Effects of pyriproxyfen exposure on damage to midgut and related gene expressions in the Bombyx mori silkworm

Silkworm is an important economic insect and very sensitive to pesticides. The pollution of pyriproxyfen leads to the detriment of the growth and cocooning of the silkworm, which seriously affects the development of sericulture. Results showed that at 24 h and 48 h after pyriproxyfen exposure, the relative expressions of digestive enzyme genes, oxidative phosphorylation genes, and antioxidant enzyme genes were reduced, suggesting the inhibition of pyriproxyfen on digestion and absorption, energy metabolism, and antioxidation in the midgut of a silkworm. However, the activities of detoxification enzymes and the expressions of detoxification-related genes were elevated in the midgut of silkworm after 24 h and 48 h of pyriproxyfen exposure, indicating the enhanced resistance of silkworm to pyriproxyfen. In general, this study revealed the silkworm's midgut response to pyriproxyfen and provided an important reference to understand the metabolic mechanism of pyriproxyfen in this insect.