Structural Organization of DNA in Chlorella Viruses
Figure 1
A: Fluorescence images of C. variabilis with ejected DNA molecules. The incubation medium contained C. variabilis cells and virus PBCV-1 at an m.o.i. of ∼100 plus the fluorescent DNA stain DAPI. The image shows a chlorella cell (cc) and the viral DNA molecule, which is propelled away from the alga cell. B: Magnification of the area indicated by the box in A. Inset: same area as in B with conventional light microscopy and phase contrast. C: same as in A but with two DNA bands projecting away from a chlorella cell (cc). D: Magnification of area indicated by box in C with loop like DNA structure. E: Electron micrograph of viral DNA projecting away from host cell wall. The cell wall of the alga exhibits the typical hole (*), which the viruses digest for infection. From this hole two linear structures project towards the left side. The part marked in E is magnified in F and presented in artificial colors in order to highlight the linear structures projecting away from the cell wall hole. G: fluorescence intensity profile along DNA molecule between arrows in B. H: Histogram of distances between individual fluorescence maxima as in E from 30 ejected DNA molecules.