Characterization of the Possible Role of Histone H4 in DNA Methylation

Abstract

One of several mechanisms by which genomic expression is regulated, DNA methylation is especially important for its role in post-transcriptional gene silencing. A number of recent investigations indicate the possibility that the core histones, around which DNA is packaged into the nucleosome, play some role in the methylation of chromosomal DNA. This study will indicate to what extent histone H4 and its associated residues are interrelated with the process of DNA methylation. Such correlations will be identified by substituting each of twenty-one isolated modifications of the gene encoding histone H4 for that same gene in a suitable strain of Neurospora Crassa. Using methylated plasmid probes in a southern analysis of each modified strain, the presence of methylated DNA in those strains can be observed qualitatively. A southern analysis also indicates whether, and to what extent, the various residues of histone H4 are involved in this genomic process.