Danilevskaya O N, Slot F, Traverse K L, Hogan N C, Pardue M L
Department of Biology, Massachusetts Institute of Technology, Cambridge 02139.
Proc Natl Acad Sci U S A. 1994 Jul 5;91(14):6679-82. doi: 10.1073/pnas.91.14.6679.
Telomeres from Drosophila appear to be very different from those of other organisms. A transposable element, HeT-A, plays a major role in forming telomeres and may be the sole structural element, since telomerase-generated repeats are not found. The structure of the HeT-A element, deduced from cloned fragments of DNA, suggests that transposition of the element is mediated by a polyadenylylated RNA intermediate. We now report analyses of HeT-A transcripts. The major RNA is of the appropriate size and strandedness to serve as a transposition intermediate. This RNA is found in cultured cells and in intact flies and is unusual in that it is associated with protein after treatments that apparently remove all protein from other RNAs.
果蝇的端粒似乎与其他生物的端粒非常不同。一种转座元件HeT - A在端粒形成中起主要作用，并且可能是唯一的结构元件，因为未发现端粒酶产生的重复序列。从DNA克隆片段推导出来的HeT - A元件的结构表明，该元件的转座是由多聚腺苷酸化的RNA中间体介导的。我们现在报告对HeT - A转录本的分析。主要RNA的大小和链性适合作为转座中间体。这种RNA存在于培养细胞和完整果蝇中，其不同寻常之处在于，在经过明显能去除其他RNA所有蛋白质的处理后，它仍与蛋白质相关联。
