Transcriptome analysis of immune-related genes in Blaps rynchopetera Fairmaire in response to bacterial attack

Given the escalating global antibiotic resistance crisis, the discovery of novel agents with low resistance potential has become an urgent research priority to combat drug-resistant pathogens. Blaps rynchopetera Fairmaire (B. rynchopetera), a traditional medicinal and edible insect in Southwest China, has long been used in folk medicine for its antibacterial, anti-inflammatory, detoxifying, and immunomodulatory properties. These characteristics highlight its potential as a valuable source of bioactive compounds, with antimicrobial peptides (AMPs) representing one important component of the insect innate immune repertoire. Insects rely on innate immunity to produce AMPs, which are currently recognized as one of the most promising alternatives to conventional antibiotics. In this study, the immune response of B. rynchopetera was activated through artificial infection with a mixed culture of Escherichia coli and Staphylococcus aureus, followed by transcriptomic profiling to identify genes involved in innate immune, particularly those encoding AMPs. The transcriptomic analysis identified 4,484 differentially expressed genes, including 3,289 upregulated and 1,195 downregulated genes. Among these, immune-related genes were significantly upregulated, including those encoding ubiquitin, proteases, AMPs, and immune recognition receptors. Furthermore, pathway enrichment analysis revealed 37 significantly enriched biological pathways, primarily associated with metabolic processes, biosynthesis, the tricarboxylic acid cycle, and antigen presentation. Collectively, these findings demonstrate that bacterial infection elicits a complex transcriptional immune response and provide a resource for identifying candidate immune-related genes, including AMPs.