japanese Bombyx mandarina

Bombyx mori and Bombyx mandarina are morphologically and physiologically similar. In this study, we compared the nucleotide variations in the complete mitochondrial (mt) genomes between the domesticated silkmoth, B. mori, and its wild ancestors, Chinese B. mandarina (ChBm) and Japanese B. mandarina (JaBm). The sequence divergence and transition mutation ratio between B. mori and ChBm are significantly smaller than those observed between B. mori and JaBm. The preference of transition by DNA strands between B. mori and ChBm is consistent with that between B. mori and JaBm, however, the regional variation in nucleotide substitution rate shows a different feature. These results suggest that the ChBm mt genome is not undergoing the same evolutionary process as JaBm, providing evidence for selection on mtDNA. Moreover, investigation of the nucleotide sequence divergence in the A+T-rich region of Bombyx mt genomes also provides evidence for the assumption that the A+T-rich region might not be the fastest evolving region of the mtDNA of insects.