A NOVEL REPEATED ELEMENT WITH Z-DNA-FORMING POTENTIAL IS WIDELY FOUND IN EVOLUTIONARILY DIVERSE EUKARYOTIC GENOMES
A NOVEL REPEATED ELEMENT WITH Z-DNA-FORMING POTENTIAL IS WIDELY FOUND IN EVOLUTIONARILY DIVERSE EUKARYOTIC GENOMES
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DOI：
10.1073/pnas.79.21.6465
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发表时间：
1982-01-01
期刊：
影响因子：
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通讯作者：
KAKUNAGA, T
中科院分区：
文献类型：
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作者：
HAMADA, H;PETRINO, MG;KAKUNAGA, T
以32p标记的poly(d[脱氧]T-dG).cntdot.poly（dC-dA）为探针进行Southern blotting和杂交分析发现，真核生物基因组中存在大量的dT-dG交替序列，该序列在某些条件下表现为Z-DNA构象。该序列存在于从酵母到人类的所有真核生物基因组中，表明了非凡的进化保守性。该序列的数量从酵母中的100个到高等真核生物中的数万个不等。对多个克隆基因中dT-dG交替区及其侧翼区核苷酸序列的比较表明，重复元件[Z（T-G）元件]仅由变长dT-dG交替序列组成。以32P-labeled poly（dG-dC）、cntdot.poly（dG-dC）为探针，采用Southern blot杂交技术对真核生物基因组中另一个嘌呤-嘧啶交替序列的存在进行了研究。dC-dG交替序列[Z（C-G）元件]的延伸在人类、小鼠和鲑鱼基因组中被发现是适度重复的。在酵母和小牛的基因组中分别发现少量和没有Z（C-G）元素的拷贝。自然界中潜在的z - dna形成序列的丰度是显而易见的。
Southern blotting and hybridization analysis using 32P-labeled poly(d[deoxy]T-dG).cntdot.poly(dC-dA) as a probe found, in eukaryotic genomes, a huge number of stretches of dT-dG alternating sequence, a sequence that was shown to adopt the Z-DNA conformation under some conditions. This sequence was found in all eukaryotic genomes examined from yeast to human, indicating extraordinary evolutionary conservation. The number of the sequence ranged from about 100 in yeast to tens of thousands in higher eukaryotes. Comparison of nucleotide sequences of dT-dG alternating regions and its flanking regions in several cloned genes showed that the repeated element [the Z(T-G) element] consists only of dT-dG alternating sequence with variable length. The presence of another purine-pyrimidine alternating sequence was also surveyed in eukaryotic genomes by Southern blot hybridization using 32P-labeled poly(dG-dC).cntdot.poly(dG-dC) as the probe. The stretches of dC-dG alternating sequence [the Z(C-G) element] were found to be moderately repetitive in human, mouse and salmon genomes. A few and no copies of the Z(C-G) element were found in yeast and calf genomes, respectively. The abundance of potential Z-DNA-forming sequences in nature is evident.