| Abstract: | Cultured quail myoblasts were labelled with 32Pi and nuclear proteins extracted before and after myoblast fusion. Histones H1, H4 and the H1-H2B-H2A complex were all phosphorylated in proliferating prefusion cultures, while histone phosphorylation was absent in B1-arrested postfusion cultures except for minor phosphorylation of the H3-H2B-H2A complex. Postfused cultures were distinguished by the appearance of the histone-like protein whch migrated slightly faster than H1. Histone phosphorylation is therefore correlated with cell proliferation, while the appearance of the new histone-like protein is associated with G1 arrest and the absence of cell division. |
