DNA SEGMENT FROM DROSOPHILA-MELANOGASTER WHICH CONTAINS 5 TANDEMLY REPEATING UNITS HOMOLOGOUS TO THE MAJOR RDNA INSERTION
DNA SEGMENT FROM DROSOPHILA-MELANOGASTER WHICH CONTAINS 5 TANDEMLY REPEATING UNITS HOMOLOGOUS TO THE MAJOR RDNA INSERTION
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DOI：
10.1016/0092-8674(80)90392-x
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发表时间：
1980-01-01
期刊：
影响因子：
64.5
通讯作者：
GLOVER, DM
中科院分区：
文献类型：
--
作者：
KIDD, SJ;GLOVER, DM
描述了黑腹果蝇 DNA (cDm219) 的克隆片段，其包含 5 个串联排列的序列单元，与 X 染色体上大多数 28S rRNA 基因中发现的 I 型插入序列同源。异源双链体研究表明，其中 2 个单位有一个缺失，对应于靠近 I 型插入右侧末端的 1.1 kb DNA 片段。另一个单元用 7.5 kb 序列 (zeta) 取代靠近 I 型 r[核糖体]DNA 插入左侧部分的 0.95 kb DNA 片段。其余 2 个单位被 Col E1 [大肠杆菌] 质粒载体中断。 cDm219 本身的单位之间以及与包含 I 型插入的克隆 rDNA 片段的限制性内切酶切割图谱相比，限制性内切酶切割图谱也存在差异。 Zeta 元件探针与限制性核酸内切酶消化物的凝胶转移杂交定量，黑腹果蝇 DNA 表明有 30-40 个 Zeta 序列拷贝，分布在单倍体基因组内的 7 个主要排列中。 zeta和插入序列探针与克隆在噬菌体.lambda中的黑腹果蝇DNA片段文库的杂交。表明至少有 4-6 个 zeta 元件拷贝可以与插入序列连接。 Zeta 序列原位杂交的常见位点是多线染色体的染色质中心异染色质。
A cloned segment of D. melanogaster DNA (cDm219) which contains 5 tandemly arranged sequence units homologous to the type I insertion sequence found in the majority of 28S rRNA genes on the X chromosome is described. Heteroduplex studies show that 2 of the units have a deletion corresponding to a 1.1 kb piece of DNA close to the right-hand end of the type I insertion. Another unit has a 7.5 kb sequence (zeta) substituted for a 0.95 kb piece of DNA close to the left-hand part of the type I r[ribosomal]DNA insertion. The 2 remaining units are interrupted by the Col E1 [Escherichia coli] plasmid vector. There are also differences in the restriction endonuclease cleavage maps both between the units of cDm219 themselves and compared to the restriction endonuclease cleavage maps of cloned rDNA segments that contain type I insertions. Quantitation of the gel transfer hybridization of zeta element probes to restriction endonuclease digests that D. melanogaster DNA indicates there are 30-40 copies of zeta sequences distributed in 7 major arrangements within the haploid genome. The hybridization of zeta and insertion sequence probes to a library of D. melanogaster DNA segments cloned in bacteriophage .lambda. indicates at least 4-6 copies of the zeta element could be linked to insertion sequences. The common site of in situ hybridization of zeta sequences is to the chromocentral heterochromatin of polytene chromosomes.