Figure 6

Flow cytometry analysis of bone marrow chimeras. Bone marrow cells from EGFP⁺ donors were injected into the yolk sac circulation of HH16 non-transgenic recipients as described in Methods. Dissociated bone marrow from 6-week-old chimeras was analyzed by fluorescence-activated cell sorting. (A) A representative scatter plot of the cells; more complex than mammalian marrow because both red cells and thrombocytes are nucleated. (B) A representative EGFP profile of control and EGFP-chimeric marrow. (C) Percentage chimerism across multiple birds analyzed; the average is 13.72 ± 2.02% (corrected for the small number of autofluorescent cells in control marrow). (D) Bone marrow cells from the newly hatched chimeric birds were cultivated in chicken CSF1 for 7 days to produce BMDM. In these cultures, large clusters of EGFP⁺ cells, approximately consistent with the level of chimerism, were detected. Images are a representative cluster in which all of the cells are EGFP⁺ (the apparent intensity varies within the cells in the cluster, depending upon how spread they are on the substratum).