RNAi insecticide materials and methods
Inventors
Scheel, Molly Duman • Severson, David W. • Eggleson, Kathleen • Wei, Na
Assignees
Indiana University Research and Technology Corp • University of Notre Dame
Publication Number
US-12302904-B2
Publication Date
2025-05-20
Expiration Date
2037-07-13
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Abstract
The present invention provides a novel class of insecticides for control of disease vector insects, particularly mosquitoes. These insecticides prevent maturation or development of larvae into adult insects using interfering RNA (iRNA). The present invention further includes compositions comprising iRNA and methods of controlling, reducing, or treating an insect infestation with the iRNA or compositions described herein.
Core Innovation
The invention provides a novel class of insecticides based on interfering ribonucleic acids (iRNA), such as small interfering RNA (siRNA), short hairpin RNA (shRNA), double-stranded RNA (dsRNA), or RNA constructs, specifically designed to target and silence genes required for the maturation or survival of insects, with a preference for mosquito species. The iRNAs are capable of preventing larvae from maturing into adult mosquitoes, or of targeting genes crucial for adult mosquito survival, thereby reducing or controlling mosquito populations that transmit diseases.
In particular, the present invention provides specific iRNA sequences, DNA constructs encoding such iRNA, and host cells (including yeast, bacterial, algal, or plant cells) engineered to express at least one iRNA, which can be delivered to mosquitoes via compositions suitable for ingestion. The iRNAs are engineered to be specific for mosquito genes, with sequences chosen to minimize or avoid homology to human or non-target organism genes, reducing off-target effects. The invention details high-throughput screening for lethal larval and adult mosquito genes and the development of iRNAs targeting conserved sequences across multiple mosquito species.
The problem addressed by this invention is the increasing resistance of mosquitoes to conventional chemical and microbial insecticides, and the negative impact of current pesticides on non-target organisms and the environment. Existing methods of larviciding have become less effective due to resistance, and there is an urgent need for the development of new, environmentally safe larvicides. The invention provides a solution by offering RNAi-based insecticides capable of species-specific action on mosquito vectors of diseases such as malaria, Zika, chikungunya, yellow fever, and dengue.
Claims Coverage
The patent contains five independent claims, each introducing key inventive features centered around mosquito-specific iRNA compositions and their methods of delivery and application.
Interfering ribonucleic acid specifically targeting conserved mosquito genes
An interfering ribonucleic acid (iRNA) comprising a 21 nucleobase sequence that is perfectly complementary to SEQ ID NO: 209, capable of inhibiting the expression of Aedes aegypti Gene ID AAEL000704 and Anopheles gambiae Gene ID AGAP007942 by RNA interference.
DNA construct encoding and expressing the specific iRNA
A DNA construct that encodes and can express the iRNA capable of targeting SEQ ID NO: 209 to inhibit the target genes in mosquito species.
Engineered cell-based iRNA production
A yeast, bacterial, algal, or plant cell engineered to produce at least one iRNA comprising a 21 nucleobase sequence matching SEQ ID NO: 209, for expression of the sequence that targets mosquito genes.
Mosquito-ingestible composition containing iRNA or an iRNA-expressing cell
A composition ingestible by mosquitoes comprising (i) the specific iRNA, (ii) a bacterial, yeast, algal, or plant cell expressing the iRNA, or (iii) the DNA construct, in combination with at least one suitable carrier, excipient, or diluent.
Method for inhibiting expression of mosquito gene by RNA interference
A method of inhibiting expression of Aedes aegypti Gene ID AAEL000704 and Anopheles gambiae Gene ID AGAP007942, or orthologs thereof with at least 85% identity to SEQ ID NO: 209, by exposing at least one mosquito larva or adult to the iRNA in an effective amount.
The inventive features collectively cover the specific iRNA targeting mosquito-lethal genes, the encoding constructs, host cells expressing the iRNA, compositions suitable for mosquito ingestion, and methods for inhibiting mosquito gene expression. The claims establish a new class of RNAi-based insecticides and delivery means targeting mosquito vector control.
Stated Advantages
The iRNA insecticides can target genes that are conserved among multiple mosquito species but not in non-target organisms, minimizing off-target effects.
By using multiple iRNA target sites and genes, the invention reduces or inhibits insecticide resistance arising from point mutations in any one target sequence.
Host cells such as yeast or bacteria expressing iRNA can be killed or inactivated before use, maintaining larvicidal potency while reducing concerns about introducing live organisms into the environment.
Yeast-based delivery systems provide additional benefits including low production cost, ease of cultivation, and the ability to distribute shelf-stable dry formulations.
The RNAi insecticides are environmentally safe alternatives to conventional chemicals and can be designed to avoid negative effects on humans and other non-target species.
The use of iRNA larvicides allows for simultaneous targeting of multiple mosquito life stages, including both larvae and adults, enhancing efficiency of vector control.
Documented Applications
Control, reduction, or treatment of mosquito infestations through inhibiting maturation of larvae to adults or killing adults, especially for vectors of diseases such as malaria, Zika, chikungunya, yellow fever, and dengue.
Field, semi-field, and simulated field applications for treating water sources, ovitraps, and natural/man-made containers where mosquito larvae breed.
Deployment of ingestible compositions (including inactivated yeast or bacteria expressing iRNA) in various formulations such as pellets, tablets, sprays, or baits to water-filled sites for mosquito larval control.
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