中文摘要：

在真核生物中，DNA甲基化是一种非常重要的表观遗传学标记，能影响染色质的结构和基因的表达。随着全基因组甲基化测序的发展，全基因组范围内的DNA甲基化水平得以了解。文章概述了基因组中启动子、基因本体、增强子、沉默子和转座子等不同元件的DNA甲基化的研究进展，以及DNA甲基化与基因表达调控间的关系。启动子的DNA甲基化对基因的表达有抑制作用，而基因本体的DNA甲基化与基因的表达关系因物种或细胞类型不同而异。增强子的DNA甲基化状态与基因活性呈反比关系，沉默子则相反呈正相关。转座子的DNA高度甲基化抑制其转座活性，从而维持基因组的稳定性。文章还探讨了DNA甲基化与组蛋白甲基化间的相互作用及其对基因表达、可变剪切、转录的调控作用，以及本领域的未来研究方向。

英文摘要：

DNA methylation is an important epigenetic marker in eukaryotes, and could affect chromatin structure and gene expression. With the development of genome-wide methylation sequencing technology, DNA methylation level in the whole genome can be evaluated. In this review, we summarize the research progress ofDNA methylation on promoter, gene body, enhancer, silencer and transposon, as well as the relationship between DNA methylation and gene expression. DNA methylation of gene promoter suppresses gene expression, while the relationship between DNA methylation of gene body and gene expression depends on species and cell types. The gene activity is inversely related with the DNA methylation level of enhancer, but positively correlated to the DNA methylation of silencer. Transposon hypermethylation restricts its transposition activity to maintain the genome stability. Furthermore, we discuss the interaction between DNA methylation and histone methylation, its roles in regulation of gene expression, alternative splicing and transcription, and directions for future studies in this field.