Sequence analysis of the genome of Bombyx mori nucleopolyhedrovirus

Abstract

The genome of the nucleopolyhedrovirus (NPV) (T3 strain) pathogenic for Bombyx mori (Bm) was sequenced and analysed. The BmNPV genome was 128,413 nucleotides long with a G+C content of 40% and contained 136 open reading frames (ORFs) encoding predicted proteins of over 60 amino acids. Although phenotypically different, the genome organizations of BmNPV and Autographa californica multinucleocapsid NPV (AcMNPV) were closely related. The BmNPV genome was over 90% identical to about three-quarters of the genome of AcMNPV. The relatedness of predicted amino acid sequences of corresponding ORFs between BmNPV and AcMNPV was about 90%. However, the BmNPV genome lacked homologues of the following AcMNPV ORFs: Ac3 (conotoxin), Ac7 (orf603), Ac48 (etm), Ac49 (pcna), Ac70 (hcf-1), Ac86 (pnk/pnl) and Ac134 (p94). In addition, BmNPV contained five ORFs related to Ac2. A high frequency of multiple 3 bp insertions was also found within BmNPV and AcMNPV coding sequences.