Adhesion Strategies of Dictyostelium discoideum - a Force Spectroscopy Study
ORAL
Abstract
Biological adhesion is essential for all motile cells and limits locomotion to
substrates displaying a compatible surface chemistry. However, organisms that face
vastly varying environmental challenges require a different strategy. Dictyostelium
discoideum (D.d.), a soil-living slime mould, faces the challenge of overcoming
variable chemistry by employing fundamental forces of colloid science. To understand the
origin of D.d. adhesion, we realized and modified a variety of conditions comprising
specific adhesion proteins,
glycolytic degradation, ionic strength, surface hydrophobicity and van der Waals interactions
by generating tailored model substrates. Employing AFM-based single cell force spectroscopy
we show that experimental force curves upon retraction exhibit two regimes. The
first part up to the critical adhesion force can be described in terms of a continuum model, while
a second regime of the curve beyond the critical adhesion force is governed by stochastic unbinding
of individual binding partners and bond clusters. This versatile mechanism allows D.d. to adhere to a large variety of natural surfaces.
substrates displaying a compatible surface chemistry. However, organisms that face
vastly varying environmental challenges require a different strategy. Dictyostelium
discoideum (D.d.), a soil-living slime mould, faces the challenge of overcoming
variable chemistry by employing fundamental forces of colloid science. To understand the
origin of D.d. adhesion, we realized and modified a variety of conditions comprising
specific adhesion proteins,
glycolytic degradation, ionic strength, surface hydrophobicity and van der Waals interactions
by generating tailored model substrates. Employing AFM-based single cell force spectroscopy
we show that experimental force curves upon retraction exhibit two regimes. The
first part up to the critical adhesion force can be described in terms of a continuum model, while
a second regime of the curve beyond the critical adhesion force is governed by stochastic unbinding
of individual binding partners and bond clusters. This versatile mechanism allows D.d. to adhere to a large variety of natural surfaces.
*We thank the Max Planck Society (fellow program), the SFB 937
‘Collective behaviour of soft and biological matter’ (Project A8)
and the Volkswagen Foundation (Living Foam) for funding.
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Presenters
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Marco Tarantola
- Max Planck Institute for Dynamics and Self-Organization