Epigenetics
Epigenetics is a subdiscipline of genetics that studies heritable changes in gene expression without changes in the nucleotide sequence of genes. It is also a common way of gene expression regulation in life phenomena. Many epigenetic phenomena are known, including DNA methylation, gene silencing, nucleolar dominance, genomic imprinting, maternal effects, dormant transposon activation, and RNA editing. Among them, DNA methylation is the most clearly studied and most important epigenetic modification form. It plays a crucial role in maintaining normal cell function, human tumorigenesis, genetic imprinting, and embryonic development, which is one of the new research hotspots.