Dynamic Alu Methylation during Normal Development, Aging, and Tumorigenesis

Figure 3

Overview of the potential causes and consequences of differential Alu methylation. Differential Alu DNA methylation might be induced by various kinds of external factors and mediated with internal cellular factors and pathways. The consequences of differential Alu methylation could be multifaceted and shown at three levels: (1) genome structure variations resulted from de novo Alu retrotransposition; (2) transcriptome diversity contributed directly by the expression of free Alu RNA or indirectly through alternative splicing and RNA editing by embedded Alu RNA; (3) gene expression regulations: transcriptional regulation of miRNA/mRNA expression mediated by Alu antisense transcripts, duplex structures, or the differential bindings of transcription factors to Alu elements. Solid lines represent experimentally validated relationships, while dashed lines are speculative relationships.