Mawassi M, Mietkiewska E, Hilf M E, Ashoulin L, Karasev A V, Gafny R, Lee R F, Garnsey S M, Dawson W O, Bar-Joseph M
S. Tolkowsky Laboratory, Department of Virology, Agricultural Research Organization, Volcani Center, Bet Dagan, Israel.
Virology. 1995 Dec 1;214(1):264-8. doi: 10.1006/viro.1995.9930.
Alemow (Citrus macrophylla) and sweet orange (C. sinensis) plants infected, respectively, with several Israeli and Florida isolates of the citrus tristeza virus (CTV) were found to contain multiple species of RNA molecules with features similar to defective-interfering RNAs. Northern blot hybridizations of dsRNAs extracted from serial passages of the Israeli VT isolate (CTV-VT) and from different plants infected with a single source of inoculum showed considerable variation both in the presence and in the relative abundance of the defective RNA (D-RNA) bands. The D-RNA molecules were found to be encapsidated in the CTV particles. Sequence analysis of two VT D-RNA molecules of 2.7 and 4.5 kb revealed that they were composed of two regions corresponding to 1818 and 4036 nucleotides from the 5' and 938 and 442 nucleotides from the 3' termini of the CTV-VT genomic RNA, respectively. A short (ca. 0.8 kb) nonencapsidated single-stranded positive-sense RNA species was also found in infected plants. This ssRNA, which copurified with dsRNAs, was shown by hybridization to encompass the 5'-terminal part of the CTV genome and might have an extensive secondary structure.
分别用几种来自以色列和佛罗里达的柑橘衰退病毒（CTV）分离株感染的阿蕾檬（Citrus macrophylla）和甜橙（C. sinensis）植株，被发现含有多种RNA分子，其特征类似于缺陷干扰RNA。从以色列VT分离株（CTV-VT）的连续传代以及从感染单一接种源的不同植株中提取的双链RNA（dsRNA）进行的Northern印迹杂交显示，缺陷RNA（D-RNA）条带的存在和相对丰度均存在相当大的差异。发现D-RNA分子被包裹在CTV颗粒中。对两个大小分别为2.7 kb和4.5 kb的VT D-RNA分子进行序列分析表明，它们分别由两个区域组成，这两个区域分别对应于CTV-VT基因组RNA 5'端的1818个核苷酸和4036个核苷酸，以及3'端的938个核苷酸和442个核苷酸。在受感染植株中还发现了一种短的（约0.8 kb）未被包裹的单链正义RNA分子。这种与dsRNA共纯化的单链RNA（ssRNA），通过杂交显示其包含CTV基因组的5'末端部分，并且可能具有广泛的二级结构。
