Aïssani B, D'Onofrio G, Mouchiroud D, Gardiner K, Gautier C, Bernardi G
Laboratoire de Génétique Moléculaire, Institut Jacques Monod, Paris, France.
J Mol Evol. 1991 Jun;32(6):493-503. doi: 10.1007/BF02102651.
The present work represents the first attempt to study in greater detail previously proposed compositional correlations in genomes, based on a body of additional data relating to gene localizations as well as to extended flanking sequences extracted from gene banks. We have investigated the correlations that exist between (1) the GC levels of exons of human genes, and (2) the GC levels of either intergenic sequences or introns associated with the genes under consideration. In both cases, linear relationships with slopes close to unity were found. The similarity of the linear relationships indicates similar GC levels in intergenic sequences and introns located in the same isochores. Moreover, both intergenic sequences and introns showed GC levels 5-10% lower than the corresponding exons. The above findings considerably strengthen the previously drawn conclusion that coding and noncoding sequences (both inter- and intragenic) from the same isochores of the human genome are compositionally correlated. In addition, we find linear correlations between the GC levels of codon positions and of the intergenic sequences or introns associated with the corresponding genes, as well as among the GC levels of codon positions of genes.
本研究首次尝试基于一系列与基因定位以及从基因库中提取的扩展侧翼序列相关的额外数据，更详细地研究先前提出的基因组组成相关性。我们研究了以下两者之间存在的相关性：（1）人类基因外显子的GC含量，以及（2）与所考虑基因相关的基因间序列或内含子的GC含量。在这两种情况下，均发现斜率接近1的线性关系。线性关系的相似性表明位于同一同线区的基因间序列和内含子具有相似的GC含量。此外，基因间序列和内含子的GC含量均比相应外显子低5 - 10%。上述发现极大地强化了先前得出的结论，即人类基因组同一同线区的编码和非编码序列（基因间和基因内）在组成上具有相关性。此外，我们发现密码子位置的GC含量与相应基因相关的基因间序列或内含子的GC含量之间存在线性相关性，以及基因密码子位置的GC含量之间也存在线性相关性。
