Chen B, Craven M G, Choi G H, Nuss D L
Roche Institute of Molecular Biology, Roche Research Center, Nutley, New Jersey 07110.
Virology. 1994 Jul;202(1):441-8. doi: 10.1006/viro.1994.1360.
Unencapsidated double-stranded viral RNAs belonging to the genus Hypovirus attenuate virulence of the chestnut blight fungus, Cryphonectria parasitica. A full-length cDNA clone of hypovirus CHV1-713 double-stranded RNA was recently shown to be infectious when introduced into the C. parasitica genome by DNA-mediated transformation. In this study, we show that the viral RNA derived from the chromosomally integrated cDNA copy is trimmed of extraneous vector nucleotide sequences. The cDNA-derived viral RNA was also found to contain a 73-bp deletion located within the 5'-noncoding leader sequence as a result of a pre-mRNA splicing event. Implications of these results are discussed in terms of hypovirus RNA replication and anticipated field studies involving engineered hypovirulent C. parasitica strains.
属于低毒病毒属的无衣壳双链病毒RNA可减弱栗疫病菌（Cryphonectria parasitica）的毒力。最近研究表明，低毒病毒CHV1 - 713双链RNA的全长cDNA克隆通过DNA介导转化导入寄生隐孢壳菌基因组时具有感染性。在本研究中，我们发现从染色体整合的cDNA拷贝衍生而来的病毒RNA去除了无关的载体核苷酸序列。由于前体mRNA剪接事件，还发现cDNA衍生的病毒RNA在5'非编码前导序列内有一个73bp的缺失。我们根据低毒病毒RNA复制以及涉及工程改造的低毒力寄生隐孢壳菌菌株的预期田间研究讨论了这些结果的意义。
