Source: Kun Yan 1xbet online casino , 785-532-4721, kzhu@k-state.edu
Pronouncer: Kun Yan 1xbet online casino is Koon Yawn Zoo
Photo available. Contact media@k-state.edu or 785-532-2535.
News release prepared by: Greg Tammen, 785-532-2535, gtammen@k-state.edu

Monday, July 19, 2010

K-STATE RESEARCHERS FIND GENE-SILENCING 1xbet online casino MAY PUT END TO PESKY SUMMER PEST

MANHATTAN -- Summer just wouldn't be complete without mosquitoes nipping at exposed skin. Or would it?

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 1xbet online casino , 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, 1xbet online casino the dsRNA may kill the developing mosquitoes or make them more susceptible to pesticides.

Gene silencing triggered by 1xbet online casino 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," 1xbet online casino . 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 1xbet online casino '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," 1xbet online casino .

Though the silencing is not yet 100 percent effective in their study, 1xbet online casino 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, 1xbet online casino .

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. 1xbet online casino 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," 1xbet online casino .

Potentially, bait containing dsRNA-based nanoparticles could be developed for insect control, 1xbet online casino .

"Because we can select specific genes for silencing, and the 1xbet online casino 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, 1xbet online casino , 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 1xbet online casino 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.

1xbet online casino 's upcoming research will focus on gene silencing in agricultural pests.