Ilyin Y V, Chmeliauskaite V G, Georgiev G P
Nucleic Acids Res. 1980 Aug 11;8(15):3439-57. doi: 10.1093/nar/8.15.3439.
Double-stranded RNA (dsRNA) sequences were isolated from either total RNA or cytoplasmic poly(A)+RNA of D. melanogaster culture cells using a method described previously /1,2/. Virtually all dsRNA was found to be of high molecular weight (> 200 base pairs) and unable to snap back after RNA melting. Thus, it corresponds to one of dsRNA classes found in mouse cells, namely, to dsRNA-A /3/. Three different cloned DNA fragments of D melanogaster which hybridized to melted dsRNa were selected among 100 randomly taken. All of them efficiently bound poly(A)+RNA and high percentage of total cellular DNA. According to these and other properties, they were assigned to a group of mobile dispersed genes of D. melanogaster. DsRNA hybridizes to all subfragments of the two mobile dispersed genes tested (mdg 1 and mdg 3). Thus, complete transcripts of mobile dispersed genes are present in dsRNA. In total RNA, transcripts from one strand are more abundant than those from another one. DsRNA is heavily enriched in the transcripts from mobile dispersed genes as compared to total or poly(A)+RNA of the cytoplasm. It has been suggested that dsRNA in D. melanogaster is formed as the result of symmetric transcription of mobile dispersed genes. At least in the cytoplasmic fraction, two complementary strands are separated in vivo and may combine during the isolation of RNA.
使用先前描述的方法从黑腹果蝇培养细胞的总RNA或细胞质聚腺苷酸加尾RNA（poly(A)+RNA）中分离双链RNA（dsRNA）序列/1,2/。实际上，所有dsRNA都具有高分子量（>200个碱基对），并且在RNA解链后不能重新形成双链。因此，它对应于在小鼠细胞中发现的dsRNA类别之一，即dsRNA-A /3/。从随机选取的100个克隆中选择了三个与解链后的dsRNA杂交的黑腹果蝇不同克隆DNA片段。它们都能有效地结合聚腺苷酸加尾RNA和细胞总DNA的很大比例。根据这些以及其他特性，它们被归为黑腹果蝇的一组移动分散基因。DsRNA与所测试的两个移动分散基因（mdg 1和mdg 3）的所有亚片段杂交。因此，移动分散基因的完整转录本存在于dsRNA中。在总RNA中，一条链的转录本比另一条链的更丰富。与细胞质的总RNA或聚腺苷酸加尾RNA相比，DsRNA在移动分散基因的转录本中高度富集。有人提出，黑腹果蝇中的dsRNA是移动分散基因对称转录的结果。至少在细胞质部分，两条互补链在体内是分开的，并且在RNA分离过程中可能会结合。
