Characterization of the deoxyuridine triphosphatase gene of Ophiusa disjungens nucleopolyhedrovirus.

Unlabelled: Ophiusa disjungens is one of the main insect pests that attack Myrtaceae species. Nucleopolyhedroviruses (NPVs) of the Baculoviridae family have been used for decades as biological pesticides to control insect pests. A new NPV, named Ophiusa disjungens nucleopolyhedrovirus (OpdiNPV), was recently isolated from OpdiNPV-infected O. disjungens larvae. In this study, a PstI fragment of OpdiNPV genome containing the deoxyuridine triphosphatase (dUTPase) gene was successfully cloned, sequenced and analyzed. Upstream of a 402 bp long ORF of the dUTPase gene, encoding a 133 aa long protein, typical transcription promoter boxes CAGT and TATA were found. The dUTPase was first expressed in his-tagged form in Escherichia coli as a 35.5 kDa protein. Then it was successfully expressed in insect Trichoplusia ni (Tn) cells in the form of an EGFP-fusion protein. It first appeared (at 24 hrs post infection (p.i.)) in the cell nucleus, but later (at 72 hrs p.i.) it was excluded from the nucleus and diffusely scattered all over the cell. These findings may serve as basis for development of engineered OpdiNPVs as biopesticides to control O. disjungens and other Lepidoptera insects.

Keywords: Ophiusa disjungens; nucleopolyhedrovirus; dUTPase.