were composed of neutrophils, monocytes/macrophages and eosinophils,
and although megakaryocyte-like cells were not observed, both
megakaryocyte markers (CD41 and GATA1) and hematopoietic
stem/progenitor cell markers (CD34 and GATA2) were detected.
Since megakaryocyte progenitor cells express GATA2 and CD34 in
mice and humans, respectively [20,21], it is possible that Type
2 colonies contained megakaryocyte progenitor cells as these are
difficult to identify using morphological characters. Type 3 colonies
were composed of neutrophils, monocytes/macrophages and eosinophils.
Thus, dolphin BMMC had numerous types of hematopoietic
progenitor cells from which new blood cells were produced by
proliferation and differentiation, implying that dolphin BMMCs were
hematopoietic cell populations and the humeral bone marrow is a
hematopoietic organ in dolphins