Avidin expression does not increase speed of kill of <i>Spodoptera litura</i> by baculovirus

Abstract

A disarmed (polhminus) Autographa californica nuclear polyhedrosis virusbased baculovirus expressing green fluorescent protein (GFP) on the strong late promotor p10 was constructed A second virus was made which also expressed the biotinbinding protein avidin from the strong late promotor polh Both viruses caused strong fluorescence in Spodoptera frugiperda cells in insect cell culture Sevendayold larvae of Spodoptera litura were inoculated by microinjection with GFP virus GFPavidin virus or tissue culture medium (control) Mortality growth rate and the development of green fluorescence were followed and after death the larvae were analysed for GFP and avidin content All virusinjected larvae developed strong fluorescence However no significant differences in growth or mortality were seen between the larvae injected with virus expressing and not expressing avidin Both GFP and avidin accumulated to high levels in the larvae The expression of avidin did not change the level of expression of GFP