1. An antagonistic relationship between myosin II and dynein controls bulk growth cone advance.
An antagonistic relationship between myosin II and dynein controls bulk growth cone advance. (A) Neurons were allowed to grow for 15 min, then treated with 50 µM blebbistatin (bl) to disrupt myosin II function for 45 min, after which 100 µM CilD was added. Paired phase and fluorescent images of mitochondria show that blebbistatin increases growth cone advance (compare blue arrows to yellow arrows), whereas subsequent CilD addition reduces it (orange arrows versus yellow arrows). (B) Kymograph of docked mitochondria in the axon shown in A. Blue bar, pre-drug; yellow bar, blebbistatin; orange bar, blebbistatin+CilD. Scale bars: 20 µm. (C) Quantitative analysis of docked mitochondria illustrates that blebbistatin causes an increase in bulk growth cone translocation and a decrease along the axon. Addition of CilD causes a subsequent reduction at all points in the axon compared with pre-treatment levels. Numbers above each bar represent the number of mitochondria in each bin. GC, the most distal mitochondria in each growth cone. Data show the mean±95% CI; *significant at α = 0.05, **significant at α = 0.01 (post-hoc Tukey's test).
Douglas H. Roossien et al. J Cell Sci 2014;127:
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