Figure 5

Bone marrow progenitors give rise to macrophages in the embryo and in adult birds. Bone marrow cells from newly hatched EGFP⁺ donors were injected into the yolk sac circulation of HH16 non-transgenic recipients as described in Methods. (A) Images are representative whole mounts taken under UV illumination at different times and locations during subsequent development, and in different recipients, to provide an indication of the ability of the transplanted cells to populate all locations in the embryo: (i) whole embryo-E4; (ii) brain cross-section-E5; (iii) hindlimb-E7; (iv) hindlimb digits-E10; (v) chorioallantoic membrane-E12; (vi) spleen-E13; (vii) femur cross section-E13; (viii) intestine-E14. (B) Images are representative whole-mount images of the spleen, liver, bursa of Fabricius, thymus, brain and skin of representative wild-type and EGFP-bone marrow chimeras at day 0, day 5 and 6 weeks of age as indicated. Scale bars = 200 μm.