Determination of the virulence of single nucleopolyhedrovirus occlusion bodies using a novel laser capture microdissection method

Abstract

Determination of the virulence of occlusion bodies (OBs), which are the horizontal transmission structures of nucleopolyhedroviruses (NPVs), is an important area of baculovirology. A method for inoculating an insect with an isolated OB was developed using Helicoverpa armigera nucleopolyhedrovirus (HearNPV) infection of second instar Helicoverpa armigera larvae as a model NPV–host pathosystem. In this novel method, laser capture microdissection (LCM) was used to directly catapult single OBs onto the surface of insect diet in bioassay containers. Since exposure via the natural oral horizontal transmission route of each larva to a single OB was established and not subject to chance variation, the method facilitated determination of the insect mortality rate (4.8%) associated with exposure to single HearNPV OBs. Droplet feeding bioassays confirmed that the novel method did not reduce OB virulence. The LCM method sets a foundation for virulence and genetic diversity studies based on single NPV OBs.

Nucleopolyhedrovirus Coocclusion Technology: A New Concept in the Development of Biological Insecticides

“…As an insect consumes a certain number of OBs when feeding on a host plant, even at the minimum dose of a single OB, the host insect receives an inoculum comprising many nucleocapsids, which provides a mechanism for the simultaneous transmission and coinfection of the host by multiple genotypic variants ( Clavijo et al, 2010 ). Dosing of larvae with individual OBs is now possible following the development of highly accurate laser capture microdissection techniques that show considerable promise for future studies on the virulence and genetic diversity of single OBs ( Munsamy and Bouwer, 2020 ).…”

Laser Capture Proteomics: spatial tissue molecular profiling from the bench to personalized medicine

“…Within this cadre of technologies, Laser Capture Microdissection (LCM) [ 4 - 6 ] has proven to be a reliable means of procuring tissue cellular populations, achieving high sensitivity and high precision for multiplex genomic and proteomic profiling [ 4 , 7 - 9 ]. LCM has been used to generate data for a wide variety of research questions, ranging from entomology [ 10 - 12 ], agriculture research [ 13 , 14 ], embryology [ 15 , 16 ], metabolic disease [ 17 - 19 ], heart disease [ 20 , 21 ], neurobiology [ 22 , 23 ], infectious disease [ 24 - 26 ], and cancer [ 6 ] (see below).…”