Effects Of Parasitization By Cotesia Vestalis On The Transcriptional Profiles Of Neuropeptide Genes Of Plutella Xylostella Larvae

Firstly, based on the brain transcriptome data of Plutella xylostella larvae,19neuropeptide EST sequences were variefied which belong to17neuropeptide families. And then,13full-length neuropeptide genes were obtained using the rapid-amplification of cDNA ends (RACE) method. At last, we use the qRT-PCR method to detect neuropeptide genes’transcriptional patterns in different developmental stages, and to investigate the effects of parasitization/parasitization by Cotesia vestalis on the transcriptional level of Plutella xylostella larvae neuropeptide genes. The results are summarized as follows:1. Clonning of neuropeptide family genes in the brain of Plutella xylostella larvae.Through the blastx analysis, more than21neuropeptide genes’EST sequences in the brain transcriptome of P. xylostella larvae were found. Using the RACE method, we obtained13full-length neuropeptide genes:Adipokinetic hormone I, Adipokinetic hormone II, Allatostatin A, Allatostatin C, CCHamide, Bursicon α&β, Allatostatin C, Ion transportpeptide, Neuroparsin, Neuropeptide F, Prothoracicotropic hormone and Allatotropin. Moreover, the3’end sequences of6neuropeptide genes were acquired, including Short neuropeptide F, Diuretic hormone, FMRFamide, Tachykinin, Neuropeptide-like peptide and Leucokinin.2. Neuropeptide genes’transcriptional patterns in different developmental stages of the Plutella xylostella larvae.Using the qRT-PCR method, we investigated19neuropeptide genes’transcriptional patterns of different development stages in the brain of Plutella xylostella larvae. The results revealed that most neuropeptide genes have an expression peak at the end of each instar.3. Effects of parasitization/pseudo-parasitization by Cotesia vestalis on the transcriptional level of neuropeptide genes in the brain of Plutella xylostella larvae.We applied the qRT-PCR method to analysis the effects of parasitization/pseudo-parasitization on the transcriptional level of neuropeptide genes, and the results indicated that there are two types of expression patterns after parasitization:Up-regulation type&Down-regulation type. The Up-regulation type including15genes, such as Adipokinetic hormone I, Adipokinetic hormone II and Allatostatin A; The Down-regulation type including Neuropeptide-like peptide, Neuroparsin, Leucokinin and Ion transport peptide. In contrast, there are also two types of expression patterns after pseudo-parasitization:Smooth type&Fluctuant type. The Smooth type including14genes, such as CCHamide, Adipokinetic hormone Ⅰ, and Allatostatin A; The Down-regulation type including Leucokinin, Adipokinetic hormone Ⅱ, Allatostatin C and Bursicon a.