Dynamics of frontal extension of an amoeboid cell

The acellular slime mould Physarum polycephalum forms giant plasmodia that consist of an apical zone, which is succeeded by a vast network of veins where protoplasm is periodically transported back and forth. The apical zone is formed by a dense layer of viscoelastic cell material, whose leading edge is characterized by the development of undulations, which are called fingers. The dynamics of finger formation and evolution was studied. The front is characterized by alternating events of front advancement and stagnation, which are reflected in the development of the fingers. Therefore, the dynamics of the front was divided into two distinct, periodically alternating regimes. The dispersion relations, i.e., the growth rates of fingers of different wavelengths, observed in these two regimes were found to be symmetric, except for the sign of the growth rates. Furthermore, finger splitting occurred once the fingers reached a critical curvature. Our findings are discussed in terms of the intracellular dynamics of this slime mould. Copyright (C) EPLA, 2014