Analysis Of Insecticide Resistance-related Genes Of The Carmine Spider Mite Tetranychus Cinnabarinus Based On High-throughput Sequencing

Carmine spider mite (CSM), Tetranychus cinnabarinus is an important pest mite worldwidly in agricultural production which develop resistance quickly against acaricide. However, the lack of genetic information on this organism is an obstacle to understand the mechanisms of resistance. So, the high-throughput sequencing technology was employed to sequence the CSM transcriptome and Digital Gene Expression Tag Profiling in order to expand the gene information resources of the species and lay a molecular foundation for future study of insecticide resistance. The main results are as follows:1. A total of45,016contigs and25,519unigenes of this species were obtained by sequencing the transcriptome. Furthermore,15,167unigenes were annotated via BLAST querying against current databases including nr, nt, SwissProt, the Clusters of Orthologous Groups (COGs), Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO)(E-value <0.00001).2. By manually searching the database, ten categories of genes were summarized from CSM transcriptome that had been reported in literatures to be related with insecticide resistance in anthropod. They are P450genes (53), GSTs genes (24), CarEs genes (22), ATPase genes (13related to insecticide resistance), AChE genes (3), GAB A receptor genes (16), sodium channel genes (1), GluCls genes (6), nAChRs genes (10) and Cyt b genes (13).3. By sequencing the Digital Gene Expression Tag Profiling of susceptible strain and fenpropathrin-resistant strain of carmine spider mites we respectively obtained7,456,152and7,072,453clean reads. Among those genes, there are23,368differentially expressed ones, including11,090up-regulated genes and12,278down-regulated genes. Meanwhile,350genes were expressed significantly differently (FDR≤0.001and the absolute value of log2Ratio≥1), including137up-regulated genes and213down-regulated genes. Expression profile’s accuracy of85%was confirmed by qPCR of20randomly selected genes. Moreover, significant enrichment of31GO terms and12Pathways were identified by GO function significant enrichment analysis and Pathway significant enrichment analysis, respectively. Many of resistance genes are likely contained in these GO terms and Pathways.4. By screening the significant differentially expressed genes, five unigenes of detoxifying enzymes were found that likely to be related with Fenpropathrin resistance, including two P450genes (Unigene12824_A and Unigene20528_A), two carboxylesterase genes (Unigene9913_A and Unigene12325_A) and one glutathione-S-transferase gene (Unigene9401_A). Finally, a role that those five genes played in the formation of Fenpropathrin resistance in T. cinnabarinus was predicted by expression patten analysis and pathway significant enrichment analysis.