Fried H M, Fink G R
Proc Natl Acad Sci U S A. 1978 Sep;75(9):4224-8. doi: 10.1073/pnas.75.9.4224.
Wild-type and mutant double-stranded RNA (dsRNA) species from the yeast Saccharomyces cerevisiae were studied by electron microscopic heteroduplex mapping to determine the sequence relationships among the different RNA molecules. Three mutant dsRNAs, 1.5, 1.4, and 0.73 kilobase, were found to be derived by the same internal deletion of the wild-type (I83 kilobases) molecule. This deletion includes a wild-type (1.83 kilobases) molecule. This deletion includes a segment of about 200 base pairs that was estimated to be nearly 100% A+U. In addition, the sequences of the two larger mutant RNA species are tandem, direct duplications. One of the duplicated molecules appears to have a second internal deletion that occurred after the duplication. The mutant dsRNAs are functionally similar to the defective interfering virus particles of animal viruses--all of the mutant species prevent the propagation of the wild-type dsRNA when both are present in the same cell. The four dsRNAs share the same sequences at their termini, a finding that may suggest that these sequences are important for the replication of the dsRNAs.
通过电子显微镜异源双链体图谱研究了酿酒酵母的野生型和突变型双链RNA（dsRNA），以确定不同RNA分子之间的序列关系。发现三种突变dsRNA，分别为1.5、1.4和0.73千碱基，是由野生型（183千碱基）分子的相同内部缺失产生的。这种缺失包括野生型（1.83千碱基）分子。这种缺失包括一段约200个碱基对的片段，估计其中A+U含量接近100%。此外，两种较大的突变RNA物种的序列是串联直接重复。其中一个重复分子似乎在重复后发生了第二次内部缺失。突变dsRNA在功能上类似于动物病毒的缺陷干扰病毒颗粒——当野生型dsRNA和突变型dsRNA同时存在于同一细胞中时，所有突变物种都会阻止野生型dsRNA的繁殖。这四种dsRNA在其末端具有相同的序列，这一发现可能表明这些序列对dsRNA的复制很重要。
