A long-range and two short-range periodicities are superimposed in the 1.706-g/cm3 satellite DNA from calf thymus.
A long-range and two short-range periodicities are superimposed in the 1.706-g/cm3 satellite DNA from calf thymus.
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来自小牛胸腺的 1.706 g/cm3 卫星 DNA 中叠加了一个长程周期性和两个短程周期性。
DOI：
10.1111/j.1432-1033.1978.tb20923.x
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发表时间：
1978
期刊：
影响因子：
--
通讯作者：
H. Zachau
中科院分区：
文献类型：
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作者：
R. Streeck;H. Zachau
通过对小牛胸腺卫星DNA的限制性核酸酶分析，研究了重复序列的组织。在1.706-g/cm~3卫星DNA(卫星III)中发现了几个新的结构特征。用限制性内切酶BSP或EcoRII切割检测到的2350个碱基对的长程周期和用Alu和Sau限制性内切酶分别消化得到的约22和11个碱基对的短程周期分别叠加在该卫星DNA的核苷酸序列中。在长程重复序列中，约有14%的DNA缺乏短程周期。长距离重复序列的长度约为22个碱基对的倍数。限制性内切酶切点在卫星DNA中的分布是非随机的。这种卫星DNA的进化不能仅用跳跃放大和随机发散来充分解释，还讨论了不等交换和附加的非随机过程。
在1.723克/厘米~3的卫星DNA(卫星II)中，用限制性内切酶Alu裂解发现了45个碱基对的周期性。这个卫星DNA的切割模式与原来同源核苷酸序列3%的随机分歧是相容的。
已经建立了1.715克/厘米~3卫星DNA(卫星I)的物理图谱，其中包含限制性内切酶Alu、Sau、Pst和EcoRI的切割位点。该卫星DNA的核苷酸序列具有1400个碱基对(Alu、Sau、EcoRI)和700个碱基对(Pst)的周期性。
用已知序列的φX174复制的I型DNA片段在小鼠、BsC-1和三个小牛卫星DNA的限制性核酸内切酶中校准了片段的大小。这些卫星DNA通过限制或部分消化产生的单体和寡聚片段提供了一套重叠的DNA片段大小标准，从20到20000个碱基对。
The organization of repetitive sequences has been studied by restriction nuclease analysis of satellite DNAs from calf thymus. Several novel structural features have been found in the 1.706-g/cm3 satellite DNA (satellite III). A long-range periodicity of 2350 base pairs detected by cleavage with restriction endonucleases Bsp or EcoRII and two short-range periodicities of approximately 22 and 11 base pairs found by digestion with restriction endonucleases Alu and Sau, respectively, are superimposed in the nucleotide sequence of this satellite DNA. About 14% of the DNA present in long-range repeats lack the short-range periodicities. The lenght of the long-range repeats varies by multiples of approximately 22 base pairs. The distribution of the restriction sites in the satellite DNA is non-random. The evolution of this satellite DNA is not adequately explained by saltatory amplification and random divergence alone; unequal crossing-over and additional non-random processes are discussed.
In the 1.723-g/cm3 satellite DNA (satellite II) a periodicity of 45 base pairs has been found by cleavage with restriction endonuclease Alu. The cleavage pattern of this satellite DNA is compatible with a 3% random divergence of an originally homogeneous nucleotide sequence.
A physical map has been established for the 1.715-g/cm3 satellite DNA (satellite I) containing the cleavage sites of restriction endonucleases Alu, Sau, Pst, and EcoRI. A periodicity of 1400 base pairs (Alu, Sau, EcoRI) and of 700 base pairs (Pst) has been observed in the nucleotide sequence of this satellite DNA.
φX174 replicative form I DNA fragments of known sequence have been used to calibrate the sizes of the fragments in restriction nuclease digests of mouse, BSC-1, and the three calf satellite DNAs. The monomeric and oligomeric fragments derived from these satellite DNAs by limit or partial digestion provide overlapping sets of size standards for DNA fragments from 20 up to 20000 base pairs.