Construction of a transposon-mediated baculovirus vector Hanpvid and a new cell line for expressing barnase

J Biochem Mol Biol. 2005 Jan 31;38(1):41-8. doi: 10.5483/bmbrep.2005.38.1.041.

Abstract

In this study we developed the transposon-mediated shuttle vector 'Hanpvid', which composed of HaNPV (Heliothis armigera nuclear polyhedrosis virus) genomic DNA and a transposon cassette from Bacmid of Bac-to-Bac system. Hanpvid replicates in E. coli in the same way as Bacmid and retains infective function in cotton bollworm cells (Hz-AM1). Using Hanpvid we constructed a recombinant virus, which could infect Hz-AM1 cells and generate recombinant HaNPV (rHa-Bar) containing the barnase gene, a ribonuclease gene from Bacillus amyloliquefaciens. Since the expression vector carrying barnase gene cannot replicate in the absence of barstar, a specific inhibitor of barnase, we constructed a new cotton bollworm cell line (AM1-NB) using the marker rescue method. In AM1-NB barstar was integrated into the cellular chromosome to sustain the replication of rHa-Bar. To screen out recombinant HaNPV for potential use as biopesticide, Hz-AM1 and AM1-NB cell lines were infected with rHa-Bar, respectively. The results obtained indicate that Viral progenies in AM1-NB were 23 and 160 times greater than those in Hz-AM1 48 h and 72 h after infection, respectively. With additional insertion of the polyhedron gene from AcNPV (Autographa californica nuclear polyhedrosis virus) into the Hanpvid genome, rHa-Bar regained the polyhedron phenotype and its pest-killing rate greatly improved. Toxic analysis showed that the lethal dosages (LD(50)) and the lethal time(s) (LT(50)) of rHa-Bar were reduced by 20 % and 30 %, respectively, compared to wt-HaNPV in the third instar larvae of cotton bollworm. This study shows that in AM1-NB barnase can be effectively produced and used as pest-killing agent for the biological control of cotton pests.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Bacillus / enzymology
  • Bacterial Proteins / metabolism
  • Baculoviridae / genetics*
  • Cell Line / enzymology
  • DNA Transposable Elements / genetics*
  • DNA, Recombinant / genetics
  • DNA, Viral / genetics
  • Genetic Engineering
  • Genetic Vectors*
  • Gossypium / virology
  • Larva / virology
  • Lepidoptera / pathogenicity
  • Lepidoptera / virology
  • Lethal Dose 50
  • Nucleopolyhedroviruses / genetics
  • Pest Control, Biological*
  • Plant Diseases / parasitology
  • Ribonucleases / genetics*
  • Ribonucleases / metabolism

Substances

  • Bacterial Proteins
  • DNA Transposable Elements
  • DNA, Recombinant
  • DNA, Viral
  • barstar protein, Bacillus amyloliquefaciens
  • Ribonucleases
  • Bacillus amyloliquefaciens ribonuclease