Interactive laser cytometry: Non-invasive microscopic approaches for the measurement of dynamic processes in animal and plant cells and tissue

Abstract

All aspects of cellular metabolic, biosynthetic, and replicative activity depend on the movement of signaling messenger molecules, macromolecules, and organelles between cellular compartments. On another level, individual cellular activity is coordinated and synchronized in tissues by the movement of molecules through trans-membrane structures forming aqueous channels between contiguous cells. The types of movement found in the cell can be discussed in terms of: a) diffusion, b) flow, and c) energy driven transport. Diffusive processes can be 1-, 2-, or 3-dimensional. An example of each type of diffusion would be the movement of control proteins along DNA/RNA strands (1-D), the lateral transport of proteins in membranes (2-D), and the intercellular movement of molecules through gap junctions or piasmodesmata (3-D). Flow processes have been most frequently observed in the bulk movement of animal cell plasma membrane and cytoplasmic streaming in plants, while energy driven transport has been most vividly demonstrated for the intracellular transport of vesicles along microtubule tracks.