Visualization of free‐running circadian rhythms in the dinoflagellatePyrocystis noctiluca

Publisher Website
Google Scholar
Abstract
In Pyrocystis noctiluca, circadian rhythms can be observed at cellular level directly in the light microscope. A rhythm of chloroplast expansion and contraction was visualized by autofluorescence of chlorophyll, a concomitant rhythm in the intracellu‐lar distribution of bioluminescent microsources was seen upon stimulation of cells by acid. Measurements of bioluminescence by means of a scintillation counter revealed the absence of a rhythm in spontaneous bioluminescence; however, the existence of a rhythmicity in stimulated bioluminescence was demonstrated by treating cells with acid.