Abstract
His-tones extracted with acid from duck, goose, turkey, pigeon, and gull erythrocyte nuclei contained a major component, electrophoretically homologous with the serine-rich histone of chicken erythrocytes. This characteristic component was lacking or adventitous in duck, goose, and turkey spleens and marrows (as well as chicken tissues), but prominent in erythrocytes from birds under various physiological conditions, in reticulocytes as well as mature erythrocytes, and in nuclei prepared under various circumstances of cytolysis. Other electrophoretic components of erythrocytes and tissues, some apparently tissue-specific, were more variable in occurrence. Electrophoretic zones corresponding to arginine-rich histones, which had previously been considered as specifically absent from chicken erythrocytes, were in fact especially refractory to acid extraction from red cell nuclei. Furthermore, variability in electrophoretic pattern of these zones was attributed in part to conformational changes, which were sensitive to B-mercaptoethanol and to urea.