Dot1 and Histone H3K79 Methylation in Natural Heterochromatic and HML/HMR Silencing

Dot1 is a methyl transferase that has been shown through a reporter gene to be involved in position effect variegation of gene expression in heterochrmatic regions such as telomeres and the mating type loci in yeast. This study examines the effect of mutation of DOT1 and two other proteins involved in H3K79 methylation, SWI4 and ARD1, on gene expression relative to wt cells. Wt, and mutants of Dot1, Swi4, or Ard1 were grown, in duplicate, in liquid media to midlog phase for extraction of RNA and comparison of gene expression on Affymetrix arrays.