Transcriptome profiling reveals differential gene expression of detoxification and mitochondrial-related enzymes in Tribolium castaneum in response to carbonyl sulfide
Carbonyl sulfide (COS) is a novel grain fumigant, introduced in 1993 as a substitute to methyl bromide and phosphine for managing stored-grain pests. While COS has demonstrated high toxicity and broad efficacy against various stored-product pests, including Tribolium castaneum, the mechanisms underlying its toxicity in insects remain largely unexplored. To elucidate the molecular basis of COS toxicity in insects, we analyzed the transcriptome to investigate gene expression in the malpighian tubules and fat body tissues of adult T. castaneum upon COS fumigation. Our analysis identified 3,034 and 2,973 differentially expressed genes (DEGs) in the malpighian tubules and fat body, respectively. Several DEGs associated with insecticide detoxification, mitochondrial functions, and carbonic anhydrase (CA) activity were significantly expressed between the COS-treated and control groups. The functional annotation and pathway analyses using Gene Ontology (GO) terms and KEGG for these DEGs identified categories related to binding, catalytic activity, cellular and biological processes, cellular anatomical entity and xenobiotic metabolism pathways. We validated 23 DEGs, which revealed consistent gene expression levels with those of transcriptomic analysis. Furthermore, we analysed the impact of acetazolamide, a CA inhibitor, on the survival rates of T. castaneum larvae and adults following COS exposure, implying that acetazolamide likely reduces COS toxicity through CA inhibition. This study presents the first comparative transcriptome investigation of the malpighian tubules and fat body in T. castaneum, enhancing our understanding of the molecular basis of COS toxicity and its potential as an effective alternative for control of this significant agricultural pest. Overall design: We investigated the differentially expressed genes between COS-treatment (malpighian tubules and fat body) and control group (whole body) of Tribolium castaneum.