Reverse engineering the motility of euglenids

MARINO ARROYO; LUCA HELTAI; DANIEL MILLÁN; ANTONIO DESIMONE

Ibiza

Congreso; V Conference on Computational Methods for Coupled Problems in Science and Engineering (COUPLED 2013); 2013

European Community in Computational Methods in Applied Sciences

Euglenids exhibit an unconventional motility strategy amongst unicellular eukaryotes, consisting of large amplitude highly concerted deformations of the entire body (euglenoid movement or metaboly). A plastic cell envelope called pellicle mediates these deformations. Unlike ciliary or flagellar motility, the biophysics of this mode is not well understood, including its efficiency and molecular machinery. We examine quantitatively video recordings of four euglenids executing such motions with statistical learning methods. We then interpret the observations in the light of a continuum theory for the pellicle kinematics, providing a precise understanding of the link between local actuation by pellicle shear and shape control, and analyze the hydrodynamics of this motility mode with numerical calculations. We systematically understand common observations, such as the helical conformations of the pellicle, and identify previously unnoticed features of metaboly. Our quantitative and detailed predictions granted by computational mechanics complement the experimental observations, and even provide information about the operation of the molecular motors responsible for the shape changes. From an engineering perspective, our results suggest that the pellicle may serve as a model for man-made active surfaces with applications in micro-fluidics.