Murine yolk sac hematopoiesis studied with the diffusion chamber technique.

The proliferation and differentiation of visceral and of parietal yolk sac cells from 9-day-old mouse embryos were studied in diffusion chambers (DC). After culture, the visceral yolk sac yielded predominantly macrophages whereas the parietal yolk sac displayed mainly plasmocyte-like cells. It is shown the latter do not synthesize immunoglobulin but rather elaborate Reichert's membrane. Neither visceral nor parietal yolk sac contained detectable pluripotent stem cells (CFUs) prior to or after DC culture, a finding which is discussed in the light of the current literature.