Figure 4. Microtubule stability differs in plus-end-out and minus-end-out neurites of mosaic arbors.

A. Representative kymographs showing EB1-GFP dynamics in a control dendrite and axon and in minus-end-out and plus-end-out regions of mosaic arbors. Minus-end-out microtubules are labelled with blue lines while red lines label plus-end-out microtubules. Scale bar: x axis = 5 µm, y axis = 60 seconds.

B. Quantification of EB1-GFP dynamics in control neurons (n=10 animals) and mosaic dendrite arbors (n=15 animals). **, P<0.01 when analyzed with student’s t-test.

C. Representative image of a ddaC neuron expressing tdEos-α-Tubulin. Microtubule polarity is indicated with red lines for plus-end-out and blue lines for minus-end-out.

D. Kymographs of the regions marked with numbers in C (from time-lapse videos of EB1-TagRFP-T comets) showing different microtubule polarity. Red lines mark plus-end-out microtubules while blue lines mark minus-end-out microtubules. Scale bar, x axis = 10 µm, y axis = 60 seconds.

E. Airyscan image of branch point of a ddaC neuron expressing tdEos-α-Tubulin and iBlueberry (soluble marker). Fluorescence intensity was measured along the white line through the branch point and is shown in the graph.

F. Quantification of EB1-TagRFP-T dynamics after normalization to tdEos-α-Tubulin intensity in a neurite (n=10 animals). *, P<0.05.

G. Schematic diagram shows plus end (EB1 comet) number is similar in control and minus-end-out regions of mosaic dendrites, but reduced in plus-end-out regions.