›› 2008, Vol. 51 ›› Issue (8): 792-797.

• RESEARCH PAPERS • Previous Articles     Next Articles

cDNA library construction and analysis of some ESTs of Chrysoperla nipponensis (Okamoto) (Neuroptera: Chrysopidae)

NIE Rui-E   

  • Online:2010-07-27 Published:2008-08-20

Abstract: Based on the construction technology of non-normalized cDNA library, the cDNA library of Chrysoperla nipponensis (Okamoto) was constructed, which aimed to preserve the resources in the form of cDNA library, to help to modify its genes and to provide the molecular basis for the classification of Chrysoperla nipponensis. The library capacity was 1.0×106, the average size of insert cDNA was 512 bp, and the recombination frequency was 80.0. In total 323 expressed sequence tags (ESTs) were generated successfully after sequencing, and 236 nonrepetitive sequences including 86 contigs and 150 singlets were obtained using cluster analysis with Phrap software. The 236 ESTs were analyzed with BlastN and BlastX of NCBI. The BlastN analysis showed that 180 (76.3%) from the 236 ESTs could not be compared, and the other 56 (23.7%) had a high homology with the available sequences from GenBank,of which one sequence was considered to be 16S rRNA gene. Based on the 16S rRNA sequences, phylogenetic tree was constructed by MEGA, and the result showed that the evolutionary relationship of Chrysoperla, Dichochrysa, Mallada and Chrysopa was relatively close, which coincides with the traditional classification. The BlastX analysis showed that among the 236 ESTs, 179 (83.5%) could be functionally annotated, and the other 39 (16.5%) had no functional information or a score less than 100. Finally, 236 ESTs were annotated by GO (gene ontology) database, and the results showed that 142 ESTs (59.7%) could be functionally annotated and expressed 40 products

Key words: Chrysoperla nipponensis, cDNA library, expressed sequence tag (EST), sequence analysis, phylogenetic tree