Ventral and Dorsal Contributions to Hematopoiesis in Xenopus -- Genetic Dissection of Hematopoiesis Using the Zebrafish -- Extra- and Intraembryonic HSC Commitment in the Avian Model -- Avian Lymphopoiesis and Transcriptional Control of Hematopoietic Stem Cell Differentiation -- Yolk Sac Development in Mice -- Long-Term Reconstituting Hematopoietic Stem Cell Capacity in the Embryo -- The Endothelium: The Cradle of Definitive Hematopoiesis? -- Endothelial and Hematopoietic Cells in the Intraembryonic Compartment -- Origin and Fate of Hematopoietic Precursors in the Early Mouse Embryo -- Hematopoietic Development in Drosophila: A Parallel with Vertebrates -- Intraembryonic Development of Hematopoietic Stem Cells during Human Ontogeny: Expression Analysis -- Gene and Cell Therapy Involving Hematopoietic Stem Cell.