Silkworm 002

The domestic silkworms, Bombyx mori, always live in groups and little is known of the outcomes of solitary living. We bred solitary silkworms and performed a comprehensive investigation of the difference between solitary and group-living silkworms. The results show that solitary silkworms had significantly lower weights than group-living counterparts. Moreover, solitary silkworms had faster movements under food luring or heat stress than the group-living ones, supported by extensive behavior experiments. These findings inferred that an increased agility resulted from solitary living. For an understanding of the molecular mechanism associated with solitary living, we performed integrated mRNA and miRNA (microRNA) sequencing of tissues for solitary and group-living silkworms. We identified 165 differently expressed genes (DEGs) and 6 differently expressed miRNAs between the solitary and group-living silkworms. Functional and pathway analyses indicated that these DEGs are associated with weight loss and agility increase. These findings compose a sketch depicting an association between the phenotypes and genes resulted from solitary living and refresh the understanding of solitary living and loneliness, which has an increased prevalence in our modern society.

Benzene can impair peripheral immunity and immune organs; however, the recovery of benzene impairment has rarely been reported. In this study, we developed an immune dysfunction mouse model using a benzene gavage (500 mg/kg). Female Balb/c mice were treated with Bombyx batryticatus (BB, 5 g/kg), raw pinellia (RP, 5 g/kg), or a combination of Valproic acid and Coenzyme Q10 (CM, 150 mg/kg VPA & 100 mg/kg CoQ10) medication for four weeks. The immune function of the peripheral blood mononuclear cells (PBMCs), spleen, and thymus was determined to evaluate whether the observed impairment could be altered by medications in the mouse model. Results showed that medications could alleviate benzene-induced structural and functional damage of spleen and thymus. Benzene exposure decreased the ATP level of PBMC, which can be improved by BB, RP or CM. Importantly, BB, RP or CM could relieve benzene induced-oxidative stress by increasing the activities of glutathione peroxidase (GSH) and superoxide dismutase (SOD) and decreasing the contents of malondialdehyde (MDA). In conclusion, BB, RP, and CM were able to alleviate the benzene-induced immune dysfunction and redox imbalance. Improvement of the oxidative and antioxidant imbalance may represent a mechanism by which medicine prevents benzene-induced immune dysfunction.

Lepidoptera (butterflies and moths) is a major insect order including important pollinators and agricultural pests, however their microbiomes are little studied. Here, using next-generation sequencing (NGS)-based shotgun metagenomics, we characterize both the biodiversity and functional potential of gut microbiota of a lepidopteran model insect, the silkworm Bombyx mori. Two metagenomes, including the standard inbred strain Dazao (P50) and an improved hybrid strain Qiufeng × Baiyu (QB) widely used in commercial silk production, were generated, containing 45,505,084 and 69,127,002 raw reads, respectively. Taxonomic analysis revealed that a total of 663 bacterial species were identified in P50 silkworms, while 322 unique species in QB silkworms. Notably, Enterobacter, Acinetobacter and Enterococcus were dominated in both strains. The further functional annotation was performed by both BlastP and MG-RAST against various databases including Nr, COG, KEGG, CAZy and SignalP, which revealed >5 × 106 protein-coding genes. These datasets not only provide first insights into all bacterial genes in silkworm guts, but also help to generate hypotheses for subsequently testing functional traits of gut microbiota in an important insect group.