HemAtlas
Mapping developmental hematopoiesis across stages, species and models

AGM (aorta-gonad-mesonephros) region is an evolutionarily-conserved hematopoietic site for definitive hematopoietic stem and progenitor cell (HSPC) generation. A specialized population of endothelial cells (ECs) in the ventral wall of dorsa aorta acquire hematopoietic fate to specify into hemogenic endothelial cells (HECs), and then produce HSPCs via endothelial-to-hematopoietic transition. AGM region also consists of perivascular cells, mesenchymal cells, and other niche cells.

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.

Hemogenic endothelial cells (HECs) or hematopoietic progenitor cells (HPCs) are derived from human induced pluripotent stem cells/embryonic stem cells via embryoid body (EB)-based direct differentiation. The HECs transfected with transcription factor cocktail are capable of giving rise to hematopoietic stem cells (HSCs) with multilineage reconstitution ability. The HPCs with Ezh1 knockdown are capable of giving rise to hematopoietic stem cells (HSCs) with multilineage reconstitution ability.

Mouse and human non-hemogenic endothelial cells transfected with transcription factor cocktail are cultured on human umbilical vein endothelial cells with E4ORF1 overexpression, and then capable of generating hematopoietic stem cells (HSCs) with multilineage reconstitution ability.

AGM (aorta-gonad-mesonephros) region is an evolutionarily-conserved hematopoietic site for definitive hematopoietic stem and progenitor cell (HSPC) generation. A specialized population of endothelial cells (ECs) in the ventral wall of dorsa aorta acquire hematopoietic fate to specify into hemogenic endothelial cells (HECs), and then produce HSPCs via endothelial-to-hematopoietic transition. AGM region also consists of perivascular cells, mesenchymal cells, and other niche cells.

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.

AGM (aorta-gonad-mesonephros) region is an evolutionarily-conserved hematopoietic site for definitive hematopoietic stem and progenitor cell (HSPC) generation. A specialized population of endothelial cells (ECs) in the ventral wall of dorsa aorta acquire hematopoietic fate to specify into hemogenic endothelial cells (HECs), and then produce HSPCs via endothelial-to-hematopoietic transition. AGM region also consists of perivascular cells, mesenchymal cells, and other niche cells.

CHT (caudal hematopoietic tissue) is a transient hematopoietic site for HSPC expansion and differentiation in zebrafish embryos. Nascent HSPCs are transferred to the CHT via blood circulation and guided into a specialized vascular niche by macrophages. The specialized vascular niche is constituted by vascular endothelial cells and stromal cells, and enriched with cytokines, chemokines, and growth factors.

KM (kidney marrow) is a hematopoietic site for adult HSPC maintenance in zebrafish. The cell components of kidney marrow include hematopoietic cells, endothelial cells, renal tubular cells, nephron epithelial cells, mucin secreting cells, multi-ciliated cells, and kidney progenitor cells. HSPCs are maintained in a highly vascularized niche and are protected from irradiation by a layer of melanocytes. In the kidney, HSPCs self-renew and differentiate into multilineage hematopoietic cells for the lifetime of the animal.