First published online June 22, 2006
Development 133, 1403e (2006)
© The Company of Biologists Limited
Vasculogenesis and haematopoiesis: an early separation
It is widely thought that haemangioblasts are precursors for both blood
cells and vascular endothelial cells. However, haematopoiesis and angiogenesis
have not been analysed in detail in mouse embryos before embryonic day (E) 7.0
when haemangioblasts appear. Furuta and co-workers now report that the
angioblast lineage diverges from mesoderm before, and independently of,
haemangioblast formation (see
p. 2771). Using
in-vitro culture to evaluate vasculogenesis and haematopoiesis in cells taken
from early mouse embryos, the researchers show that endothelial progenitors
are present by E5.50 but stroma-dependent haematopoietic progenitors are not
seen until E6.75; colony-forming units (the precursors of macrophages,
erythrocytes and megakaryocytes) appear at E7.50. At this time, vasculogenic
and haematopoietic precursors both express the transcription factor Oct3/4,
which maintains the pluripotency of embryonic stem cells, but expression of
CD31 (platelet endothelial cell adhesion molecule 1) divides them into
angioblast (Oct3/4+, CD31-) and haemangioblast (Oct3/4+,
CD31+) lineages. Thus, the authors conclude, there are distinct
pathways for vasculogenesis and haematopoiesis that are independent of
haemangioblasts.
Related articles in Development:
- Discordant developmental waves of angioblasts and hemangioblasts in the early gastrulating mouse embryo
- Chie Furuta, Hideo Ema, Shin-ichiro Takayanagi, Takunori Ogaeri, Daiji Okamura, Yasuhisa Matsui, and Hiromitsu Nakauchi
Development 2006 133: 2771-2779.
[Abstract]
[Full Text]
