FIGURE 1:

(A) Schematic of MT polarity pattern in the axon. Green lines represent MTs and black tips represent the plus-end. Long MTs have a nearly uniform plus-end-out polarity pattern, while short MTs are occasionally oriented with minus-end-out (highlighted with red dashed line). (B) Schematic of motor-based polarity sorting of MTs in vitro. A minus-directed motor such as dynein transports MTs with their plus ends leading, giving rise to regions of uniform MT polarity.