Gisselson, L. L-┼. University of Kalmar, lars-ake.gisselson@ng.hik.se
GranÚli, E. L-┼. University of Kalmar, edna.graneli@ng.hik.se
Carlsson, P. P. University of Kalmar, per.carlsson@ng.hik.se

 
APPLICABILITY OF CELL CYCLE ANALYSIS USING MICROSCOPY-BASED DNA QUANTIFICATION TO ESTIMATE IN SITU GROWTH RATE OF THE DINOFLAGELLATE DINOPHYSIS ACUMINATA
 
In an attempt to use cell cycle analysis to estimate in situ growth rate of the dinoflagellate Dinophysis acuminata, epifluorescence microscopy in combination with a image analysis system was used to measure the relative DNA content of DAPI stained D. acuminata nucleii. Samples collected in situ every second hour during a 48 h period were used to construct DNA histograms containing DAPI fluorescence from 400 cells per sample. The degree of synchronization in the studied population was low. Moreover, the S phase was low throughout the studied period. The poor resolution of the DNA histiograms resulted in considerable noise in the phase fraction curves, especially in the S phase estimation. The presence of double-nucleated cells and a constantly high percentage of cells with double genomes indicate that the population was actively dividing, but not clearly in synchrony with the light/dark cycle. We conclude that cell cycle analysis using DNA quantification requires DNA measurments on a much larger number of cells per sample than is practical using epifluorescence microscopy. To obtain DNA histograms with sufficient resolution to detect a low degree of synchrony in the phase fraction curves, several thousand cells per sample must be measured e.g. using flow cytometry.
 
Day: Tuesday, Feb. 2
Time: 04:15 - 04:30pm
Location: Sweeney Center
 
Code: SS41TU0415S