Videos
Gunther Gerisch's Demonstration Movies:
1. Micropipet-mediated aggregation. MPG
2. Single Dictyostelium cell exposed to a cyclic AMP gradient from a micropipette. Concentration of cyclic AMP changes ~20% across the cell. MPG
3. Stepwise chemotactic movements of Dictyostelium cells towards an aggregation center. MPG
4. Chemotaxis of
neutrophil chasing a bacterium.
GFP-Tagged Chemoattractant Receptors and G-protein Subunits in Chemotaxing D. discoideum Cells
5. Green fluorescent protein-tagged receptors in living cells undergoing chemotaxis. Micropipette is initially at the top of the frame, and then moved to the
lower portion of the frame.
6. Green fluorescent protein-tagged receptors in living cells undergoing chemotaxis. Micropipette was moved to the upper right hand portion of the
frame.
7. Colorized confocal image of GFP-Gb
in chemotaxing cells. Gb-GFP was
used to rescue the null phenotype of Gb
null cells.
PH-GFP Biosensors Reporting PIP3 Levels in Chemotaxing D. discoideum Cells
8. Kinetic analysis of translocation of CRAC-GFP in response to a uniform increase
in chemoattractant concentration. Frames are taken every two seconds and chemoattractant
was added just before cell goes out of focus.
9. CRAC-GFP translocates to the leading edge of newly elicited pseudopods in
chemotactically moving cells. The micropipette is located in the center of the converging
cells.
10. Wild-type cells
expressing PH-GFP carrying out chemotaxis towards cyclic AMP.
11. Same cells as 9 treated
with LY429033.
12. Dynamics of the CRAC-GFP redistribution. A large increment in chemoattractant was
applied by increasing the microinjector pressure and the cells immediately respond. As the
gradient of cAMP is restored, the polarization of CRAC-GFP is re-established.
13. Response of CRAC-GFP to an approaching wave of
chemoattractant. Pipette located on
the right side of the cell was briefly "turned on" for six seconds at three
times during the sequence.
14. Response of CRAC-GFP to an approaching wave of
chemoattractant. Pipette located on
the left side of the same cell as in #6 was briefly "turned on" for six seconds
at three times during the sequence.
15. Translocation of CRAC-GFP in cells lacking actin filament formation. Cells
chemotaxing towards pipette in lower portion of field were poisoned with Latrunculin A and
followed for the next several minutes.
16. Latrunculin immobilized
cells were stimulated with a uniform increment in cyclic AMP.
17. Latrunculin immobilized
cells exposed to micropipette containing cyclic AMP.
18. Latrunculin A
immobilized cells were exposed to a pipette in upper portion of field. The pipet was then
moved around the cells and the binding sites for PH-domains move around the
cell on the inner face of the membrane.
19. Polarized translocation of
PH-GFP
in highly polarized cells. Micropipet was located in the lower
region beyond the field. Cells were rapidly exposed to a
saturating dose of attractant.
20. Latrunculin immobilized
cells were exposed to a micropipette containing cyclic AMP.
Note the directional responses of the cell as the micropipette is
repositioned.
21. Latrunculin immobilized
cell was exposed to two opposing cyclic AMP gradients (see two micropipettes).
The strength of the two gradients was alternated during the video.
22. Cells expressing PH-GFP
carrying out phagocytosis of yeast particles. Total time of video is
~4 minutes.
Single Molecule Imaging by Masahiro Ueda and Toshio Yanagida
23. Single molecule imaging
of the binding of CY3-cyclic AMP to the basal surface of a cell.
Lifetime of binding events is ~1.5 seconds.
24. Single molecule imaging
of PH-GFP molecules moving from the cytosol to the plasma membrane on the
basal surface of the cell.
Role of PTEN in Directional Sensing
25. Pten- cells
expressing PH-GFP. Cells were exposed to a sudden increase in cyclic
AMP (white flash). Total time of video represents ~3.5 minutes of
stimulation.
26. Chemotaxis of
wild-type cells expressing PH-GFP towards cyclic AMP filled micropipette
in lower left hand corner of field.
27. Chemotaxis of pten-
cells towards cyclic AMP filled micropipette in upper right hand corner of
field. Cells are expressing PH-GFP.
28. Distribution of PTEN-GFP
in cells chemotaxing towards cyclic AMP. Note that PTEN localizes to
the back of the cell.
29. Pten- cells
expressing PH-GFP exposed to a cyclic AMP gradient coming from a
micropipette in the middle of the field.
30. Same cells as in 27
treated with 30 μm mg of LY429033.
Kees Wiejer and Florian Seigert's Videos
This page was last edited 03/25/2005