title: Both contractile axial and lateral traction force dynamics drive amoeboid cell motility.
abstract: Chemotaxing Dictyostelium discoideum cells adapt their morphology and migration speed in response to intrinsic and extrinsic cues. Using Fourier traction force microscopy, we measured the spatiotemporal evolution of shape and traction stresses and constructed traction tension kymographs to analyze cell motility as a function of the dynamics of the cell's mechanically active traction adhesions. We show that wild-type cells migrate in a step-wise fashion, mainly forming stationary traction adhesions along their anterior-posterior axes and exerting strong contractile axial forces. We demonstrate that lateral forces are also important for motility, especially for migration on highly adhesive substrates. Analysis of two mutant strains lacking distinct actin cross-linkers (mhcA(-) and abp120(-) cells) on normal and highly adhesive substrates supports a key role for lateral contractions in amoeboid cell motility, whereas the differences in their traction adhesion dynamics suggest that these two strains use distinct mechanisms to achieve migration. Finally, we provide evidence that the above patterns of migration may be conserved in mammalian amoeboid cells.
authors.affiliation: Department of Mechanical and Aerospace Engineering and 2 Department of Bioengineering, Jacobs School of Engineering; 3 Section of Cell and Developmental Biology, Division of Biological Sciences; and 4 Institute for Engineering in Medicine, University of California, San Diego, La Jolla, CA 92093.
authors.forename: Effie
authors.initials: E
authors.lastname: Bastounis
authors.forename: Ruedi
authors.initials: R
authors.lastname: Meili
authors.forename: Begoña
authors.initials: B
authors.lastname: Álvarez-González
authors.forename: Joshua
authors.initials: J
authors.lastname: Francois
authors.forename: Juan C
authors.initials: JC
authors.lastname: del Álamo
authors.forename: Richard A
authors.initials: RA
authors.lastname: Firtel
authors.forename: Juan C
authors.initials: JC
authors.lastname: Lasheras
mesh_terms: D001696:Biomechanical Phenomena; D002448:Cell Adhesion; D048430:Cell Shape; D002633:Chemotaxis; D004023:Dictyostelium / Q000166:cytology / Q000502:physiology*; D018922:HL-60 Cells; D006801:Humans; D007700:Kinetics; D008856:Microscopy, Fluorescence; D008954:Models, Biological; D059008:Time-Lapse Imaging