Release of genetically modified viruses

Extraction and detection of baculoviral DNA from lake water, detritus and forest litter

AIMS

This paper describes a quick, reproducible, sensitive method for baculoviral DNA extraction, purification and detection from freshwater and forest litter environments.

METHODS AND RESULTS

The extraction protocol utilizes enzymatic and chemical lysis and physical disruption. To assess the efficiency of the extraction and purification protocol, PCR was used to detect a 530 bp DNA fragment from the genome of a genetically-modified baculovirus, Choristoneura fumiferana NPVegt-/lacZ+. The detection limit of PCR amplification was routinely about 4.1 x 102 occlusion bodies (OBs) 450 microl-1 lake water. Template DNA from the detritus and forest litter samples required 100-fold dilutions before use in PCR reactions. The detection limits for detritus and forest litter samples were routinely about 7.41 x 103 and 2.08 x 104 OBs 0.5 g-1 dry weight, respectively.

CONCLUSION

The DNA extraction and purification methodology is reproducible, sensitive and can be used in lieu of, or in conjunction with, insect bioassays.

SIGNIFICANCE AND IMPACT OF THE STUDY

The DNA extraction and purification protocol described in this paper will facilitate risk assessment and ecological studies of both wild-type and genetically-modified baculoviruses.

Use of baculoviruses as biological insecticides

Naturally occurring baculoviruses can be used to control a wide range of insect pests. Most baculoviruses are used as biopesticides, that is, they are sprayed onto high-density pest populations in a manner akin to the use of synthetic chemical pesticides. However, other strategies that use the biological features of the viruses are also possible and should increase as we expand our knowledge of baculovirus ecology. In order to develop a baculovirus control program, several areas need to be studied before progressing to large scale field studies and commercialization. These range from laboratory efficacy testing and the development of production systems to detailed study of pest behavior and the development of appropriate application strategies.