[Effect of rabbit serum against mouse brain on bone marrow cells forming granulocyte-macrophage colonies in in vitro and in vivo agar cultures].

Pretreatment of mouse bone marrow cells with rabbit antiserum to mouse brain (RAMB) decreases the capacity of these cells to form granulocyte-macrophage colonies in agar culture in vivo (CFU-DC) and does not affect the formation of colonies in agar culture in vitro (CFU-C). Mouse bone marrow CFU-DC are analogous to the pluripotent hemopoietic stem cells (CFU-C) forming spleen colonies in lethally irradiated mice as regards the ability for being inactivated with RAMB but differ from CFU-C. CFU-DC were found in the mouse thymocyte population.