Cytoplasmic streaming in Chara corallina studied by laser light scattering

Abstract

An apparatus is described by means of which the power versus frequency spectrum of the photomultiplier current can be obtained for laser light scattered by streaming cytoplasm in the algal cell Chara corallina. A Doppler peak is noted in the spectrum which is abolished when cytoplasmic streaming is arrested by electrical stimulation. For 5 cells of Chara, this simple laser-Doppler velocimeter gave streaming velocities (46-7 mum s-1, S.D. +/− 4–8 at 20 degrees C) similar to those obtained for the same cells using the light microscope (44-3 mum s-1, S.D. +/− 5-3 at 20 degrees C). A narrow distribution of streaming velocities is indicated. The technique described provides a rapid, quantitative assay of the in vivo rheological properties of cytoplasm.

Langevin and Navier-Stokes Simulations of Three-dimensional Protoplasmic Streaming and a Nontrivial Effect of Boundary Fluid Circulation

“…5(b) and (e), where two vertical dashed lines are drawn at the two peaks. The peaks at smaller V represent Brownian motion of fluid particles [22], and those at larger V correspond to the boundary velocity. The positions V of the peaks on lattice A are the same as those on lattice B.…”

“…Approximately 25 years after Kamiya and Kuroda's measurement, Mustacich and Ware observed streaming by the laser-light scattering technique [19][20][21][22]. They reported that the spectra of scattered light show two different peaks at V → 0 and V = 0 (Fig.…”

“…These peaks indicate that two different velocities of particles reflect streaming. The first peak at V → 0 is caused by the Brownian motion of particles [22], and the second peak at V = 0 is due to the velocity of particles dragged by the molecular motor at the cell periphery (Fig. 1(a)).…”

Cytoplasmic streaming in plant cells: the role of wall slip

“…Earlier experiments on cytoplasmic streaming based on laser light scattering experiments on Nitella [8,9] and Chara [10] cells showed that the fluid velocity distribution is quite narrow. While Sattelle & Buchan [10] speak of plug-like motion for both Chara and Nitella, Mustacich & Ware [9] underscore the fact that the peak in the spectrum of scattered light is not sharp enough for the streaming flow of a plug but indicates that most particle velocities are within 10% of the most likely velocity.…”

“…Earlier experiments on cytoplasmic streaming based on laser light scattering experiments on Nitella [8,9] and Chara [10] cells showed that the fluid velocity distribution is quite narrow. While Sattelle & Buchan [10] speak of plug-like motion for both Chara and Nitella, Mustacich & Ware [9] underscore the fact that the peak in the spectrum of scattered light is not sharp enough for the streaming flow of a plug but indicates that most particle velocities are within 10% of the most likely velocity. Experiments agree that it is unlikely that any particles move at substantially larger velocities than those carried by cytoplasmic streaming -in other words, the fluid velocity has to be very close to that of the vesicles dragged along by the motors and driving the flow.…”