OCCURRENCE OF LONG TRANSCRIPTION UNITS AMONG THE X-RIBOSOMAL AND Y-RIBOSOMAL GENES OF DROSOPHILA-MELANOGASTER - TRANSCRIPTION OF INSERTION SEQUENCES
OCCURRENCE OF LONG TRANSCRIPTION UNITS AMONG THE X-RIBOSOMAL AND Y-RIBOSOMAL GENES OF DROSOPHILA-MELANOGASTER - TRANSCRIPTION OF INSERTION SEQUENCES
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DOI：
10.1007/bf00344483
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发表时间：
1979-01-01
期刊：
影响因子：
1.6
通讯作者：
CHOOI, WY
中科院分区：
文献类型：
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作者：
CHOOI, WY
D.通过EM观察到的黑腹果蝇的长度约为8 kb [DNA酶]，该长度对应于D.黑腹果蝇散布在这些rTU中的是比rTU预期的8kb长得多（高达14.6kb）的转录单位。这些较大的长度估计值中的一些可以归因于拉伸，但重要的一部分明显更大，每个基因具有多达60个以上的纤维。这些较大的转录单位可能是由插入序列组成的核糖体基因。长的转录单位在如先前报道的含有插入序列的rTU的预期大小内。它们的RNP [核糖核蛋白]纤维与针对核糖体蛋白质的抗体发生交叉反应，其方式类似于对核糖体RNP所观察到的方式。它们散布在X染色体中的rTU之间。这些假定的携带插入物的核糖体基因既存在于X染色体中，也存在于Y染色体中，尽管程度较小，正如它们存在于俄勒冈州R女性和基因型sc4sc8/sc4sc8/y + Y女性的滋养细胞中所表明的那样。长TU的纤维模式的分析支持插入区域被转录的假设。发现长TU与长度不均匀的非转录间隔区串联，平均长度为1.53 ± 1.53。0.61μ m（或8.5 ± 1.5 μ m）。3.4 kb）。
Most of the ribosomal transcription units (rTU) in D. melanogaster observed by EM measure about 8 kb [kilobases], a length which corresponds to the size of the 38S precursor to rRNA in D. melanogaster. Interspersed among these rTU are transcription units that are much longer (up to 14.6 kb) than the 8 kb expected for rTU. Some of these larger length estimates can be attributed to stretching but an important fraction is significantly larger and has up to 60 more fibers per gene. These larger transcription units may be ribosomal genes consisting of insertion sequences. The long transcription units are within the sizes expected for rTU containing insertion sequences as previously reported. Their RNP [ribonucleoprotein] fibers cross-react with antibodies raised against ribosomal proteins in a manner similar to that observed for ribosomal RNP. They are interspersed among rTU in the X chromosome. These putative ribosomal genes carrying insertions are present both in the X and, although to a lesser extent, in the Y ribosomal chromatin as indicated by their existence in nurse cells of both Oregon R females and females of the genotype sc4sc8/sc4sc8/y+ Y. Analysis of the fiber patterns of long TU supports the hypothesis that the insertion region is being transcribed. Long TU are found in tandem with non-transcribed spacer regions which are heterogeneous in length with a mean of 1.53 .+-. 0.61 .mu.m (or 8.5 .+-. 3.4 kb).