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リエゾンラボ研究会
発表内容

Title:
Development of the hematopoietic system

Toshiyuki Yamane
Associate Professor
Mie University Graduate School of Medicine

Abstract:
Hematopoietic cells are produced in mesoderm-derived tissues during the early stages of embryonic development. The first blood cells to appear during ontogeny are primitive erythrocytes. Primitive erythropoiesis is a transient wave of hematopoiesis that occurs in a lineage-restricted manner. Primitive erythropoiesis is followed by multilineage hematopoiesis, which produces the entire repertoire of myeloid and lymphoid lineages. The authentic hematopoietic stem cells that can repopulate the body over a long period of time appear after the first lymphomyeloid progenitors are noted. However, the lineage relationship of cells that comprise embryonic hematopoietic system is not well characterized. To attain a better understanding of the process, we fractionated the mesodermal cell populations based on cell-surface marker expression and carefully analyzed the cell-intrinsic differentiation potentials of isolated cells using in vitrocultures of mouse embryonic cells and ES cells. Through the analysis, we identified the bipotential cell stage for primitive erythrocytes and multipotent hematopoietic progenitors, which were previously thought to be separate cell lineages. I will discuss the implications of our findings to the current understanding of the embryonic hematopoietic system.

References:
Yamane, T., Washino, A., and Yamazaki, H. (2013) Common Developmental Pathway for Primitive Erythrocytes and Multipotent Hematopoietic Progenitors in Early Mouse Development. Stem Cell Reports 1: 590-603.

Yamane, T., Hosen, N., Yamazaki, H., and Weissman, I. L. (2009) Expression of AA4.1 marks lymphohematopoietic progenitors in early mouse development. Proc Natl Acad Sci USA 106: 8953-8958.