Figure 2

Myosin ii and F-actin dynamics and motor activity are required for coordinated movement of the Golgi and cell body. CGNs were transfected to express the Golgi label GalNAcT2-Venus (green) and the nucleus label H2B-mCherry (red). Velocity of the Golgi and soma in migrating neurons was measured by time-lapse imaging. After 24 minutes of migration, 100 μM blebbistatin or 5 μM jasplakinolide were added to the culture, and imaging continued for a further 36 minutes. (A) Shows representative time-lapse images. Both drugs potently inhibited forward movement of the Golgi and cell body. (B) Cell body and Golgi velocity before and after drug treatment. Upper panel: 100 μM blebbistatin reduced mean cell body velocity from 0.009 ± 0.002 (SD) to 0.002 ± 0.001 μm/sec (n = 36). Golgi mean velocity was reduced from 0.010 ± 0.003 to 0.003 ± 0.001 μm/sec (n = 48). Lower panel: 5 μM jasplakinolide similarly reduced average velocity of the soma and Golgi. Mean cell body velocity was reduced from 0.010 ± 0.003 to 0.004 ± 0.002 μm/sec (n = 28), and mean Golgi velocity was reduced from 0.009 ± 0.002 to 0.004 ± 0.001 μm/sec (n = 39). All changes in velocity were statistically significant (P <0.0001, t-test). (C, D) Reduction of mean velocity of Golgi (green) and cell body (red) after addition of (C) 5 μM jasplakinolide (n = 39 Golgi, 28 cell bodies) or (D) 100 μM blebbistatin (n = 48 Golgi, 36 cell bodies).