Molecular Biology of insect-borne Plant Reovirus

对水稻矮缩病毒（RDV）、水稻黑条矮缩病毒（RBSDV）和水稻锯齿矮缩病毒（RRSV）的基因组结构进行了分析。RDV S9和S10的完整核苷酸序列。检测RRSV S9、RBSDV S10。在这些片段中发现了位于5‘和3’末端区域的片段特异性反向重复序列，表明该结构在病毒复制中起重要作用。分析了RDV的末端序列。结果发现，RDV S3-S12的5′端序列为5′gguaaa—或5′ggcaaa—，在RDV S3-S12的3′端最后4个核苷酸（-UGAU3′）是除s9以外的所有片段共有的，其中末端第4个核苷酸从u变为C。这些保守序列也与植物呼肠孤病毒亚群的另一成员伤口肿瘤病毒相同或相似。这表明这两种病毒具有共同的祖先起源。保守的末端序列也表明它在病毒基因组复制中是不可缺少的。此外，从RRSV第9段和RBSDV第10段的序列分析中推断出RRSV和RBSDV的推定末端保守序列，表明它们之间存在差异。

Genome structures of rice dwarf viurs (RDV), rice black streaked dwarf virus(RBSDV), and rice ragged stunt virus (RRSV) were analyzed. Complete nucleotide sequences of RDV S9 and S10. RRSV S9, and RBSDV S10 were determined. Segment specific inverted repeats located at both 5' and 3' terminal regions were found in these segments indicating that this structure plays an importnat role in replication of the viruses. Terminal sequences of RDV were analyzed. It was found that the last four nucleotides (-UGAU3') at the 3' terminus were common to all the segments except for the S 9, where the fourth from the terminus was changed to C from U. 5' terminal sequence of RDV S3-S12 was determined to be 5'GGUAAA-- or 5'GGCAAA--. These conserved sequences were also common or similar to that of wound tumor virus , another member of plant reovirus subgroup 1. This indicates common ancestral origin of the two viruses. The conserved terminal sequence also indicates that it is indispensable in replicationof the viral genome. Furthermore presumed terminal conserved sequences of RRSV and RBSDV deduced from the sequence analyses of RRSV segment 9 and RBSDV segment10 indicated that they are different from each other.