Chromatophores--models for studying cytomatrix translocations.

Teleost chromatophores have proven valuable in the study of the cytomatrix and its involvement in intracellular transport. These cells, which move their pigment rapidly, can be isolated from the scales of fish and maintained in culture for several days. Their transport activity can be followed with the light microscope and recorded by cinematography. Individual pigment granules can be seen moving radially toward the cell center in aggregation, then back toward the cortices during dispersion. These two motions are different . In aggregation, the granules move smoothly and rapidly (5-10 Am/s), reminding one of the behavior of chromosomes during anaphase. In dispersion, which takes twice as long as aggregation, the granules move haltingly, first out (orthograde) and then back (retrograde). This saltatory motion continues throughout dispersion but ceases suddenly at the onset of the next aggregation.