Molecular Alliance of Lymantria dispar Multiple Nucleopolyhedrovirus and a Short Unmodified Antisense Oligonucleotide of Its Anti-Apoptotic IAP-3 Gene: A Novel Approach for Gypsy Moth Control.

Volodymyr Oberemok,Igor Kasich,Valentin Makarov,Alexey Agranovsky,Mikhail Gorlov,Oleksii Skorokhod,Aleksei Zaitsev,Viktoriya Bekirova,Maksym Shumskykh,Nikita Gal’Chinsky,Anatoly Kubyshkin,Kateryna Laikova,Vladimir Gushchin,Ilya Zubarev,Iryna Fomochkina

doi:10.3390/ijms18112446

Abstract

Baculovirus IAP (inhibitor-of-apoptosis) genes originated by capture of host genes. Unmodified short antisense DNA oligonucleotides (oligoDNAs) from baculovirus IAP genes can down-regulate specific gene expression profiles in both baculovirus-free and baculovirus-infected insects. In this study, gypsy moth (Lymantria dispar) larvae infected with multiple nucleopolyhedrovirus (LdMNPV), and LdMNPV-free larvae, were treated with oligoDNA antisense to the RING (really interesting new gene) domain of the LdMNPV IAP-3 gene. The results with respect to insect mortality, biomass accumulation, histological studies, RT-PCR, and analysis of DNA apoptotic fragmentation suggest that oligoRING induced increased apoptotic processes in both LdMNPV-free and LdMNPV-infected insect cells, but were more pronounced in the latter. These data open up possibilities for promising new routes of insect pest control using antisense phosphodiester DNA oligonucleotides.

Highlights

The use of unmodified nucleic acids as insecticides looks very promising, since they can work selectively, are subject to fast biodegradation in ecosystems, and the commercial synthesis of nucleic acids in vitro is becoming more affordable.RNA interference (RNAi) and the use of double-stranded RNA fragments is a viable possibility for use in the control of insect pests, lepidopterans [1,2]
In this study we investigate further the insecticidal effect of the oligoRING fragment antisense to RING domain of the larvae infected with multiple nucleopolyhedrovirus (LdMNPV) IAP-3 gene on both non-infected and LdMNPV-infected gypsy moth larvae, and show how to turn this possible weakness into a strength by applying this approach to insect pest management
It is known that LdMNPV is widespread among gypsy moth populations and may be transmitted transovarially [23,24]

Summary

Introduction

RNA interference (RNAi) and the use of double-stranded RNA (dsRNA) fragments is a viable possibility for use in the control of insect pests, lepidopterans [1,2]. Application of short pest-specific unmodified antisense DNA fragments (DNA insecticides) against the gypsy moth Lymantria dispar, a major insect pest of hardwood trees, was followed by significant larval mortality [5]. The induction of insect mortality by topical application of single-stranded DNA or double-stranded RNA could be explained by their passage into interior tissues via the tracheal system, which is not covered by chitinous exoskeleton [1] or via diffusion through the soft thin cuticle of young instars

Methods

Results

Conclusion