Table 1.

Primitive versus definitive hematopoiesis in the mouse model

	Primitive lineage	Transient-definitive lineage	Definitive lineage	References
Erythrocytes	Nucleated when released in blood flow, before enucleation. Diameter: 12mm Embryonic hemoglobins (βH1, ε, ζ)	Enucleation before release into circulation Diameter: 10mm Fetal hemoglobins (βH1 and β1-adult)	Enucleation before release into circulation Diameter: 8mm Adult hemoglobin (β-major)	Craig and Russel [31]; Wong et al. [32]; McGrath et al. [22]; Kingsley et al. [34], McGrath et al. [48] )
Megakaryocytes	Average size: 9 um Polyploidy < 4N	No information	Average size: 20 um Polyploidy > 16N	Tober et al. [37]; Xu et al. [38]
Macrophages	Maternal-derived macrophages: Not produced by the YS. Initially described as primitive macrophages by-passing the monocytic stage			Takahashi et al. [43]; Naito et al. [42]; Naito et al. [41]; Bertrand et al. [30]
	YS-derived macrophages: CD45+ Mac1+ CSF1R+ CX3CR1+ F4/80+ Derive from a monopotent (Mϕ-restricted) progenitors, through a monocytic stage Proliferative capacity Colonize all embryonic tissues	EMP-derived macrophages: CD45+ Mac1+ CSF1R+ CX3CR1+ F4/80+ Produced in the fetal liver environment	BM-derived macrophages: CD45+ Mac1+, CSF1R+ CX3CR1+ F4/80+ Derive from a Common Myeloid Progenitor, through a monocytic stage No proliferative capacity Colonize tissues upon inlfammation	Palis et al. [44]; Bertrand et al. [29]; Bertrand et al. [30]; Ovchinnikov [66]