Immunospecificity of nonhistone chromatin proteins tightly bound to DNA from chicken thrombocytes and erythrocytes

Erythroid cell-specific antisera capable of detecting tightly bound nonhistone chromatin protein--DNA complexes were obtained by injecting rabbits with dehistonized chicken reticulocyte chromatin. The antisera showed no crossreactivity with chromatin of thrombocytes which are regarded as cells genealogically closely related with erythrocytes. The lack of thrombocyte chromatin immunoactivity was not caused by conformational constrains. Tightly bound nonhistone protein--DNA complexes isolated from thrombocyte chromatin showed no immunological similarity with these of erythrocyte chromatin.