Transcriptome Analysis Reveals the Gene Expression Changes in the Silkworm (Bombyx mori) in Response to Hydrogen Sulfide Exposure.

Hydrogen sulfide (H2S) has been recognized for its beneficial influence on physiological alterations. The development (body weight) and economic characteristics (cocoon weight, cocoon shell ratio, and cocoon shell weight) of silkworms were increased after continuous 7.5 µM H2S treatment. In the present study, gene expression changes in the fat body of silkworms at the 5th instar larvae in response to the H2S were investigated through comparative transcriptome analysis. Moreover, the expression pattern of significant differentially expressed genes (DEGs) at the 5th instar larvae was confirmed by quantitative real-time PCR (qRT-PCR) after H2S exposure. A total of 1200 (DEGs) was identified, of which 977 DEGs were up-regulated and 223 DEGs were down-regulated. Most of the DEGs were involved in the transport pathway, cellular community, carbohydrate metabolism, and immune-associated signal transduction. The up regulated genes under H2S exposure were involved in endocytosis, glycolysis/gluconeogenesis, the citrate cycle (TCA cycle), and the synthesis of fibroin, while genes related to inflammation were down-regulated, indicating that H2S could promote energy metabolism, the transport pathway, silk synthesis, and inhibit inflammation in the silkworm. In addition, the expression levels of these genes were increased or decreased in a time-dependent manner during the 5th instar larvae. These results provided insight into the effects of H2S on silkworms at the transcriptional level and a substantial foundation for understanding H2S function.