Identification and stress-induced expression of Drosomycin and Termicin genes in Shelfordella lateralis

Antimicrobial peptides (AMPs) are vital components of the insect innate immune system and play important regulatory roles in responses to microbial infection and environmental stress. Drosomycin and Termicin are important classes of insect antimicrobial peptides, yet their molecular characteristics and expression regulation in cockroaches have not been systematically investigated. In this study, three Drosomycin genes ( SlDro2 , SlDro3 , and SlDro4 ) and three Termicin genes ( SlTer1 , SlTer2 , and SlTer3 ) were identified and cloned based on transcriptome data from the red runner cockroach, Shelfordella lateralis . These genes exhibited distinct expression patterns across different developmental stages, tissues, and stress treatments, indicating potential functional differentiation in immune responses. Stress assays further showed that Escherichia coli and Staphylococcus aureus significantly induced the expression of multiple SlDro and SlTer genes, although the timing and magnitude of induction varied among genes. In contrast, deltamethrin exposure significantly upregulated only SlTer2 , whereas the remaining genes were mainly suppressed or showed no significant changes, suggesting strong gene-specific regulatory effects of deltamethrin exposure on AMP expression. Collectively, these results indicate that Drosomycin and Termicin genes in S. lateralis may be involved in immune regulation in response to bacterial infection and abiotic stress. This study provides foundational data for further investigations into the biological functions and regulatory mechanisms of antimicrobial peptides in cockroaches.