Fig. 2.

Organelle trafficking and dendrite morphogenesis. (A) Schematic of Golgi distribution in Drosophila da neurons. Golgi outposts are localized to dendritic branch points and excluded from the axon. The predominant minus-end distal arrangement of microtubules in these dendrites is also shown. (B-E) Dendritic morphologies of wild-type and mutant class IV Drosophila da neurons. Arrows indicate dendrites. (B) Tracing of a wild-type class IV da neuron. (C) Tracing of a sar1 mutant class IV da neuron that shows reduced branch complexity. Sar1 is involved in the formation of COPII vesicles during trafficking from ER to the Golgi. (D) Tracing of a class IV da neuron with a mutation in dynein light intermediate chain (Dlic2) showing reduced dendrite length and redistribution of branches to areas nearer to the cell body (shown in black). Dlic2 is a component of the dynein complex, a minus-end-directed microtubule motor. (E) Tracing of a class IV da neuron expressing a dominant-negative Rab5 [Rab5(S43N)]. Dominant-negative Rab5 abrogates the proximal hyperbranching phenotype of Dlic2 mutations. Rab5 is a GTPase that functions in early endocytosis. Tracings in B,C adapted with permission from Ye et al. (Ye et al., 2007). Tracings in D,E adapted with permission from Satoh et al. (Satoh et al., 2008). Scale bars: 75 μm.