There are significant changes in gene expression that occur with cellular senescence and
organismic aging. Genes residing in compacted heterochromatin domains are typically
silenced due to an altered accessibility to transcription factors. Heterochromatin domains
and gene silencing are set up in early development and were initially believed to be
maintained for the remainder of the lifespan. Recent data suggest that there may be a net
loss of heterochromatin with advancing age in both yeast and mice. The gradual loss of …