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ZFIN ID: ZDB-PUB-180823-4
Anisotropic organization of circumferential actomyosin characterizes hematopoietic stem cells emergence in the zebrafish
Lancino, M., Majello, S., Herbert, S., De Chaumont, F., Tinevez, J.Y., Olivo-Marin, J.C., Herbomel, P., Schmidt, A.
Date: 2018
Source: eLIFE   7: (Journal)
Registered Authors: Herbomel, Philippe, Lancino, Mylène, Majello, Sara, Schmidt, Anne
Keywords: actomyosin, blood flow, cell biology, cell extrusion, developmental biology, hematopoiesis, junctions, stem cells, zebrafish
MeSH Terms:
  • Actin Cytoskeleton/metabolism
  • Actins/metabolism
  • Actomyosin/metabolism*
  • Amino Acid Sequence
  • Animals
  • Anisotropy
  • Biomechanical Phenomena
  • Endothelial Cells/cytology
  • Endothelial Cells/metabolism
  • Hematopoiesis
  • Hematopoietic Stem Cells/cytology
  • Hematopoietic Stem Cells/metabolism*
  • Hemodynamics
  • Intercellular Junctions/metabolism
  • Models, Biological
  • Mutation/genetics
  • Myosin Light Chains/metabolism
  • Phenotype
  • Phosphorylation
  • Time Factors
  • Zebrafish/metabolism*
PubMed: 30132756 Full text @ Elife
Hematopoiesis leads to the formation of blood and immune cells. Hematopoietic stem cells emerge during development, from vascular components, via a process called the endothelial-to-hematopoietic transition (EHT). Here, we reveal essential biomechanical features of the EHT, using the zebrafish embryo imaged at unprecedented spatio-temporal resolution and an algorithm to unwrap the aorta into 2D-cartography. We show that the transition involves anisotropic contraction along the antero-posterior axis, with heterogenous organization of contractile circumferential actomyosin. The biomechanics of the contraction is oscillatory, with unusually long periods in comparison to other apical constriction mechanisms described so far in morphogenesis, and is supported by the anisotropic reinforcement of junctional contacts. Finally, we show that abrogation of blood flow impairs the actin cytoskeleton, the morphodynamics of EHT cells, and the orientation of the emergence. Overall, our results underline the peculiarities of the EHT biomechanics and the influence of the mechanical forces exerted by blood flow.