Analysis Of Olfactory Genes Diversity And Expression In Arma Chinensis

Base on a third trophic levels,predators often perceive volatiles that released by herbivore-injured plants,secretions or substances associated with prey,to locate their victims.Arma chinensis(Fallou)is carnivorous during both the adult and larval stages and is an important natural enemy of many agricultural and forestry pests from Lepidoptera,Coleoptera,Hymenoptera and Hemipteraand.A.chinensis is known as a prospective indigenous biological control agent in the Palaearctic region,including China.Study of olfactory gene function and olfactory behavior of A.chinensis is imperative to enhance its efficacy in biological pest control using highly effective "push-pull" strategy,in which combinations of repellent and attractive stimuli are employed to regulate the populations of insect pests and their natural enemies.In this study,several kinds of olfactory genes putatively involved in olfactory reception in A.chinensis were identified base on an antennae transcriptome analysis of A.chinensis by Illumina Genome Analyzer ?x.Systematically functional studied of six key olfactory proteins were investigated,including odorant-binding proteins(OBPs),chemosensory proteins(CSPs),odorant receptors(ORs),ionotropic receptors(IRs),gustatory receptors(GRs)and sensory neuron membrane proteins(SNMPs).The main results are summarized as follows:1.Paire-end sequencing obtained 125272934 clean data(clean reads)by removing reads containing adapter,reads containing ploy-N and low quality reads from raw data.The unigenes length range is distributed between 201 bp-15428 bp.2.The transcript abundance of chemical perception is high(above 75%).93 olfactory genes among the top 500 unigenes with the highest expression level,including OBPs;GOBPs;PBPs;CSPs;Ors;P450;antennal-enriched UDP-glycosyltransferase;antennal oxidoreductase;antennal aldehyde oxidase;antennal binding protein;SNMPs.3.93 odorant-binding proteins(OBPs),13 chemosensory proteins(CSPs),96 odorant receptors(ORs),13 ionotropic receptors(IRs),47 gustatory receptors(GRs),2 types of sensory neuron membrane proteins(SNMPs)were obtained.75 OBPs?9 CSPs?11 IRs?29 GRs and 85 ORs have complete open reading frame.All OBPs were determined as Classical OBPs,"Plus-C" OBPs and Atypical OBPs.The OR co-receptor,named AchiOrco was found.The two IR co-receptors AchiIR8a and AchiIR25a were readily detected.Motif results indicate that all the OBP genes have 10 motifs,the conserved C sites were distributed among the motifl to motif5,and CSP genes have 20 motifs,the conserved C sites were distributed among the motifl to motif3.4.A total of 6801 genes are differentially expressed,2974 genes were up-regulated and 3827 genes were down-regulated.151 olfactory genes are significantly different expressed,including 42 OBPs,10 CSPs,73 ORs,7 IRs,12 GRs and 7 SNMPs.5.The expression level of olfactory genes in adults was significantly higher than that in nymphs,especially the expression of ORs were the most significant.