RNA sequencing and transcriptome analyses reveal differentially expressed genes in the defensive glands of the medicinal beetle Blaps rhynchopetera

Blaps rhynchopetera (Coleoptera: Tenebrionidae) is a beetle that is widely used in folk medicine in Southwest China. The defensive glands of B. rhynchopetera secrete a complex mixture of defensive fluids, which are invaluable sources of bioactive substances for potential biotechnological applications. To provide broader insight into the genetic and biochemical basis of these defensive secretions, we performed RNA sequencing and transcriptome analysis on the defensive glands of B. rhynchopetera. We also identified differentially expressed genes (DEGs) in the defensive gland tissue using selected muscle tissue as a control. We then performed GO and KEGG enrichment analysis on the DEGs to analyze expression patterns characteristic of the defensive glands. In total, we obtained 283,921,912 high-quality clean reads, which we assembled into 39,735 transcripts with a mean length of 1,300.94 bp. These transcripts were then assembled into 27,104 unigenes with an average length of 1,143.05 bp. DEG analysis showed that 1,666 genes were significantly up-regulated and 2,565 genes were significantly down-regulated in defense gland tissues. GO enrichment analysis of these DEGs revealed that most genes were enriched in GO terms related to substance metabolism and transport. KEGG pathway enrichment results showed that lysosome-related pathways were the most highly enriched in DEGs, while many pathways related to specific metabolic pathways-such as N-glycan biosynthesis and insect hormone biosynthesis-were significantly up-regulated. Finally, it is also important to note that most GO terms related to pathogen defense as well as genes enriched in associated KEGG pathways were also significantly down-regulated in defensive gland tissue.