Use of transgenic fluorescent reporter mouse lines to monitor hematopoietic and erythroid development during embryogenesis.

The use of fluorescent reporter proteins such as GFP, RFP, and their variants to tag and track cells within the embryo has revolutionized developmental biology. Expression of these proteins within restricted populations has been achieved through the use of lineage-specific regulatory elements. This approach has proven especially powerful in the hematopoietic system, where it has been possible to monitor the generation, expansion, maturation, and migration of primitive erythroid cells, macrophages, and megakaryocytes during embryogenesis at unprecedented resolution. Such analyses have provided novel insights into the development of these lineages. In this chapter, we discuss the design considerations and methodologies involved in the production and analysis of transgenic mouse lines in which fluorescent reporters are expressed in the hematopoietic system of the mouse embryo.