Molecular detection and characterisation of RNA viruses of honeybees

Abstract

Propagation methods for honeybee viruses have not changed since these viruses were discovered. There are no suitable cell lines or cell culture techniques available for honeybee viruses. Honeybee viruses have to be manually injected with virus in order for the virus to multiply and be extracted. With the presence of inapparent viruses which could co-infect pupae, a method for pure virus propagations needs to be found. Recombinant baculovirus systems have been used extensively to produce foreign proteins from different viruses using vectors and recombinant technology. In this chapter we inserted the capsid gene from BQCV into a transfer vector under the control of the p10 promoter of Autographa californica. Fractions of the sucrose gradient containing the virus like particles (VLPs) were seen under the electron microscope. A Western blot showed the four capsid proteins at the expected sizes for BQCV capsid. This study therefore has shown that a heterologous system such as baculovirus can be used for virus like particle production. Infectious virus technology has helped gain insight into how viruses work. Using this technology altering honeybee viruses could be used to observe different functionalities of the viruses. An attempt was made to interchange the open reading frames of ABPV and BQCV to observe any changes in virus assembly and infectivity. A fusion PCR strategy was employed to interchange the 5’ and 3’ ORFs of APBV and BQCV. The strategy however was unsuccessful. Alternative strategies could improve the chances of obtaining a chimeric virus.