Transcriptome analysis in the thiamethoxam resistance of seven-spot ladybird beetle, Coccinella septempunctata (Coleoptera: Coccinellidae)

The seven-spot ladybird beetle, Coccinella septempunctata Linnaeus (Coleoptera: Coccinellidae) has been used as the main biological control agent against all kinds of aphids in farmland and greenhouse. In this study, a thiamethoxam-resistant strain (ThR) and a susceptible strain (SS) of seven-spot ladybird beetle were established, and differentially expressed genes (DEGs) associated with thiamethoxam resistance were recorded through de novo Illumina HiSeq 4000 sequencing. A total of 53.5 Gb of clean data were obtained and finally assembled into 21,217 unigenes from ThR and SS transcriptomes. 1798 DEGs were identified between the ThR libraries and the SS libraries, including 560 up-regulated genes and 1238 down-regulated genes. Some cytochrome p450 monooxygenases (CYP450s), UDP-glycosyltransferases (UGTs), esterases (ESTs) and ATP-binding cassette (ABC) transporters were observed to be up-regulated and the nicotinic acetylcholine receptors (nAChRs) alpha subunit gene down-regulated in the ThR strain compared to the SS strain. This study provides genetic information for further studies on thiamethoxam resistance mechanisms in the seven-spot ladybird beetle.

Automated summary

This study identified differentially expressed genes associated with thiamethoxam resistance in the seven-spot ladybird beetle through transcriptome sequencing. Up-regulation of certain metabolic enzymes and transport proteins, as well as down-regulation of nicotinic acetylcholine receptor gene, were observed in the resistant strain.