Observations sur la différenciation in vitro descellules myéloïdes d’embryons de poulet

Observations on the differentiation in vitro of erythropoietic cellsof the chick embryo Erythrocytes differentiated fromexplantsof bone marrow cultured in association with embryonic chick liver by the technique of Wolff & Haffen show certain morphological and biochemical differences from those found in peripheral blood or normal bone marrow. The mean values of cell size and N/P ratio of the erythrocytes from explants are different from those of controls of corresponding age. The globin and haem content of erythrocytes fromexplantsis less than that of controls. The presence of small quantities of RNA in the cytoplasm of expiant erythrocytes is probably related to a retarded maturation process. Haemoglobin synthesised in vitro shows the same electrophoretic behaviour as that of in vivo controls.