Hemangioblast: an in vitro phantom
1Stem Cell Research Group, Riken Center for Developmental Biology, Kobe, Japan. nishikawa@cdb.riken.jp
The hemangioblast, a bipotent progenitor that generates both endothelial cells (EC) and blood cells (BC) in the blood islands (BI) of the yolk sac (YS) has been a core notion of developmental hematology since the early 20th century. However, its actual presence has not been directly addressed for long. At the very end of the 20th century, the hemangioblast was revisited as a result of the development of new technologies that enable detection of such bipotent precursors in vitro. Such studies provided evidence for the presence of bipotent precursors for EC and BC. On the other hand, subsequent studies analyzing the processes occurring within BI strongly argued against the notion of hemanigioblasts and suggest that the hemangioblast is an in vitro artefact. In this article, I overview the history of the study of the hemangioblast and try to explain why hemangioblast that can be defined in vitro cannot be detected in BI.
The hemangioblast, a bipotent progenitor that generates both endothelial cells (EC) and blood cells (BC) in the blood islands (BI) of the yolk sac (YS) has been a core notion of developmental hematology since the early 20th century. However, its actual presence has not been directly addressed for long. At the very end of the 20th century, the hemangioblast was revisited as a result of the development of new technologies that enable detection of such bipotent precursors in vitro. Such studies provided evidence for the presence of bipotent precursors for EC and BC. On the other hand, subsequent studies analyzing the processes occurring within BI strongly argued against the notion of hemanigioblasts and suggest that the hemangioblast is an in vitro artefact. In this article, I overview the history of the study of the hemangioblast and try to explain why hemangioblast that can be defined in vitro cannot be detected in BI.
