Fig. 1

WD progresses through three phases. (A-D) Trigeminal axons were severed and time-lapse imaged at 20 minute intervals for 12 hours. Time series of confocal image stack projections, time stamps are minutes after axotomy. Arrow indicates the site of axotomy, which was performed at 54 hpf (see Movie 1 in the supplementary material). (E-H) Tracings of degenerating severed branch corresponding to A-D. (I-L) Time series of two-photon image stack projections collected every minute after axotomy to observe acute degeneration. Arrow indicates axotomy site, arrowheads indicate transient beading of severed distal fragment, asterisk marks slight fragmentation (see Movie 2 in the supplementary material). (M-P) Time series of confocal image stack projections collected every 2 minutes to capture fragmentation. Time zero in M is the last frame before fragmentation began. Broken lines outline the severed branch (see Movie 3 in the supplementary material). Scale bars: 50 μm. (Q) Quantification of total axon fragment length over time, showing three representative severed axons. (R) Quantification of number of axon fragments over time, showing three representative severed axons. Parts of the trace corresponding to the lag, fragmentation and clearance phases are indicated.