Leonard I. Zon300 Longwood Ave
Our laboratory focuses on the developmental biology of hematopoiesis. Hematopoietic stem cells are derived early in vertebrate embryogenesis, during gastrula stages. The mammalian embryo is difficult to evaluate at this particular time due to its development in utero. We have used the zebrafish, which is externally fertilized, as an alternative model system to study embryonic hematopoiesis. The zebrafish embryo is completely clear, and all organs can be visualized, including circulating blood. In addition, a large number of animals can be kept in a relatively small space, and each mother lays 200300 eggs weekly. These qualities enable a forward genetic approach to vertebrate blood formation. Our studies demonstrate that the zebrafish can provide information about the hematopoietic program that is relevant to vertebrate biology and to clinical disorders of blood formation.