Analysis of the phylogenetic distribution of isochores in vertebrates and a test of the thermal stability hypothesis
Analysis of the phylogenetic distribution of isochores in vertebrates and a test of the thermal stability hypothesis
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DOI：
10.1007/s00239-002-2333-1
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发表时间：
2002-09-01
影响因子：
3.9
通讯作者：
Eyre-Walker, A
中科院分区：
文献类型：
--
作者：
Belle, EMS;Smith, N;Eyre-Walker, A
温血脊椎动物在其染色体上显示出 G + C 含量的大规模变化，而冷血脊椎动物似乎基本上不存在这种模式。然而，异温动物的组成变异通常是通过超速离心而不是序列分析来研究的。在本文中，我们利用 DNA 序列分析研究了多种脊椎动物变温动物编码序列的组成特性。我们发现，平均而言，异温动物的第三密码子位置 GC 含量 (GC3) 低于恒温动物，但某些异温动物的平均 GC3 值较高。我们发现大多数变温动物的 GC3 变异程度低于恒温动物，但某些物种的 GC12 和 GC3 之间存在相关性，这表明其基因组中的碱基组成存在系统变异。我们还证明斑马鱼（Danio rerio）基因的 GC3 与人类基因的 GC3 相关，这表明脊椎动物具有基本的等容线结构。然而，我们发现 GC3 平均值或 GC3 标准差与体温之间没有相关性。
Warm-blooded vertebrates show large-scale variation in G + C content along their chromosomes, a pattern which appears to be largely absent from cold-blooded vertebrates. However, compositional variation in poikilotherms has generally been studied by ultracentrifugation rather than sequence analysis. In this paper, we investigate the compositional properties of coding sequences from a broad range of vertebrate poikilotherms using DNA sequence analysis. We find that on average poikilotherms have lower third-codon position GC contents (GC3) than homeotherms but that some poikilotherms have higher mean GC3 values. We find that most poikilotherms have lower variation in GC3 than homeotherms but that there is a correlation between GC12 and GC3 for some species, indicating that there is systematic variation in base composition across their genomes. We also demonstrate that the GC3 of genes in the zebrafish, Danio rerio, is correlated with that in humans, suggesting that vertebrates share a basic isochore structure. However, we find no correlation between either the mean GC3 or the standard deviation in GC3 and body temperature.