Determining physical properties of the cell cortex

A. Saha, M. Nishikawa, M. Behrndt, C.-P.J. Heisenberg, F. Julicher, S. Grill, Biophysical Journal 110 (2016) 1421–1429.

Download
OA 1.97 MB

Journal Article | Published | English
Author
; ; ; ; ;
Department
Abstract
Actin and myosin assemble into a thin layer of a highly dynamic network underneath the membrane of eukaryotic cells. This network generates the forces that drive cell- and tissue-scale morphogenetic processes. The effective material properties of this active network determine large-scale deformations and other morphogenetic events. For example, the characteristic time of stress relaxation (the Maxwell time τM) in the actomyosin sets the timescale of large-scale deformation of the cortex. Similarly, the characteristic length of stress propagation (the hydrodynamic length λ) sets the length scale of slow deformations, and a large hydrodynamic length is a prerequisite for long-ranged cortical flows. Here we introduce a method to determine physical parameters of the actomyosin cortical layer in vivo directly from laser ablation experiments. For this we investigate the cortical response to laser ablation in the one-cell-stage Caenorhabditis elegans embryo and in the gastrulating zebrafish embryo. These responses can be interpreted using a coarse-grained physical description of the cortex in terms of a two-dimensional thin film of an active viscoelastic gel. To determine the Maxwell time τM, the hydrodynamic length λ, the ratio of active stress ζΔμ, and per-area friction γ, we evaluated the response to laser ablation in two different ways: by quantifying flow and density fields as a function of space and time, and by determining the time evolution of the shape of the ablated region. Importantly, both methods provide best-fit physical parameters that are in close agreement with each other and that are similar to previous estimates in the two systems. Our method provides an accurate and robust means for measuring physical parameters of the actomyosin cortical layer. It can be useful for investigations of actomyosin mechanics at the cellular-scale, but also for providing insights into the active mechanics processes that govern tissue-scale morphogenesis.
Publishing Year
Date Published
2016-03-29
Journal Title
Biophysical Journal
Acknowledgement
S.W.G. acknowledges support by grant no. 281903 from the European Research Council and by grant No. GR-7271/2-1 from the Deutsche Forschungsgemeinschaft. S.W.G. and C.-P.H. acknowledge support through a grant from the Fonds zur Förderung der Wissenschaftlichen Forschung and the Deutsche Forschungsgemeinschaft (No. I930-B20). We are grateful to Daniel Dickinson for providing the LP133 C. elegans strain. We thank G. Salbreux, V. K. Krishnamurthy, and J. S. Bois for fruitful discussions.
Volume
110
Issue
6
Page
1421 - 1429
IST-REx-ID

Cite this

Saha A, Nishikawa M, Behrndt M, Heisenberg C-PJ, Julicher F, Grill S. Determining physical properties of the cell cortex. Biophysical Journal. 2016;110(6):1421-1429. doi:10.1016/j.bpj.2016.02.013
Saha, A., Nishikawa, M., Behrndt, M., Heisenberg, C.-P. J., Julicher, F., & Grill, S. (2016). Determining physical properties of the cell cortex. Biophysical Journal, 110(6), 1421–1429. https://doi.org/10.1016/j.bpj.2016.02.013
Saha, Arnab, Masatoshi Nishikawa, Martin Behrndt, Carl-Philipp J Heisenberg, Frank Julicher, and Stephan Grill. “Determining Physical Properties of the Cell Cortex.” Biophysical Journal 110, no. 6 (2016): 1421–29. https://doi.org/10.1016/j.bpj.2016.02.013.
A. Saha, M. Nishikawa, M. Behrndt, C.-P. J. Heisenberg, F. Julicher, and S. Grill, “Determining physical properties of the cell cortex,” Biophysical Journal, vol. 110, no. 6, pp. 1421–1429, 2016.
Saha A, Nishikawa M, Behrndt M, Heisenberg C-PJ, Julicher F, Grill S. 2016. Determining physical properties of the cell cortex. Biophysical Journal. 110(6), 1421–1429.
Saha, Arnab, et al. “Determining Physical Properties of the Cell Cortex.” Biophysical Journal, vol. 110, no. 6, Biophysical Society, 2016, pp. 1421–29, doi:10.1016/j.bpj.2016.02.013.
All files available under the following license(s):
Creative Commons License:
CC-BY-NC-NDCreative Commons Attribution-NonCommercial-NoDerivs (CC BY-NC-ND 4.0)
Main File(s)
Access Level
OA Open Access
Last Uploaded
2018-12-12T10:10:54Z


Export

Marked Publications

Open Data IST Research Explorer

Search this title in

Google Scholar