Fig. 4.

Chp2 and Swi6 proteins and their associated HDACs collaborate to limit Pol II occupancy at pericentromeric heterochromatic repeats. (A) Chp2 and Swi6 cooperatively contribute in transcriptional silencing of the pericentromeric heterochromatin regions. Pol II distributions were determined by ChIP-chip analysis in the indicated mutants and wt strains. Changes in Pol II occupancy in the mutants compared with wt (mutant/wt) were plotted on a log₂ scale. (B) Clr3 and Clr6 cooperatively contribute to transcriptional silencing of the pericentromeric heterochromatin regions. Differential Pol II occupancy in indicated mutant strains compared with wt strains (mutant/wt) were plotted on a log₂ scale. (C) Expression profiles for the indicated strains, at the right pericentromeric repeat region of cen2, are shown. Expression ratios (mutant/wt) for forward strand (Upper, red) and reverse strand (Lower, blue) probes were plotted on a log₂ scale.