Fig. 4

Mutant Tau^AT worms show aberrant localization of presynaptic components in mechanosensory neurons. a Schematic representation of presynaptic cargo distribution in a normal healthy mechanosensory neuron and a neuron in an aged animal. b Day-1 old worms visualized after crossing them into vdEx262:[Pmec-4::mCherry::rab-3] transgene that expresses mCherry fused to synaptic vesicle associated RAB-3 in mechanosensory neurons. Tau^wt-lo and Tau^wt-hi show a similar distribution as non-tg reporter strain. Tau^AT-lo worms show accumulation of mCherry::RAB-3 in the end neuron (yellow arrowhead), cell body (CB, white arrowhead) and posterior neurite (white arrow). By contrast, the mid-neuron of Tau^AT-lo shows less puncta (6 ± 3 measured per 40 μm length) than non-tg (15 ± 5) and Tau^wt-lo (17 ± 6) worms. On day 3, mislocalization of mCherry::RAB-3 worsens in Tau^AT-lo worms, whereas Tau^wt-lo and Tau^wt-hi start accumulating mCherry:RAB-3 puncta in the distal axon and posterior neurite (see Additional file 12)