Search bioRxiv⌕ Search
Home/Archive/bioRxiv

bioRxiv · 10.1101/2024.10.15.618468

rRNA-specific antisense DNA and dsDNA trigger rRNA biogenesis and cause potent insecticidal effect on insect pest Coccus hesperidum L.

Oberemok, V. V.·Gal'chinsky, N. V.·Novikov, I. A.·Sharmagiy, A. K.·Yatskova, E. V.·Laikova, E. V.·Plugatar, Y. V.
View original source ↗Export metadata ↓

Abstract

Invented in 2008, contact unmodified antisense DNA biotechnology (CUADb) is built on the use of short antisense DNA oligonucleotides (oligos) for insect pest control. Being a novel class of insecticides, oligonucleotide insecticides target pest rRNAs and/or pre-rRNAs and recently showed high insecticidal potential against sap-feeding insect pests, main vectors of plant DNA viruses and one of the most economically-damaging groups of herbivorous insects. In order to use all possible opportunities of CUADb, in this article insecticidal potential of short 11-mer antisense DNA oligos was investigated for Coccus hesperidum control in comparison with long 56-mer single-stranded and double-stranded DNA sequences and lower efficiency of the latter was found. At the end of the experiment, on the 9th day, the highest mortality rate among antisense oligos was reached for Coccus-11 group (97.66 {+/-} 4.04 %), while for long sequences the highest mortality rate was obtained for double-stranded DNA fragment in dsCoccus-56 group (77.09 {+/-} 6.24 %). Also in this article architecture of DNA containment (DNAc) mechanism is described representing interesting and important for insect cell life interplay between rRNAs and different types of DNA oligos. During DNAc, Coccus-11 caused increased ribosome biogenesis and ATP production through metabolic switch in energy synthesis from carbohydrates to lipids but eventually caused kinase disaster through downregulation of most kinases due to insufficient level of ATP produced. In the course of DNAc, hypercompensation of target rRNA is triggered by all highly and all somewhat complementary DNA oligos but more pronounced later degradation of target rRNA and significant insect pest mortality is seen only in the case of perfect complementarity of oligonucleotides to target rRNA. For both short and long oligonucleotide insecticides substantial decrease in rRNA concentration after rRNA hypercompensation in average by 3.75-4.25 fold, is explained by the work of DNA-guided rRNase, like RNase H1. We detected significant upregulation of RNase H1 after application of Coccus-11 in this study. On the contrary, for short and long random DNA oligos concentration of rRNA decreased in average by 2-3 fold after rRNA hypercompensation due to normal half-life of rRNAs in insect cells provided by ribonucleases. Fundamentally important, obtained results show completely new principle of regulation of rRNA expression in the cell via complementary interaction between rRNAs and unmodified antisense sequences of exogenous DNA. Practically important, this minimalist approach of using short antisense DNA dissolved in water is potent and eco-friendly innovation against sternorrhynchans and other pests, and reveals entirely new dimension to plant protection - DNA-programmable insect pest control.

Source connections

Explore related subjects

molecular biologyPreprint

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Oberemok, V. V., Gal'chinsky, N. V., Novikov, I. A., Sharmagiy, A. K., Yatskova, E. V., Laikova, E. V., Plugatar, Y. V.. 2024-10-17. rRNA-specific antisense DNA and dsDNA trigger rRNA biogenesis and cause potent insecticidal effect on insect pest Coccus hesperidum L.. https://doi.org/10.1101/2024.10.15.618468

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

bioRxiv2026

Simvastatin and Primaquine Identified as Potential Endometriosis Therapeutics via a Novel Epithelial-Stromal Assembloid Drug Screening Assay

