Heterochromatin and euchromatin. Nucleosomes in heterochromatin are tightly packed together, and the DNA is transcriptionally silent. Nucleosomes in euchromatin are spaced farther apart, and the DNA can be decondensed by the loss of histone H1, thus becoming accessible to the transcription machinery. The two chromatin states are regulated by histone modifications (represented by red asterisks) and the binding of other factors (see Chapter 10).