Department of Genetics, University of Georgia, Athens, GA 30602, USA.
Department of Microbiology, University of Georgia, Athens, GA 30602, USA.
Trends Genet. 2019 Nov;35(11):818-827. doi: 10.1016/j.tig.2019.07.007. Epub 2019 Aug 6.
Chemical modification of nucleotide bases in DNA provides one mechanism for conveying information in addition to the genetic code. 5-methylcytosine (5mC) represents the most common chemically modified base in eukaryotic genomes. Sometimes referred to simply as DNA methylation, in eukaryotes 5mC is most prevalent at CpG dinucleotides and is frequently associated with transcriptional repression of transposable elements. However, 5mC levels and distributions are variable across phylogenies, and emerging evidence suggests that the functions of DNA methylation may be more diverse and complex than was previously appreciated. We summarize the current understanding of DNA methylation profiles and functions in different eukaryotic lineages.
除了遗传密码外，DNA 中核苷酸碱基的化学修饰为信息传递提供了另一种机制。5-甲基胞嘧啶（5mC）是真核生物基因组中最常见的化学修饰碱基。在真核生物中，5mC 通常在 CpG 二核苷酸中最为常见，并且经常与转座元件的转录抑制相关，有时简称为 DNA 甲基化。然而，5mC 的水平和分布在系统发育上是可变的，新出现的证据表明，DNA 甲基化的功能可能比以前认为的更加多样化和复杂。我们总结了不同真核生物谱系中 DNA 甲基化谱和功能的现有认识。
