Two Pseudogenes of Cotesia plutellae Bracovirus in Parasitized Diamondback Moth, Plutella xylostella

It has been proposed that two novel genes have been found in Cotesia plutellae bracovirus (CpBV) based on the results of a full genome sequencing project. The putative open reading frame (ORF) of CpBV-DBL1 encodes 644 amino acids with one intron, while that of CpBV-DUF1 does 646 amino acids with four introns. Analyses of Southern hybridization and genomic polymerase chain reaction (PCR) confirmed that both genes were located on CpBV genome in the C. plutellae chromosome. However, Northern hybridization and reverse transcriptase-PCR revealed no specific expression in Plutella xylostella that had been parasitized by C. plutellae. Moreover, no putative promoter/enhancer region was found at the 5′ upstream end of CpBV-DBL1. Additionally, although CpBV-DUF1 contained a putative promoter/enhancer, its ORF was interrupted by another putative ORF in a reverse reading direction. These results indicate that both CpBV-DBL1 and CpBV-DUF1 are pseudogenes in parasitized P. xylostella.