Regensburg 2019 – wissenschaftliches Programm

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BP: Fachverband Biologische Physik

BP 6: Poster I

BP 6.18: Poster

Montag, 1. April 2019, 17:30–19:30, Poster B2

C. Elegans Nematodes Deform like Elastic Rods. — •Octavio Albarran¹, Peter Weist¹, Eugenia Butkevich¹, Renata Garces¹, and Christoph Schmidt^{1, 2} — ¹Drittes Physikalisches Institut - Biophysik Friedrich-Hund-Platz 1 37077 Goettingen — ²Department of Physics, Duke University, Durham, NC 27708, USA.

To perform undulatory locomotion, C. elegans nematodes generate forces with their body-wall muscles acting on the surrounding environment and against their own body deformation resistance. The knowledge of the body rigidity is crucial to understand the dynamic functions of the worm.

It has been hypothesized that the worm kinematics can be understood in terms of viscoleastic beam theory. However, to date, mechanical studies in the large deformation regime, typical of native undulatory locomotion, are lacking. We here present a micro-needle-based experiment imposing large strains. Living worms were kept straight by clamping their extremities onto agar plates. We laterally displaced the centers of worms with a glass cantilever of known spring constant. To separate passive responses from muscle activity, we varied the contraction relaxation state of the muscles using pharmacological interference. We directly probed the beam theory through the analysis of the loading curves. Interestingly, we found that linear constitutive relations (without viscous effects) are sufficient to explain the experimental data. We provide a synthesis of the typical range of magnitudes of effective elastic modulus for different muscles states of the worms.