When the chromatin decondenses, the DNA is open to entry of molecular machinery. Fluctuations between open and closed chromatin may contribute to the discontinuity of transcription, or transcriptional bursting. Other factors are probably involved, such as the association and dissociation of transcription factor complexes with chromatin. Specifically, RNA polymerase and transcriptional proteins have been shown to congregate into droplets via phase separation, and recent studies have suggested that 10 nm chromatin demonstrates liquid-like behavior increasing the targetability of genomic DNA.Maeshima, K., Ide, S., Hibino, K., & Sasai, M. (2016). Liquid-like behavior of chromatin. Current opinion in genetics & development, 37, 36–45. https://doi.org/10.1016/j.gde.2015.11.006 The interactions between linker histones and disordered tail regions act as an electrostatic glue organizing large-scale chromatin into a dynamic, liquid-like domain. Decreased chromatin compaction comes with increased chromatin mobility and easier transcriptional access to DNA. The phenomenon, as opposed to simple probabilistic models of transcription, can account for the high variability in gene expression occurring between cells in isogenic populations.
When the chromatin decondenses, the DNA is open to entry of molecular machinery Fluctuations between open and closed chromatin may contribute to the discontinuity of transcription, or transcriptional bursting. Other factors are probably involved, such as the association and dissociation of transcription factor complexes with chromatin. Specifically, RNA polymerase and transcriptional proteins have been shown to congregate into droplets via phase separation, and recent studies have suggested that 10 nm chromatin demonstrates liquid-like behavior increasing the targetability of genomic DNA.Maeshima, K., Ide, S., Hibino, K., & Sasai, M. (2016). Liquid-like behavior of chromatin. Current opinion in genetics & development, 37, 36–45. https://doi.org/10.1016/j.gde.2015.11.006 The interactions between linker histones and disordered tail regions act as an electrostatic glue organizing large-scale chromatin into a dynamic, liquid-like domain. Decreased chromatin compaction comes with increased chromatin mobility and easier transcriptional access to DNA. The phenomenon, as opposed to simple probabilistic models of transcription, can account for the high variability in gene expression occurring between cells in isogenic populations.