Methylation of genomes and genes at the invertebrate-vertebrate boundary
Methylation of genomes and genes at the invertebrate-vertebrate boundary
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DOI：
10.1128/mcb.17.3.1469
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发表时间：
1997-03-01
影响因子：
5.3
通讯作者：
Bird, A
中科院分区：
文献类型：
--
作者：
Tweedie, S;Charlton, J;Bird, A
众所周知，动物基因组中的DNA甲基化模式从明显缺乏修饰碱基到基因组的一小部分甲基化，到全基因组的甲基化，来自10个无脊椎动物门的代表性基因组主要包括非甲基化的DNA和(通常但不总是)一小部分甲基化的DNA，相比之下，所有27种脊椎动物基因组都表现出全基因组的甲基化。我们对脊索动物基因组的研究表明，从部分甲基化到全局甲基化的转变发生在脊椎动物的起源附近，因为文昌鱼具有典型的无脊椎动物甲基化模式，而原始脊椎动物(七目鳗和七鳃鳗)具有典型脊椎动物的模式，令人惊讶的是，在这种转变之前的基因甲基化，因为许多无脊椎动物基因被证明是高度甲基化的，甲基化不会优先影响表达高度调控的基因，因为在高度甲基化的部分发现几个管家基因，而在非甲基化部分发现几个组织特异性表达的基因。
Patterns of DNA methylation in animal genomes are known to vary from an apparent absence of modified bases, via methylation of a minor fraction of the genome, to genome-wide methylation, Representative genomes from 10 invertebrate phyla comprise predominantly nonmethylated DNA and (usually but not always) a minor fraction of methylated DNA, In contrast, all 27 vertebrate genomes that have been examined display genome-wide methylation. Our studies of chordate genomes suggest that the transition from fractional to global methylation occurred close to the origin of vertebrates, as amphioxus has a typically invertebrate methylation pattern whereas primitive vertebrates (hagfish and lamprey) have patterns that are typical of vertebrates, Surprisingly, methylation of genes preceded this transition, as many invertebrate genes have turned out to be heavily methylated, Methylation does not preferentially affect genes whose expression is highly regulated, as several housekeeping genes are found in the heavily methylated fraction whereas several genes expressed in a tissue-specific manner are in the nonmethylated fraction.