Genome-wide screen identifies host genes affecting viral RNA recombination.
Rapid evolution of RNA viruses with mRNA-sense genomes is a major concern to health and economic welfare because of the devastating diseases these viruses inflict on humans, animals, and plants. To test whether host genes can affect the evolution of RNA viruses, we used a Saccharomyces cerevisiae single-gene deletion library, which includes approximately 80% of yeast genes, in RNA recombination studies based on a small viral replicon RNA derived from tomato bushy stunt virus. The genome-wide screen led to the identification of five host genes whose absence resulted in the rapid generation of new viral RNA recombinants. Thus, these genes normally suppress viral RNA recombination, but in their absence, hosts become viral recombination "hotbeds." Four of the five suppressor genes are likely involved in RNA degradation, suggesting that RNA degradation could play a role in viral RNA recombination. In contrast, deletion of four other host genes inhibited virus recombination, indicating that these genes normally accelerate the RNA recombination process. A comparison of deletion strains with the lowest and the highest recombination rate revealed that host genes could affect recombinant accumulation by up to 80-fold. Overall, our results demonstrate that a set of host genes have a major effect on RNA virus recombination and evolution.
Serviene
Elena
E
Department of Plant Pathology, University of Kentucky, Plant Science Building, Lexington, KY 40546, USA.
Shapka
Natalia
N
Cheng
Chi-Ping
CP
Panavas
Tadas
T
Phuangrat
Bencharong
B
Baker
Jannine
J
Nagy
Peter D
PD
D017931:DNA Primers; D019143:Evolution, Molecular; D017353:Gene Deletion; D015723:Gene Library; D005798:Genes, Bacterial / Q000235:genetics*; D005820:Genetic Testing / Q000379:methods; D012328:RNA Viruses / Q000235:genetics*; D011995:Recombination, Genetic / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012441:Saccharomyces cerevisiae; D017864:Tombusvirus / Q000235:genetics*
D017931:DNA Primers