Tissue-specific transcriptome analysis in Propsilocerus akamusi provides novel insights into the regulatory mechanisms under deltamethrin exposure

Abstract

Deltamethrin is extensively utilized in agricultural pest control and its toxicological impacts on aquatic insects have drawn significant attention. However, the mechanisms of deltamethrin modulates gene expression framework in different tissues remain largely unknown. Herein, we selected non-biting midge, Propsilocerus akamusi (Diptera: Chironomidae), to investigate the gene repertoires in hemolymph, fat body, midgut and Malpighian tubules under the different concentrations of deltamethrin. Distinct tissue-specific gene expression patterns and pH levels were found in the response of P. akamusi to deltamethrin. Deltamethrin induced transcriptional perturbations in cuticle formation-, xenobiotic detoxification-, oxygen transport, and calcium signaling-related genes. The midgut and fat body mainly functioned on oxygen transportation, with the Malpighian tubules engaging in the calcium-ion transmembrane transport, and the overexpression of cuticular protein genes found in the hemolymph. In addition to the key role of detoxification genes, we inferred that deltamethrin perhaps activates calcium signaling pathways that protect against toxins found in the hemolymph and Malpighian tubules. Both organs exhibited upregulation of calcium/calmodulin-dependent protein Kinase II (CaMKII) and voltage-gated calcium channel (VGCC) genes, along with a rise in the pH level. Furthermore, we have compared the tertiary structures of the CaMKII genes in P. akamusi and identified CaMKII members in six other chironomids to explore the characteristics of these species that inhabit adverse environments. Our findings revealed the tissue-specific gene framework for P. akamsui, with particularly high expression detected in the hemolymph, which is instrumental in seeking target organs to develop effective biomarkers for water quality measurement.