| The olfaction of insects plays an important role in a series of behavioral responses such as hosts orientation, feeding, oviposition, mating. The research of insect's olfaction can explore the mechanism of it's behaviour and explain the coevolutionary mechanism between the insect's behavioral responses and host plants. In the meantime, it can provide the basis for developing effective insect attractants and repellents which are friendly to environment and safe to natural enemy.Ostrinia furnacalis (Guenée) is the dominant species in all insects which damage corn .In the eary stage of growth cycle, it eats plant's stem frequently, causing of the damaged plants losing water seriously, malnutrition; after tasseling, the insect transfer todamage tassel, which leads to the fruit not be filled completely, production decline, annual loss of 10% to 30%. In this paper, As Ostrinia furnacalis (Guenée) for material and taking advantage of molecular biology, we cloned and researched the quantitative expression of general odorant binding protein gene, in addition, the 18S rRNA was asllo successfully be cloned from the genome of Ostrinia furnacalis (Guenée), it provided an important internal reference to quantitative analysis of gene expression of general odorant binding proteins. The main results were summaried as follows:(1) Using the technology of RT-PCR and 3'RACE (rapid-amplification of cDNA ends), we got the gene of general odorant binding protein 2 (GOBP2) from Ostrinia furnacalis (Guenée). The sequencing result indicated that the open reading frame's (ORF) length of OfurGOBP2 was 489bp and encoded 162 amino acid residues, we predicted its molecular weight wad 18.3Kda, the isoelectric point was 5.09, it was named OfurGOBP2 the accession number was DQ673101 in genbank. It was be predicted N-terminal hydrophobic region contains 25 amino acid signal peptide, and have six conserved cysteine among amino acid sequence. So it has the typical features of odorant binding protein. Homology analysis showed that, amino acids sequences of OfurGOBP2 and other insects consistency are more than 70%, indicating that Molecular Evolution of the insect's GOBP2 is obvious conservative. (2) Based on the GOBP1 sequence from Genbank, we designed the degenerate primers to amplify this gene fragment, and used RT-PCR to clone this gene. the framework of the gene which we obtained has 386bp nucleotides and encoded 128 amino acid. Comparing with other insect's gene of GOBP1, The sequence has higher similar through blast analysis homology analysis revealed that among GOBP1 of Lepidoptera consistency were more than 50%, so this end is partial GOBP1 sequence of the Ostrinia furnacalis (Guenée).(3) Cloned 18S rRNA gene from Ostrinia furnacalis (Guenée), the results showed that the sequence length was 1901 bp and sequence alignment indicates that the gene and 18S rRNA genes of other insects have a higher consistency. Using some purpose of some Hexapoda which which obtained from Genbank, we constructed 18S rRNA gene phylogenetic tree of the full sequence and the most conserved sequence. Systemic tree analysis suggested that the evolution relation consist with traditionally taxonomic results when using the most conserved 18S rRNA domain to construct phylogenetic tree. According to comparing, the Trichoptera and Lepidoptera had a closest relationship, it correspond with the traditional classification. The gene has been logged in Genbank, the accession number is GU205787.(4) Using RT-PCR methods, and 18S rRNA gene as internal reference, we researched the gene expression condition of GOBP1 and GOBP2 of Ostrinia furnacalis (Guenée) at different developmental stages and tissues. The results showed that they both expressed specifically in the antennae, and expression between male and female had no difference, GOBP1 and GOBP2 expression time and rule were similar, they began to express in the middle stage of pupal.
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