Student Major/Year in School
Biochemistry, first year
Faculty Mentor Information
Neal Dittmer, Department of Biochemisrty and Molecular Biophysics
Abstract
The goal of this research is to find an improved method for interfering with gene expression in insects, which can be important agricultural pests. Genes contain the information that tell cells/organisms how to function. When a gene is expressed, a copy of the gene is made of RNA; this copy is known as messenger RNA (mRNA). One method to study a gene’s importance would be to interfere with its expression and observe the effect it has on the organism. This can be accomplished by a technique called RNA interference (RNAi). When double stranded RNA (dsRNA) is introduced into a cell, it is recognized as being non-natural to the cell and a possible indication of viral infection. If the cell finds an mRNA that is a match to the dsRNA, it is targeted for degradation. In RNAi, if we introduce dsRNA that matches a gene we are interested in, the corresponding mRNA will be degraded. This method has proven to be very useful for studying gene function. However, this technique has not been very successful in butterflies and moths, possibly because of enzymes that break down the dsRNA before it can get into cells. A method to protect the dsRNA could make this method more effective. Branched Amphiphilic Peptide Capsules (BAPCs) are small protein nanocapsules that have been used successfully to deliver dsRNA in insects. We want to test if BAPCs will be helpful to deliver dsRNA in the caterpillar of the moth Manduca sexta. To test this technique, we targeted the two genes that encode for insecticyanin, a protein that is responsible for the green color of the caterpillars. If successful, the color of the caterpillars should be lighter green or white. Caterpillars were fed a solution that contained dsRNA for insecticyanin complexed with BAPCs. The caterpillars were monitored for a week to observe their color pattern. We also monitored the color of their hemolymph (blood) which is also green because of the presence of insecticyanin. In preliminary experiments, caterpillars fed the dsRNA/BAPC complexes looked similar to caterpillars fed a sugar solution. This suggests that either RNAi didn’t work or was too minimal to affect insecticyanin protein levels.
Creative Commons License
This work is licensed under a Creative Commons Attribution-Noncommercial 4.0 License
Recommended Citation
Holloman, Kierra (2019). "Investigating RNAi in Manduca sexta using BAPCs," Kansas State University Undergraduate Research Conference. https://newprairiepress.org/ksuugradresearch/2019/posters/50
Investigating RNAi in Manduca sexta using BAPCs
The goal of this research is to find an improved method for interfering with gene expression in insects, which can be important agricultural pests. Genes contain the information that tell cells/organisms how to function. When a gene is expressed, a copy of the gene is made of RNA; this copy is known as messenger RNA (mRNA). One method to study a gene’s importance would be to interfere with its expression and observe the effect it has on the organism. This can be accomplished by a technique called RNA interference (RNAi). When double stranded RNA (dsRNA) is introduced into a cell, it is recognized as being non-natural to the cell and a possible indication of viral infection. If the cell finds an mRNA that is a match to the dsRNA, it is targeted for degradation. In RNAi, if we introduce dsRNA that matches a gene we are interested in, the corresponding mRNA will be degraded. This method has proven to be very useful for studying gene function. However, this technique has not been very successful in butterflies and moths, possibly because of enzymes that break down the dsRNA before it can get into cells. A method to protect the dsRNA could make this method more effective. Branched Amphiphilic Peptide Capsules (BAPCs) are small protein nanocapsules that have been used successfully to deliver dsRNA in insects. We want to test if BAPCs will be helpful to deliver dsRNA in the caterpillar of the moth Manduca sexta. To test this technique, we targeted the two genes that encode for insecticyanin, a protein that is responsible for the green color of the caterpillars. If successful, the color of the caterpillars should be lighter green or white. Caterpillars were fed a solution that contained dsRNA for insecticyanin complexed with BAPCs. The caterpillars were monitored for a week to observe their color pattern. We also monitored the color of their hemolymph (blood) which is also green because of the presence of insecticyanin. In preliminary experiments, caterpillars fed the dsRNA/BAPC complexes looked similar to caterpillars fed a sugar solution. This suggests that either RNAi didn’t work or was too minimal to affect insecticyanin protein levels.
