December 1 2018
Nagai H, Shin M, Weng W, Nakazawa F, Jakt LM, Alev C, Sheng G.
Int J Dev Biol. 2018;62(1-2-3):137-144. doi: 10.1387/ijdb.170291gs.
In simple language:
Step-wise lineage segregation of ventral mesoderm cells towards the smooth muscle, blood and endothelial fates takes place during primitive hemopoiesis, the first wave of blood cell generation in embryonic development. Coelomic epithelium is an evolutionally important element that gives rise to both vertebrate and invertebrate blood/vascular system. Hiroki Nagai, a research specialist in Prof. Guojun Sheng's lab at IRCMS, uses the chicken model as an example and offers a comprehensive overview of hematopoietic and vascular development in vertebrate animals.
The field of hematopoietic and vascular developmental research owes its origin to the chick embryo. Many key concepts, such as the hematopoietic stem cell, hemangioblast and hemogenic endothelium, were first proposed in this model organism. Genetically tractable models have gradually replaced the chick in the past two decades. However, advances in comparative genomics, transcriptomics and promoteromics promise a re-emergence of the chick embryo as a powerful model for hematopoietic/vascular research. This review summarizes the current status of our understanding of early blood/vascular development in the chick, focusing primarily on the processes of primitive hematopoiesis and early vascular network formation in the extraembryonic and lateral plate mesoderm territories. Emphasis is given to ontological and molecular association between the blood and endothelial cells and to the evolutionary relationship between the hemangioblasts, common precursors for the blood and endothelial lineages, and the coelomic epithelial lining cells. Links between early blood/vascular development and later definitive hematopoiesis are also discussed. Finally, potential applications of the chick model for comparative and omics-level studies of the blood/vascular system are highlighted.