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VatM-GFP
labeling of vacuolar proton pumps in the contractile vacuole system and
endosomal compartment of Dictyostelium cells.
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Video 1. 137sor.mov, 363x360 pixels, 5.6MB compressed
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Contractile
vacuole system in a Dictyostelium AX2 cell expressing VatM-GFP, viewed
by fluorescence (green) and interference reflection microscopy (red). The
interconversion of vacuolar and tubular elements can be seen as vacuoles
empty. The frames were collected at 1-second intervals using a Solamere
video camera and a Yokogawa spinning disk scan head. |
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Video 2. 584dsor.mov, 219x220 pixels, 6.7MB compressed |
Phagocytosis
of yeast particles by Dictyostelium cells whose endosomes had previously
been labeled with TRITC-dextran. The upper cell is ingesting a yeast particle
on its left in the first frame; the yeast particle becomes surrounded by
endosomes in subsequent frames. Arrows mark the appearance of TRITC dextran
at the bud neck, indicative of endosome fusion. In the meantime, the lower
cell has also ingested a yeast particle (outlined). The phagosome containing
this particle presently fuses with a pre-existing multi-particle phagosome.
TRITC-dextran (arrow) collects at the site of fusion as well as at the bud
neck. In the last frame (9 minutes after uptake), the VatM-GFP fluorescence
in the membrane of the new phagosome resembles that of earlier phagosomes.
Frames were collected at 5-second intervals using a Zeiss 410 confocal
microscope. |
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Video 3. 763Lsor.mov, 512x512 pixels, 1MB compressed |
Exocytosis
of the indigestible remnants of a yeast particle. This Dictyostelium
cell has two yeast-filled phagosomes with VatM-GFP labeled membranes and
a third phagosome that has no label (top). As the movie progresses, the
focus is shifted from the upper region of the cell, where the phagosomes
are located, to a plane close to the substratum, to reveal the bright labeling
of the contractile vacuole system. Returning to the phagosome-rich focal
plane, a ring of TRITC-dextran can be seen at the neck of the unlabeled
phagosome, demonstrating that it is a late phagosome from which vacuolar
proton pumps have been retrieved. A few frames later, the digested yeast
particle is exocytosed. Frames were collected at 5-second intervals
using a Zeiss 410 confocal microscope. |
| last updated: March 26, 2004 |  To obtain the QuickTime viewer, visit http://www.apple.com/quicktime/ |
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