A lumped parameter model of endoplasm flow in Physarum polycephalum explains migration and polarization-induced asymmetry during the onset of locomotion

摘要: The plasmodial slime mold Physarum polycephalum exhibits strong, periodic flow of cytoplasm through the veins its network. In special case mesoplasmodia, a newly described starvation-induced, shape-constant morphotype, this endoplasm streaming is basis locomotion. Furthermore, we presume that also involved in signal transmission and processing. Mesoplasmodia motility resembles amoeboid contrast to other amoebae, however, mesoplasmodia move without extending pseudopods retain coherent, fan-shaped morphology throughout their steady Attaining sizes up 2 mm2, are much bigger than amoebae. We characterize particular type locomotion identify patterns movement. By using analogy between pulsatile fluid network elastic tubes electrical circuits, build lumped model explains observed patterns. Essentially, mesoplasmodium acts as low-pass filter, permitting only low-frequency oscillations propagate from back front. This frequency selection serves optimize reduces power dissipation. introduce distributed element into explain cell polarization during onset chemotaxis: Biochemical cues (internal or external) lead local softening actin cortex, which turn causes an increased area and, thus, net forward conclude internal actin-enclosed vein gives high measure control over transport, especially by hardening, leads