Induction of ER stress, antioxidant and detoxification response by sublethal doses of chlorantraniliprole in the silk gland of silkworm, Bombyx mori.

Sublethal doses of chlorantraniliprole (CAP) disrupt spinning disorder in the silkworm Bombyx mori (B. mori) and cause reduced cocoon production. In the present study, we investigated the effects of trace amounts of CAP on morphology and gene expression of the B. mori silk gland, found the posterior silk gland cells were possessed of disintegrated Endoplasmic reticulum (ER), unevenly distributed chromatin after exposure to CAP (0.01 mg/L). Gene expression analysis revealed that IRE1 and ATF6 ER stress-signaling pathways were inhibited, the PERK/CncC pathway was activated. Digital gene expression (DGE) analysis showed that detoxification-related genes, antioxidant genes and genes involved in ER protein processing pathway were expressed differentially in CAP-treated silkworm larvae. Notably, the transcript levels of the detoxification-related genes (CYP4M5 , CYP6AB4 , GSTD3 and GSTS1) and the antioxidant genes (CAT , TPX and SOD) were significantly increased, and the expression of ER protein processing-related genes (Sec61β , Sec61γ , Sec23α and ERGIC-53) was significantly decreased after CAP exposure. The results showed that sublethal doses of CAP exposure caused ER stress, oxidative damage to the silk gland and the perturbation of protein processing in ER, thereby probably leading to abnormal growth of the silk gland and triggering the spinning failure in silkworm. Unlabelled Image • Silk gland cells were possessed of swelling ER exposed to sublethal doses of CAP. • Sublethal doses of CAP activated ER stress in silk gland. • The activation of PERK/CncC might induced detoxification and antioxidant responses. [ABSTRACT FROM AUTHOR]