TY - JOUR
T1 - Rice dwarf viruses with dysfunctional genomes generated in plants are filtered out in vector insects
T2 - Implications for the origin of the virus
AU - Pu, Yingying
AU - Kikuchi, Akira
AU - Moriyasu, Yusuke
AU - Tomaru, Masatoshi
AU - Jin, Yan
AU - Suga, Haruhisa
AU - Hagiwara, Kyoji
AU - Akita, Fusamichi
AU - Shimizu, Takumi
AU - Netsu, Osamu
AU - Suzuki, Nobuhiro
AU - Uehara-Ichiki, Tamaki
AU - Sasaya, Takahide
AU - Wei, Taiyun
AU - Li, Yi
AU - Omura, Toshihiro
PY - 2011/3
Y1 - 2011/3
N2 - Rice dwarf virus (RDV), with 12 double-stranded RNA (dsRNA) genome segments (S1 to S12), replicates in and is transmitted by vector insects. The RDV-plant host-vector insect system allows us to examine the evolution, adaptation, and population genetics of a plant virus. We compared the effects of long-term maintenance of RDV on population structures in its two hosts. The maintenance of RDV in rice plants for several years resulted in gradual accumulation of nonsense mutations in S2 and S10, absence of expression of the encoded proteins, and complete loss of transmissibility. RDV maintained in cultured insect cells for 6 years retained an intact protein-encoding genome. Thus, the structural P2 protein encoded by S2 and the nonstructural Pns10 protein encoded by S10 of RDV are subject to different selective pressures in the two hosts, and mutations accumulating in the host plant are detrimental in vector insects. However, one round of propagation in insect cells or individuals purged the populations of RDV that had accumulated deleterious mutations in host plants, with exclusive survival of fully competent RDV. Our results suggest that during the course of evolution, an ancestral form of RDV, of insect virus origin, might have acquired the ability to replicate in a host plant, given its reproducible mutations in the host plant that abolish vector transmissibility and viability in nature.
AB - Rice dwarf virus (RDV), with 12 double-stranded RNA (dsRNA) genome segments (S1 to S12), replicates in and is transmitted by vector insects. The RDV-plant host-vector insect system allows us to examine the evolution, adaptation, and population genetics of a plant virus. We compared the effects of long-term maintenance of RDV on population structures in its two hosts. The maintenance of RDV in rice plants for several years resulted in gradual accumulation of nonsense mutations in S2 and S10, absence of expression of the encoded proteins, and complete loss of transmissibility. RDV maintained in cultured insect cells for 6 years retained an intact protein-encoding genome. Thus, the structural P2 protein encoded by S2 and the nonstructural Pns10 protein encoded by S10 of RDV are subject to different selective pressures in the two hosts, and mutations accumulating in the host plant are detrimental in vector insects. However, one round of propagation in insect cells or individuals purged the populations of RDV that had accumulated deleterious mutations in host plants, with exclusive survival of fully competent RDV. Our results suggest that during the course of evolution, an ancestral form of RDV, of insect virus origin, might have acquired the ability to replicate in a host plant, given its reproducible mutations in the host plant that abolish vector transmissibility and viability in nature.
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U2 - 10.1128/JVI.02147-10
DO - 10.1128/JVI.02147-10
M3 - Article
C2 - 21191024
AN - SCOPUS:79952390995
VL - 85
SP - 2975
EP - 2979
JO - Journal of Virology
JF - Journal of Virology
SN - 0022-538X
IS - 6
ER -