Department of Biology, York University, 4700 Keele Street, Toronto, Ontario M3J 1P3, Canada.
Microbiology (Reading). 2013 Nov;159(Pt 11):2386-2394. doi: 10.1099/mic.0.071191-0. Epub 2013 Aug 22.
Movement of nuclei, mitochondria and vacuoles through hyphal trunks of Neurospora crassa were vector-mapped using fluorescent markers and green fluorescent protein tags. The vectorial movements of all three were strongly correlated, indicating the central role of mass (bulk) flow in cytoplasm movements in N. crassa. Profiles of velocity versus distance from the hyphal wall did not match the parabolic shape predicted by the ideal Hagen-Poiseuille model of flow at low Reynolds number. Instead, the profiles were flat, consistent with a model of partial plug flow due to the high concentration of organelles in the flowing cytosol. The intra-hyphal pressure gradients were manipulated by localized external osmotic treatments to demonstrate the dependence of velocity (and direction) on pressure gradients within the hyphae. The data support the concept that mass transport, driven by pressure gradients, dominates intra-hyphal transport. The transport occurs by partial plug flow due to the organelles in the cytosol.
使用荧光标记物和绿色荧光蛋白标签，对粗糙脉孢菌菌丝干中的核、线粒体和液泡的运动进行了向量映射。这三种物质的向量运动具有强烈的相关性，表明在粗糙脉孢菌中，细胞质运动的中心作用是质量（体积）流。与低雷诺数下理想的哈根-泊肃叶流动模型所预测的速度与距离菌丝壁的抛物线形状不同，速度曲线是平坦的，这与由于胞质溶胶中细胞器浓度高而导致部分塞流的模型一致。通过局部外部渗透处理来操纵菌丝内的渗透压梯度，以证明速度（和方向）对菌丝内压力梯度的依赖性。这些数据支持了这样的概念，即由压力梯度驱动的质量传输主导了菌丝内的传输。由于胞质溶胶中的细胞器，运输通过部分塞流发生。
