Figure 5.

Selective restoration of TRPM7 expression in sensory neurons is sufficient to restore touch-evoked responses. A, Top, Lateral view of a 55 hpf larva labeled with a riboprobe against trpm7 showing that trpm7 is expressed widely in the larva. Boxed area indicates enlarged area shown below. Scale bar 200 μm. Bottom, Enlarged area highlighting a few RB sensory neurons expressing trpm7, with some RBs indicated with arrows. Scale bar, 50 μm. B, Top, Rescue plasmid comprised of the sensory neuron enhancer/promoter construct zCREST2-hsp70:TRPM7-eGFP. Bottom, Lateral view of the dorsal spinal cord following injection of the sensory enhancer/promoter construct labeled with anti-GFP showing that TRPM7-eGFP is expressed by many RBs, some of which are marked by arrows. Dashed line denotes the dorsal boundary of the spinal cord. Green labeling above dashed line was also observed in uninjected embryos, indicating that is background labeling of the skin by anti-GFP. Scale bar, 50 μm. C, Expression of TRPM7 selectively in RBs rescues touch-responsiveness in touchdown mutant larvae. Video frames of touch-evoked swimming from a 55 hpf hypopigmented touchdown mutant expressing the rescue plasmid. 0 ms is the video frame preceding contact of the embryo by the stimulating probe. Scale bar, 500 μm.