Identification And Analysis Of Differential Expressed Genes Of Antennal Odorant Binding Proteins Of Apriona Germari Hope

The insects perceive semi-chemicals released from plants or insects in environment by their sensitive olfactory system,and then they are stimulated to initiate host selection,feeding,courtship,mating and other behaviors.Having a deep understanding olfactory receptive mechanism of insects is an important basis for exploring non-pollution pest control techniques.In this study,we used the molecular biological techniques to construct a cDNA library of antennae of Apriona germari for further understanding its olfactory receptive mechanism,the differentially expressed genes in the antennae and other parts of A.germari were analyzed preliminarily,and the odor-binding proteins of A.germari were identified and their gene expression levels was analyzed.The main results are as follows:The antennal cDNA library of A.germari adults was successfully constructed and its antennal transcriptome was sequenced by the Illumina Hi-seq 2000.The transcriptome data was assembled by Trinity software,a total of 20 OBPs were identified in the antennae of the male and female beetles through genome annotation.The gene length of these OBPs was from 381 to 642 bp.In which,there were 5 protein sequences contained 6 conserved cysteine residues which were Classic OBPs:AgerOBP1,AgerOBP4,AgerOBP9,AgerOBP11 and AgerOBP16.Other 15 protein sequences were classified as Minus-C OBPs whose second and fifth cysteine residues were lost.The analysis of phylogenetic tree of A.germari and other Coleoptera insects showed that they were clusterd into the independent and same evolutionary branch though the great differences existed in the OBPs of same or different species,indicating they were homologous.The q-PCR results indicated that AgerOBP4,AgerOBP9 and AgerOBP16 were highly expressed in antennae of A.germari.In which,AgerOBP9 and AgerOBP16 were expressed in female higher than that of male,AgerOBP4 was highly expressed in the male.And then the AgerOBP9 and AgerOBP16 expressed in the female antennae were speculated to function on host plants recognition,while the AgerOBP4 expressed in the male antennaeis was related to recognizing female surface sex pheromone.AgerOBP2 and AgerOBP13 were highly expressed in female genitalia,AgerOBP19 was highly expressed in male genitalia.It was speculated that AgerOBP2,AgerOBP13 and AgerOBP19 played a role in the mating behavior of both sexes.The different expression genes of both sexes of A.germari adults was analyzed by DESeq2.The results showed great significant differeneces existed in the antennae of female and male beetles,involving 132 up-regulated genes and 1304down-regulated genes.There were obvious differences between up-regulated and down-regulated genes expressed in the female and male antennae.The up-regulated genes were enriched in lysine degradation,phenylalanine metabolism,phenylalanine,tyrosine and tryptophan biosynthesis in the amino acid metabolism subclass;They were mainly enriched in spliceosomes in the genetic information processing subclass,and peroxisomes,endocytosis and lysosomes in the transport and metabolism subclass,a phosphorous AMPK signaling pathway and MAPK signaling pathway in the signal transduction subclass.The down-regulated genes were enriched in the tricarboxylic acid cycle in the carbohydrate metabolism subcategory,ribosomes of the translation subcategory,peroxisomes of the transport and metabolism subcategory,the cGMP-PKG signal pathway and cAMP signal pathway of the signal transduction subclass,the synthesis and secretion of aldosterone of the endocrine system subclass.