Restricted epigenetic inheritance of H3K9 methylation

Abstract

Inheritance of a covalent histone modification Genomic DNA is the repository of all genetic information and is packaged into chromatin. Chromatin is also a repository of regulatory information in the form of covalent marks added to the histones that package the DNA. These marks can determine tissue- and organ-specific gene expression patterns, which must be transmitted to daughter cells to maintain their identity. Ragunathan et al. and Audergon et al. show that in fission yeast, a chromatin mark, like genetic information, can be inherited across many cell generations. The mark can be inherited independently of DNA sequence, DNA methylation, or RNA interference. Thus, histone marks constitute true epigenetic information. Science , this issue 10.1126/science.1258699 ; see also p. 132