HemAtlas
Mapping developmental hematopoiesis across stages, species and models

Placenta is an extra-embryonic hematopoietic organ for HSPC development in eutherian mammals. The cell components of placenta include endothelial cells, stromal cells, trophoblast cells, and primitive endodermal cells. The HSPC activity is detected in the vasculature niche after E10 in mouse placenta or 6 weeks in human placenta.

FL (fetal liver) is a transient hematopoietic organ for HSPC maturation, expansion, and differentiation in mammalian embryos. Nascent HSPCs reside in the fetal liver functional units, which are constituted by vascular endothelial cells, stromal cells, hepatoblasts, and macrophages and enriched with cytokines, chemokines, and growth factors.

BM (bone marrow) is a hematopoietic site for adult HSPC maintenance in mammals. The cell components of bone marrow include endothelial cells, mesenchymal stromal cells, osteoblasts, osteoclasts, hematopoietic cells, and neurons. HSPCs locate at the perivascular niche, which is near trabecular bone and constituted by mesenchymal stromal cells and endothelial cells. In the bone marrow, HSPCs self-renew and differentiate into multilineage hematopoietic cells for the lifetime of the animal.