Time course of CFUs and stromal cells' phenotype with gestational maturation of murine and human livers.

(A) Colony-forming cells (assayed in methylcellulose). Results represent the mean ± sem of data from 3 experiments for mouse CFUs and 1 experiment for human CFUs. (B) Immunofluorescence studies (performed after 10 days' culture onto chamber slides, as described in Figure 1). In the mouse at 14.5 dpc, almost all cells are double-labeled with anti–CK-8 (green) and anti-ASMA (yellow, because of the intensity of the labeling). At 18.5 dpc, there is a focus of ASMA⁺, CK-8⁻ myofibroblasts surrounded by ASMA⁻, CK-8⁺ hepatocytes. For human cells at 14 gw, all cells are double-labeled with anti–CK-8 (green) and anti-ASMA (red). At 28 gw, ASMA⁻, CK-8⁺hepatocyte is surrounded by ASMA⁺, CK-8⁻myofibroblasts. Scale bar = 10 μm. Liver cells were cultured for 10 days in long-term culture medium and then collected for CFU and immunofluorescence studies.