Much is known among scientists about the fruit fly's innate immunity the immunity it is born with against bacterial and fungal pathogens, but little is known about the insect's antiviral response. The new research provides the first evidence that "RNA silencing" acts as an innate immunity mechanism to protect fruit flies from infection by viruses.
RNA, which is short for ribonucleic acid, is a molecule present in the cells of all living beings and required to synthesize proteins. RNA silencing refers to the specific destruction of RNA to inhibit the expression of a gene. Also called RNA interference (RNAi), the mechanism controls expression of more than one third of human genes.
Study results appear in the March 23 issue of Science Express.
"We've been able to pinpoint which mechanism protects fruit flies against viral infections," said Shou-Wei Ding, a professor of plant pathology at UCR and the lead author of the paper. "We now understand how this viral immunity works at the molecular level. Our work shows that it is the genes involved in RNA silencing that play a crucial role in the ability of fruit flies to overcome viral infection."
Viruses are tiny pockets of proteins packaging either DNA or RNA as the genetic material. They reproduce only inside a host's living cell, unlike bacterial and fungal pathogens, and are responsible for some of the most serious communicable diseases, such as influenza, herpes, hepatitis B and C, and HIV.