Histone H1(0): a maintainer of the differentiated cell state?

Functional and structural effects of histones H1 and H1(0) were studied on isolated chromatin and nuclei from embryonic skeletal muscle as well as on cultured cells. The results showed that: H1 was responsible for a greater compaction of chromatin than H1(0) as evidenced by sedimentation. In contrast, H1(0) inhibited DNA synthesis in chromatin and cells to a greater extent than H1. No significant difference between the two histones on RNA synthesis inhibition was observed. histones H1 and H1(0) evidenced a quantitative increase in developing muscle cells. The results indicate that H1(0) may not be the inducer of the differentiated cell state, but rather assists in the maintenance of that state.