Cytoplasmic streaming in an onion epidermis cell
This sequence shows organelles moving through cytoplasmic strands and in the thin perinuclear layer of cytoplasm in an epidermis cell of an onion bulb. The nucleus appears as a clear oval spot, but the big central vacuole is translucent. The organelles exhibit a fast saltatory movement described as circulation streaming. The movement of organlles (mitochondria, plastids, Golgi vesicles) likely depends on actin filaments, whereas the positioning of the nucleus seems to be controled by microtubules.
Imaging/Web text: Department of General Instrumentarion (KUN) (E.S. Pierson, B. van der Linden)