Figure 6.
Accumulation of intracellular vesicles in the mutant dynactin p150
Glued mice.
A–F
, Motor neurons from wild-type p150
Glued (
A
,
G
) and mutant p150
Glued mice (
B–F
). Toluidine blue-stained section (1 μm) shows a motor neuron with eccentric nucleus (
B
).
C–F
, EM showed a number of vesicular structures, some of which were distinctive double-membraned autophagosomes in the mutant p150
Glued mice at 3 months of age (
C
,
D
). At 5 months of age, there is a massive accumulation of vesicles observed within the cell body of the motor neurons (
E
,
F
). Arrows indicate organelle containing vesicles; arrowheads indicate vesicles not containing organelles. Boxes indicate area enlarged in
F
. No accumulation of vesicles is observed in wild-type p150
Glued mice (12 months of age) (
G
).
H
, Quantification of the number of vesicles present in the motor neurons of mutant p150
Glued mice shows an increased number of dilated endoplasmic reticulum structures (mutant, left bar) and an increase in autophagosomes (mutant, left bar) compared with those of wild-type p150
Glued mice.
I
, Increased level of LC3-II species relative to LC3-I in mutant p150
Glued mice compared with nontransgenic controls. Scale bars:
A
,
B
, 10 μm;
C
, 2 μm;
D
, 100 nm,
E
,
G
, 500 nm;
F
, 100 nm.