Identification of key genes associated with overwintering in Histia rhodope larva using gene co-expression network analysis

BACKGROUND: Histia rhodope (Cramer) (Lepidoptera: Zygaenidae) is an important pest that damages the landscape of Bischofia polycarpa (Levl.) trees. Its larval feeding on the leaves impairs tree growth and urban landscapes, causing significant impacts on local economic and ecological benefits. The insect often overwinters as a cocoon of mature larvae in places such as leaf litter, brick crevices, and tree bark. The low temperatures in winter directly affect the distribution of insect populations, so it is important to explore the molecular mechanisms of overwintering in H. rhodope. RESULTS: RNA-seq technology was used to obtain transcriptome data from 5 different overwintering stages of H. rhodope, and 30 genes related to cold tolerance were screened from the annotation information of differentially expressed gene database (DEGs). Two modules (blue and green) were found to be associated with overwintering by weighted gene co-expression network analysis (WGCNA), identifying translocon-associated protein, thioredoxin, glycine cleavage system H protein, ribosomal proteins, and ATP synthase genes as hub genes. In addition, cytochrome P450 genes were screened. Protein-protein interaction (PPI) network analysis showed that 60 S and 40s ribosomal proteins, putative serine/threonine protein kinase, and heat shock protein 90 had the highest number of direct interactions with other proteins. They might help the larvae successfully overwinter. Ten selected genes were subjected to qRT-PCR to verify the reliability of RNA-seq results. CONCLUSIONS: In this study, we obtained transcriptomic data from five different overwintering stages of H. rhodope, revealing key genes associated with this process. This provides a theoretical basis for further research on the molecular mechanisms of overwintering in H. rhodope.