Migration of zebrafish primordial germ cells: a role for myosin contraction and cytoplasmic flow.
The molecular and cellular mechanisms governing cell motility and directed migration in response to the chemokine SDF-1 are largely unknown. Here, we demonstrate that zebrafish primordial germ cells whose migration is guided by SDF-1 generate bleb-like protrusions that are powered by cytoplasmic flow. Protrusions are formed at sites of higher levels of free calcium where activation of myosin contraction occurs. Separation of the acto-myosin cortex from the plasma membrane at these sites is followed by a flow of cytoplasm into the forming bleb. We propose that polarized activation of the receptor CXCR4 leads to a rise in free calcium that in turn activates myosin contraction in the part of the cell responding to higher levels of the ligand SDF-1. The biased formation of new protrusions in a particular region of the cell in response to SDF-1 defines the leading edge and the direction of cell migration.
Blaser
Heiko
H
Germ Cell Development, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany.
Reichman-Fried
Michal
M
Castanon
Irinka
I
Dumstrei
Karin
K
Marlow
Florence L
FL
Kawakami
Koichi
K
Solnica-Krezel
Lilianna
L
Heisenberg
Carl-Philipp
CP
Raz
Erez
E
D000199:Actins / Q000502:physiology; D000818:Animals; D002462:Cell Membrane / Q000502:physiology; D016764:Cell Polarity; D054377:Chemokine CXCL12; D019743:Chemokines, CXC / Q000502:physiology; D002633:Chemotaxis; D003593:Cytoplasm / Q000502:physiology*; D003599:Cytoskeleton / Q000502:physiology; D005854:Germ Cells / Q000502:physiology*; D009218:Myosins / Q000502:physiology*; D011554:Pseudopodia / Q000502:physiology; D019718:Receptors, CXCR4 / Q000502:physiology; D015027:Zebrafish / Q000196:embryology / Q000502:physiology*; D029961:Zebrafish Proteins / Q000502:physiology*
D000199:Actins; D054377:Chemokine CXCL12; D019743:Chemokines, CXC; D019718:Receptors, CXCR4; D029961:Zebrafish Proteins; D009218:Myosins