In vitro transcription of partially deproteinised and reconstituted chromatins from pigeon erythroid cells.

The role of protein fractions extracted from chromatin preparations with NaCl concentrations up to 0.7 M in the additional repression of pigeon erythrocyte genome was investigated. The chromatins from erythroblasts and erythrocytes were dissociated with 0.7 M NaCl and reconstituted from dissociated components to obtain the "original" and "hybrid" chromatins. The protein fraction extracted from erythrocyte chromatin at 0.7 M NaCl was more efficient in the restriction of transcription with partially deproteinised chromatin from both erythroblasts and erythrocytes. The partially deproteinised chromatin from both erythorblasts and erythrocytes. The partially deproteinised chromatins were also complexed in various conditions with purified F1 or F2c histones. In such complexes, F2c histone was a stronger inhibitor of template activity than histone F1.