Haematopoietic defects of W/WV mice studied with the spleen colony, agar colony, and diffusion chamber techniques.

Bone marrow progenitor cells from anaemic W/WV mice were compared with normal +/+ cells utilizing the spleen colony, the agar colony and the diffusion chamber techniques. Spleen colony formation from W/WV cells was markedly defective, and more so for erythroid than for granuloid colonies. The progenitor cell concentration was apparently normal as measured by the two other techniques. The concentration of circulating progenitor cells also seemed to be normal. On the other hand, the cell formation per progenitor cell was subnormal in all three assay systems. The initial proliferative response of W/WV spleen colony-formers and agar colony-formers to short-term diffusion chamber culturing was apparently normal. The incorporation of 3H-thymidine, related to the number of proliferative granulocytes present in the chambers, also seemed to be normal. The results indicate that the W/WV defect is not limited to the multipotent stem cells. A possible interpretation is that it is the capacity for continued self-renewal of immature cells that is defective.