Towards a new classification of intracellular particle movements based on quantitative analyses.
A survey study of organelle movements in a variety of cell types of plant and animal origin was made with the aid of video-enhanced contrast, differential interference contrast (AVEC-DIC) microscopy followed by fine analysis of the motile behavior of the individual organelles. We found that there exists besides Brownian motion a wide spectrum of active motions in cells, i.e. motion that is directionally biased through the expenditure of metabolic energy. The types of active motion seen range from a continuous motion (sometimes appearing as streaming) in plant cells and neurons to various types of less ordered and less well directed motion. We did not see any clear-cut qualitative difference between plant and animal cells or between systems presumed to be actin- and microtubule-based. A preliminary classification of the types of active motion is presented. The ongoing research activities, which aim at a more precise definition of the different types of motion by a set of quantitative parameters, are described, and the progress made so far is reported.
D G
DG
Weiss
F
F
Keller
J
J
Gulden
W
W
Maile
D000818:Animals; D003400:Astacoidea / Q000648:ultrastructure; D001370:Axonal Transport; D001693:Biological Transport, Active; D000460:Chlorophyta / Q000648:ultrastructure; D003593:Cytoplasm / Q000502:physiology; D003595:Cytoplasmic Streaming; D004734:Energy Metabolism; D005399:Fishes / Q000033:anatomy & histology; D008853:Microscopy; D009068:Movement; D009940:Organoids / Q000502:physiology*; D010944:Plants / Q000648:ultrastructure; D012984:Software; D014741:Video Recording