Rizzo T M, Palukaitis P
Department of Plant Pathology, Cornell University, Ithaca, NY 14853.
Mol Gen Genet. 1990 Jul;222(2-3):249-56. doi: 10.1007/BF00633825.
Full-length cDNA copies of cucumber mosaic virus (CMV) RNAs 1 and 2 of the Fny strain were constructed from partial cDNA clones and were cloned downstream of bacteriophage T7 promoters. In one pair of clones, transcription proceeded from an unaltered T7 promoter such that in vitro transcripts representing RNAs 1 and 2 contained an additional 17 nucleotides at their 5' termini. In a second pair of clones, the T7 promoter/cDNA junction was altered by oligonucleotide-directed mutagenesis such that the in vitro transcripts contained only an additional G residue at their 5' ends. In addition, a full-length cDNA copy of Fny-CMV RNA 3 was constructed from two overlapping cDNA clones and was cloned downstream of an altered T7 promoter such that the resultant in vitro transcripts also contained only an additional G residue at their 5' ends. In vitro transcripts derived from all clones contained an additional C residue at their 3' ends. In vitro transcripts representing RNAs 1, 2 and 3 which contained an additional residue at each terminus were shown to be infectious together in several hosts of CMV.
黄瓜花叶病毒（CMV）Fny株系的RNA 1和RNA 2的全长cDNA拷贝由部分cDNA克隆构建而成，并克隆到噬菌体T7启动子的下游。在一对克隆中，转录从未改变的T7启动子开始，使得代表RNA 1和RNA 2的体外转录本在其5'末端含有另外17个核苷酸。在第二对克隆中，通过寡核苷酸定向诱变改变T7启动子/cDNA连接，使得体外转录本在其5'末端仅含有另外一个G残基。此外，Fny-CMV RNA 3的全长cDNA拷贝由两个重叠的cDNA克隆构建而成，并克隆到一个改变的T7启动子的下游，使得所得的体外转录本在其5'末端也仅含有另外一个G残基。来自所有克隆的体外转录本在其3'末端含有另外一个C残基。在CMV的几种宿主中，代表RNA 1、2和3且在每个末端都含有另外一个残基的体外转录本被证明一起具有感染性。
