For a half-century, the commercial wild silkworm, Antheraea pernyi, has been protected by coumaphos, which is an internal organophosphorus insecticide used to kill the potential parasitic fly larvae inside. Knowledge about the detoxification genes of A. pernyi as well as the detoxification mechanism for this species remains severely limited. In this study, we identified 281 detoxification genes (32 GSTs, 48 ABCs, 104 CYPs, and 97 COEs) in the genome of this insect, which are unevenly distributed over 46 chromosomes. When compared to the domesticated silkworm, Bombyx mori, a lepidopteran model species, A. pernyi has a similar number of ABCs, but a greater number of GSTs, CYPs, and COEs. By transcriptome-based expression analysis, we found that coumaphos at a safe concentration level significantly changed the pathways related to ATPase complex function and the transporter complex in A. pernyi. KEGG functional enrichment analysis indicated that protein processing in the endoplasmic reticulum was the most affected pathway after coumaphos treatment. Finally, we identified four significantly up-regulated detoxification genes (ABCB1, ABCB3, ABCG11, and ae43) and one significantly down-regulated detoxification gene (CYP6AE9) in response to coumaphos treatment, suggesting that these five genes may contribute to detoxification of coumaphos in A. pernyi. Our study provides the first set of detoxification genes for wild silkworms from Saturniidae and highlights the importance of detoxification gene repertoire in insect pesticide tolerance.

Insects have evolved diapause to cope with harsh environmental conditions, during which their metabolism undergoes significant remodeling. The silkworm, Bombyx mori , enters diapause in the early embryonic stage, a process critically regulated by the sorbitol metabolism pathway and its key enzyme, sorbitol dehydrogenase (SDH). Nevertheless, the precise involvement of SDH in the diapause regulation of the silkworm remains to be fully understood. In this study, we identified that BmSdh2 is highly expressed in diapause-destined silkworm embryos through RNA-seq analysis. Genetic manipulation of BmSdh2 expression significantly influenced diapause progression: complete homozygous knockout of BmSdh2 led to diapause termination, whereas partial loss-of-function mutations maintained the wild-type diapause phenotype. Furthermore, integrative LC-MS/MS, metabolomic, and lipidomic analyses demonstrated that BmSdh2 dosage critically modulates diapause maintenance. These findings highlight BmSdh2 as a novel and potentially central molecular regulator in the silkworm diapause pathway.

In the silkworm, Bombyx mori (Lepidoptera: Bombycidae), the sex determination cascade is regulated by the cooperative actions of P-element somatic inhibitor (BmPSI) and Masculinizer (BmMasc), which control the sex-specific splicing of doublesex (Bmdsx). However, the functional interplay between these two critical factors remains poorly understood. In this study, we investigated the cooperative roles of BmPSI and BmMasc through transgenic overexpression and pull-down assays coupled with mass spectrometry. Co-overexpression of BmPSI and BmMasc resulted in female-specific lethality, whereas overexpression of either gene alone caused no lethality. Pull-down coupled with mass spectrometry identified 52 common interacting proteins of BmPSI and BmMasc, including Lethal(3)neo18, a mitochondrial respiratory chain Complex I core subunit, suggesting a potential link between sex determination and mitochondrial function. Transcriptome analysis of previously generated Bmdsx knockout mutants (Bmdsx^M, Bmdsx^F, and Bmdsx^C) revealed 703 commonly dysregulated genes, which were predominantly expressed in gonads and enriched in cytoskeletal and metabolic pathways. Notably, the oxidative phosphorylation pathway was enriched in both the Bmdsx mutant transcriptome and the BmPSI/BmMasc common interactome. Collectively, these findings indicate that BmPSI and BmMasc cooperate to regulate sex determination, and raise the possibility that synergistic disruption of mitochondrial function may underlie the female-specific lethality observed upon their co-overexpression. This study provides new insights into the molecular crosstalk between sex determination and mitochondrial metabolism in insects.