Potentiality of the murine colony-forming cells detected by an in vivo diffusion chamber culture system

Culture of a mixture of bone marrow cells with and without T6 chromosome marker in diffusion chambers in mice yielded colonies (CFU- DG) containing cells of a single karyotype, suggesting clonality. Injection of individual CFU-DG colonies into lethally irradiated mice resulted in increased spleen colony formation on day 12 (CFU-S). The possibility of endogenous origin was excluded by demonstrating the presence of T6 marker in both CFU-DG and CFU-S colonies in karyotypically normal hosts. These findings suggest that the cells giving rise to granulocytic colonies in diffusion chambers also can give rise to multipotential hemopoietic cells.

Potentiality of the murine colony-forming cells detected by an in vivo diffusion chamber culture system

Culture of a mixture of bone marrow cells with and without T6 chromosome marker in diffusion chambers in mice yielded colonies (CFU- DG) containing cells of a single karyotype, suggesting clonality. Injection of individual CFU-DG colonies into lethally irradiated mice resulted in increased spleen colony formation on day 12 (CFU-S). The possibility of endogenous origin was excluded by demonstrating the presence of T6 marker in both CFU-DG and CFU-S colonies in karyotypically normal hosts. These findings suggest that the cells giving rise to granulocytic colonies in diffusion chambers also can give rise to multipotential hemopoietic cells.

In vivo induction of granulopoiesis in visceral yolksac cells by foetal hepatic factors

In order to evaluate the hypothetical activity of foetal hepatic factors on putative yolk-sac haemopoietic stem cells we used the Double Diffusion Chamber (DDC) technique. The DDC were made of a regulator compartment, where foetal hepatic tissue was introduced and a test compartment where visceral yolk-sac cells were cultured. In this system a hepatic signal induced the yolk-sac stem cells to differentiate along the granulocytic pathway but did not stimulate yolk-sac CFUs growth. Contrary to CFUs originating from foetal liver or adult bone marrow, yolk-sac CFUs do not increase numerically in diffusion chamber culture.