Investigation of mode of action of DNA insecticides on thebasis of LdMNPV IAP-3 gene

Abstract

This study investigates the mechanism of action of DNA insecticides, a novel preparation against gypsy moth (Lymantria dispar) based on the DNA fragments of the antiapoptotic gene of its nuclear polyhedrosis virus. In our experiments gypsy moth showed significant susceptibility to applied DNA insecticides on the basis of BIR and RING domains fragments of LdMNPV IAP-3, whereas common fruit fly and tobacco hornworm did not. PCR with the same fragments of BIR and RING domains of the LdMNPV IAP-3 gene as primers revealed parts of the genomes of gypsy moth, common fruit fly, and tobacco hornworm. Part of the gypsy moth genome cloned with the fragments of BIR and RING domains of the LdMNPV IAP-3 gene as primers has an overlap with the corresponding part of the LdMNPV IAP-3 gene and Lymantria dispar IAP-1 mRNA for an inhibitor of apoptosis protein with the high cover of the latter by query, which allows assuming that we cloned a part of a gypsy moth antiapoptosis gene. This finding suggests that DNA insecticides might act through the mechanisms characteristic for blocking of posttranscriptional expression of gypsy moth antiapoptosis genes.

Original Article. Topical treatment of LdMNPV-infected gypsy moth caterpillars with 18 nucleotides long antisense fragment from LdMNPV IAP3 gene triggers higher levels of apoptosis in infected cells and mortality of the pest

“…In our opinion, in the case of non-infected gypsy moth caterpillars, a host anti-apoptosis mRNA serves as target mRNA for complementary interaction with viral Oligo-IAP fragments initiating post-transcriptional silencing of the target host anti-apoptosis gene which subsequently leads to apoptosis and death of the insect. Our recent fi ndings prove this hypothesis (Oberemok and Skorokhod 2014;Oberemok and Nyadar 2015;Oberemok et al 2016). Interestingly, Yamada et al (2012) found that the LdMNPV IAP3 gene induced apoptosis in Ld652Y cells in a transient expression assay but the authors say that it remains inconclusive as to whether virus Ld-IAP2 and Ld-IAP3 function as pro--apoptotic proteins in LdMNPV-infected Ld652Y cells or not.…”

“…Recently we tested IAP-specifi c DNA oligonucleotides (Oligo-IAPs) as potential insecticides. We used two Oligo-IAP sequences which were based on the fragments of BIR (sense chain) and RING (antisense chain) domains from Lymantria dispar multicapsid nuclear polyhedrosis virus (LdMNPV) IAP3 gene (Oberemok 2008a;Oberemok 2011;Simchuk et al 2012;Oberemok and Skorokhod 2014;Oberemok and Nyadar 2015). Th e insecticidal eff ect of Oligo--IAP fragments was detected on LdMNPV-free caterpillars (Oberemok and Skorokhod 2014;Oberemok et al 2015a, b;Oberemok et al 2016).…”

Biological control of gypsy moth (Lymantria dispar): an RNAi-based approach and a case for DNA insecticides

“…RNAi-based crops are expensive to produce and have a high risk of resistance breakdown: topical application is underway as a non-transformative approach that might enable RNAi-based insect management in species with low responses to environmental RNAi [11,23]. Another avenue in the post-genomic approach to insect pest management includes preparations of DNA insecticides based on short single-stranded DNA fragments of baculovirus anti-apoptosis (IAP) genes [4][5][6].…”

“…Another interesting post-genomic approach to insect pest control is based on the topical use of short single-stranded fragments of baculovirus anti-apoptosis genes. This novel idea and its application have recently shown reliable results in gypsy moth control [4][5][6].…”

A small molecule for a big transformation: Topical application of a 20-nucleotide-long antisense fragment of the DIAP-2 gene inhibits the development of Drosophila melanogaster female imagos

“…In today's post-genomic era, antisense oligonucleotides are facing a renaissance, and they could be applied as an effective and species-specific tool for controlling insect pests. Antisense oligoIAP fragments, termed in our investigations as "DNA insecticides" [13,27,28], are powerful tools that can increase our understanding of the functions of IAPs that contain conservative RING domains. RING domains function as modules for ubiquitination that can additionally regulate gene expression, and which play a role in the sex determination of several animals [29].…”