Complete CDNA Sequences Of Storage Proteins Of Boettcherisca Peregrina And Their Expression Affected By Parasitization

Two cDNA sequences of hexameric storage protein,SpeAry and SpeLSP-2,were cloned from Boettcherisca peregrine and their gene expression patterns were revealed. Then the effects of parasitization by Nasonia vitripennis(Hymenoptera:Pteromalidae)on the expressional and transcriptional levels were investigated.The results are as follows:1 Cloning the cDNAs of SPs subunit in B.peregrine and sequence analysisBy using the homology searching software of GenBank,full length of the cloned Speary cDNA was found to be 2,534 bp with 2,346 b.p of open reading frame.The molecular weight of the SpeAry deduced by amino acid sequence was 95.42 kDa.The calculated isoelectric point was 5.01.Utilizing online software,SignalP,the signal peptide was consisted of 15 amino acids at the 3'- end excluding the poly(A)-tail.The deduced primary structure indicated a high content of aromatic amino acids up to 23.8%.Full length of the cloned SpeLSP-2 cDNA was 2,235 bp with 2,106 bp of ORF.We also found a polyadenylation signal peptide with 19 amino acid at the poly-A initiation site.The putative protein encoded by the SpeLSP-2 gene was with a molecular weight of 82.96 kDa, an isoelectric point of 5.94.The primary structure with a content of about 11.1%aromatic amino acids which was less than 15%,showed a strong homology with other LSP-2 gene sequences.Clustal W and phylogenetic tree analysis showed that S.peregrine arylphorin was most closely related with CviAry in amino acid sequence and should belong to the same cluster. Furthermore,SpeLSP-2 was most closely related to CviLSP-2.According to the taxonomy that if the evolutionary relationship was nearer and the conservative were higher.SPs of S.peregrine and other insect storage proteins had relatively high similarity,from which we can conclude that they were highly conservative.2 The transcriptional dynamics of the two SPs from B.peregrine with instar and its changes after parasitization. By pre-experiment,we determined the conditions for Semi-quantitative RT-PCR of the fat body genes of B.peregrine.The results of showed the transcriptional levels of SpeAry and SpeSP2 had strong correlation with instar.The transcription level increased gradually from the first to the third instar,then decreased significantly in prepupae,and disappeared in late pupae and adult.The transcription trend of SpeSP2 was similar with that of SpeAry,with exception that there was no transcription in the first instar.This revealed that transcription of SpeSP2 was later than that of SpeAry.In addition,there was no transcritption observed in the fat body of either parasitized or non-parasitized pupae, from which we can conclude that parasitization had no influence on the transcription.3 Effects of parasitization by Nasonia vitripennis on the compositions and contents of soluble proteins and arylphorin in its host B.peregrin pupaeIn this article,the changes in compositions and contents of soluble proteins and Arylphorin,in fat body and hemolymph or B.peregrine pupae parasitized by N.vitripennis are investigated.The composition of soluble proteins and Arylphorin in fat body and hemolymph of parasitized pupae are similar to those of non-parasitized pupae.In contrast, their contents in both fat body and hemolymph of parasitized pupae are significantly lower than those of non-parasitized ones.Similarly,the composition of soluble proteins in hemolymph of parasitized pupae is likely to that of non-parasitized ones,while their contents are lower.In contrast to fat body,12 h after parasitization the hemolymph of parasitized pupae possess two bands reacting with the polyclonal antiserum against arylphorin in the western-blotting membrane.It is implicated that the Arylphorin in hemolymph might be broken down,which is earlier in parasitized than in non-parasitized pupae.The difference in the content of arylphorin in hemolymph is not significant between parasitized and non-parasitized pupae,except 12h after parasitization.