Figure 1.

Histone availability as a strategy to control gene expression. Induced depletion of canonical histones leads to DNA damage and chromosomal alterations and also to changes in transcription and RNA processing. Many of these changes recapitulate those observed in the senescence and aging process, which are associated to histone depletion. This observation leads to the hypothesis that senescence and aging and maybe other processes such as dedifferentiation and cancer are, to some extend, a consequence of a programmed reduction in the levels of canonical histones.