Background: Endometriosis is an estrogen-driven, inflammatory disorder affecting ~10% of menstruators, causing severe pain. Current treatments that reduce estrogen or inflammation have inconsistent efficacy and poor tolerability. Therapies identified via drug-repositioning methods, which target patient-specific pathways, offer a promising alternative. Simvastatin and primaquine were identified as potential treatments, strongly reversing endometriosis-associated gene expression pathways, and behavioral testing in an animal model showed that these drugs diminish endometriosis-associated pain. This paper examines their effects in human assembloids to provide proof-of-concept validation and insights into their mechanisms of action relevant to endometriosis. Methods: We established human endometrial assembloids using immortalized epithelial (12Z) and stromal fibroblast (iEc) cell lines, as well as primary tissue from patients. Assembloids were generated in 96-well agarose molds with both cell types. We tested ibuprofen, fenoprofen, primaquine, and simvastatin. Following a 24-hour exposure, assembloids and monolayer cultures were harvested and stranded mRNA-seq libraries were sequenced on an Illumina NovaSeqX Plus System. Results: Gene set enrichment analysis showed key pathway reversals: Primaquine reversed the chemical carcinogenesis ROS pathway in assembloids. Simvastatin reversed cytokine-cytokine receptor interaction in both epithelial and stromal cell lines, and the cytoskeleton in muscle cells pathway in stromal cell lines. Fenoprofen reversed the calcium signaling pathway in stromal cell lines. Conclusion: Simvastatin induced the most significant gene expression changes, notably reversing cytokine-cytokine receptor interactions in both cell lines, mirroring findings from our rat model. Despite the small sample size limitation, these experiments highlight the promise of assembloid models to test therapeutic candidates for endometriosis.

molecular biology↗
bioRxiv2026

A feed-forward UHRF1 read-write mechanism supports H3 multi- mono-ubiquitination and DNA methylation maintenance at CpG-sparse regions

The epigenetic inheritance of mammalian DNA methylation requires DNMT1 and its E3 ligase cofactor UHRF1. At newly replicated chromatin, UHRF1 recognition of hemi-methylated DNA and histone H3 N-terminal tails directs catalysis of H3K14, H3K18, and/or H3K23 mono-ubiquitination to recruit DNMT1. While it is appreciated that UHRF1 can deposit multiple mono-ubiquitin marks on a single H3 tail and that DNMT1 recognizes this state through tandem ubiquitin interacting motifs, the mechanism that promotes successive ubiquitination and the biological function of multi-mono-ubiquitination are unknown. Here, we show that UHRF1 directly binds its mono-ubiquitinated H3 products through a previously uncharacterized LGDDSL loop in Tudor 2 of its tandem Tudor domain (TTD) to promote further ubiquitin deposition. Disruption of this ubiquitin reading activity impairs H3 multi-mono-ubiquitination and accelerates DNA methylation loss within late-replicating, CpG-sparse genomic regions that are characteristic of partially methylated domains (PMDs) in cancer and aging cells. These methylation defects overlap those observed by disruption of UHRF1 ubiquitin ligase activity, providing convergent evidence that both writing and reading of H3 ubiquitination support CpG-sparse DNA methylation maintenance. Together, these findings establish a feed-forward ubiquitin read-write mechanism that generates multi-mono-ubiquitinated H3 and safeguards DNMT1-dependent DNA methylation maintenance at vulnerable genomic regions of the mammalian methylome.

molecular biology↗
bioRxiv2026

Calcium dysregulation amplifies fibrotic responses to TGFβ in human Friedreich's ataxia fibroblasts

Friedreich's ataxia (FA) is an inherited disease caused by loss of frataxin (FXN) and characterized by neurodegeneration and fatal cardiomyopathy. Cardiac fibrosis contributes to cardiomyopathy by stiffening the heart wall, yet the underlying mechanisms remain unknown. Here, we investigated pro-fibrotic predisposition in FA patient-derived fibroblasts, focusing on the role of cytosolic calcium (Ca) in TGF{beta}-driven fibroblast-to-myofibroblast transition (FMT). We found pro-fibrotic transcriptional priming in FA fibroblasts, alongside elevated expression of genes controlled by the Ca-responsive transcription factor NFAT. Upon FMT, FA myofibroblasts showed amplified induction of pro-fibrotic (CCN2, NOX4) and suppression of anti-fibrotic (CCN3) genes, which were inversely correlated with residual FXN. Mechanistically, FA fibroblasts exhibited elevated cytosolic Ca and strongly downregulated expression of the Na-Ca exchanger NCX1, which directly correlated with FXN. Furthermore, NCX1 inhibition in control fibroblasts recapitulated FA Ca phenotypes, whereas NCX1 transduction in FA fibroblasts normalized Ca dynamics and blunted CCN2 induction in FMT. These findings highlight NCX1 as a modulator of fibrotic reprogramming in FA and identify Ca dyshomeostasis as an intrinsic mechanism of fibrosis that could be targeted therapeutically.

molecular biology↗