Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Review
. 2014 Jan 28:5:3.
doi: 10.3389/fphys.2014.00003. eCollection 2014.

Primitive and definitive erythropoiesis in mammals

James Palis  1
Affiliations
Review

Primitive and definitive erythropoiesis in mammals

James Palis. Front Physiol. .

Abstract

Red blood cells (RBCs), which constitute the most abundant cell type in the body, come in two distinct flavors- primitive and definitive. Definitive RBCs in mammals circulate as smaller, anucleate cells during fetal and postnatal life, while primitive RBCs circulate transiently in the early embryo as large, nucleated cells before ultimately enucleating. Both cell types are formed from lineage-committed progenitors that generate a series of morphologically identifiable precursors that enucleate to form mature RBCs. While definitive erythroid precursors mature extravascularly in the fetal liver and postnatal marrow in association with macrophage cells, primitive erythroid precursors mature as a semi-synchronous cohort in the embryonic bloodstream. While the cytoskeletal network is critical for the maintenance of cell shape and the deformability of definitive RBCs, little is known about the components and function of the cytoskeleton in primitive erythroblasts. Erythropoietin (EPO) is a critical regulator of late-stage definitive, but not primitive, erythroid progenitor survival. However, recent studies indicate that EPO regulates multiple aspects of terminal maturation of primitive murine and human erythroid precursors, including cell survival, proliferation, and the rate of terminal maturation. Primitive and definitive erythropoiesis share central transcriptional regulators, including Gata1 and Klf1, but are also characterized by the differential expression and function of other regulators, including myb, Sox6, and Bcl11A. Flow cytometry-based methodologies, developed to purify murine and human stage-specific erythroid precursors, have enabled comparative global gene expression studies and are providing new insights into the biology of erythroid maturation.

Keywords: cytoskeleton; definitive erythropoiesis; globin; primitive erythropoiesis; yolk sac.

PubMed Disclaimer

Figures

Figure 1
Figure 1
Overview of primitive and definitive erythropoiesis. Both forms of erythroid cell production are characterized by the progressive movement of cells through three compartments: progenitors, erythroblast precursors, and red blood cells (RBCs). Erythroid progenitors (BFU-E, CFU-E, and EryP-CFC) are defined by their capacity to form colonies of maturing erythroid cells in vitro. Erythroid precursors are defined morphologically as proerythroblasts (ProE), basophilic erythroblasts (Baso), polychromatophilic erythroblasts (PolyE), and orthochromatic erythroblasts (OrthoE). OrthoE enucleate to form a pyrenocyte, that contains the condensed nucleus, and a reticulocyte (Retic), that goes on to mature into a RBC. Definitive erythropoiesis in the adult organism is derived from hematopoietic stem cells (HSC), while primitive erythropoiesis occurs just once from mesoderm cells in the early embryo.
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

References

    1. Basu P., Lung T. K., Lemsaddek W., Sargent T. G., Williams D. C., Jr., Basu M., et al. (2007). EKLF and KLF2 have compensatory roles in embryonic beta-globin gene expression and primitive erythropoiesis. Blood 110, 3417–3425 10.1182/blood-2006-11-057307 - DOI - PMC - PubMed
    1. Bateman A. E., Cole R. J. (1971). Stimulation of haem synthesis by erythropoietin in mouse yolk-sac-stage embryonic cells. J. Embryol. Exp. Morphol. 26, 475–480 - PubMed
    1. Bennett G. D., Kay M. M. (1981). Homeostatic removal of senescent murine erythrocytes by splenic macrophages. Exp. Hematol. 9, 297–307 - PubMed
    1. Bethlenfalvay N. C., Block M. (1970). Fetal erythropoiesis. Maturation in megaloblastic (yolk sac) erythropoiesis in the c57bl/6j mouse. Acta Haematol. 44, 240–245 10.1159/000208685 - DOI - PubMed
    1. Blazsek I., Chagraoui J., Peault B. M. (2000). Ontogenic emergence of the hematon, a morphogenic stromal unit that supports multipotential hematopoietic progenitors in mouse bone marrow. Blood 96, 3763–3771 - PubMed