Electron Micrographic Mapping of Deletions, Insertions, Inversions, and Homologies in the DNAs of Coliphages Lambda and Phi 80
Electron Micrographic Mapping of Deletions, Insertions, Inversions, and Homologies in the DNAs of Coliphages Lambda and Phi 80
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Coliphages Lambda 和 Phi 80 DNA 中删除、插入、倒位和同源性的电子显微图谱
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发表时间：
1971
期刊：
影响因子：
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通讯作者：
W. Szybalski
中科院分区：
文献类型：
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作者：
M. Fiandt;Z. Hradečná;H. Lozeron;W. Szybalski
在过去几年中，对几种噬菌体DNA分子的功能组织的研究一直是该实验室主要关注的问题（见Szybalski， 1969, Szybalski, 1970， Szybalski等人，1969，Szybalski等人，1970）。一项主要的研究致力于阐明羔羊样噬菌体的转录模式和控制（例如，Szybalski等人，1966；Taylor等人，1967；Kumar等人，1969；Lozeron和Szybalski, 1969； Bovre和Szybalski, 1969； Nijkamp等人，1970）。这些噬菌体基因的物理图谱是转录模式定量研究中不可缺少的工具，并引导我们开发了一种新技术，称为异双工DNA的电子显微图谱（Westmoreland et al., 1969）。在这个过程中，两种不同的噬菌体DNA链被预先分离，第一种DNA的一条链在含甲酰胺的溶液中与第二种DNA的互补链退火，并通过电子显微镜检查得到的异双工DNA分子。异质双聚体的同源区域表现为双链，更刚性的DNA片段，而未配对的单链，更细，更弯曲，在非同源区域可见。简单的缺失或插入导致单链“环”从不间断的双链DNA的一点发出（见图2中的点1），而替换或反转出现为“气泡”，即由两条未配对的单链组成的双链DNA的中断（见图2中的区域2至3）。运用这种技术，它……
The study of the functional organization of the DNA molecules of several bacteriophages has been the primary concern of this laboratory during the past few years (see the reviews of Szybalski, 1969see the reviews of Szybalski, 1970, and Szybalski et al., 1969, and Szybalski et al., 1970). A major effort has been devoted to the elucidation of the patterns and controls of transcription in the lambdoid coliphages (e.g., Szybalski et al., 1966; Taylor et al., 1967; Kumar et al., 1969; Lozeron and Szybalski, 1969; Bovre and Szybalski, 1969; Nijkamp et al., 1970). Physical mapping of the genes of these phages is an indispensable tool in the quantitative study of the transcription patterns, and has led us to develop a novel technique, designated electron micrographic mapping of heteroduplex DNA (Westmoreland et al., 1969). In this procedure the strands of two distinct phage DNAs are preparatively separated, one strand of the first DNA is annealed to the complementary strand of the second DNA in a formamide-containing solution, and the resulting heteroduplex DNA molecules are examined by electron microscopy. The regions of homology in the heteroduplexes appear as double-stranded, more rigid DNA segments, whereas unpaired single strands, thinner and kinkier, are visualized in the nonhomologous regions. Simple deletions or insertions result in single-stranded “loops” emanating from one point of the otherwise uninterrupted double-stranded DNA (see point 1 in Fig. 2), whereas substitutions or inversions appear as “bubbles,” i.e., interruptions in the double-stranded DNA composed of two single unpaired strands (see region 2 to 3 in Fig. 2). Applying this technique, which...