Saliva of Lygus lineolaris digests double stranded ribonucleic acids.
The prospects for development of highly specific pesticides based on double stranded ribonucleic acid have been a recent focus of scientific research. Creative applications have been proposed and demonstrated. However, not all insects are sensitive to double stranded RNA (dsRNA) gene knockdown effects; applications in the order Lepidoptera, for example, have met with varied success. Gene knockdown has been demonstrated in several species in the order Hemiptera. In our laboratory, knockdown experiments relied on microinjection of dsRNA into the hemocoel of the tarnished plant bug, Lygus lineolaris. Subsequent experiments delivering dsRNA to insects by feeding were repeatedly unsuccessful in demonstrating knockdown, and a hypothesis was formulated that the dsRNA was digested and degraded by the insect prior to contact with the insect cells. Exposure of dsRNA to insect saliva, insect salivary glands, and insect hemolymph was compared with commercial RNAase III. The saliva of L. lineolaris was found to rapidly digest double stranded RNA. RNAase inhibitor did not affect the activity but heat treatment slowed enzymatic activity.
U. S. Department of Agriculture, Agricultural Research Service, Biological Control of Pests Research Unit, 59 Lee Road, Stoneville, MS 38776, USA.meg.allen@ars.usda.gov
Margaret L
ML
Allen
William B
WB
Walker
D000818:Animals; D004247:DNA; D005260:Female; D055785:Gene Knockdown Techniques; D006430:Hemiptera / Q000378:metabolism*; D006458:Hemolymph / Q000378:metabolism*; D006358:Hot Temperature; D051034:Inhibitor of Apoptosis Proteins; D008297:Male; D012330:RNA, Double-Stranded / Q000378:metabolism*; D043244:Ribonuclease III; D012463:Saliva / Q000378:metabolism*; D012469:Salivary Glands / Q000378:metabolism*
D051034:Inhibitor of Apoptosis Proteins; D012330:RNA, Double-Stranded; D004247:DNA; D043244:Ribonuclease III