Nussinov R
J Mol Evol. 1984;20(2):111-9. doi: 10.1007/BF02257371.
Analysis of the sequence data available today, comprising more than 500,000 bases, confirms the previously observed phenomenon that there are distinct dinucleotide preferences in DNA sequences. Consistent behaviour is observed in the major sequence groups analysed here in prokaryotes, eukaryotes and mitochondria. Some doublet preferences are common to all groups and are found in most sequences of the Los Alamos Library. The patterns seen in such large data sets are very significant statistically and biologically. Since they are present in numerous and diverse nucleotide sequences, one may conclude that they confer evolutionary advantages on the organism. In eukaryotes RR and YY dinucleotides are preferred over YR and RY (where R is a purine and Y a pyrimidine). Since opposite-chain nearest-neighbour purine clashes are major determinants of DNA structure, it appears that the tight packaging of DNA in nucleosomes disfavors, in general, such (YR and RY) steric repulsion.
对如今可得的包含超过50万个碱基的序列数据进行分析，证实了之前观察到的现象，即DNA序列中存在明显的二核苷酸偏好。在此分析的原核生物、真核生物和线粒体的主要序列组中观察到了一致的行为。一些双联偏好为所有组所共有，并且在洛斯阿拉莫斯数据库的大多数序列中都能找到。在如此庞大的数据集中看到的模式在统计学和生物学上都非常显著。由于它们存在于众多不同的核苷酸序列中，人们可以得出结论，它们赋予了生物体进化优势。在真核生物中，RR和YY二核苷酸比YR和RY更受青睐（其中R为嘌呤，Y为嘧啶）。由于反链最近邻嘌呤冲突是DNA结构的主要决定因素，因此似乎核小体中DNA的紧密包装通常不利于此类（YR和RY）空间排斥。
