Identification And Expression Profiling Of The Olfactory Related Genes In Conogethes Punctiferalis (Lepidoptera: Crambidae)

The communication between the insects and the environment mainly depend on smelland gustatory system. The olfactory system has been developed to a highly specific andsensitive chemical detector in long-term evolutionary process. The olfactory system cantransform the chemical signals from the environment into electrical signals, and thenregulate the insect’s behavior, such as searching for food, mates, hosts, habitat, ovipositionsites, or escaping the adversity, so it is essential for the survival and reproduction of insects.Several proteins help insects to recognize the environmental cues, such as odorant bindingproteins, chemosensory proteins, odorant receptor protein and odorant degrading enzymes.In addition, in insect pest control, these proteins can be used as new targets to interfere therecognition of odors and affect insects’ normal activities during the insect pest controlprocedure. The yellow peach moth, Conogethes punctiferalis (Guenée) is one of the mostdestructive insect pests in agricultural and forestry, which has a wide range of hosts, so itcauses serious yield losses every year. During the recent years, chemical control has beenmainly undertaken to prevent the yellow peach moth, however the yellow peach mothcould beome resistant to insecticides. In this study, cDNA library was constructed from theantennae of C. punctiferalis and then several olfactory related genes were discovered bybioinformatics analysis for further study of the gene’s function, and provide theoreticalsupport for the biological control of the yellow peach moth. The mainly results are asfollows:1. By using SMART method, cDNA library was constructed from the antennae C.punctiferalis. As a result, total1867ESTs were obtained through large-scale sequencing,and28olfactory related genes were discovered by bioinformatics analysis, including11odorant binding proteins,4pheromone binding proteins,1general odorant bindingprotein,1antennal binding protein,8chemosensory proteins and3odorant receptors.2. The olfactory receptor co-receptor（Orco）gene and reference gene β-actin were clonedfor the first time. The two genes had been submitted into GenBank and the accessionnumber were JX101681and JX119014. The open reading frame of CpunOrco gene is1,425bp in length, encoding475amino acid with seven transmembrane region. Theexpression level of this gene in different tissues was analyzed by real-time quantitative PCR. The results showed that CpunOrco gene was expressed in all tissues we tested,such as antennae, proboscises, maxillary palp, legs, abdomen and thorax with asignificant difference. It indicated that CpunOrco was mainly expressed in the antennaeand maxillary palp of C. punctiferalis, while expressed in other tissues at a relatively lowlevel. The expression level of CpunOrco was higher in antennae of male adults than inantennae of female adults.3.The expression levels of soluble proteins OBP and CSP in different tissues of bothfemale and male moth of C. punctiferalis were analyzed by semi-quantitative PCR. Theresults showed that OBP and CSP were mainly expressed in the antennae, whileCpunGOBP2，CpunOBP1~4，CpunOBP10also expressed in maxillary palp. Theexpression level of CpunOBP3~5and CpunOBP8~11in the antennae of male werehigher than the female. The distribution of CSP is wider than OBP, CpunCSP1~2，CpunCSP5~6and CpunCSP8were widely expressed in all tissues of both genders, andhighest expressed in antennae. The expression levels of CpunCSP4，CpunCSP7in malemoth were higher than in female moth.