Molecular Biology of insect-borne Plant Reovirus

对水稻矮缩病毒（RDV）、水稻黑条矮缩病毒（RBSDV）和水稻裂叶矮缩病毒（RRSV）的基因组结构进行了分析。RDV S9和S10的完整核苷酸序列。测定了RRSV S9和RBSDV S10。在病毒的5'和3'端均发现了片段特异性的反向重复序列，表明这种结构在病毒的复制中起着重要作用。对RDV的末端序列进行了分析。结果表明，除S9外，所有片段的3'末端的最后4个核苷酸（-UGAU 3'）是相同的，其中S9末端的第4个核苷酸由U变为C。RDV S3-S12的5'端序列为5' GGUAAA-或5 'GGCAAA-。这些保守序列也与植物呼肠孤病毒亚组1的另一成员伤口肿瘤病毒的保守序列相同或相似。这表明这两种病毒有共同的祖先起源。保守的末端序列也表明它在病毒基因组的复制中是不可缺少的。此外，从RRSV第9节和RBSDV第10节的序列分析中推测的RRSV和RBSDV的末端保守序列表明它们是不同的。

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.