| Abstract: | In spite of the presence of nucleus, genetic activity and mitosis are totally depressed in avian erythrocytes. If phosphorylation of histone is involved in such genetic depression, a comparative study of phosphorylation of avian erythrocyte histone can be expected to furnish information about the mechanism of gene control. The present study is the examination of susceptibility of chicken erythrocyte histone to histologically different (liver and muscle) and phylogenically different (avian, mammalian and ichthic) protein kinases. It was found that chicken erythrocyte F1 histone was phosphorylated not only by heterologous (rat and trout liver) but also by homologous (chicken liver and muscle) protein kinases. Addition of cAMP could not elicit phosphorylation of this histone, while phosphorylation of other histones was significantly enhanced by this drug. Avian erythrocyte-specific histone, F2c, was markedly phosphorylated not only by avian enzymes but also by mammalian enzyme. All the enzymes tested phosphorylated F2b histone. F3 histone was phosphorylated at least by avian and mammalian enzymes. F2a1 and F2a2 histones were poor substrate to all the enzymes tested. |
