Research conducted by a Kansas State University team may help solve a problem that scientists and pest controllers have been itching to for years.
Kun Yan Zhu, professor of entomology, and teammates Xin Zhang, graduate student in entomology from China, and Jianzhen Zhang, a visiting scientist from Shanxi University, China, investigated using nanoparticles to deliver double-stranded ribonucleic acid, dsRNA -- a molecule capable of specifically triggering gene silencing -- into mosquito larvae through their food. By silencing particular genes, Zhu said the dsRNA may kill the developing mosquitoes or make them more susceptible to pesticides.
Gene silencing triggered by dsRNA or small interfering RNA, siRNA, is known as RNA interference, or RNAi.
"RNAi is a specific and effective approach for loss of function studies in virtually all eukaryotic organisms," Zhu said. Eukaryotic organisms have cells that contain a nucleus within which genetic material is carried and can therefore be manipulated. Almost all animals, plants and fungi are eukaryotes.
Once RNAi is triggered, it destroys the messenger RNA, or mRNA, of a particular gene. This prevents the translation of the gene into its product, silencing it. In the case of Zhu's research, RNAi was used to silence genes responsible for the production of chitin, the principle constituent of the exoskeleton in insects, crustaceans and arachnids.
"Since our RNAi is focused on chitin synthesis, the dsRNA that is delivered into the mosquito larvae can basically block the production of chitin," Zhu said.
Though the silencing is not yet 100 percent effective in their study, Zhu said it does leave the mosquito's body with less ability to combat insecticides, which must penetrate the mosquito's exoskeleton. If the gene, called chitin synthase, could be completely silenced, the mosquitoes may die without the use of pesticides because the chitin biosynthesis pathway would be blocked, Zhu said.
Zhu theorized using nanoparticles to deliver dsRNA to mosquito larvae might work because of the low success of manually injecting larvae with dsRNA. Mosquito larvae live in water but because dsRNA quickly dissipates in water, it can't be directly added to the larvae's food source. Zhu's group discovered that using nanoparticles assembled from dsRNA facilitates their ingestion by mosquito larvae because the nanoparticles don't dissolve in water. Zhu said the nanoparticles may also stabilize the dsRNA in water.
"Now insects will have a much greater likelihood of getting these nanoparticles containing the dsRNA into their gut through feeding," Zhu said.
Potentially, bait containing dsRNA-based nanoparticles could be developed for insect control, Zhu said.
"Because we can select specific genes for silencing, and the nanoparticles are formed from chitosan -- a virtually non-toxic and biodegradable polymer -- this pest control technology could target specific pest species while being environmentally friendly," he said.
Mosquitoes were chosen, Zhu said, because of the abundant research on them as human disease vectors. Other insects, though, can have their genes silenced. Zhu and his collaborators also have investigated gene silencing in the European corn borer and in grasshoppers, a major insect pest in China. Nanoparticles did not have to be used because grasshoppers and European corn borers are not aquatic. However, nanoparticle-based RNAi may facilitate the studies on the functions of new genes.
The team's paper, "Chitosan/double-stranded RNA nanoparticle-mediated RNA interference to silence chitin synthase genes through larval feeding in African malaria mosquito (Anopheles gambiae)," was recently accepted by the journal, Insect Molecular Biology. It has been published online in advance of print.
The research was partially funded by the Kansas Agricultural Experiment Station.
Zhu's upcoming research will focus on gene silencing in agricultural pests.
Kun Yan Zhu, 785-532-4721, firstname.lastname@example.org
Kun Yan Zhu | Newswise Science News
How brains surrender to sleep
23.06.2017 | IMP - Forschungsinstitut für Molekulare Pathologie GmbH
A new technique isolates neuronal activity during memory consolidation
22.06.2017 | Spanish National Research Council (CSIC)
An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.
Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...
Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.
Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...
Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.
As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...
Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.
With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...
Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine
Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...
19.06.2017 | Event News
13.06.2017 | Event News
13.06.2017 | Event News
23.06.2017 | Physics and Astronomy
23.06.2017 | Physics and Astronomy
23.06.2017 | Information Technology