Biology Reference
In-Depth Information
(a)
(b)
(c)
Figure 18.4. Mitochondrial displacements following AFM indentation. (a) An overlay
of images taken before (red) and after (green) indentation. (b c) Magniied section
of the cell, where mitochondrial structures clearly show displacements into different
and, in some cases, opposite directions (b, arrows). Scale bars are 10 μ m.
5 μ M CytD), prior to experimentation. We found that the average natural
displacement of mitochondria in cells treated with CytD was 56 ± 3 nm
and 58 ± 3 nm (
> 0.6) after perturbation with the AFM tip ( Fig. 18.5a ).
For nocodazole-treated cells, the average natural displacement was 57 ± 2
nm and 54 ± 2 nm (
P
> 0.3) after perturbation ( Fig. 18.5a ). Therefore, the
results show no statistically signiicant difference between the pre- and post-
perturbation displacements, in both cases. These results clearly show that
mitochondrial displacements following a locally applied force are completely
dependent on an intact actin and MT cytoskeletal network. However, the
natural displacements of the mitochondria in cells pretreated with CytD and
nocodazole are signiicantly different (
P
P
< E-20) compared with untreated
(a)
(b)
(c)
Figure 18.5. (a) Comparison of the difference in mean average displacement of
mitochondria between the control (white bars) and the post-perturbation (grey
bars) images for cells left untreated and treated with the CytD, nocodazole and RA.
The average displacement of mitochondria in untreated cells increased ~40% in
response to perturbation with the AFM tip. The natural displacement of mitochondria
in cells treated with CytD and nocodazole was ~50% lower than control cells, and
there was no signiicant increase in displacement in response to locally applied
forces. (b) Focal adhesions (red) appear as point-like structures at the end of F-actin
ilaments (green) and act to anchor the cell to the substrate (scale bar = 10 μ m).
(c) After treatment with retinol, the number of focal adhesions per cell is greatly
reduced throughout the cell contact area.
 
Search WWH ::




Custom Search