Higher-order orchestration of hematopoiesis: Is cohesin a new player?

Hematopoiesis the process that generates distinct lineage-committed blood cells from a single multipotent hematopoietic stem cell is a complex process of cellular differentiation regulated by a set of dynamic transcriptional programs. Cytokines and growth factors, transcription factors, chromatin remodeling, and modifying enzymes have been suggested to enact critical roles during hematopoiesis, leading to the development of myeloid, lymphoid, erythroid and platelet precursors. How is such a complex process orchestrated? Is there a higher order of hematopoiesis regulation? These are some of the unresolved questions in the field of henuitopoiesis. Here, we suggest that cohesin, which is known to mediate chromosomal cohesion between sister chromatids, may have a central role in the orchestration of hematopoiesis and serve as a master transcriptional regulator. (C) 2012 ISEH - Society for Hematology and Stein Cells. Published by Elsevier Inc.