RNA interference as a tool for the analysis of gene function in the Colorado potato beetle, Leptinotarsa decemlineata (Say)

RNA interference is used as a tool for the functional analysis of genes.  Introducing double-stranded RNA into an organism suppresses expression of the corresponding gene.  The requirements for using RNAi as a functional tool include a targeted gene knockdown that is both systemic and persistent, and not immediately lethal.  We are developing simple and effective methods of RNAi as a tool for the functional analysis of genes for the Colorado potato beetle, Leptinotarsa decemlineata (Say). L. decemlineata is a devastating pest to the plant Solanaceae family and therefore an important model for the study of insect-plant interactions.  As a proof of concept, we are focusing on the laccase-2 gene.  Silencing laccase-2 has been shown to result in the reduction of cuticular pigmentation in the western corn rootworm, Diabrotica virgifera virgifera (LeConte) and the red flour beetle Tribolium castaneum.  The conspicuous but not immediately lethal phenotypic effect of suppressing laccase-2 by RNAi makes it an ideal target gene for investigating RNAi as a functional tool.  The RNAi-induced knockdown effect of laccase-2 can be evaluated phenotypically and by qPCR.  We plan to investigate and evaluate functional RNAi in the egg and larval stages of L. decemlineata and use it as a tool to investigate insect-plant interaction.