概述 4 Definition of epigenetics O Any changes in gene expression resulting from either a dnA and chromatin modification or resulting from a post transcriptional mechanism. However, it does not reflect a difference in the dna code 4 An unifying definition of epigenetics:(Adrian Bird nature, 2007) o the structural adaptation of chromosomal regions so as to register, signal or perpetuate altered activity states. o This definition is inclusive of chromosomal marks. because transient modifications associated with both DNA repair or cell-cycle phases and stable changes maintained across multiple cell generations qualify.2021年12月23日 8 概 述 ❖Definition of Epigenetics ⚫ Any changes in gene expression resulting from either a DNA and chromatin modification or resulting from a post￾transcriptional mechanism. However, it does not reflect a difference in the DNA code。 ❖An unifying definition of epigenetics: (Adrian Bird, nature, 2007) ⚫ the structural adaptation of chromosomal regions so as to register, signal or perpetuate altered activity states. ⚫ This definition is inclusive of chromosomal marks, because transient modifications associated with both DNA repair or cell-cycle phases and stable changes maintained across multiple cell generations qualify. 8