High-speed microscopic imaging of flagella motility and swimming in Giardia lamblia trophozoites

Abstract

We report, in this paper, several findings about the swimming and attachment mechanisms of Giardia lamblia trophozoites. These data were collected using a combination of a high-contrast CytoViva imaging system and a particle image velocimetry camera, which can capture images at speeds greater than 800 frames/s. Using this system, we discovered that, during rapid swimming of Giardia trophozoites, undulations of the caudal region contributed to forward propulsion combined with the beating of the flagella pairs. It was also discovered, in contrast to previous studies with 10 times slower image sampling technique, that the anterior and posterolateral flagella beat with a clearly defined power stroke and not symmetrical undulations. During the transition from free swimming to attachment, trophozoites modified their swimming behavior from a rapid rotating motion to a more stable planar swimming. While using this planar swimming motion, the trophozoites used the flagella for propulsion and directional control. In addition to examination of the posterolateral and anterior flagella, a model to describe the motion of the ventral flagella was derived, indicating that the ventral flagella beat in an expanding sine wave. In addition, the structure of the ventrocaudal groove creates boundary conditions that determine the form of beating of the ventral flagella. The results from this study indicate that Giardia is able to simultaneously generate both ciliary beating and typical eukaryotic flagellar beating using different pairs of flagella.cell motility | cytoskeleton | swimming microorganism | ciliary and flagellar motion | bio-robotics

Hybrid Structured Illumination Expansion Microscopy Reveals Microbial Cytoskeleton Organization

“…25,30 The ventral flagella exhibit a sinusoidal motion unique among the eight flagella of Giardia , and the paraflagellar rod and fin contributes to the ability of the ventral flagella to generate propulsive force. 42 Fourth, ExSIM also revealed that DAP16263 displayed weaker, but notable localization patterns on basal bodies and proximal regions of the axonemes. In particular, the appearance of filaments along the anterior surface of the anterior flagella suggests that DAP16263 is likely involved in the network of proteins observed by scanning electron microscopy to link the anterior axonemes to the marginal plate.…”

Myosin-independent cytokinesis in Giardia utilizes flagella to coordinate force generation and direct membrane trafficking

“…Notably, high-speed imaging has revealed that Giardia's four flagella pairs have different modes of movement. The caudal flagella, which originate near the nuclei and have approximately two thirds of their length running through the cell, are used to undulate the anterior of the cell so that this region acts like a flipper while the anterior and posterolateral flagella generate canonical power strokes (39). Corresponding with the parental disk opening, daughter cells moved in opposition to each other.…”

Coarse-Graining the Fluid Flow around a Human Sperm

“…For instance, flows have been reconstructed from the flagellar waveform for the algae C. reinhardtii, using numerical simulation [7,8], though validation of simulations to actual swimmer dynamics has been limited to the approximation of resistive force theory [9] and required resistance coefficients that varied extensively between different sperm. Furthermore, flows around microswimmers have been measured using micro-PIV for Gardia protozoan flagellates [10], though reported with limited resolution. Analogous studies have been pursued for C. reinhardtii, though reported with an averaging, either temporal or spatial, [11,12] or in a single plane [12,13].…”